ObjectiveTo investigate the frequency of stroke and code stroke activation, and the factors influencing code stroke management in postoperative cardiac surgical patients.DesignA retrospective quality improvement study conducted between January 1st, 2016, and December 31st, 2021.SettingCardiac Surgery Recovery Unit (CSRU) at London Health Sciences Centre (LHSC) in London, Ontario, Canada.ParticipantsPost-cardiac surgery patients aged 18 years or older who developed ischemic stroke during their admission to the CSRU.InterventionsNo specific interventions were administered as part of this study. “Code Stroke" activation mobilizes a specialized team. The objectives include assessment by a physician within 10 minutes, obtaining neuroimaging and interpretation within 45 minutes, and commencement of treatment within 60 minutes.Measurements and Main ResultsThe incidence rate of stroke in the CSRU was 1.3%, and 34% of these cases had code stroke activated. The last known well time was 11 +/- 8 hours. The most common reasons for not activating code stroke were not meeting both timing and clinical criteria. The average time to Computed Tomography (CT) scan was 36 +/- 22 minutes. Among patients who had code stroke activated, 24% had large vessel occlusion (LVO), and 67% of those with LVO had an established stroke on their initial CT.ConclusionCode stroke was activated in only one-third of patients who experienced a stroke following cardiac surgery. Additionally, out of those who had code stroke activated, only one-fourth were diagnosed with LVO. Among those with LVO, two-thirds were found to have a well-established stroke on non-contrast CT scans and were deemed ineligible for intervention.

Accurate models of the mitral valve are highly valuable for studying the physiology of the heart and its various pathologies, as well as creating physical replicas for cardiac surgery training. Currently, heart simulator technologies are used which rely on patient-specific data to create valve replicas. Alternatively, mathematical models of the mitral valve have been developed for computational applications. However, there are no studies that mathematically model both the mitral valve's leaflets and its saddle-shaped annulus in a single design together in current l iterature. This results in anatomic inaccuracies in current models, as either only the leaflets or the saddle-shaped annulus are realistically modelled. Mathematical models to date have not been replicated as dynamic, physical valves and validated in a heart simulator system. We propose a new parametric representation of the mitral valve based on a combination of valve models from prior literature, combining both accurate leaflet shape, and annular geometry. A physical silicone replica of the model is created and validated in a pulse duplicator. Using a transesophageal echocardiography probe with color Doppler imaging, we demonstrate that our combined model replicates healthy valve behaviour, showing no regurgitation at realistic pressure gradients across the valve.

Segmentation of the mitral annulus is an important step in many cardiac applications. Current methods to delineate the mitral annulus often require extensive user interaction. Several methods have been proposed to automate mitral annulus segmentation, but often use methods which require sampling 2D planes from the 3D volume, discarding some of the contextual information contained in the original 3D volume. We propose a new 4D mitral annulus segmentation method based on 3D CNN regression of Fourier coefficients describing the shape of predicted annulus. Our model predicts a set of ten coefficients for each of the three image axes, which can then be used to sample annulus coordinates through the inverse Fourier transform. We acquired a dataset of 90 cases from diagnostic imaging of mitral valve patients, with corresponding annulus segmentations. This was split into training, validation and test sets of 75, 5, and 10 cases respectively. Following training, our model achieves a curve-to-curve accuracy of 5.5 ± 2.2 mm on the test set, with training accuracy of 0.46 ± 0.21 mm. Our model achieves accuracy similar to current state-of-the-art methods, and can achieve inference speed of 40 frames-per-second, which is suitable for use in real-time image guidance applications.

IN THIS ISSUE of the Journal, Bertini et al. (JCVA-D-22-00988) reported a meta-analysis of the regional oxygen saturation index (rSO2) values in patients who received extracorporeal cardiopulmonary resuscitation (ECPR) either in-hospital or out-of-hospital. The authors only were able to identify 3 trials (245 participants for inclusion) for analyses, but the results of their analyses suggested that low rSO2 may predict mortality. The authors found that a low precannulation rSPO2 was associated with an increased risk of mortality and overall worse neurologic outcomes in patients who underwent ECPR. However, the interpretation of this meta-analysis raises significant concerns about clinical validity. Firstly, the small sample size of the meta-analysis, and, secondly, the included studies used the initial measurement of near-infrared spectroscopy (NIRs) values after a significant period of CPR for out-of-hospital arrest and limited CPR for in-hospital arrest; whereas many of the other CPR trials looked at changes in NIRs during CPR. More importantly, although the mortality in the low rSO2 group was high, it was not 100% suggesting that failing to proceed with ECPR would result in additional deaths. Finally, one of the trials was published in 2011, so it may not reflect contemporary practice. In the article, low rSO2 was defined as a pre-ECPR value of <16%, the lowest value detectable by the INVOS system (Medtronic, PLC; used in all the trials), with mortalities in the 2 groups of 64.9% in the high group and 92.5% in the low group. Likewise, the authors identified an association with neurologic outcomes, with patients in the high-rSO2 group having good neurologic outcomes (27.8%) versus those in the low-rSO2 group (2.1%). However, interestingly, if you look at the survivors, those in the high group had a similar rate of good neurologic outcomes, similar to those in the low-rSO2 group (42 of 151 patients in the high group v.s. 2 of 7 in the low group), suggesting that poor neurologic outcome may not be as easy to predict using NIRs. The use of NIRs in CPR has had mixed results. Some trials suggested that NIRs can predict a return of spontaneous circulation, a lower bar than mortality, whereas others suggested no such ability.1Ahn A Nasir A Malik H et al.A pilot study examining the role of regional cerebral oxygen saturation monitoring as a marker of return of spontaneous circulation in shockable (VF/VT) and non-shockable (PEA/Asystole) causes of cardiac arrest.Resuscitation. 2013; 84: 1713-1716Abstract Full Text Full Text PDF PubMed Scopus (66) Google Scholar, 2Prosen G Strnad M Doniger SJ et al.Cerebral tissue oximetry levels during prehospital management of cardiac arrest - A prospective observational study.Resuscitation. 2018; 129: 141-145Abstract Full Text Full Text PDF PubMed Scopus (27) Google Scholar, 3Wyckoff MH Singletary EM Soar J et al.2021 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations: Summary From the Basic Life Support; Advanced Life Support; Neonatal Life Support; Education, Implementation, and Teams; First Aid Task Forces; and the COVID-19 Working Group.Resuscitation. 2021; 169: 229-311Abstract Full Text Full Text PDF PubMed Scopus (48) Google Scholar It should be noted that many of these trials looked at the change in baseline rSO2 with CPR. However, the identified cutoff values were inconsistent among these studies and those presented in the paper by Bertini et al. An interesting paper4Nemoto EM Yonas H Kassam A. Clinical experience with cerebral oximetry in stroke and cardiac arrest.Crit Care Med. 2000; 28: 1052-1054Crossref PubMed Scopus (78) Google Scholar by Nomoto-Nemoto showed that patients who were brain-dead had NIRs values of 60-to-65, suggesting blood flow but not extraction, which may make neurologic recovery difficult to determine the basis of NIRs measurements alone. Recently, 2 randomized controlled trials were conducted and published to answer a clinically significant question about the relationship between blood oxygen saturation during cardiac arrest and patient prognosis.5Schmidt H Kjaergaard J Hassager C et al.Oxygen targets in comatose survivors of cardiac arrest.N Engl J Med. 2022; 387: 1467-1476Crossref PubMed Scopus (40) Google Scholar,6Bernard SA Bray JE Smith K et al.Effect of lower vs higher oxygen saturation targets on survival to hospital discharge among patients resuscitated after out-of-hospital cardiac arrest: The EXACT randomized clinical trial.JAMA. 2022; 328: 1818-1826Crossref PubMed Scopus (23) Google Scholar In one paper, 789 patients who experienced out-of-hospital cardiac arrest were randomized into 2 groups.5Schmidt H Kjaergaard J Hassager C et al.Oxygen targets in comatose survivors of cardiac arrest.N Engl J Med. 2022; 387: 1467-1476Crossref PubMed Scopus (40) Google Scholar One group was targeted to have a PaO2 level of 68-to-75 mmHg, whereas the other group was targeted to have a level of 98-to-105 mmHg. The study results showed no significant differences in 90-day mortality or the rates of severe disability or coma. A separate study,6Bernard SA Bray JE Smith K et al.Effect of lower vs higher oxygen saturation targets on survival to hospital discharge among patients resuscitated after out-of-hospital cardiac arrest: The EXACT randomized clinical trial.JAMA. 2022; 328: 1818-1826Crossref PubMed Scopus (23) Google Scholar conducted by Bernard et al. in 2022, investigated the impact of oxygen saturation on survival after out-of-hospital cardiac arrest. A total of 1,719 patients who underwent resuscitation were assigned randomly to the following 2 groups: a high-oxygen group with a saturation level of 94%, and a low-oxygen group with a level of 90%. The results showed no significant difference in the survival rate to hospital discharge between the 2 groups. These findings suggested that the blood oxygen concentration and hemoglobin saturation (SpO2) may not play a significant role in survival after cardiac arrest. Hirakawa et al.7Hirakawa H Terao T Ishii N. A case of facial pain in somatic symptom disorder responding to duloxetine.J Clin Psychopharmacol. 2020; 40: 512-513Crossref PubMed Scopus (2) Google Scholar examined pre-ECMO pO2 and its relationship with ischemic stroke and found no association. However, the incidence of stroke was associated with lower pre-ECMO pH and higher pO2 value measured 24 hours after ECMO was established. It is important to remember that in a retrospective study, only correlations can be demonstrated, not causation. The more factors there are, the more likely some will be correlated. Further thorough investigation and well-designed randomized controlled trials are necessary to establish causation. It is important to note that none of the papers analyzed in the current meta-analysis included long-term follow-up or reported on any vital organ dysfunctions. Without this information, caution must be exercised when making clinical decisions about ECMO, as it is a costly and resource-intensive procedure. The decision to initiate and discontinue ECMO should be based on multiple factors. Making decisions solely based on precannulation rSPO2 values would be reckless without considering all relevant data. Also of concern is the small sample size of this meta-analysis. For example, in the current meta-analysis, there were around 100 patients in the high- and low-rSO2 groups. Using such a small number of patients to make inferences is unreliable and raises questions about the conclusions' generalizability. Additionally, the finding that patients with precannulation rSO2 >60% had a worse prognosis than 40% < rSO2 < 60% was based on a smaller sample size than 10, which further underscores the importance of caution when interpreting the results. The authors noted that all of the studies analyzed lacked information on the timing of rSO2 measurement, oxygen administration, and CPR. It is important to note that oxygen administration can impact rSO2 readings significantly, and this should be considered when interpreting the results. Looking closely at 3 papers analyzed in the meta-analysis, Joo et al. investigated 121 patients using the large Japanese database whose data was taken from 15 different centers. This study was retrospective and not blinded. The timing of rSO2 measurements is not specified in the paper. Ito et al. 8Ito N Nanto S Nagao K et al.Regional cerebral oxygen saturation: A novel index for prompt clinical outcome prediction before starting extracorporeal cardiopulmonary resuscitation in out of hospital cardiac arrest patients.J Am Coll Cardiol. 2011; 57: E908Crossref Google Scholar looked at 27 consecutive patients undergoing ECPR. The results from 2011 were only ever published as an abstract and have not undergone peer review. This should raise questions about the quality of the published data and should have resulted in a clear statement within the trial that one of the studies was in abstract form only and a subsequent sensitivity analysis looking at the impact on the results of including or excluding the trial. Wiest et al. published a short paper9Wiest C Philipp A Foltan M et al.Does cerebral near-infrared spectroscopy (NIRS) help to predict futile cannulation in extracorporeal cardiopulmonary resuscitation (ECPR)?.Resuscitation. 2021; 168: 186-190Abstract Full Text Full Text PDF PubMed Scopus (6) Google Scholar describing a study investigating 97 patients undergoing ECPR retrospectively. In this study, rSO2 was measured upon the arrival of the resuscitation team. It is crucial to carefully evaluate the quality and representation of the studies included in the meta-analysis, and to consider these limitations and potential sources of bias when interpreting the results. This will ensure that the meta-analysis results are accurate and reliable and provide a more comprehensive understanding of the topic under investigation. Generating data in trials of CPR is challenging, and results in many small trials or retrospective observational studies, making definitive conclusions difficult. In addition, any test's ability to predict good and bad outcomes is inherently related to the pretest probability of the event occurring. Analysis of a test's ability to predict outcomes should rely on the test's positive and negative predictive values, and not solely on the positive association, as Bertini et al. showed. As such, deciding what cutoffs to employ for appropriate sensitivity and specificity is clinically challenging, especially when the outcome is irreversible. The use of NIRs as a predictor for outcomes in both CPR and ECPR remains unclear, and further work needs to be done to assess its clinical usefulness. None. Regional Cerebral Oxygen Saturation to Predict Favorable Outcome in Extracorporeal Cardiopulmonary Resuscitation: A Systematic Review and Meta-AnalysisJournal of Cardiothoracic and Vascular AnesthesiaVol. 37Issue 7PreviewThis systematic review and meta-analysis aimed to investigate the role of regional cerebral oxygen saturation (rSO2) in predicting survival and neurologic outcomes after extracorporeal cardiopulmonary resuscitation (ECPR). Full-Text PDF

Vascular navigation is an essential component of transcatheter cardiovascular interventions, conventionally performed using either 2D fluoroscopic imaging or CT- derived vascular roadmaps which can lead to many complications for the patients as well as the clinicians. This study presents an open-source and user-friendly 3D Slicer module that performs vessel reconstruction from tracked intracardiac ultrasound (ICE) imaging using deep learning-based methods. We also validate the methods by performing a vessel-phantom study. The results indicate that our Slicer module is able to reconstruct vessels with sufficient accuracy with an average distance error of 0.86 mm. Future work involves improving the speed of the methods as well as testing the module in an in-vivo setting. Clinical adaptation of this platform will allow the clinicians to navigate the vessels in 3D and will potentially enhance their spatial awareness as well as improve procedural safety.

Purpose A clinical conflict often presented with hip fracture patients is whether to proceed with timely surgery or delay surgery until a formal echocardiogram is conducted. This study aimed to assess the impact of incorporating point-of-care lung and cardiac ultrasound (LUCAS) scans as part of the preoperative assessment for hip fracture patients. Methods We recruited 225 consecutive adult patients booked for urgent hip arthroplasty surgery. A LUCAS scan was performed for each patient. The anesthesiologists were asked to provide their anesthetic plans before and after acknowledging the results of the LUCAS scans. The primary endpoint was a composite outcome of changes to the anesthetic plan. The secondary outcomes included anesthesiologists’ opinions of the LUCAS scans. Results One-hundred-ninety-eight patients were included. The majority of LUCAS findings were not severe. A common abnormal finding was hypovolemia (31%). One-hundred-and-six anesthetic management decisions were changed, with 59 of these changes being an escalation of the anesthetic plan, and 47 of these changes being a de-escalation. Eighty-three percent of anesthesiologists agreed that LUCAS affirmed their anesthetic plans and should be an integral part of the perioperative assessment. Conclusion This study found that LUCAS scans did not significantly alter the anesthetic plan for hip fracture patients. Nevertheless, LUCAS scans can rule out severe cardiopulmonary conditions and allow for both escalation and de-escalation of care. In the setting of early hip surgery, LUCAS presents a viable option in selected patients to address the unmet need to allow for both timely surgery and comprehensive patient evaluation. Study registration ClinicalTrials.gov (NCT03275129); registered 8 July 2018.

A recent publication by Holm et al., the OCTOBER trial, demonstrated that the use of optical coherence tomography (OCT) guidance in percutaneous coronary intervention (PCI) was shown to reduce the risk of major adverse cardiac events in patients with complex coronary artery bifurcation lesions.1 A total of 1,201 adult patients with a clinical indication for PCI and a complex bifurcation lesion were assigned to receive either OCT-guided PCI or angiography-guided PCI. At a median follow-up of 2 years, it was shown that OCT-guided PCI was associated with a lower incidence (adjusted hazard ratio, 0.71; 95% CI 0.51-0.98) of a composite of death from a cardiac cause, target-lesion myocardial infarction, or ischemia-driven target-lesion revascularization versus angiography-guided PCI.

Tricuspid valve (TV) interventions face the challenge of imaging the anatomy and tools because of the ‘TEE-unfriendly’ nature of the TV. In edge-to-edge TV repair, a core step is to position the clip perpendicular to the coaptation gap. In this study, we provide a semi-automated method to localize the VC from Doppler intracardiac echo (ICE) imaging in a tracked 3D space, thus providing a pre-mapped location of the coaptation gap to assist device positioning. A magnetically tracked ICE probe with Doppler imaging capabilities is employed in this study for imaging three patient-specific TVs placed in a pulsatile heart phantom. For each of the valves, the ICE probe is positioned to image the maximum regurgitant flow for five cardiac cycles. An algorithm then extracts the regurgitation imaging and computes the exact location of the vena contracta on the image. Across the three pathological, patient-specific valves, the average distance error between the detected VC and the ground truth model is $$({1.22 \pm 2.00})$$ mm. For each of the valves, one case represented the outlier where the algorithm misidentified the vena contracta to be near the annulus. In such cases, it is recommended to retake the five-second imaging data. This study presented a method for ultrasound-based localization of vena contracta in 3D space. Mapping such anatomical landmarks has the potential to assist with device positioning and to simplify tricuspid valve interventions by providing more contextual information to the interventionalists, thus enhancing their spatial awareness. Additionally, ICE can be used to provide live US and Doppler imaging of the complex TV anatomy throughout the procedure.

Three-dimensional ultrasound mosaicing can increase image quality and expand the field of view. However, limited work has been done applying these compounded approaches for cardiac procedures focused on the mitral valve. For procedures targeting the mitral valve, transesophageal echocardiography (TEE) is the primary imaging modality used as it provides clear 3D images of the valve and surrounding tissues. However, TEE suffers from image artefacts and signal dropout, particularly for structures lying below the valve, including chordae tendineae, making it necessary to acquire alternative echo views to visualize these structures. Due to the limited field of view obtainable, the entire ventricle cannot be directly visualized in sufficient detail from a single image acquisition in 3D. We propose applying an image compounding technique to TEE volumes acquired from a mid-esophageal position and several transgastric positions in order to reconstruct a high-detail volume of the mitral valve and sub-valvular structures. This compounding technique utilizes both fully and semi-simultaneous group-wise registration to align the multiple 3D volumes, followed by a weighted intensity compounding step based on the monogenic signal. This compounding technique is validated using images acquired from two excised porcine mitral valve units and three patient data sets. We demonstrate that this compounding technique accurately captures the physical structures present, including the mitral valve, chordae tendineae and papillary muscles. The chordae length measurement error between the compounded ultrasound and ground-truth CT for two porcine valves is reported as 0.7 ± 0.6 mm and 0.6 ± 0.6 mm.

ALTHOUGH THE PRIMARY AIM of publication often is focused on reporting a new finding or novel technique, its primary purpose should instead be to provide information to allow other researchers to repeat the experiment and, thus, confirm the findings, moving the medical community closer to the truth of the risks and benefits of the intervention. Providing enough information in a concise but precise manner is, thus, the goal of any author. Observational trials have become increasingly popular as a form of medical discovery, as it frequently is felt that it offers a less daunting path than the design and conduct of a randomized trial. In addition, for outcomes focusing on real-world data or those looking at risk, an outcome expected to occur at a much lower frequency, observational trials are ideally suited. Although randomized trials may be more arduous to design and complete, they often are easier to analyze and report because of the time and effort taken in the design of the trial. Observational studies (predominantly in the cardiac anesthesia literature this refers to case-control or case-series trials) often are easier to conduct but are much more complex to analyze and far more challenging to produce an appropriate and informative manuscript, keeping in mind the aforementioned goal of allowing other researchers to reproduce the results. Frequently, reports from observational studies lack important details and do not address pitfalls associated with this type of study design; namely, bias and confounding. In order to address what were seen as frequent errors in the reporting of observational trials, the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) consortium was developed to create a checklist of important items to aid in the reporting of these studies.1von Elm E Altman DG Egger M et al.Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement: Guidelines for reporting observational studies.BMJ. 2007; 335: 806-808Crossref PubMed Google Scholar Certainly, the Journal of Cardiothoracic and Vascular Anesthesia continues to see manuscripts that struggle with the reporting of important trial characteristics, manuscripts that fail to address the importance of confounding and bias, and so the aim of this editorial is to provide readers, reviewers, and authors with some material to aid when writing, reading, or reviewing observational studies. Before reviewing the STROBE criteria, let's be clear what STROBE is not. It is not designed as a tool to aid in the design of observational trials, nor is it a guide on how to write, stylistically, a manuscript on randomized trials. It is simply a checklist that aides authors in ensuring that enough information has been included to allow another investigator to repeat the trial. However, it also ensures that the investigators have given careful thought to the advantages and disadvantages of observational trial designs and have addressed these strengths and weaknesses in their report. The STROBE checklist can be found at https://www.equator-network.org/reporting-guidelines/strobe/ and consists of a series of three specific guides (case-control, cohort, and crossover studies) along with one generic checklist to cover all observational trials. In this manner it is equivalent to the Consolidated Standards of Reporting Trials (CONSORT) checklist for randomized trials2Schulz KF Altman DG Moher D et al.CONSORT 2010 statement: Updated guidelines for reporting parallel group randomised trials.BMJ. 2010; 340: c332Crossref PubMed Scopus (4306) Google Scholar and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist for meta-analyses.3Moher D Liberati A Tetzlaff J et al.Preferred reporting items for systematic reviews and meta-analyses: The PRISMA statement.BMJ. 2009; 339: b2535Crossref PubMed Scopus (13816) Google Scholar Although it is beyond the scope of this editorial to review the entire STROBE checklist (Fig 1), the aim of this discussion will focus on some common mistakes frequently seen in submitted observational trials, with the aim of helping to constructively improve the reporting of trials. By way of example, we will review the trial published by Moll et al in the Journal of Cardiothoracic and Vascular Anesthesia titled “Erector Spinae Regional Anesthesia for Robotic Coronary Artery Bypass Surgery Is Not Associated With Reduced Postoperative Opioid Use: A Retrospective Observational Study” and apply the STROBE checklist to this trial.4Moll V Ward CT Jabaley CS et al.Erector spinae regional anesthesia for robotic coronary artery bypass surgery is not associated with reduced postoperative opioid use: A retrospective observational study [epub ahead of print].J Cardiothorac Vasc Anesth. 2020; (Accessed January 12, 2021)https://doi.org/10.1053/j.jvca.2020.09.112Abstract Full Text Full Text PDF Scopus (7) Google ScholarFig 1Strobe checklist.View Large Image Figure ViewerDownload Hi-res image Download (PPT) One frequent deviation from the structured reporting in the STROBE checklist is the omission of the type of observational study and the frequent use of the terms “retrospective” and “prospective.” In the case of Moll et al, it would have been helpful to include the design of the study directly within the title, a case-control study, for example, in place of the term “a retrospective observational trial.” The use of the terms “retrospective” or “prospective” (present in 40% of titles in the Journal of Cardiothoracic and Vascular Anesthesia that contain the term “observational”) unfortunately is ambiguous. “Retrospective” sometimes is used to imply case-control studies, whereas “prospective” is reserved for cohort studies, but the term sometimes is used to imply the timing of the project relative to data collection. A third type of usage of the term is based on the presence of the exposure of interest during case selection.5Vandenbroucke JP. Prospective or retrospective: What's in a name?.BMJ. 1991; 302: 249-250Crossref PubMed Scopus (37) Google Scholar The design and source of the participants should be clearly identified in the methods section. In the study by Moll et al, they clearly stated their participant pool “18 years of age or older who were admitted to the cardiothoracic surgery intensive care unit (CTS ICU) after a robotic MIDCAB from January 1, 2015, to May 31, 2019.” It is helpful to provide dates, and not just time durations, as the phrase “over four years,” for example, is far more ambiguous. It would have been helpful to the reader if, early in the methods section, the authors had specifically stated the cases and the controls for the study, including a no-block group; again, aiming to help the reader clarify the comparison groups. The indication for placement into the case or control group should be explicitly discussed, and in this example, it was clear that the type of regional block received determined the case and control groups. The selection of cases and controls, and usually the selection of controls in particular, must be carefully considered so as to minimize the potential to introduce confounders into the study. The methods section should also clearly identify the source of data and whether it is a secondary use of databases collected for other uses (for example, the patient chart), or whether the data specifically was gathered for the purpose of conducting the study. In their report, Moll et al clearly stated that the data were abstracted from patient charts, so the limitations of the available data may be appreciated by the reader. The authors also stated that this study was linked with another analysis that was performed on the same cohort of patients and included data previously presented and analyzed. This makes assessment of the totality of the literature on this topic far more robust when duplicate data can be easily identified. The methods section should include a justification of the proposed sample size. Frequently, in observational trials, the sample size is a convenience sample, as in the study by Moll et al, in which they included all patients who underwent a specific type of regional technique. However, it still is encouraged when feasible to provide a sample size based on effect estimates around the intervention. When sample sizes are not given, the use of a 95% CI around the odds ratios can serve as a surrogate and allow the reader a visual estimate of the robustness of the findings in the trial. Post hoc sample size analysis should not be attempted. As a general rule, the number of patients required using simple statistical calculations is likely to underestimate the number required if significant confounders are present and need adjustment. Bias is a systematic deviation of a study result from a true result and should not be confused with confounding. Bias in the study by Moll et al may have included, for example, observer bias. When the administration of analgesic doses may be influenced by the provider being aware of the patient's status regarding a regional technique, does the nurse administering analgesics know which patients have catheters, which expect less pain and so provide less analgesic? Bias must be considered in any trial design and should be included as part of the report in the methods; and the possible impact of bias discussed, including its possible magnitude and direction of effect. Bias is an important issue and its effects even can creep into randomized trials.6Hróbjartsson A Thomsen ASS Emanuelsson F et al.Observer bias in randomized clinical trials with measurement scale outcomes: A systematic review of trials with both blinded and nonblinded assessors.CMAJ. 2013; 185: E201-E211Crossref PubMed Scopus (326) Google Scholar Confounding is another important issue in observational trials that needs to be addressed, and the method to address confounding must be clearly stated in the methods and clearly presented in the results. It is beyond the scope of this article to review methods to detect confounding.7Sato K Bainbridge D. Transesophageal echocardiography and outcomes in coronary artery bypass grafting surgery: Dealing with confounders in observational studies.J Cardiothorac Vasc Anesth. 2020; 34: 696-697Abstract Full Text Full Text PDF PubMed Scopus (1) Google Scholar Many manuscripts continue to be submitted that use Student t test to demonstrate no difference in baseline characteristics between cases and controls, thus suggesting that no confounding exists. This methodology is incorrect. Broadly speaking, the use of propensity scoring or, in the case of Moll et al, the more commonly seen regression analysis, should be performed to ensure that confounding is controlled for in the analysis. The authors also should have carefully considered which variables to include in the study to reduce the effects of confounding. Finally, it is important to address how missing data were handled. Missing data in cases and controls may be most easily dealt with by omitting the subjects. This may itself create bias if the subjects with missing data are not representative of the sample included (for example, if patients missing data were more likely to stay for a shorter duration in the hospital). The missing data can be divided into two broad categories, missing completely at random and missing not at random.8Donders AR van der Heijden GJ Stijnen T et al.Review: A gentle introduction to imputation of missing values.J Clin Epidemiol. 2006; 59: 1087-1091Abstract Full Text Full Text PDF PubMed Scopus (1510) Google Scholar Data missing completely at random is defined when the probability of data missing is equal for all subjects. Missing not at random is when the missing data is dependent on specific data itself (if older patients are more likely to have data about age omitted, for example). It is not always clear into which category the missing data fall. However, missing data have the potential to introduce bias and must appropriately be handled. There are numerous methods to deal with missing data and, again, the authors should be explicit with their approach.8Donders AR van der Heijden GJ Stijnen T et al.Review: A gentle introduction to imputation of missing values.J Clin Epidemiol. 2006; 59: 1087-1091Abstract Full Text Full Text PDF PubMed Scopus (1510) Google Scholar,9Lee K Tilling K Cornish R et al.Framework for the treatment and reporting of missing data in observational studies: The TARMOS framework [epub ahead of print].J Clin Epidemiol. 2020; (Accessed January 12, 2021)https://doi.org/10.1016/j.jclinepi.2021.01.008Abstract Full Text Full Text PDF Scopus (23) Google Scholar When presenting results, the authors specifically should outline who was included, who was excluded, and why. This was done well in the study by Moll et al, in which their first figure outlined the inclusion and exclusion of all study patients in the trial. Figures frequently are easy to follow and are recommended in the STROBE guidelines. When presenting data for observational trials, it is recommended that the uncorrected data be presented first, followed by the data corrected for confounders. A good discussion always should focus on the key results of the trial, how the trial compares to other similar trials already published, and, finally, and perhaps most importantly, an earnest discussion of the limitations of the trial from the perspective of the trial design. This was addressed by Moll et al early in the discussion, pointing to unmeasured confounders and limitations in the data available from the chart as causing limitations in the analysis and conclusions. The intent of this brief review is to provide authors, readers, and reviewers with a brief overview of the STROBE criteria to improve the reporting of observational trials in the Journal. Readers are encouraged to read the accompanying explanation to the STROBE guidelines that provide a more comprehensive review of the topic.10Vandenbroucke JP von Elm E Altman DG et al.Strengthening the Reporting of Observational Studies in Epidemiology (STROBE): Explanation and elaboration.PLoS Med. 2007; 4: e297Crossref PubMed Scopus (2038) Google Scholar By providing a more robust framework to the reports of observational trials, it is hoped to make it easier to understand the complexities and uncertainties in observational trial design and adequately address confounding and bias. No conflict of interest declared.

The Ross procedure offers the only viable, living valve substitute for the diseased aortic valve, by transposing the pulmonary autograft into the aortic position and replacing the pulmonary valve with a pulmonary homograft (Fig 1).1Ross DN. Replacement of aortic and mitral valves with a pulmonary autograft.Lancet. 1967; 2: 956-958Abstract PubMed Google Scholar,2Ibrahim M Spelde AE Carter TI et al.The Ross operation in the adult: What, why, and when?.J Cardiothorac Vasc Anesth. 2018; 32: 1885-1891Abstract Full Text Full Text PDF PubMed Scopus (5) Google Scholar Since it first was described by Donald Ross in 1967, the Ross procedure has experienced fleeting waves of enthusiasm and has undergone multiple iterative improvements in surgical technique and perioperative care. Critics have voiced concerns about reproducibility and durability secondary to increased technical complexity, creation of two-valve disease out of single-valve disease, and potential complexities of reoperations. However, dedicated centers recently have published long-term outcomes that have demonstrated excellent late outcomes with near-normal hemodynamics, high freedom from valve-related complications and need for reoperation, and, most importantly, restored survival out to 20 years comparable to the age- and sex-matched general population. In the most recent addition of the Journal of the American College of Cardiology, Aboud et al. presented the late results of 2,444 patients from the German Ross Registry who had undergone a Ross procedure.3Aboud A Charitos EI Fujita B et al.Long-term outcomes of patients undergoing the Ross procedure.J Am Coll Cardiol. 2021; 77: 1412-1422Crossref PubMed Scopus (16) Google Scholar This multicenter series reported a median follow-up period of 9.2 years (range 0-27.4 years) and represents the largest published series of the Ross procedure to date. The mean age at surgery was 44 ± 12 years and 63% had a bicuspid aortic valve. They employed several techniques for the pulmonary autograft including subcoronary root replacement, and root replacement with additional reinforcement techniques and for the pulmonary valve, a mixture of aortic or pulmonary homografts or biologic valve prostheses. The German Ross registry demonstrated excellent results, with a mean 30-day mortality of 1%. Reoperation occurred in 5% of patients (0.69% per patient-year) for the autograft (aortic valve position) and 4.4% (0.62% per patient-year) for the pulmonary/right ventricular outflow tract graft. The long-term survival of 75.8% at 25 years was similar to the expected survival of the age- and sex-matched general population. They concluded that the “Ross procedure is a very favorable treatment option for nonelderly adults with aortic valve disease” and that it “achieves long-term survival rates similar to that of the general population, and suggests that life expectancy can be largely restored.” This was yet another study that is adding to the growing body of evidence supporting the use of the Ross procedure for the treatment of aortic valvopathy. There have been several metaanalyses investigating the outcomes following Ross procedures. In 2018, Etnel et al. investigated observational studies of the Ross procedure, including 99 published reports involving 13,129 patients, including both adults and children.4Etnel JRG Grashuis P Huygens SA et al.The Ross procedure: A systematic review, meta-analysis, and microsimulation.Circ Cardiovasc Qual Outcomes. 2018; 11e004748Crossref PubMed Scopus (32) Google Scholar The adult population represented 6,892 patients, with a mean age of 42, across 35 studies. They reported a pooled (adult) early mortality rate of 2.01% (95% CI 1.44-2.82) and a reoperation rate of 0.83% (0.68-1.01) for the autograft and 0.47% (0.37-0.59) for the right ventricular outflow tract. A study by Um et al., published in 2018, examined trials comparing adults undergoing the Ross procedure versus those undergoing conventional aortic valve repair (AVR) and focused on hemodynamics.5Um KJ McClure GR Belley-Cote EP et al.Hemodynamic outcomes of the Ross procedure versus other aortic valve replacement: A systematic review and meta-analysis.J Cardiovasc Surg (Torino). 2018; 59: 462-470PubMed Google Scholar Their study included 13 observational and two randomized trials, 5,336 patients in total (256 in the two randomized trials). The mean follow-up for the observational data was 4.7 years for the observational trials and 8.8 years for the two randomized trials. For both the observational cohort and randomized controlled trials, there was no difference in early mortality relative risk (RR) 0.93 (95% CI 0.47-1.83) for cohort trials versus RR 0.33 (95% CI 0.04-3.15) for randomized controlled trials. There was, however, a difference in late mortality RR 0.49 (95% CI 0.30-0.81) and RR 0.39 (95% CI 0.13-1.16) favoring the Ross procedure. Although the results were compelling, they, unfortunately, were forced to conclude that although favorable toward the Ross procedure, too many trials had moderate-to high-risk of bias to form any specific conclusions. A study by Mazine et al. looked at the Ross procedure compared to those specifically undergoing a mechanical AVR.6Mazine A Rocha RV El-Hamamsy I et al.Ross procedure vs mechanical aortic valve replacement in adults: A systematic review and meta-analysis.JAMA Cardiol. 2018; 3: 978-987Crossref PubMed Scopus (26) Google Scholar They identified a total of 18 studies including one randomized trial, ten adjusted observational studies, and seven unadjusted observational studies. In total, 3,516 patients were included, 1,552 underwent a Ross procedure, and 1,964 underwent mechanical aortic valve replacement. The median follow-up was 5.8 (3.4-9.2) years. Patients undergoing the Ross procedure had a reduction in the primary outcome of all-cause mortality incidence rate ratios (IRRs) of 0.54; (95% CI, 0.35-0.82), which equated to a mortality rate of 0.05%/y versus 0.10%/y favoring the Ross procedure over mechanical AVR. The incidence of valve- or cardiac-related mortality also was lower in the Ross group, with an IRR of 0.42; (95% CI, 0.18-0.97), equating to a mortality of 0.04%/y versus 0.09%/y. There was no significant difference in perioperative mortality, with RR of 0.73 (95% CI, 0.37-1.44). There was a higher rate of reintervention in the Ross patients, with IRR of 1.76 (95% CI, 1.16-2.65), which equates to a reoperation rate of 0.12%/y versus 0.06%/y. Much of the metaanalysis presented above contain the same trials; that is, to again state that the evidence base primarily was retrospective, involving observational studies and variable follow-up periods. This limitation was appropriately self-identified in all the studies quoted7Um KJ Belley-Cote EP McClure GR et al.A tale as old as time: Higher-quality evidence needed for the Ross procedure.J Cardiothorac Vasc Anesth. 2019; 33: 590-591Abstract Full Text Full Text PDF PubMed Scopus (1) Google Scholar and may be contributory to the undervalued guideline support for the Ross surgery. The Ross procedure remains a class IIb recommendation in the most recent American College of Cardiology/American Heart Association guidelines and was removed completely from the European guidelines without a recommendation at all.8Otto CM Nishimura RA Bonow RO et al.2020 ACC/AHA Guideline for the Management of Patients With Valvular Heart Disease: A report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines.J Am Coll Cardiol. 2021; 77: e25-197Crossref PubMed Scopus (152) Google Scholar,9Baumgartner H Falk V Bax JJ et al.2017 ESC/EACTS Guidelines for the management of valvular heart disease.Eur Heart J. 2017; 38: 2739-2791Crossref PubMed Scopus (2) Google Scholar Thus, the recent publication by Aboud et al. confirmed the excellent late durability and survival benefit of the Ross procedure, as reported by others, but these important confirmatory data add value, as it was the largest series published to date and came from multiple centers with very late follow-up. Globally, the Ross procedure remains underutilized, having disappeared completely from most cardiac centers10Yacoub MH El-Hamamsy I Sievers HH et al.Under-use of the Ross operation—a lost opportunity.Lancet. 2014; 384: 559-560Abstract Full Text Full Text PDF PubMed Scopus (44) Google Scholar; hopefully, this growing evidence will support the ongoing efforts for a Ross renaissance. The options for treating aortic valve disease truly have multiplied in the last several years. Conventional aortic valve replacement, with standard bioprosthetic or mechanical prosthesis, remained the predominant option for many decades. Sutureless and rapid-deployment prostheses have been developed to reduce myocardial ischemic times and address calcified aortic roots. Surgical techniques have evolved to include less-invasive hemisternotomy and minithoracotomy options; however, bioprosthetic valves continue to suffer from limited durability, restricted hemodynamics, and need for reoperation. Mechanical prostheses continue to decline as valve of choice, are thrombogenic, and require lifelong anticoagulation, and, thus, are associated with important risks of bleeding and thromboembolic complications. Regardless, young patients who receive either a tissue or mechanical prosthesis experience significantly impaired survival, which should not be overlooked.11Goldstone AB Chiu P Baiocchi M et al.Mechanical or biologic prostheses for aortic-valve and mitral-valve replacement.N Engl J Med. 2017; 377: 1847-1857Crossref PubMed Scopus (235) Google Scholar Over the last decade, transcatheter valve prostheses have emerged as an overriding option in elderly patients, with younger patient age thresholds advancing each year. An important area of great interest is the role of AVR rather than aortic valve replacement in patients with noncalcified, pliable aortic cusps with predominant aortic insufficiency.12Rimmer L Ahmad MU Chaplin G et al.Aortic valve repair: Where are we now?.Heart Lung Circ. 2019; 28: 988-999Abstract Full Text Full Text PDF PubMed Scopus (9) Google Scholar Aortic valve repair techniques have evolved and matured significantly over the past decade, demonstrating good function and long-lasting durability, with most of the supportive evidence originating from centers of expertise.13David TE David CM Ouzounian M et al.A progress report on reimplantation of the aortic valve.J Thorac Cardiovasc Surg. 2021; 161: 890-891Abstract Full Text Full Text PDF PubMed Scopus (13) Google Scholar,14Schneider U Hofmann C Schope J et al.Long-term results of differentiated anatomic reconstruction of bicuspid aortic valves.JAMA Cardiol. 2020; 5: 1366-1373Crossref PubMed Scopus (18) Google Scholar Arguments for valve repair are similar to those made for the Ross procedure, including optimal hemodynamics, avoidance of anticoagulation, with the additional avoidance of other prosthetic valve–related complications. In 2020, Buratto et al. published a small but interesting report looking at a series of children who had undergone primary Ross surgery compared to primary AVR with secondary Ross.15Buratto E Wallace FRO Fricke TA et al.Ross procedures in children with previous aortic valve surgery.J Am Coll Cardiol. 2020; 76: 1564-1573Crossref PubMed Scopus (12) Google Scholar In a propensity score–matched analysis, they found that secondary Ross procedure was associated with superior ten-year survival and freedom from autograft reoperation than primary Ross and concluded that a primary AVR strategy followed by delayed Ross procedure may provide better long-term survival and pulmonary autograft durability. Although these data would be impossible to generalize to young adults, it does raise the importance of a primary AVR strategy in patients with favorable repair anatomy and that a delayed Ross procedure, if necessary, may provide the optimal strategy in the lifetime management of aortic valve disease in young adults. The explosive growth in the management of aortic valve disease over the last 20 years, both through the development of new techniques and prosthetic designs, and the reevaluation of older methods, has led to dilemmas and clinical challenges in selecting optimal management strategies for patients. Innovation and procedural advancements have created many options; now personalized aortic valve management strategies must be developed that embrace individual patient preferences and values while prioritizing valve durability, hemodynamics, freedom from valve-related complications, and. above all else, excellent early and late survival. Current evidence remains limited by small, retrospective, single-center series with limited follow-up. However, Aboud et al. have provided tantalizing evidence, in a large multicenter study with 25-year follow-up, that patients indeed may benefit from a Ross procedure, as it is associated with very good valve durability, high freedom from valve-related complications, and excellent early and late survival, comparable to the age- and sex-matched general population. The profession must continue to raise the bar and develop larger, multicenter prospective randomized studies to confirm the small retrospective observational articles currently populating the evidence base.

Echocardiography is widely used for obtaining images of the heart for both preoperative diagnostic and intraoperative purposes. For procedures targeting the mitral valve, transesophageal echocardiography (TEE) is the primary imaging modality used as it provides clear 3D images of the valve and surrounding tissues. However, TEE suffers from image artifacts and signal dropout, particularly for structures lying below the valve including chordae tendineae. In order to see these structures, alternative echo views are required. However due to the limited field of view obtainable, the entire ventricle cannot be directly visualized in sufficient detail from a single image acquisition in 3D. This results in a large learning curve for interpreting these images as the multiple views must be reconciled mentally by a clinician. We propose applying an image compounding technique to TEE images acquired from a mid-esophageal position and a number of transgastric positions in order to reconstruct a high-detail image of the mitral valve and sub-valvular structures. This compounding technique utilizes a semi-simultaneous group-wise registration to align the multiple 3D volumes, followed by a weighted intensity compounding step. This compounding technique is validated using images acquired of a custom silicone phantom, excised porcine mitral valve units, and two patient data sets. We demonstrate that this compounding technique accurately captures the physical structures present, including the mitral valve, chordae tendineae and papillary muscles.

WHAT IS the purpose of trial registration and why is it so important to the integrity of research? Clinical trial registration serves the following purposes. First, by preregistering the trials, the primary outcome (why do the study) and method (how to do the study) get disclosed to the public. This makes certain biases unlikely to interfere with the interpretation of the results. Second, preregistration prevents conscious or unconscious manipulation of the results. This protects the integrity of the study.

Recently, developments have been made towards modelling patient-specific deformable mitral valves from transesophageal echocardiography (TEE). Thus far, a major limitation in the workflow has been the manual process of segmentation and model profile definition. Completing a manual segmentation from 3D TEE can take upwards of two hours, and existing automated segmentation approaches have limitations in both computation time and accuracy. Streamlining the process of segmenting the valve and generating a surface mold is important for the scalability and accuracy of patient-specific mitral valve modelling. We present DeepMitral, a fully automatic, deep learning based mitral valve segmentation approach that can quickly and accurately extract the geometry of the mitral valve directly from TEE volumes. We developed and tested our model on a data set comprising 48 diagnostic TEE volumes with corresponding segmentations from mitral valve intervention patients. Our proposed pipeline is based on the Residual UNet architecture with five layers. Evaluation of our proposed pipeline was assessed using manual segmentations performed by two clinicians as a gold-standard. The comparisons are made using the mean absolute surface distance (MASD) between the boundaries of the complete segmentations, as well as the 95 0.59 ± 0.23mm and average 95 1.99 ± 1.14mm . Additionally, we report a Dice score of 0.81. The resulting segmentations from our approach successfully replicate gold-standard segmentations with improved performance over existing state-of-the-art methods. DeepMitral improves the workflow of the mitral valve modelling process by reducing the time required for completing an accurate mitral valve segmentation, and providing more consistent results by removing user variability from the segmentation process.