Background: Mitral Annular Disjunction (MAD) refers to embryologic fibrous separation between mitral annular ring and basal left ventricular myocardium. Since its original description, the role of MAD in arrhythmic mitral valve prolapse (MVP) has been subject of active research. In this study we sought to assess prognostic and imaging characteristics of MVP patients with and without underlying MAD. Methods: Patients with posterior or bi-leaflet MVP were retrospectively identified via a review of all patients referred to our cardiac magnetic resonance (CMR) imaging laboratory from January 2015 to May 2022. MVP patients were further stratified by underlying MAD status. CMR characteristics including late gadolinium enhancement (LGE) distribution, clinical characteristics, and data on mitral valve intervention were determined. Results: A total of 100 MVP patients undergoing CMR imaging (52 MVP patients with posterior MAD) were retrospectively identified with female comprising 55% of the cohort. MVP patients with MAD were more likely to have an abnormal basal inferolateral/ papillary muscles LGE (51% vs 21%, p<0.01). Posterior MAD longitudinal disjunction gap in ‘mm’ was a predictor of ventricular tachycardia (VT) [1.23, p=0.03)]. Similarly, posterior MAD as a binary variable was predictor of VT (11, p<0.01), ventricular arrhythmia (composite of VT, and non-sustained VT) (2.4, p=0.03), and major adverse cardiac events (MACE) (composite of VT, syncope, and mitral valve intervention) (2.5, p=0.03). Using ROC curve analysis, a disjunction gap of > 4 mm was predictive of VT (AUC-0.71, p<0.01), and incorporation of LGE in ROC model further improved AUC to 0.78 confirmed via Akaike information criterion (p<0.05), see Figure. Conclusion: Abnormal LGE involving basal inferolateral myocardium and papillary muscles may provide substrate for arrythmia in MVP patients. Further, for the first time, a MAD threshold of > 4 mm is demonstrated to stratify the VT risk.

Assessment of therapeutic interventions in patients with pulmonary arterial hypertension (PAH) suffers from several commonly encountered limitations: (1) patient studies are often too small and short-term to provide definitive conclusions, (2) there is a lack of a universal set of metrics to adequately assess therapy and (3) while clinical treatments focus on management of symptoms, there remain many cases of early loss of life in a seemingly arbitrary distribution. Here we provide a unified approach to assess right and left pressure relationships in PAH and pulmonary hypertension (PH) patients by developing linear models informed by the observation of Suga and Sugawa that pressure generation in the ventricle (right or left) approximately follows a single lobe of a sinusoid. We sought to identify a set of cardiovascular variables that either linearly or via a sine transformation related to systolic pulmonary arterial pressure (PAPs) and systemic systolic blood pressure (SBP). Importantly, both right and left cardiovascular variables are included in each linear model. Using non-invasively obtained cardiovascular magnetic resonance (CMR) image metrics the approach was successfully applied to model PAPs in PAH patients with an r2 of 0.89 (p < 0.05) and SBP with an r2 of 0.74 (p < 0.05). Further, the approach clarified the relationships that exist between PAPs and SBP separately for PAH and PH patients, and these relationships were used to distinguish PAH vs. PH patients with good accuracy (68%, p < 0.05). An important feature of the linear models is that they demonstrate that right and left ventricular conditions interact to generate PAPs and SBP in PAH patients, even in the absence of left-sided disease. The models predicted a theoretical right ventricular pulsatile reserve that in PAH patients was shown to be predictive of the 6 min walk distance (r2 = 0.45, p < 0.05). The linear models indicate a physically plausible mode of interaction between right and left ventricles and provides a means of assessing right and left cardiac status as they relate to PAPs and SBP. The linear models have potential to allow assessment of the detailed physiologic effects of therapy in PAH and PH patients and may thus permit cross-over of knowledge between PH and PAH clinical trials.

Introduction: Despite decades of initiatives, assessment of absolute pulmonary arterial pressures (PAP) by CMR has remained an elusive goal. We introduce a means to predict the PAP from routine image data easily obtained by CMR. The image data is directly used to calculate the impedance between the LV and the aorta (IMP LV ) and between the RV and the main PA (IMP RV ) which are combined to predict PAP. Methods: Patients (n=33, 82% F), 51 ±12 yrs) with a diagnosis of (PHTN) underwent evaluation by CMR to assess the blood flow through the aorta and PA at the interface to the LV and RV, respectively. Phase velocity mapping flow data at single plane (acquisition time 2min) was used to calculate the previously described and validated impedance for the LV and RV: IMP LV and IMP RV . IMP was calculated using the formula:IMP = (end systolic ejection time) x (mean blood velocity) / (vessel diameter). Systolic PAP was measured during a right heart cath examination performed within one week of the CMR. A multiple linear regression model was generated to predict systolic PAP, with parameters retained with a significance <0.05. Results: The parameters that best predicted the systolic PAP were IMP LV , IMP RV and the distance of the measured IMP LV from the center position of the data range of IMP LV (r = 0.69, p<0.001), Fig 1. The standard major-axis line was fitted to the data (p<0.001). Conclusions: This is the first demonstration of the utility of a CMR-measured left and right ventricular impedance value to directly predict systolic PAP. Critically, the correlation coefficient, identical to Echo, holds over a very wide physiologic range, and has never been demonstrated before by CMR. Of central importance is the distinguishing feature that no calibration of the data is required, thus, unlike typical Echo-derived estimates of PAP or newer implanted pressure monitors, no estimate of CVP or RAP is required. Thus, this is the first-in-man CMR demonstration of a virtual RHC.

Background The treatment of symptomatic severe aortic stenosis (AS) has rapidly evolved over the past decade, in both transcatheter (TAVR) and surgical aortic valve replacement (SAVR), resulting in reported improved clinical outcomes. Operator experience and technical improvements have improved outcomes especially for patients undergoing TAVR. We sought to determine and compare 1-year outcomes using a contemporary meta-analysis. Method We searched the Medline (MESH), Cochrane and Google scholar databases using keywords “AS”, “atrial fibrillation” (AFib) and “stroke”. We performed a meta-analysis to compare TAVR with SAVR populations for post-procedural stroke, all-cause and cardiovascular mortality at 1-year. Results A total of 23 studies met criteria for analysis with total population of 66,857 patients, of which 61,913 had TAVR and 4944 had SAVR. Temporal trends demonstrated overall improvement in outcome for both, TAVR and SAVR groups through the decade. Outcomes, in terms of stroke (3.1% vs. 5%), all-cause (12.4% vs. 10.3%) and cardiovascular mortality (7.2% vs. 6.2%) were similar at 1-year, in TAVR versus SAVR, respectively. Conclusion Despite overall gradual improvement in both TAVR and SAVR outcomes over the decade, there is a statistical overlap in confidence intervals for all-cause, cardiovascular mortality and postprocedural stroke at 1-year. While 23 individual studies demonstrate considerable advantages of each technique in certain cohorts, integrating over 65,000 pts with our stratified surgical analysis suggests that TAVR is comparable to SAVR for low and intermediate risk population while superior to SAVR only in the highest-risk population for short and intermediate term outcomes. This has substantial socio-economic implications as we contemplate expanding our TAVR indications to low/intermediate risk populations.

Introduction: In patients with pulmonary hypertension (PHTN), after initial hemodynamic assessment, it is common practice to perform the six minute walk test (6MWT). The absolute distance walked represents an integration of pulmonary artery pressure (PAP) and right heart function. Thus, the initial distance walked for each patient is generally used as the benchmark to compare to future 6MWT to assess therapy/prognosis. Here we show that the absolute 6MWT distance (6MWD) is less ambiguously interpreted as the measured impedance between the LV and the aorta. Methods: Patients (n=33, 82% F), age 51± 12yrs) with PHTN (>80% WHO I) underwent CMR to assess phasic blood flow through the aorta at the interface to the LV. CMR- phase velocity mapping flow data at single plane (acquisition time: 2min) was used to calculate the previously described and validated LV impedance (IMP LV ). IMP LV was calculated using the formula: IMP LV = (cardiac beat interval; CL) x (mean blood velocity) / (aortic diameter). Systolic PAP was measured during a right heart cath performed within one week of CMR and at the time of 6MWT. Multiple linear regression models were generated to predict the 6MWT distance. Results: A model predicting 6MWT was generated: systolic PAP, RVEF and age (r= 0.41, with PAP and RVEF not attaining significance). A second model entering IMP LV and age attained significance (r = 0.68, p<0.01). Fig 1. Conclusions: This is the first demonstration of the utility of the 6MWT distance to reflect a uniform measure of the status of the PH patient, less so PAP, even at baseline. The impedance between the LV and the aorta incorporates the dual components of RV and the LV integrated ventricular/arterial function along with the systolic PAP, making it a more fundamental measure of PHTN health status. Thus, despite >50 years of 6MWT used as the cornerstone for PHTN/PAH patients, we now show that this common application is really a predictor of impedance, and in turn, 6MWT was the right test for the wrong reason.

Introduction: The evolution of pacemaker/ICD safety in the magnetic field has triggered considerable interest in more clinical routine use. However, many limitations to widespread adoption of this seemingly implausible idea just a few years ago remain: unresolved impact of the high magnetic field, RF amplitude and oscillatory forces on electronics with possible high field damage to capacitor, solenoid and microcircuitry. However, given recent vender refinements over the last 10 years, we hypothesized that the impact on such circuitry may be far less than expected. Method: Consecutive interrogation of 940 pts who underwent clinically indicated MRI were evaluated over 5 years. This cohort was comprised of neuro/neurosurgical (72%), orthopedic (11%) and cardiac (17%) cases. Routine interrogation was performed within 10 min of entry into the bore of a dedicated Cardiac MRI (GE, 1.5T, WI). As well, reinterrogation was performed within 10 min of departure MRI (average 21±12min). At the time of interrogation pre and post MRI, a separate, repeat interrogation was performed within 5 min of each other such that 2 sets of PM/ICD parameters were obtained pre and post MRI. Result: No complications to either pt or device occurred during the MRI comprising 564 PMs and 376 ICDs. A cardiologist was present guiding the interrogation, configuration, and reconfiguration of the PM/ICD as well was present for entire MRI. There were no significant differences in common clinical parameters. More importantly, there was no difference in any parameter when compared in any order pre to post MRI scan. See Table. Conclusion: Intrinsic variability and inherent changes triggered by MRI environments are clinically insignificant and statistically negligible thereby removing yet another of the last remaining fears and apprehensions for primary PM/ICD failure and destruction as we move towards a more uniform acceptance of this technology for clinically meaningful use, dissemination and acceptance.

Objective:To study the influence of a flow-based Impedance Index to attempt to explain the persistent late failure rate of Pulmonary Vein Isolation (PVI) in patients with Atrial Fibrillation (AF).Background:We recently described a flow-based Impedance Index for left ventricular ejection into the aorta and noted an association with Major Adverse Cardiovascular Event Rate (MACE). While the Impedance Index is not routinely measured in PVI patients it approximates to measures derivable from the left ventricular ejection fraction (EF). We sought to assess the Impedance Index's influence on PVI failure rate in combination with indices of left atrial size.Methods:In AF patients (n=100) undergoing a Cardiovascular Magnetic Resonance (CMR) imaging examination prior to undergoing PVI we assessed baseline characteristics for their influence on the PVI failure rate at 3-12 months. Uni-variable and multi-variable binary logistic models were performed to find predictors of the PVI failure rate at follow-up.Results:All patients underwent PVI and CMR imaging. A total of 26 (26%) patients had late AF recurrence at 3-12 months follow-up. Multi-variable models that predicted PVI failure were: 1) the baseline Impedance Index and LA volume index (p<0.05) and 2) the baseline Impedance Index and the degree of mitral valve regurgitation (MR) (p<0.001). While the Impedance Index was derived from EF, EF per se was not a predictor of PVI failure (p=0.28).Conclusions:We have provided evidence of the influence of a flow-based Impedance Index on the PVI late failure rate which is significant and remains explanatory when adjusting for measures of atrial size, MR grade and LA volume index. Direct measure of the Impedance Index was not available here and was derived from EF measures. Further work is needed to directly measure the Impedance Index in a PVI population and determine the mechanism for the influence on PVI failure, which may lead to modification of the ablation procedure to improve the success rate.

BACKGROUND:This study aims to study the feasibility and safety of measuring volumetric and pressure parameters noninvasively using simultaneous cardiovascular magnetic resonance (cMR) volumetric data and time-resolved pressure waveforms from previously implanted CardioMEMS devices in pulmonary arterial hypertension (PAH) patients. Opportunities to intervene during clinically occult phases in PAH promise to herald a key transformation in our current practice for treating this complex population. Currently, it is possible and convenient to monitor daily pulmonary arterial (PA) pressures in PAH patients using the CardioMEMS device to determine clinically silent progression. Supplementation of these pressures with other prognostic measurements of right ventricular (RV) contractility, PA resistance and RV/PA coupling could add further predictive capabilities.METHODS:PAH patients (n=17) with New York Hospital Association (NYHA) class III or IV heart failure (HF) and recent HF related hospitalizations were implanted with the CardioMEMS device as part of a NHLBI sponsored Trial. Implanted patients were then assessed using cMR imaging of the right ventricle (RV) along with measurement of pulmonary artery flow. Patients were imaged at one-month post implant (baseline) and at 4-month follow-up time (n=12). At baseline, patients were studied at rest and then under three different physiologic conditions: inhaled nitric oxide (INO), dobutamine (Dob) stress and volumetric stress (Vol), using a multiple slice short-axis imaging and a rapid imaging protocol.RESULTS:All patients were safely imaged, with no artifacts obscuring the cMR images. RV volumes were measured successfully at rest and under each stress condition using a reduced scan approach that required calibration for each patient which achieved a correlation r2 of 0.98. Variables measured included the maximal pulmonary artery elastance (Ea), maximal RV myocardial elastance (Emax) and ventricular-vascular coupling ratio (VVC). The response to stressors was determined on a patient basis. No complications occurred during the cMRI examination.CONCLUSIONS:It is safe and feasible to perform cMR imaging with simultaneous pulmonary artery pressure readings from the CardioMEMS device. A reduced scan approach was developed to allowed measurement of RV volumes during stress conditions. Volumetric and pressure measurements can be combined to assess fundamental myocardial properties (e.g., Emax, Ea and VVC) in PAH patients serially over time. In the future, these parameters can be tested as serial predictors of outcome and response to therapies in PAH.

As CMRI has been increasingly applied to diverse populations, it has been used to characterize the normal range of features such as EF. However, beyond being able to identify how far a pt is from “normal”, such designations fail to identify optimal conditions that are feasible to attain for that

BACKGROUND:After successful pulmonary vein isolation (PVI) for atrial fibrillation (AF), the left atrium (LA) undergoes reverse remodeling. However, few studies have directly studied pulmonary vein (PV) remodeling and focused on whether pre PVI-PV conditions could predict outcome of the procedure. We hypothesize that: (I) post PVI, in addition to LA remodeling the PVs undergo a parallel degree of remodeling; and (II) that PV characteristics pre PVI can be used to identify patients more likely to sustain normal sinus rhythm (NSR). METHODS:Patients (n=100) scheduled for PVI had a cardiovascular magnetic resonance (CMR) imaging before and 6±2 months following PVI. PV cross sectional areas (CSA) within 0.5 cm of the ostium and LA volumes were measured. Patients were categorized as responders (R) or non-responders (NR), based on two separate 14-day Holter monitoring. RESULTS:PVs CSA were significantly reduced post procedure in both groups, R (233±53 to 192±52 mm2, P<0.001) and NR (241±54 to 207±44 mm2, P<0.001), however, the difference between R and NR post PVI was not significant (192±52 to 207±44 mm2, P=0.19). Reduction in PVs CSAs post procedure moderately correlated with the 3D LA volume reduction (r=0.48, P<0.001). CONCLUSIONS:PVs mirror the LA in that they significantly change in size following PVI yet they were not found to directly predict maintenance of NSR.