BACKGROUND:Out-of-hospital cardiac arrest is associated with high mortality and substantial healthcare costs. The British Cardiovascular Interventional Society's conveyance algorithm prioritises direct transfer of patients with an initial shockable rhythm to specialist Cardiac Arrest Centres to support access to advanced cardiac intervention, neurocritical care, and structured rehabilitation. This study evaluated the cost-effectiveness of implementing the conveyance algorithm in a large regional population. METHODS:A hybrid decision-analytic model, combining a decision tree and Markov model was developed to assess the cost-effectiveness of the algorithm, compared with standard of care over a lifetime horizon. Model inputs were derived from a contemporary, observational pilot study. Health outcomes were expressed in quality-adjusted life years, and healthcare costs were discounted at an annual rate of 3.5%. Cost-effectiveness was assessed using the incremental cost-effectiveness ratio and net monetary benefit. RESULTS:The conveyance algorithm was cost-effective, with an incremental cost-effectiveness ratio of £2926 per quality-adjusted life year gained. Reductions in intensive care, hospital ward, post-assessment, and ambulance costs were partially offset by slightly higher costs related to admission, neuroprognostication, and longer-term care. Probabilistic analysis showed an 86.0% probability of cost-effectiveness at a willingness-to-pay threshold of £35,000 per quality-adjusted life year. CONCLUSION:Selective rhythm-based transfer to specialist cardiac arrest centres improved resource efficiency with minimal additional cost. Although clinical outcome differences remain exploratory due to observational data, this economic evaluation supports further prospective, multi-centre evaluation to confirm broader clinical and health system benefits.

Exercise treadmill testing measures functional capacity and inducible myocardial ischemia and has historically served as an endpoint in phase 2 trials. The Precision Medicine with Zibotentan in Microvascular Angina trial evaluated the selective endothelin-A receptor antagonist zibotentan as a potential disease-modifying therapy for microvascular angina. The trial had a randomized, double-blind, cross-over design and the primary outcome was exercise duration. Compared with placebo, zibotentan at a dose of 10-mg daily for 12-weeks did not improve exercise duration or angina symptoms. In this prespecified analysis, exercise duration was compared across four sequential study visits and the factors associated with within-trial changes were evaluated. Exercise test duration increased progressively in all participants during sequential trial phases, independent of treatment with either zibotentan or placebo. This improvement in exercise duration was associated with female sex (interaction p-value = .0213; effect estimate [95% confidence interval]) 34.95 [13.99, 55.78] seconds, P = .002). In conclusion, the exercise test has limitations as an objective endpoint of efficacy in randomized trials. PRIZE; https://clinicaltrials.gov/study/NCT04097314 Clinicaltrials.gov Registration: NCT04097314.

Mechanical cardiopulmonary resuscitation (mCPR) devices are increasingly used during percutaneous coronary intervention (PCI) in intracardiac arrest patients. However, the optimal invasive hemodynamic parameter to guide mCPR remains unclear. This study compared the hemodynamic performance of two devices, LUCAS and Corpuls, using invasive blood pressure (IBP) measurements during early mCPR. This retrospective, single-center study included adult patients undergoing catheterization laboratory procedures (2021-2024). Invasive blood pressure readings were recorded every 10 seconds during initial manual CPR and the first 5 minutes of mCPR. Hemodynamic parameters and return of spontaneous circulation (ROSC) outcomes were analyzed. Twenty-five cases were analyzed (15 LUCAS, 10 Corpuls; mean age 79.1 ± 14 years; 56% male). Both devices generated higher IBP compared with manual CPR. Corpuls produced greater increases from the manual CPR baseline in ΔDBP (delta diastolic blood pressure) and ΔMAP (delta mean arterial blood pressure), whereas ΔSBP (delta systolic blood pressure) did not differ significantly. Variability metrics were comparable, and ROSC rates were similar. Both devices provided effective hemodynamic support during cardiac arrest in the catheterization laboratory. Although Corpuls produced greater increases in diastolic and MAP from baseline, no clear device superiority was demonstrated. Larger prospective studies are required to define optimal hemodynamic targets during mechanical CPR.

BACKGROUND:Microvascular injury (MVI), commonly assessed on cardiac magnetic resonance (CMR) as microvascular obstruction (MVO), is frequently observed in patients with ST-elevation myocardial infarction (STEMI) despite timely primary percutaneous coronary intervention (PPCI), and is key to adverse left ventricular (LV) remodelling and poor outcomes. Established invasive indices, such as the index of microvascular resistance (IMR), are obtained after reperfusion and therefore do not capture microvascular compromise present during coronary occlusion. Coronary wedge pressure (CWP), obtained during balloon occlusion, is a simple invasive marker of microvascular function, but its clinical value remains uncertain. OBJECTIVES:To determine whether pre-reperfusion CWP, coronary flow pressure index (CFPI) and related pressure-derived indices are associated with (i) the presence of CMR-defined MVO and (ii) MVO extent in anterior STEMI patients treated with selective intracoronary hypothermia (SIH). Secondary objectives were associations with intramyocardial haemorrhage (IMH) and myocardial salvage index (MSI). METHODS:In this EUROICE substudy, distal coronary pressure was recorded during culprit LAD occlusion in patients randomised to selective intracoronary hypothermia. Systolic, diastolic and mean CWP, CFPI and outflow time (τ) were derived. CMR at 2-7 days quantified MVO, intramyocardial haemorrhage (IMH) and myocardial salvage index (MSI). Associations were analysed using Spearman correlation, parsimonious multivariable logistic regression, and receiver operating characteristic analysis. RESULTS:Of 94 patients randomised to selective intracoronary hypothermia, 82 had paired pre-reperfusion physiology and CMR data available, of whom 65 had interpretable coronary pressure traces. Mean wedge pressure was 21.4 ± 11.0 mmHg, CFPI 0.24 ± 0.11, and τ 5.2 ± 2.6 s. MVO was present in 64% of patients (mean extent 2.7 ± 4.6% of LV mass). Lower CWP and CFPI were associated with MVO presence and extent (CFPI ρ = -0.33, p = 0.008), whereas τ was not. Lower CWP and CFPI were inversely related to IMH, but not to MSI. In complete-case multivariable models, lower CFPI remained associated with MVO presence (adjusted OR 0.91 per 0.01 increase, 95% CI 0.86-0.97, p = 0.002), as did lower mean CWP (adjusted OR 0.91 per 1 mmHg increase, 95% CI 0.85-0.97, p = 0.003). CFPI showed moderate discrimination for MVO, with an AUC of 0.74 (95% CI 0.61-0.87), while mean CWP showed similar discrimination, with an AUC of 0.74 (95% CI 0.61-0.86). CONCLUSIONS:Lower CWP before reperfusion and CFPI during balloon occlusion were associated with greater MVO and IMH on early CMR in anterior STEMI. These indices support the feasibility of pre-reperfusion physiological phenotyping to aid on-table microvascular risk stratification.

BACKGROUND AND AIMS:Guidelines recommend that survivors of out-of-hospital cardiac arrest (OHCA) be transported to a cardiac arrest centre (CAC), though supporting evidence remains limited. This study evaluated whether implementation of the BCIS algorithm, based on initial rhythm, improves survival outcomes. METHODS:This observational, multicentre study compared consecutive OHCA cases before and after algorithm implementation across Essex. In the Standard Care phase (April-September 2022), CAC transfer was based on clinical discretion, typically for STEMI or suspected cardiac cause. In the BCIS Protocol phase (October 2022-August 2025), all patients with an initial shockable rhythm were conveyed directly to CAC, as were those with STEMI on pre-arrest or post-ROSC ECG irrespective of initial rhythm (standard care); others were taken to district general hospitals (DGH) or discussed with CAC.The primary outcome was 30-day all-cause mortality; the secondary outcome was survival with favourable neurological status (CPC 1-2). RESULTS:Among 850 patients (mean age 66.5±13.7 years, 69% male), 162 received standard care and 688 were managed under the BCIS protocol. Initial shockable rhythm conveyance adherence to CAC was seen in 84% cases, resulting in 40% absolute increase in the proportion of patients with an initial shockable rhythm being transported directly to CAC (44% in the standard care group vs 84% in the BCIS group).Algorithm implementation was associated with significantly reduced 30-day mortality (81% vs 67%; p<0.001) and increased survival with favourable neurological outcome (16% vs 30%; p<0.001). Improvements were most evident in patients with shockable rhythms (62% vs 42%; p=0.001). No difference was observed for non-shockable rhythms (94% vs 93%; p=0.81). CONCLUSIONS:Implementation of the BCIS conveyance algorithm improves 30-day survival and neurological outcomes in OHCA patients with shockable rhythms when transported directly to a CAC.

BACKGROUND:In stable coronary artery disease, the primary goal of percutaneous coronary intervention (PCI) is symptom relief. Fractional flow reserve (FFR) and nonhyperemic pressure ratios such as resting full-cycle ratio (RFR) are used to guide revascularization. Although these indices correlate with myocardial ischemia, they have never been validated against the onset of angina. The physiological thresholds for angina, FFRangina and RFRangina, angina (FFRangina at rest and during exercise remain undefined. METHODS:ORBITA-FIRE (Finding the Invasive Threshold for Symptom Relief in Exertional Angina) was a multicenter, double-blind, randomized, placebo-controlled study in patients with stable angina and single-vessel coronary artery disease. After imaging-guided PCI, an in-stent balloon was incrementally inflated until angina occurred at rest. This angina threshold was verified against placebo inflation, and corresponding FFRangina and RFRangina values were recorded at symptom onset. The protocol was repeated during low- and high-intensity exercise to assess changes in angina thresholds with increasing cardiac workload. RESULTS:Sixty-five patients were enrolled (mean age, 63.9±8.7 years; 74% male; 69% hypertensive; 23% diabetic; 91% with Canadian Cardiovascular Society class II-III angina). Median pre-PCI FFR was 0.59 (interquartile range [IQR], 0.46-0.70) and RFR was 0.61 (IQR, 0.40-0.82). Median FFRangina at rest was 0.29 (IQR, 0.23-0.35), increasing to 0.38 (IQR, 0.30-0.48) during low-intensity exercise and 0.45 (IQR, 0.36-0.55) during high-intensity exercise. RFRangina similarly increased from 0.22 (IQR, 0.16-0.30) at rest to 0.26 (IQR, 0.18-0.36) and 0.32 (IQR, 0.23-0.46) during low- and high-intensity exercise. All thresholds were significantly lower than clinical diagnostic cut points (P<0.001). Lower FFRangina and RFRangina thresholds were associated with greater symptom reproducibility across rest, low- and high-intensity exercise conditions (FFRangina: P=0.008, P<0.001, P<0.001, respectively; RFRangina: P=0.015, P<0.001, P=0.002, respectively). Lower angina thresholds across all conditions predicted higher baseline angina burden and greater symptom relief with PCI (probability of interaction >0.999). CONCLUSIONS:Physiological thresholds for angina, FFRangina and RFRangina, are highly individualized, vary with cardiac workload, and are consistently lower than the universal ischemia-based thresholds used to guide revascularization. These findings support integrating personalized, symptom-linked physiology to refine patient selection and to improve symptomatic response to PCI.

Background: Near-infrared spectroscopy combined with intravascular ultrasound (NIRS–IVUS) allows simultaneous assessment of plaque composition and vessel structure. The lipid core burden index (LCBI) and the maximum lipid core burden index over 4 mm (maxLCBI4mm) are established markers of lipid-rich and potentially vulnerable plaques. However real-world reproducibility data for these indices using the contemporary Dualpro™ NIRS–IVUS catheter is unknown. This study aimed to evaluate the reproducibility of LCBI and maxLCBI4mm across repeated NIRS–IVUS pullbacks performed within the same coronary segment using the current-generation catheter system. Methods: This single-center study included consecutive patients who underwent percutaneous coronary intervention (PCI) with adjunctive NIRS–IVUS imaging and had repeated pullbacks of the same coronary segment during the procedure. LCBI and maxLCBI4mm were recorded for each pullback. Reproducibility was assessed using Spearman correlation and intraclass correlation coefficients (ICC), and consistency for the clinically relevant thresholds of maxLCBI4mm was evaluated. Results: A total of 87 paired pullbacks were analyzed (37 pre-PCI, 15 post-lesion preparation, and 35 post-stenting). LCBI demonstrated excellent reproducibility (ρ = 0.95; ICC = 0.95) and maxLCBI4mm also showed strong reproducibility (ρ = 0.90; ICC = 0.91). The threshold of maxLCBI4mm > 400 was concordant between runs in 90% of cases, and the post-stent threshold of >200 showed concordance in 89% of cases. Conclusion: The contemporary Dualpro™ NIRS–IVUS catheter provides highly reproducible measurements of both LCBI and maxLCBI4mm. These findings support the reliability of NIRS–IVUS for identifying lipid-rich plaques and strengthen its suitability for research and clinical applications focused on plaque vulnerability.

BACKGROUND:In the randomized EBC MAIN trial (European Bifurcation Club Left Main Coronary Stent), target lesion revascularization at 3 years poststenting of left main (LM) bifurcations was more frequent with upfront dual-stenting compared with the stepwise provisional approach. Restenosis location and its relation to stent technique are poorly characterized. The aim of this study was to investigate restenosis location after LM bifurcation stenting, and the impact of stent implantation technique. METHODS:Patients from the EBC MAIN trial who underwent target lesion revascularization during the 3-year follow-up had restenosis location assessed by the core laboratory. Restenosis was defined as ≥50% lesion diameter stenosis. RESULTS:Among 48 patients with target lesion revascularization (mean age 70.3±10.6 years, 72.9% men), 31 were randomized to and treated with upfront dual-stenting, while 17 were randomized to the stepwise provisional technique, of whom 4 had dual-stent implantation. The treatment groups therefore comprised 35 dual-stented and 13 single-stented patients. The commonest pattern of subsequent restenosis was isolated ostial circumflex restenosis (58% of patients), regardless of dual- or single-stent implantation. The ostial circumflex was the culprit lesion for target lesion revascularization in 34 (71%) patients overall (dual- versus single-stented patients: 77% versus 54%; P=0.115). During the 3-year follow-up, the mean % diameter stenosis at the circumflex ostium was similar after dual- versus single-stent implantation (64.6% versus 60.5%, coefficient, -0.12 [95% CI, -0.46 to 0.22]; P=0.473). Single stenting from LM to the circumflex artery was associated with worse subsequent mean % diameter stenosis in the ostium of the left anterior descending artery versus single stenting from LM- left anterior descending (49.8% versus 19.8%, coefficient, 0.57 [95% CI, 0.003-1.13]; P=0.049). CONCLUSIONS:The circumflex ostium is the commonest site requiring revascularization after LM bifurcation stenting, irrespective of whether 1 or 2 stents were deployed. Strategies are needed to improve the long-term success of percutaneous coronary intervention to the circumflex artery ostium. REGISTRATION:URL: https://www.clinicaltrials.gov; Unique identifier: NCT02497014.

BACKGROUND AND AIMS:Guidelines suggest non-traumatic out-of-hospital cardiac arrest (OHCA) be conveyed to cardiac arrest centres (CAC). We hypothesised that (a) a pre-hospital conveyance algorithm based on initial presenting rhythm following OHCA is feasible and (b) that would demonstrate survival advantage. METHODS:This observational pilot study included all consecutive patients with OHCA from suspected cardiac aetiology from the county of Essex, United Kingdom from April 2022-April 2023. For the first 6 months, OHCA patients had conveyance as standard of care. For the next 6 months, consecutive OHCA patients with STEMI or initial shockable rhythm were directly conveyed to the CAC, initial non-shockable rhythm without STEMI continued to be taken to the nearest Emergency Department (BCIS protocol). Primary outcome was death from any cause at 30 days. Secondary outcome was survival with favourable neurological outcome. RESULTS:Of 330 patients (mean age 67.5 ± 13.1, 66% male), 162 patients were in the standard care group and 168 in the BCIS conveyance group. Algorithm implementation was associated with numerically lower all cause 30-day mortality [(81% vs 73%, RR 1.10 (95% CI 0.98-1.24) p = 0.10] and numerically higher 30-day survival with favourable neurological outcome [15% vs 19%, RR 1.05 (0.95-1.15), p = 0.38]. Post hoc analysis showed that the BCIS conveyance algorithm was associated with lower 30 day mortality in those with an initial shockable rhythm [(61% vs 41%, RR 1.5 (95% CI 1.05-2.13) p = 0.02 and in those with a MIRACLE2 score ≤ 5 [(63%% vs 38%, RR 0.59 (95% CI 0.61-0.86) p = 0.005]. CONCLUSIONS:The BCIS algorithm is feasible and did not impact overall mortality, but there is signal that direct conveyance of OHCA patients with an initial shockable rhythm and low MIRACLE2 score, to a dedicated CAC may improve survival.

BACKGROUND: ORBITA-2 (the Placebo-Controlled Trial of Percutaneous Coronary Intervention for the Relief of Stable Angina) provided evidence for the role of percutaneous coronary intervention (PCI) for angina relief in stable coronary artery disease. Fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) are often used to guide PCI; however, their ability to predict placebo-controlled angina improvement is unknown. METHODS: Participants with angina, ischemia, and stable coronary artery disease were enrolled, and anti-anginal medications were stopped. Participants reported angina episodes daily for 2 weeks using the ORBITA smartphone symptom application (ORBITA-app). At the research angiogram, FFR and iFR were measured. After sedation and auditory isolation, participants were randomized to PCI or placebo before entering a 12-week blinded follow-up phase with daily angina reporting. The ability of FFR and iFR, analyzed as continuous variables, to predict the placebo-controlled effect of PCI was tested using Bayesian proportional odds modeling. RESULTS: Invasive physiology data were available for 279 patients (140 PCI and 139 placebo). The median (interquartile range) age was 65 years (59.0-70.5), and 223 (79.9%) were male. Median FFR was 0.60 (0.46-0.73), and median iFR was 0.76 (0.50-0.86). The lower the FFR or iFR, the greater the placebo-controlled improvement with PCI across all end points. There was strong evidence that a patient with an FFR at the lower quartile would have a greater placebo-controlled improvement in angina symptom score with PCI than a patient at the upper quartile (FFR, 0.46 versus 0.73: odds ratio, 2.01; 95% credible interval, 1.79-2.26; probability of interaction, >99.9%). Similarly, there was strong evidence that a patient with an iFR at the lower quartile would have greater placebo-controlled improvement in angina symptom score with PCI than a patient with an iFR at the upper quartile (iFR, 0.50 versus 0.86: odds ratio, 2.13; 95% credible interval, 1.87-2.45; probability of interaction, >99.9%). The relationship between benefit and physiology was seen in both Rose angina and Rose nonangina. CONCLUSIONS: Physiological stenosis severity, as measured by FFR and iFR, predicts placebo-controlled angina relief from PCI. Invasive coronary physiology can be used to target PCI to those patients who are most likely to experience benefit.

Percutaneous techniques to treat obstructive coronary artery disease continue to evolve and the evidence base informing our practice is shared and summarised in international guidelines. In the UK, the British Cardiovascular Intervention Society represents and supports interventional cardiologists undertaking both coronary and structural interventions. Procedural data are collected in a national registry and these inform our understanding of UK practice and outcomes. These recommendations, pertaining to coronary intervention alone, are an update of those published in 2015 and describe the provision of percutaneous coronary intervention in the UK intended to provide optimal patient care.