71545 , Biventricular Pressure-Volume Loops During Mitral Transcatheter Edge-to-Edge Repair: The Relationship Between Physiology and Health Status Outcomes

Abstract

Background: Around 30% of patients fail to derive benefit after transcatheter edge-to-edge repair (M-TEER), and this treatment response heterogeneity is poorly understood. We examined the acute and medium-term effects of M-TEER, through invasive characterisation of biventricular physiology and impact on health status. Method(s): STRESS-MR is a UK multi-centre prospective study of 53 M-TEER patients in 2024. Pre and post M-TEER assessments included invasive biventricular pressure-volume loops (PVL) and cardiac catheterisation.Troponin I, NT-proBNP, echocardiography, NYHA class and Kansas City Cardiomyopathy Questionnaire (KCCQ) were measured at baseline and 6-12 months. Result(s): Deterioration of load-independent indices of right ventricular (RV) systolic function (end-systolic elastance, Ees) following M- TEER was associated with cardiovascular death (CVD) and heart failure hospitalisation (HFH). A fall in LV hemodynamic efficiency (stroke work/pressure-volume area, SW/PVA) was associated with increased symptom burden (NYHA class >=3) at follow-up. At baseline, compared to primary MR, secondary MR patients demonstrated significantly lower LV ventriculo-arterial coupling (Ees/Ea) (1.07 vs 1.81,p=10-point increase in KCCQ was associated with greater improvements in CI (0.46 vs 0.22 L/min/m2, p=0.048), RV SW /PWA (0.54 vs 0.36, p=0.013), and Ees/Ea (0.69 vs 0.34, p=0.006). Conclusion(s): RV systolic dysfunction and LV inefficiency predict higher CVD/HFH risk and symptom burden after M-TEER. Hemodynamic responders showed improved Ees/Ea, and SW/PVA, correlating with better health status. SMR patients have distinct baseline physiology and saw less improvement in CI, remodelling, and health status. Considering physiological suitability and identifying responders is important in identifying the right treatment approach for patients. Copyright © 2025