Baseline atrial–ventricular strain coupling and ventricular contractile reserve determine long-term outcomes after transcatheter aortic valve replacement
R Wimolwattanaphan, W Luangphiphat, P Rawangban, C Wuttichaipradit, N Sririsreetreerux, C Wongsinkongman, V Muangsillapasart, A TunhasiriwetAbstract
Background
Transcatheter aortic valve replacement (TAVR) effectively relieves valvular obstruction in severe aortic stenosis, yet long-term cardiovascular outcomes remain heterogeneous. While structural remodeling may occur after valve intervention, adverse events are ultimately governed by baseline myocardial function. The prognostic importance of baseline atrial–ventricular mechanical integration, which determines ventricular filling efficiency and pressure transmission, has not been well defined.
Objectives
To determine whether baseline atrial–ventricular strain coupling and ventricular contractile reserve predict major adverse cardiovascular events (MACE) after TAVR and enable clinically meaningful risk stratification.
Methods
We retrospectively studied 186 consecutive patients undergoing TAVR for severe symptomatic aortic stenosis. Baseline pre-procedural echocardiography assessed left atrial reservoir strain, left ventricular global longitudinal strain, atrial–ventricular strain coupling expressed as the left atrial–to–left ventricular (LA/LV) strain ratio, and left ventricular end-systolic elastance (Ees) as a measure of contractile reserve. Ees was estimated noninvasively as 0.9 × systolic blood pressure divided by left ventricular end-systolic volume. The primary outcome was MACE, defined as a composite of all-cause mortality, myocardial infarction, heart failure hospitalization, and stroke. Cox proportional hazards models were constructed using physiologically guided variable selection.
Results
Mean age was 80 ± 5 years; 54% male; atrial fibrillation 12%, coronary artery disease 68%. During a median follow-up of 3 years, 39 patients experienced MACE. Baseline atrial–ventricular strain coupling was the strongest independent predictor of MACE (hazard ratio [HR] 0.27, 95% CI 0.11–0.61; p = 0.001), exceeding the prognostic contribution of age, CAD, and AF. Greater baseline ventricular contractile reserve was independently associated with lower risk (HR 0.85 per unit increase in Ees, 95% CI 0.72–0.97; p = 0.012). Risk stratification using cutoffs of LA/LV strain ratio 1.26 and Ees 6.24 identified a high-risk phenotype characterized by impaired atrial–ventricular coupling and reduced contractile reserve, with graded separation of event-free survival (log-rank p = 0.0006).
Conclusions
Long-term outcomes after TAVR are determined predominantly by baseline myocardial physiology rather than by valvular obstruction alone. Atrial–ventricular strain coupling captures baseline myocardial vulnerability that may persist despite relief of valvular obstruction, while Ees reflects the heart’s adaptive contractile capacity. Together, these complementary measures provide a physiologically grounded framework for pre-procedural risk stratification in patients undergoing TAVR.Figure1