Prognostic impact of cardiovascular magnetic resonance-derived left atrioventricular coupling index in patients with severe aortic stenosis undergoing transcatheter aortic valve replacement

Aims Transcatheter aortic valve replacement (TAVR) is an established therapy improving outcome in patients with severe aortic stenosis (AS). Cardiovascular magnetic resonance (CMR)-derived left atrioventricular coupling index (LACI) has demonstrated prognostic value, however, its prognostic utility in severe AS remains unknown. Methods and Results Between January 2017 and September 2023 138 patients (80 years (70-83), 62% male) consecutive patients with severe AS referred for TAVR were prospectively recruited for pre-procedural CMR imaging. LACI was defined as the ratio of the left atrial (LA) end-diastolic volume index (LA EDVi) and left ventricular (LV) end-diastolic volume index (LV EDVi). The primary endpoint was cardiovascular (CV)-mortality. The cohort was dichotomized at a median of 44.1% (high vs. low LACI). Patients with increased LACI (≥44.1%) had higher symptom burden (NYHA III/IV prevalence (68.1% vs.44.9%; p=0.047)), more frequently atrial fibrillation (50.7% vs.14.5%; p<0.001), and elevated NT-proBNP (2017 ng/L vs.1012 ng/L; p=0.007). Over a median follow-up of 2.7 years (IQR 1.7–3.6), high LACI was associated with higher CV mortality (log-rank p=0.016). In multivariable Cox regression models, LACI remained independently associated with CV-mortality after adjustment for established parameters of left atrial or ventricular function (LA reservoir strain: HR 2.10, 95% CI 1.05–3.57, p=0.036; LV GLS: HR 2.21 95% CI 1.00 – 4.9, p=0.049). Conclusion CMR-derived LACI yields independent prognostic value for mortality in patients with severe AS undergoing TAVR. Its simplicity and routine availability may optimize periprocedural risk stratification.