Prognostic interaction of aortic regurgitation and left atrial strain beyond guideline-based intervention criteria

Patients with significant aortic regurgitation (AR) not meeting current surgical criteria may develop heart failure with preserved ejection fraction (HFpEF). Left atrial reservoir strain (LASr) reflects atrial-diastolic function and may provide prognostic information beyond conventional left ventricular (LV) metrics.

We retrospectively included 182 patients with significant AR and 182 age- and sex-matched controls who underwent transthoracic echocardiography between 2017 and 2023. LASr was quantified using automated vendor-independent software. The primary endpoint was all-cause mortality or HF hospitalization. Fine-Gray competing risk models adjusted for age, atrial fibrillation, LV ejection fraction, LV end-systolic diameter, and E/e' were used to evaluate the association of LASr with the primary endpoint. Patients were also grouped into four strata according to AR status and LASr threshold (≥40% vs <40%).

Over a median follow-up of 38.5 months, the composite endpoint occurred in 52 AR patients (30.1%) and 30 controls (16.5%). LASr was lower in AR patients (31.6 ± 14.7% vs 35.9 ± 16.0%, p = 0.007). In AR patients, lower LASr independently predicted adverse outcomes (SHR 1.18 per 5% decrease, 95% CI 1.02-1.36, p = 0.025). In the full cohort, event rates were lowest in No-AR/LASr ≥40% (1.4%) and highest in AR/LASr <40% (36.9%; adjusted SHR 10.96, 95% CI 1.49-80.53, p = 0.019).

Significant AR without guideline-based surgical criteria is associated with a high burden of HF events. LASr identifies an HFpEF phenotype in which atrial-diastolic dysfunction, rather than LV remodeling, is more strongly associated with clinical outcomes.