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

BACKGROUND

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.

METHODS

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%).

RESULTS

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).

CONCLUSIONS

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.