Association of cardiovascular magnetic resonance-derived left atrial function with cardiovascular outcomes in hypertension-associated cardiac remodeling: a retrospective cohort study

Background Left ventricular ejection fraction may not fully characterize the cumulative diastolic burden and atrial remodeling associated with hypertension. This study examined the associations of cardiovascular magnetic resonance (CMR)-derived left atrial (LA) functional and volumetric indices with cardiovascular outcomes in patients with clinically attributed hypertension-associated cardiac remodeling. Methods This retrospective cohort included 166 consecutive patients who underwent contrast-enhanced 3.0-T CMR between July 2017 and July 2024. The primary endpoint was the first occurrence of all-cause mortality, heart failure hospitalization, non-fatal myocardial infarction, or stroke. Because only 23 events occurred, each prespecified imaging marker was evaluated in a separate Cox model adjusted for age, sex, and systolic blood pressure. The model discrimination was summarized descriptively using Harrell’s concordance index (C-index). Results The cohort included 144 men and 22 women. During a median follow-up of 30.8 months, 23 patients (13.9%) experienced the composite endpoint. In separate adjusted models, lower LA ejection fraction (LAEF; hazard ratio [HR] per 1% increase, 0.962; 95% confidence interval [CI] 0.930–0.995; P = 0.023), higher LA minimum volume index (HR per 1 mL/m 2 increase, 1.036; 95% CI 1.010–1.063; P = 0.007), higher LA maximum volume index (HR, 1.024; 95% CI 1.001–1.048; P = 0.044), and less negative left ventricular global circumferential strain (HR per 1% increase, 1.081; 95% CI 1.020–1.145; P = 0.009) were associated with the endpoint. Adding LAEF to the clinical model increased the C-index from 0.591 to 0.650. However, LAEF was attenuated in a combined model with left ventricular global circumferential strain ( P = 0.206) and in an analysis restricted to all-cause mortality or heart failure hospitalization (13 events; P = 0.279). Binary visual late gadolinium enhancement was not associated with the composite endpoint. Conclusions CMR-derived LA functional and volumetric indices were associated with a heterogeneous composite cardiovascular endpoint in separate parsimonious models. These findings are exploratory and do not establish independent prognostic utility or a clinically actionable LAEF threshold. External validation in larger, phenotypically defined cohorts is required.