Associations of atrial cardiomyopathy markers with incident heart failure

Atrial cardiomyopathy (AtCM) is increasingly recognized as an important substrate for heart failure (HF), but the comparative prognostic value of markers across different AtCM domains remains unclear. We included 30,052 UK Biobank participants without prevalent HF. Selected AtCM markers were derived from cardiovascular magnetic resonance imaging and electrocardiography. Associations with incident HF were examined using multivariable Cox proportional hazards models and restricted cubic splines. The optimal left atrial ejection fraction (LAEF) cutoff was identified using maximally selected rank statistics. Incremental predictive value beyond the Atherosclerosis Risk in Communities HF risk score was assessed using time-dependent receiver operating characteristic analyses. Over follow-up, 288 participants developed incident HF. Left atrial markers, including left atrial maximum volume index (LAViMax), left atrial minimum volume index (LAViMin), and LAEF, were independently associated with incident HF. In contrast, right atrial markers and P-wave duration were not consistently associated with HF risk. Restricted cubic spline analyses revealed a significant nonlinear association between LAEF and incident HF, with HF risk increasing at lower LAEF values. An LAEF threshold of approximately 50% identified participants at elevated HF risk. Incorporating LAEF < 50% into the ARIC HF risk model significantly improved discrimination for incident HF at both 3 and 5 years. Among the available AtCM markers evaluated, left atrial markers were independently associated with incident HF. LAEF < 50% identified individuals at increased HF risk and improved risk prediction beyond the ARIC HF risk model, supporting its incremental prognostic information for HF risk stratification.