Atrial Cardiomyopathy Refines Cardiovascular Mortality Risk Across Cardiometabolic Risk Factor Burden

Background: Electrocardiographic markers of atrial cardiomyopathy (AtCM) are associated with adverse cardiovascular outcomes. Whether AtCM further refines cardiovascular disease (CVD) mortality risk across increasing cardiometabolic risk factor (CMRF) burden is unclear. Methods: We analyzed 7,083 adults free of baseline CVD. AtCM was defined by the presence of ≥1 ECG marker: prolonged P-wave duration ≥120 ms in lead II, abnormal P-wave axis outside 0-75, or deep terminal negativity of the P wave in V1 <-100 μV. CMRF burden was defined as the presence of 0, 1, or ≥2 of hypertension, diabetes, and obesity. CVD mortality was ascertained through December 31, 2006. Results: Among 7,083 participants (mean age 58 years and 48% men), CVD mortality rates increased progressively across the six combined exposure groups. In a multivariable adjusted Cox proportional hazard analysis, AtCM identified higher-risk subgroups within each CMRF burden category, with risk increasing progressively across combined exposure groups and highest among participants with ≥2 risk factors and AtCM (HR 2.25, 95% CI 1.75-2.87). In secondary analyses, a similar pattern was observed for individual CMRFs, with the combination of AtCM and hypertension, diabetes, or obesity conferring the highest risk compared with participants with neither condition (HR (95% CI): 1.58 (1.31-1.89); 2.08 (1.62-2.68); and 1.47 (1.19-1.82), respectively). Conclusions: ECG-defined AtCM refined CVD mortality risk across increasing CMRF burden. Individuals with both AtCM and multiple CMRFs had the highest risk. These findings support the potential role of ECG-based AtCM assessment as a scalable approach to improve cardiovascular risk stratification among individuals with CMRFs.