Community Screening for Nonischemic Cardiomyopathy in Asymptomatic Subjects ≥65 Years With Stage B Heart Failure
A process to identify and target a selected population at risk of heart failure (HF) could facilitate screening and prevention. We sought to develop an effective screening process from clinical characteristics, functional capacity, and electrocardiogram (ECG). Asymptomatic subjects ≥65 years, with ≥1 HF risks were recruited from the community. Subjects with valvular disease, ejection fraction <40%, and atrial fibrillation were excluded. All underwent clinical evaluation including assessment of HF risk using Framingham HF score and Atherosclerosis Risk in Communities (ARIC) score, ECG, echocardiography, and 6-minute walk (6 MW) test. After 14 ± 4 months, new HF was assessed using Framingham criteria. A randomly selected derivation cohort was used to integrate ARIC score and 6 MW in a classification and regression tree (CART) analysis, with the remaining population used for validation. Of the 419 subjects (age 70 ± 5; 48% men), 52 developed HF. ARIC was more effective than the Framingham HF score (area under the curve 0.65 vs 0.53, p = 0.01). CART selected ARIC (>9.5%) and 6 MW (<501 m) as cutoffs to define low-, intermediate-, and high-risk groups. Abnormal ECG further divided the intermediate group into high and low risks. The 134 subjects identified as high risk by a combined clinical and electrocardiographic strategy showed more echocardiographic features of cardiac dysfunction including LV mass, mitral e', mitral E/e', and longitudinal strain (p <0.01). New HF was significantly more frequent than in the remaining patients (20% vs 10%, p = 0.003; hazard ratio 2.08, 95% confidence interval 1.21 to 3.57, p = 0.008). Thus, initial clinical risk and electrocardiographic assessment facilitate effective HF screening by identifying a high-risk group.