Echocardiography, Natriuretic Peptides, and Risk for Incident Heart Failure in Older Adults The Cardiovascular Health Study

OBJECTIVES This study sought to examine the potential utility of echocardiography and N-terminal pro-B-type natriuretic peptide (NT-proBNP) for heart failure (HF) risk stratification in concert with a validated clinical HF risk score in older adults. BACKGROUND Without clinical guidance, echocardiography and natriuretic peptides have suboptimal test characteristics for population-wide HF risk stratification. However, the value of these tests has not been examined in concert with a clinical HF risk score. METHODS We evaluated the improvement in 5-year HF risk prediction offered by adding an echocardiographic score and/or NT-proBNP levels to the clinical Health Aging and Body Composition (ABC) HF risk score (base model) in 3,752 participants of the CHS (Cardiovascular Health Study) (age 72.6 +/- 5.4 years; 40.8% men; 86.5% white). The echocardiographic score was derived as the weighted sum of independent echocardiographic predictors of HF. We assessed changes in Bayesian information criterion (BIC), C index, integrated discrimination improvement (IDI), and net reclassification improvement (NRI). We examined also the weighted NRI across baseline HF risk categories under multiple scenarios of event versus nonevent weighting. RESULTS Reduced left ventricular ejection fraction, abnormal E/A ratio, enlarged left atrium, and increased left ventricular mass were independent echocardiographic predictors of HF. Adding the echocardiographic score and NT-proBNP levels to the clinical model improved BIC (echocardiography: 43, NT-proBNP: -64.1, combined: -68.9; all p < 0.001) and C index (baseline: 0.746; echocardiography: +0.031, NT-proBNP: +0.027, combined: +0.043; all p < 0.01), and yielded robust IDI (echocardiography: 43.3%, NT-proBNP: 42.2%, combined: 61.7%; all p < 0.001), and NRI (based on Health ABC HF risk groups; echocardiography: 11.3%; NT-proBNP: 10.6%, combined: 16.3%; all p < 0.01). Participants at intermediate risk by the clinical model (5% to 20% 5-yr HF risk; 35.7% of the cohort) derived the most reclassification benefit Echocardiography yielded modest reclassification when used sequentially after NT-proBNP. CONCLUSIONS In older adults, echocardiography and NT-proBNP offer significant HF risk reclassification over a clinical prediction model, especially for intermediate-risk individuals. (J Am Coll Cardiol Img 2012;5:131-40) (C) 2012 by the American College of Cardiology Foundation