Development of an Echocardiographic Risk-Stratification Index to Predict Heart Failure in Patients With Stable Coronary Artery Disease: The Heart and Soul Study

Transthoracica 2-dimensional echocardiogram and Doppler flow examination (TTE) generate plethora of high-quality anatomic and physiologic data. However, the abundance and variety of these data can complicate acquisition and analysis, limiting effective integration into clinical settings. To relevantly and efficiently aggregate this information, it is desirable to identify the most potent predictors of dysfunction and adverse outcomes among them. Left ventricular (LV) ejection fraction (EF) is commonly used to predict heart failure (HF) in patients with coronary artery disease (CAD) (1) but is an overtaxed descriptor of systolic function. Numerous TTE-derived measurements can detect subtle changes in myocardial structure and function that offer prognostic information beyond EF. For example, left ventricular mass index (LVMI) predicts mortality independent of other cardiovascular risk factors and electrocardiogram-derived LV hypertrophy (2). Likewise, left atrial enlargement, mitral regurgitation (MR), and diastolic dysfunction (DD) have been shown to predict cardiovascular events, HF, and mortality (3– 6). Other techniques such as Doppler-derived stroke distance (i.e., left ventricular outflow tract velocity–time integral [VTILVOT]) have potential applications in describing global function that might carry unique prognostic relevance (7). The Heart and Soul Study has completed 4.4 years of follow-up on a population of 1,024 subjects with CAD. A comprehensive quantitative echocardiogram and Doppler examination was administered to each participant at enrollment. This study, therefore, provided a suitable vehicle from which to stratify and aggregate TTE data and to determine the most effective combination of noninvasive parameters for the prediction of congestive HF hospital stay. We hypothesized that an array of TTE-derived measurements shown to independently predict congestive HF hospital stay can be combined into a risk-stratification index predictive of HF (the TTE Heart Failure Index). We intend for this index to be readily accessible and to streamline communication among providers.