How reliable are serial echocardiographic measurements in detecting regression in left ventricular hypertrophy and changes in function?

Left ventricular (LV) mass and geometry determined by echocardiography have convincingly been shown to predict cardiovascular morbidity and mortality independent of other cardiovascular disease (CVD) risk factors (1–7). For example, in the Framingham Heart Study, subjects $40 years old without clinically apparent CVD who were followed for four years demonstrated a risk factor–adjusted relative risk of death of 1.5 in men and 2 in women for each 50-g increment of echocardiographically determined LV mass adjusted for height (1). In addition, various reports have suggested that echocardiographic LV mass may be a suitable measure of subclinical disease, reflecting a stage in the process beyond, and the accumulated effects of traditional CVD risk factors (e.g., hypertension, hyperlipidemia, obesity) (8,9). Furthermore, echocardiography has been shown to be a more sensitive tool than electrocardiography for the detection of LV hypertrophy (10,11). Although the data are still sparse, regression of LV hypertrophy, as demonstrated by echocardiography, appears to be associated with reduced cardiovascular morbidity (12,13). Consequently, reliable estimation of LV mass has been an important goal for researchers and clinicians interested in topics such as CVD risk stratification, detection of subclinical disease and measurement of potential regression of LV hypertrophy related to treatments designed to reduce blood pressure and control obesity (14). In addition, measurements of LV function (e.g., global LV ejection fraction) have also been shown to be important indicators of cardiovascular prognosis (15).