Outcome after abnormal exercise echocardiography for patients with good exercise capacity: Prognostic importance of the extent and severity of exercise-related left ventricular dysfunction

Abstract

ObjectivesWe sought to define the prognostic implications of the extent and severity of exercise echocardiographic abnormalities in patients with good exercise capacity. BackgroundThe exercise capacity of patients with known or suspected coronary artery disease (CAD) is of prognostic importance, as is the extent of exercise-related left ventricular (LV) hypoperfusion or dysfunction. MethodsWe examined the outcomes of 1,874 patients with known or suspected CAD (mean age 64 ± 10 years, 64% men) who had good exercise capacity (≥5 metabolic equivalents [METs] for women, ≥7 METs for men) but abnormal exercise echocardiograms and analyzed the potential association between clinical, exercise and echocardiographic variables and subsequent cardiac events. ResultsMultivariate predictors of time to cardiac death or nonfatal myocardial infarction (MI) were diabetes mellitus (risk ratio [RR] 1.88; 95% confidence interval [CI] 1.2 to 3.0), history of MI (RR 2.44; 95% CI 1.6 to 3.6) and an increase or no change in LV end-systolic size in response to exercise (RR 1.61; 95% CI 1.1 to 2.5). Using echocardiographic variables that were of incremental prognostic value, we were able to stratify the cardiac risk of the study population; cardiac death or nonfatal MI rate per person-year of follow-up was 1.6% for patients who had a decrease in LV end-systolic size in response to exercise (n = 1,330) and 1.2% for patients who did not have any severely abnormal LV segments immediately after exercise (n = 868). ConclusionsIn patients with good exercise capacity, echocardiographic descriptors of the extent and severity of exercise-related LV dysfunction were of independent and incremental prognostic value. Stratification of patients into low- and higher risk subgroups was possible using these exercise echocardiographic characteristics.