Prognostic Value of Mitral Regurgitation Assessment During Exercise Echocardiography in Patients with Known or Suspected Coronary Artery Disease

Abstract

Although mitral regurgitation (MR) may be assessed during exercise echocardiography (EE) there are no data regarding its value for predicting outcome in large series of patients. We sought to determine whether the predictive value of EE is maintained over clinical variables and resting echocardiography when the latter included information on MR, and to verify whether postexercise MR may improve the value of EE for predicting outcome. In all, 1916 patients (mean age +/- 1SD = 62 +/- 11 years; mean left ventricular ejection fraction +/- 1SD = 56 +/- 11) referred for EE were followed up for 1.9 +/- 1.4 years. There were 87 cardiac events before revascularization: 67 events occurred in 948 patients with abnormal EE and 20 events occurred in 968 patients with normal EE (P < .0001), whereas there were 24 events in the 218 patients with moderate or higher resting MR and 63 events in the 1698 patients with no or mild MR (P < .0001). Previous myocardial infarction, resting MR, peak double product, and peak left ventricular ejection fraction were independently associated to hard events (chi2 model = 144, P < .0001). The same variables were associated to cardiac death (chi2 model = 141, P < .0001). Predictors of cardiac events in patients with abnormal EE were resting MR, resting wall-motion score index, metabolic equivalents, peak double product, and MR worsening (incremental P value of MR worsening = .03). Predictors of cardiac death were resting MR, peak double product, peak left ventricular ejection fraction, and MR worsening (incremental P value of MR worsening = .03). EE maintains its higher prognostic value over resting echocardiography even when the latter incorporates information on resting MR. MR worsening provides significant incremental prognostic information in patients with abnormal EE.