Prognostic value of peak and post-exercise treadmill exercise echocardiography in patients with known or suspected coronary artery disease

Abstract

AimsAlthough peak may have higher sensitivity than post-treadmill exercise echocardiography (EE) for the detection of coronary artery disease (CAD), its prognostic value remains unknown. We sought to assess the relative values of peak and post-EE for predicting outcome in patients with known/suspected CAD.Methods and resultsWe studied 2947 patients who underwent EE. Wall motion score index (WMSI) was evaluated at rest, peak, and post-exercise. Ischaemia was defined as the development of new or worsening wall motion abnormalities with exercise. Separate analyses for all-cause mortality and major cardiac events (MACE) were performed. Ischaemia developed in 544 patients (18.5). Among them, ischaemia was detected only at peak exercise in 124 patients (23), whereas 414 (76) had ischaemia at peak plus post-exercise imaging and six patients (1) had ischaemia only at post-exercise. During follow-up, 164 patients died. The 5-year mortality rate was 3.5 in patients without ischaemia, 15.3 in patients with peak ischaemia alone, and 14 in patients with post-exercise ischaemia (P < 0.001 normal vs. ischaemic groups). In the multivariate analysis, post-exercise WMSI was an independent predictor of MACE [hazard ratio (HR) 1.87, 95 confidence interval (CI) 1.09-2.19, P = 0.02]. Peak exercise WMSI was an independent predictor of MACE (HR 2.19, 95 CI 1.30-3.69, P = 0.003) and mortality (HR 1.58, 95 CI 1.07-2.35, P = 0.02). The addition of peak EE results to clinical, resting echocardiography, exercise variables, and post-EE provided incremental prognostic information for MACE (P = 0.04) and mortality (P = 0.04).ConclusionPeak treadmill EE provides significant incremental information over post-EE for predicting outcome in patients with known or suspected CAD.