Utilization of stress echocardiography in patients with multivessel coronary artery disease.

Objective: The purpose of this study was to evaluate the role of stress echocardiography in the risk stratification and prognosis of patients with multivessel coronary artery disease (CAD).

Background: Stress echocardiography is an established technique for diagnosis, risk stratification, and prognosis of patients with known or suspected CAD.

Methods: We evaluated 409 patients (65 ± 10 years; 63% men) referred for stress echocardiography (45% treadmill, 55% dobutamine), who underwent stress echocardiography and coronary angiography within 3 months. All patients had multivessel CAD as defined by coronary stenosis (≥50% left main or ≥70% in two or more major epicardial vessels or branches). The left ventricle was divided into 16 segments and was scored on a five-point scale of wall motion. Patients with abnormal results on stress echocardiography were defined as those with stress-induced ischemia (increase in wall motion score of ≥1 grade).

Results: Follow-up (3.1 ± 1.3 years) for nonfatal myocardial infarction (n = 35) and cardiac death (n = 25) was obtained. In patients with multivessel CAD, stress echocardiography effectively risk-stratified normal (no ischemia, n = 83) vs. abnormal (ischemia, n = 326) groups for cardiac events (event rate 1.9 vs. 5.4%/year; P < 0.01). Multivariable Cox proportional-hazards regression model identified stress-induced ischemia (hazard ratio 5.5, 95% confidence interval 1.9-15.9, P = 0.002) as the most significant predictor of adverse cardiac events. A stepwise Cox proportional-hazards model demonstrated significant incremental prognostic value of stress echocardiography over clinical variables, stress electrocardiography and resting left ventricular function (P < 0.0001), with the highest global chi-square value.

Conclusions: In patients with angiographically significant multivessel CAD, despite normal-stress echocardiography, there was an intermediate cardiac event rate (1.9%/year); abnormal-stress echocardiography identified a high-risk group (5.4%/year); and stress echocardiography provided incremental prognostic value for risk stratification and prediction of cardiac events.