Value of pharmacologic stress echocardiography in risk stratification of patients with single-vessel disease: report from the echo-persantine and echo-dobutamine international cooperative studies

Objectives. This study sought to verify the effectiveness of pharmacologic stress echocardiography in risk stratification of patients with single-vessel disease. Background. Noninvasive prognostic assessment of single-vessel disease is an unresolved issue to date. Methods. The study evaluated prospectively collected dat from 754 patients with angiographic single-vessel disease who underwent either dipyridamole (n = 576) or dobutamine (n = 178) stress echocardiography. Invasive treatment (coronary revascularization within 3 months of stress testing) was performed in 260 patients and medical treatment in 494. Results. Echocardiographic positivity was observed in 421 patients (56%). Patients treated invasively had higher incidence of stress test positivity (69% vs. 49%, p < 0.001) and left anterior descending coronary artery involvement (60% vs. 46%, p < 0.001) than patients maintained with medical therapy. During mean follow-up of 37 months, 54 hard cardiac events occurred (14 deaths, 40 nonfatal infarctions): 37 in medically and 17 in invasively treated patients (7.5% vs. 6.5%, p = NS). On Cox analysis, positive result on stress testing was the only independent prognostic predictor in medically treated patients (relative risk 2.92, 95% confidence interval 1.29 to 6.59). The 4-year infarction-free survival rate was higher for negative than positive stress test result in medically (93.9% vs. 87.3%, p = 0.009) but not invasively treated patients (92.7% vs. 97.1%, p = 0.545). Moreover, significantly higher 4-year infarction-free survival rate was found in invasively versus medically treated patients with positive (p = 0.012), but not in those with negative, stress test result (p = 0.853). Conclusions. Pharmacologic stress echocardiography is effective in risk stratification of single-vessel disease and can accurately discriminate patients in whom coronary revascularization can have the maximal beneficial effect. These findings have potential favorable impact on the cost-effectiveness of invasive procedures.