The prognostic value of myocardial viability recognized by low dose dipyridamole echocardiography in patients with chronic ischaemic left ventricular dysfunction

Abstract

Aims: The aim of this study was to assess the prognostic value of myocardial viability recognized as a contractile response to vasodilator stimulation in patients with left ventricular dysfunction in a large scale, prospective, multicentre, observational study. Methods and Results: Three hundred and seven patients (mean age 60 ± 10 years) with angiographically proven coronary artery disease, previous ( > 3 months) myocardial infarction and severe left ventricular dysfunction (ejection fraction <35%; mean ejection fraction: 28 ± 7%) were enrolled in the study. Each patient underwent low dose dipyridamole echo (0.28 mg kg-1 in 4 min). Myocardial viability was identified as an improvement of ≥ 0.20 in the wall motion score index. By selection, all patients were followed up for a median of 36 months. One-hundred and twenty-four were revascularized either by coronary artery bypass grafting (n = 83) or coronary angioplasty (n = 41). The only end-point analysed was cardiac death. In the revascularized group, cardiac death occurred in one of the 41 patients with and in 16 of the 83 patients without a viable myocardium (2.4% vs 19.3%, P < 0.01). Outcome, as estimated by Kaplan-Meier survival, was better for patients with, compared to patients without, a viable myocardium, who underwent coronary revascularization (97.6 vs 77.4%, P = 0.01). Using a Cox proportional hazards model, the presence of myocardial viability was shown to exert a protective effect on survival (chi-square 4.6, hazard ratio 0.1, 95% CI 0.01-0.8, P < 0.03). The survival rate in medically treated patients was lower than in revascularized patients irrespective of the presence of a viable myocardium (79.7% vs 86.2, P = ns). Conclusion. In severe left ventricular ischaemic dysfunction, myocardial viability, as assessed by low dose dipyridamole echo, is associated with improved survival in revascularized patients. © 2001 The European Society of Cardiology.