Dobutamine stress echocardiography and the effect of revascularization on outcome in diabetic and non-diabetic patients with chronic ischemic left ventricular dysfunction

AIM: To evaluate the interaction between prognostic effect of revascularization and viability in diabetic and non-diabetic patients with ischaemic left ventricular dysfunction. METHODS: 612 patients with angiographically proven coronary artery disease and left ventricular ejection fraction 35% underwent dobutamine stress echocardiography to assess viability (peak-rest wall motion score index 0.4). 262 patients (75 diabetics, 187 non-diabetics) underwent revascularization and 350 (88 diabetics, 262 non-diabetics) were on medical therapy. RESULTS: During follow-up 215 patients died. Independent predictors of mortality in revascularized patients were resting left ventricular ejection fraction (HR40 (HR=0.44, 95% CI 0.23-0.85, p=0.01), and age (HR=1.03, 95% CI 1.00-1.06, p=0.04). In medically treated patients, independent predictors of mortality were diabetes mellitus (HR=1.64, 95% CI 1.13-2.38, p=0.009), number of diseased vessels (HR=1.27, 95% CI 1.03-1.56, p=0.02), and age (HR=1.02, 95% CI 1.00-1.04, p=0.03). In revascularized patients, 4-year mortality was 15% in those with viability and 26% in those without viability (p=0.04), there was no difference between diabetics and non-diabetics (24% vs 22%; p=0.24). CONCLUSIONS: Viability at dobutamine stress echocardiography independently predicts improved outcome following revascularization in non-diabetics as well as diabetic patients with ischaemic left ventricular dysfunction.