Benefits of coronary revascularisation in diabetic and non-diabetic patients with ischaemic cardiomyopathy: role of myocardial viability.

Background: Diabetes mellitus in patients with coronary artery disease is associated with poor outcome. In this study, the relation between myocardial viability, diabetes, coronary revascularisation and outcome was evaluated.
Methods: 129 patients (31 diabetic, 98 non-diabetic) with ischaemic cardiomyopathy underwent dobutamine stress echocardiography to assess myocardial viability. Patients with >or=4 viable segments were defined as viable and patients with <4 viable segments as nonviable. Left ventricular ejection fraction (LVEF) was assessed before and 9-12 months post-revascularisation. At the same time-points, LV volumes were measured to evaluate LV remodelling. Finally, cardiac events were noted during 5-year follow-up.
Results: The extent of viable myocardium was comparable between diabetic and non-diabetic patients. After revascularisation, LVEF increased >or=5% in 44% of diabetic and in 40% of non-diabetic patients. LVEF only improved in patients with viable myocardium. Ongoing LV remodelling occurred in 36% and 35% of diabetic and non-diabetic patients respectively, and was related to non-viability, whereas viability protected against ongoing LV remodelling, both in diabetic and non-diabetic patients. Viability was the only predictor of survival after revascularisation.
Conclusions: Diabetic, viable patients with ischaemic LV dysfunction exhibit improvement in LVEF post-revascularisation with prevention of ongoing LV remodelling, similar to non-diabetic patients. Myocardial viability was also the only predictor of long-term outcome.