Diabetes and the occurrence of ventricular arrhythmic events in patients with severe left ventricular dysfunction.

Abstract

Diabetes is associated with a higher risk of ischaemic heart disease and heart failure, which frequently lead to rhythm disorders. However, experimental and clinical studies are inconsistent with regard to the risk of arrhythmic events in patients with diabetes. We studied the frequency of ventricular arrhythmic events in patients with and without diabetes. The study group included 207 patients with severe heart failure. The severity of ventricular arrhythmias was assessed by 24-h Holter monitoring, using prospectively defined measures of ventricular arrhythmic burden. Patients with diabetes comprised 48% of the study group. All measures of ventricular ectopy were much lower in patients with diabetes. Mean hourly ventricular pairs (13.3+/-3.7 vs 7.2+/-2.0, p=0.03), mean hourly repetitive ventricular beats (32+/-9 vs 17+/-5, p=0.01), and the frequency of ventricular tachycardia episodes per 24 h (36+/-13 vs 16+/-6, p=0.01) were lower in patients with diabetes. After inclusion of clinical variables and drug therapies in a multivariate analysis, the negative relationship between diabetes and the frequency of ventricular pairs (p=0.03), repetitive ventricular beats (p=0.04), and ventricular tachycardia (p=0.03) remained independent. In multivariate logistic regression, the risk of developing ventricular tachycardia was lower in patients with diabetes with an adjusted odds ratio of 0.41 (95% CI, 0.22 to 0.75, p=0.004). Diabetes confers a protective effect with regard to the occurrence of ventricular arrhythmias in the setting of decompensated heart failure. The precise mechanism of this phenomenon requires further investigation.