Implantation of Left Ventricular Assist Device Results in Immediate Improvement of Glucose Metabolism in Patients With and Without Diabetes Mellitus

Background: Several studies demonstrated improvement in diabetes mellitus (DM) following left ventricular assist device (LVAD) implantation, but the timing of these changes has not been identified. We sought to determine if favourable metabolic changes occur immediately, within the initial hospitalisation following LVAD implantation. We also wanted to see whether favourable changes in glucose metabolism occur in patients without diabetes. Methods: This is a retrospective analysis of patients receiving LVADs at our institution. We collected the data on fasting blood glucose (FBG) and total daily insulin requirements before the LVAD implantation and before the discharge. Patients served as their own controls. Results: We studied 70 consecutive patients, half of them diabetic. In both diabetics and non-diabetics there was a significant reduction in FBG after LVAD implantation. In diabetic patients, there was an overall reduction in insulin requirements from the average 29.2 units of insulin per day before the LVAD to 16.2 units per day (p = 0.038) before discharge. Specifically, insulin requirement decreased in 16 patients by a median of 25.2 units per day (the interquartile range [IQR)]: -47.8 to -9.2), increased in 10 patients (by 7.3 units/day, IQR 0.7 to 15.3), and remained unchanged in six patients. Conclusions: Favourable metabolic changes on LVAD support occurred almost immediately, within initial hospitalisation, in diabetics and non-diabetics alike. Decline in insulin requirements should be considered when managing diabetics following LVAD implantation.