Positive Impact of Continuous-Flow Left Ventricular Assist Device Implantation on Glycemic Control in Patients with Type 2 Diabetes Mellitus and Advanced Chronic Systolic Heart Failure

Study Objective To evaluate the impact of continuous-flow left ventricular assist device (LVAD) implantation on glycemic control in patients with type 2 diabetes mellitus and advanced chronic systolic heart failure. Design Retrospective medical record review. Setting Large academic tertiary and quaternary care hospital. Patients Eighty-three adults with type 2 diabetes mellitus and advanced chronic systolic heart failure who underwent implantation of a continuous-flow LVAD between July 1, 2008, and June 30, 2013. Measurements and Main Results Baseline demographic data and laboratory values pertinent to glycemic control (hemoglobin A1c [A1C], total daily insulin requirements, noninsulin antidiabetic medication use, and body mass index [BMI]) were collected for each patient. Pre-LVAD data were compared with data obtained during the 24 months after LVAD implantation. The mean age of the study population was 61.3 years, 70% were men, and 63% had ischemic cardiomyopathy. The first available mean ± SD A1C after LVAD implantation was 6.21 ± 1.5% at a median of 4.8 months (interquartile range 3.3–8.9), which represented a significant decrease from the pre-LVAD A1C of 7.46 ± 1.5% (p<0.001). Average daily insulin requirements decreased by 22.9 units at the end of 24 months (p<0.001). Over half of patients with prescriptions for noninsulin antidiabetic medications were able to discontinue therapy by the end of the study. Of note, BMI increased in the second year after LVAD implantation from a baseline of 32.3 kg/m2 to 34.9 kg/m2 (p=0.004). Regression analysis revealed that baseline A1C was the only independent predictor of change in A1C. Conclusion LVAD implantation was associated with a significant improvement in glycemic control. Further prospective studies are needed to evaluate the long-term impact of LVAD implantation on the clinical course of diabetes.