Impact of Diabetes and Glycemia on Cardiac Improvement and Adverse Events Following Mechanical Circulatory Support

Abstract

Background Type 2 diabetes is prevalent in cardiovascular disease and contributes to excess morbidity and mortality. We sought to investigate the effect of glycemia on functional cardiac improvement, morbidity, and mortality in durable left ventricular assist device (LVAD) recipients. Methods and Results Consecutive patients with an LVAD were prospectively evaluated (n=531). After excluding patients missing pre‐LVAD glycated hemoglobin (HbA1c) measurements or having inadequate post‐LVAD follow‐up, 375 patients were studied. To assess functional cardiac improvement, we used absolute left ventricular ejection fraction change (ΔLVEF: LVEF post‐LVAD−LVEF pre‐LVAD). We quantified the association of pre‐LVAD HbA1c with ΔLVEF as the primary outcome, and all‐cause mortality and LVAD‐related adverse event rates (ischemic stroke/transient ischemic attack, intracerebral hemorrhage, gastrointestinal bleeding, LVAD‐related infection, device thrombosis) as secondary outcomes. Last, we assessed HbA1c differences pre‐ and post‐LVAD. Patients with type 2 diabetes were older, more likely men suffering ischemic cardiomyopathy, and had longer heart failure duration. Pre‐LVAD HbA1c was inversely associated with ΔLVEF in patients with nonischemic cardiomyopathy but not in those with ischemic cardiomyopathy, after adjusting for age, sex, heart failure duration, and left ventricular end‐diastolic diameter. Pre‐LVAD HbA1c was not associated with all‐cause mortality, but higher pre‐LVAD HbA1c was shown to increase the risk of intracerebral hemorrhage, LVAD‐related infection, and device thrombosis by 3 years on LVAD support ( P <0.05 for all). HbA1c decreased from 6.68±1.52% pre‐LVAD to 6.11±1.33% post‐LVAD ( P <0.001). Conclusions Type 2 diabetes and pre‐LVAD glycemia modify the potential for functional cardiac improvement and the risk for adverse events on LVAD support. The degree and duration of pre‐LVAD glycemic control optimization to favorably affect these outcomes warrants further investigation.