Endothelial Dysfunction: A Contributor to Adverse Cardiovascular Remodeling and Heart Failure Development in Type 2 Diabetes beyond Accelerated Atherogenesis

Endothelial dysfunction, associated with depressed nitric oxide (NO) bioavailability, is a well-recognized contributor to both accelerated atherogenesis and microvascular complications in type 2 diabetes (DM). However, growing evidence points to the comorbidities-driven endothelial dysfunction within coronary microvessels as a key player responsible for left ventricular (LV) diastolic dysfunction, restrictive LV remodeling and heart failure with preserved ejection fraction (HFpEF), the most common form of heart failure in DM. In this review we have described: (1) multiple cellular pathways which may link depressed NO bioavailability to LV diastolic dysfunction and hypertrophy; (2) hemodynamic consequences and prognostic effects of restrictive LV remodeling and combined diastolic and mild systolic LV dysfunction on cardiovascular outcomes in DM and HFpEF, with a focus on the clinical relevance of endothelial dysfunction; (3) novel therapeutic strategies to improve endothelial function in DM. In summary, beyond associations with accelerated atherogenesis and microvascular complications, endothelial dysfunction supplements the multiple interwoven pathways affecting cardiomyocytes, endothelial cells and the extracellular matrix with consequent LV dysfunction in DM patients. The association amongst impaired endothelial function, reduced coronary flow reserve, combined LV diastolic and discrete systolic dysfunction, and low LV stroke volume and preload reserve-all of which are adverse outcome predictors-is a dangerous constellation of inter-related abnormalities, underlying the development of heart failure. Nevertheless, the relevance of endothelial effects of novel drugs in terms of their ability to attenuate cardiovascular remodeling and delay heart failure onset in DM patients remains to be investigated.