Endothelial dysfunction predicts bleeding and cardiovascular death in acute coronary syndrome.

Backgrounds: Recently, there has been increasing awareness that bleeding may lead to adverse outcomes. Endothelial dysfunction is associated with increased risk of cardiovascular and bleeding events. This study aimed to investigate the association of endothelial dysfunction with major bleeding and specific causes of death in addition to major adverse cardiovascular events in patients with acute coronary syndrome.

Methods: This single-centre retrospective observational study was conducted at a tertiary-care hospital; patients with acute coronary syndrome were included between June 2010 and November 2014 (median follow-up, 6.1 years). The reactive hyperaemia index was assessed before their discharge; reactive hyperaemia index <1.67 was defined as endothelial dysfunction. The main outcomes were the incidence of major bleeding, all-cause death, cardiovascular death, non-cardiovascular death, resuscitated cardiac arrest, non-fatal myocardial infarction, non-fatal stroke, and hospitalisation for heart failure.

Results: Among the included 674 patients with acute coronary syndrome, 264 (39.2%) had endothelial dysfunction. Multivariable Cox-hazard analyses revealed an independent predictive value of endothelial dysfunction for major bleeding (hazard ratio 2.29, 95% confidence interval 1.17-4.48, P = 0.016) and major adverse cardiovascular events (hazard ratio 2.04, 95% confidence interval 1.43-2.89, P < 0.001). The endothelial dysfunction group patients had a 2.5-fold greater risk of cardiovascular death; however, no association was found with non-cardiovascular death.

Conclusion: Endothelial dysfunction assessed using reactive hyperaemia index predicted future major cardiovascular event as well as major bleeding and cardiovascular death in patients with acute coronary syndrome.