Vascular endothelial dysfunction and mortality risk in patients with chronic heart failure

Background - Endothelial function is known to be impaired in subjects with chronic heart failure (CHF), but the association between endothelial function and subsequent mortality risk in CHF has not been previously reported. Methods and Results - Biomarkers of endothelial function in the systemic arterial circulation ( flow-mediated dilation [FMD] in the brachial artery) and the pulmonary circulation ( exhaled nitric oxide [ NO] production during submaximal exercise) were prospectively assessed in 259 subjects with New York Heart Association class II - III CHF. In subjects with FMD measurements ( n = 149), there were 12 deaths and 5 urgent transplantations over a median follow-up period of 841 days. In subjects with exhaled NO production measurements ( n = 110), there were 18 deaths and 1 urgent transplantation over a median follow-up period of 396 days. Both decreased FMD and decreased exhaled NO production were associated with increased risk of death or urgent transplantation after adjustment for other known CHF prognostic factors ( age, etiology of CHF, functional class, left ventricular ejection fraction) in Cox multivariate proportional-hazards models ( adjusted hazard ratio [HR] estimate for a 1% decrease in FMD = 1.20; 95% confidence interval [CI], 1.03 to 1.45; P = 0.027; adjusted HR estimate for a 1-ppb/min decrease in exhaled NO production = 1.31, 95% CI, 1.01 to 1.69, P = 0.04). Conclusions - Endothelial dysfunction in CHF, as assessed by FMD in the brachial artery and exhaled NO production during submaximal exercise, is associated with an increased mortality risk in subjects with both ischemic and nonischemic CHF.