Improvement effect on endothelial function in patients with congestive heart failure treated with cardiac resynchronization therapy

Background and purpose: Cardiac resynchronization therapy (CRT) is a beneficial strategy to improve severe cardiac dysfunction in patients with congestive heart failure (CHF). The improvement of endothelial function in CHF patients treated with CRT is reflected in the mortality risk reduction. However the precise mechanisms of the relationship between CRT and vascular endothelial function have not been well discussed.

Methods and subjects: Twenty-two severe consecutive CHF patients associated with dilated cardiomyopathy [New York Heart Association (NYHA) class 3.3 ± 0.5, left ventricular ejection fraction (LVEF) 24.4 ± 5.9%] were included in this study. We evaluated endothelial function, measured by reactive hyperemia peripheral arterial tonometry (RH-PAT), between optimal medical therapy alone group (medical therapy group: n = 10) and CRT group (n = 12) at the study enrolment and 12 weeks later. Furthermore we analyzed the association between the RH-PAT and cardiac function.

Essential results: Both therapies significantly and equally improved NYHA class, LVEF, end-diastolic left ventricular dimension and plasma levels of brain natriuretic peptide (BNP). CRT significantly increased RH-PAT index (medical therapy group: 1.5 ± 0.2 to 1.5 ± 0.3, p = 0.824; CRT group: 1.4 ± 0.2 to 1.7 ± 0.4, p = 0.003) and cardiac output (medical therapy group: 3.3 ± 1.1 to 3.5 ± 1.0, p = 0.600; CRT group: 2.7 ± 0.6 to 4.3 ± 1.5, p = 0.001), compared to the medical therapy group. There was significant positive correlation between the change in RH-PAT index and cardiac output (r = 0.600, p = 0.003).

Conclusions: CRT significantly improved endothelial function through the improvement of cardiac output in CHF patients, compared to optimal medical therapy.