Peripheral endothelial function may predict the effectiveness of beta-blocker therapy in patients with idiopathic dilated cardiomyopathy.

OBJECTIVES

Beta-blockers have improved the prognosis of patients with dilated cardiomyopathy as they improve left ventricular (LV) systolic function and structure, which are crucial for myocardial recovery. However, to date, no accurate methods can predict the effectiveness of β-blocker therapy. Our goal was to evaluate whether peripheral endothelial function could be a useful predictor for β-blocker responses and related LV reverse remodeling (LVRR) in patients with idiopathic dilated cardiomyopathy (IDC).

METHODS

Fifty-two IDC patients were recruited and underwent brachial artery flow-mediated dilation (FMD). Beta-blockers were titrated to doses tolerable for each patient. LV function and structure were measured by echocardiography. A positive response to β-blockers was defined as an increase of ≥10% in LV ejection fraction (LVEF). LVRR was defined as an increase of ≥10% in LVEF and a decrease of ≥15% in LV end-systolic volume (LVESV).

RESULTS

Baseline FMD was 8.4±3.0% in IDC patients and significantly lower than healthy controls. At three-month follow-up, 54% of patients had a positive β-blocker response and 40% achieved LVRR. Patients with a positive response to β-blockers or with LVRR had significantly higher baseline FMD values than those without. FMD was the most significant predictor of changes in LVEF and LVESV. The sensitivity and specificity of baseline FMD to predict β-blocker responses was 64.3% and 83.3%, respectively, and to predict LVRR was 61.9% and 80.6%, respectively. Beta-blockers themselves did not influence FMD values.

CONCLUSIONS

FMD could serve as an independent predictor for monitoring β-blocker therapy effectiveness in IDC patients.