Vascular endothelial function in patients with coronary slow flow and the effects of nebivolol.

Arquivos brasileiros de cardiologia

PubMedID: 22011806

Gunes Y, Gumrukcuoglu HA, Akdag S, Simsek H, Sahin M, Tuncer M. Vascular endothelial function in patients with coronary slow flow and the effects of nebivolol. Arq Bras Cardiol. 2011;97(4):275-80.
BACKGROUND
Brachial endothelial function has been associated with coronary slow flow (CSF). Increasing blood flow to brachial artery provokes endothelium to release nitric oxide (NO) with subsequent vasodilatation. Besides its ß1-blocker activity, nebivolol causes vasodilatation by increasing endothelial NO release.

OBJECTIVE
To assess the effects of nebivolol on vascular endothelial function in patients with CSF.

METHODS
Forty-six patients with CSF and 23 individuals with normal epicardial coronary arteries were examined with transthoracic echocardiography and brachial artery ultrasonography. The patients were reevaluated two months after treatment with aspirin or aspirin plus nebivolol.

RESULTS
Patients with CSF had higher body mass index (26.5 ± 3.3 vs. 23.8 ± 2.8, p < 0.001), mitral inflow isovolumetric relaxation time (IVRT) (114.9 ± 18.0 vs. 95.0 ± 22.0 msec, p < 0.001) and lower left ventricular ejection fraction (LVEF) (63.5 ± 3.1% vs. 65.4 ± 2.2, p = 0.009), HDL-cholesterol (39.4 ± 8.5 vs. 45.8 ± 7.7 mg/dL, p = 0.003) and brachial flow-mediated dilatation (FMD) (6.1 ± 3.9% vs. 17.6 ± 4.5%, p < 0.001). There were significant correlations between FMD and the presence of CSF (r = 0.800, p < 0.001) and HDL-cholesterol (r = 0.349, p = 0.003). Among Patients with CSF, although pretreatment mean FMD values were similar (6.1 ± 4.3% vs. 6.0 ± ,6%, p = 0.917) compared to aspirin alone group, posttreatment FMD was significantly higher in patients treated with aspirin plus nebivolol (6.0 ± 3.5% vs. 8.0 ± 2.9%, p = 0.047). Treatment with nebivolol was associated with a significant increase in FMD (6.0 ± 3.6 to 8.0 ± 2.9 %, p = 0.030) whereas treatment with aspirin alone was not.

CONCLUSION
Endothelial function may be impaired in both coronary and brachial arteries in patients with CSF and nebivolol may be effective in the improvement of endothelial function in patients with CSF.