Beneficial effects of nifedipine on vasodilator response to acetylcholine in coronary and brachial arteries in the patients with coronary artery disease.

BACKGROUND: Nifedipine has been reported to improve endothelial function. However, there are few simultaneous studies on the effects of nifedipine on coronary and peripheral endothelial function in humans.

METHODS: To investigate the effects of nifedipine on endothelial function in coronary artery (CA) and brachial artery (BA) in coronary artery disease (CAD), we measured vasodilator responses of CA and BA to acetylcholine (ACh, endothelium-dependent dilation) in 13 patients (63+/-10 years old) with CAD before and after sublingual administration of nifedipine 10 mg. To measure blood flow, a Doppler guidewire was inserted into the major branch of CA and the left BA. ACh was infused at 10(-7) mol/l for 3 min into CA and at 15.0 microg/ml for 5 min into BA, respectively. The vasodilator response to ACh was assessed by the ratio of ACh-induced flow/baseline flow (CAVR index, the ratio of CA flow changed by ACh; BAVR index, the ratio of BA flow changed by ACh).

RESULTS: Nifedipine significantly increased both the CAVR and BAVR index:CAVR index, from 1.33+/-0.54 to 1.76+/-0.52 (32%) and BAVR index, from 1.74+/-0.83 to 2.18+/-0.93 (25%), respectively, p<0.05. In addition, nifedipine-induced changes in CAVR tended to correlate with those of BAVR (r=0.42. p=0.06).

CONCLUSIONS: Acute administration of nifedipine improves both coronary and brachial artery vasodilator responses to ACh. Nifedipine improves coronary and peripheral endothelial function in patients with CAD.