Effect of atenolol and celiprolol on acetylcholine-induced coronary vasomotion in coronary artery disease

Earlier studies have reported on the potentiated muscarinic vasoconstrictio n of intracoronary acetylcholine after metoprolol application in patients w ith coronary artery disease. The present study investigated the effect of c eliprolol, atenolol and placebo on acetylcholine-induced vasomotion in pati ents with coronary artery disease. Furthermore, direct effects on coronary vasomotion and on hemodynamics were evaluated. Acetylcholine (intracoronary concentrations of 6.3 x 10(-7), 2.0 x 10(-6), and 6.3 x 10(-6) M) was give n before and after double-blind celiprolol (0.30 mg/kg NJ, atenolol (0.15 m g/kg IV), or placebo in 3 x 12 patients. Vasomotion was investigated by qua ntitative coronary angiography in proximal and distal segments of epicardia l coronary arteries, and by the determination of the coronary resistance in dex based on Doppler-flow measurements. The investigated drugs had no direc t affect on the diameter of the epicardial coronary arteries. However, celi prolol in contrast to atenolol, significantly reduced systemic vascular res istance (change after atenolol: from 1,855 +/- 308 to 2,161 +/- 550 dyne s cm(-5); celiprolol: 1,691 +/- 435 to 1,411 +/- 343 dyne s cm(-5); and place bo: 1,722 +/- 215 to 1,710 +/- 213 dyne s cm(-5), p < 0.001) and the corona ry resistance index (change after atenolol: 2.52 +/- 3.58 to 2.86 +/- 4.24; celiprolol: 2.70 +/- 1,55 to 2.49 +/- 2.26; and placebo: 1.97 +/- 1.35 to 1.92 +/- 1.25, p <0.01). Celiprolol, atenolol, and placebo did not have dif ferent effects on acetylcholine-induced coronary vasomotion of epicardial c onductance vessels (diminution of proximal lumen diameter before/after aten olol: 0.42 +/- 0.39/0.44 +/- 0.39 mm; celiprolol: 0.32 +/- 0.26/0.30 +/- 0. 24 mm; and placebo: 0.36 +/- 0.29/0.43 +/- 0.40 mm) and of coronary resista nce vessels (reduction of coronary resistance index before/after atenolol: 1.95 +/- 4.74/1.92 +/- 3.74; celiprolol: 0.98 +/- 0.73/1.41 +/- 1.50; and p lacebo: 1.16 +/- 1.29/1.16 +/- 1.04). In contrast to atenolol, celiprolol p ossesses vasodilative properties in systemic and coronary resistance vessel s. There wets no direct effect on the diameter of conductance vessels, Acet ylcholine-induced coronary vasomotion both in conductance and resistance ve ssels was not influenced by the beta blockers that were studied. This sugge sts that atenolol and celiprolol do not influence endothelium-dependent, ni tric oxide related vasomotion. (C) 2000 by Excerpta Medica, inc.