Effects of ketanserin on epicardial coronary arteries after coronary angioplasty in patients with stable angina

Previous studies have demonstrated the development of vasoconstrictionimmediately after percutanous coronary angioplasty (PTCA), distalto the dilated stenosis, presumably resulting from endothelialinjury. We have investigated the role of 5-HT₂ receptors inmediating vasomotor changes in proximal and distal coronarysegments and coronary stenoses, immediately after successfulPTCA in patients with chronic stable angina. We compared theeffects of the intracoronary infusion of 1 mg ketanserin (5-HT₂receptor antagonist) on proximal and distal coronary arterialsegments immediately after PTCA in both vessels subjected toPTCA and control vessels. Coronary diameters, before and afterangioplasty and after ketanserin administration, of proximaland distal segments and coronary stenoses were measured by computerizedquantitative coronary angiography (CAAS system) in 12 patients(10 male, two female; mean age 54 ±6 years) with stableangina subjected to PTCA. After coronary angioplasty, vasoconstrictionwas observed in the segment distal to the dilated stenosis butnot in the distal segments of control vessels ( – 0.12± 0.04 and – 0.02 ± 0.02 mm respectively,P<0.05). After ketanserin infusion significant dilatationwas found in the distal segments of both PTCA vessels and controlvessels, but the dilatation was greater in the PTCA vessels(P<0.05). No significant changes were found in the proximalsegments of either PTCA or control vessels, or at the PTCA site.In conclusion, the vasoconstriction distal to the site of PTCAis mediated, at least in part, via 5-HT₂ receptors.     

The reactivity of the contralateral artery at the time of balloon dilation during coronary angioplasty

The response of the contralateral arteries was investigatedduring balloon angioplasty of the left anterior descending artery.Thirty patients were studied. Coronary arteriograms were obtainedat baseline, during maximal balloon inflation and at the endof the procedure. Luminal diameter was measured by a quantitativecoronary arteriography analysis system. During balloon inflationthe luminal diameter of the proximal segment of the right coronaryartery increased by 24 ± 6% (P<0·05), and thatof the left circumflex artery increased by 0·6 ±6% (P=ns). Both returned to near baseline values after angioplasty.in patients with increased collaterals during balloon inflationthe left circumflex proximal segment increased more significantlythan in patients with unchanged collaterals. The luminal diameterof the distal segment of the right coronary artery increasedby 9 ± 8% (P<0·001) and that of the left circumflexartery by 8 ± 11% (P<0·01) during balloon inflation,returning to near baseline values after angioplasty. Thus, vasodilation of the contralateral arteries during ballooninflation at the time of coronary angioplasty occurs mainlyin the distal segments and appears to be related to an increasein collateral filling.