REVERSAL OF ABNORMAL CORONARY VASOMOTION BY CALCIUM-ANTAGONISTS IN PATIENTS WITH HYPERCHOLESTEROLEMIA

Background-It has been shown that exercise-induced coronary vasodilati on of angiographically normal coronary vessels is reduced in hyperchol esterolemic patients. The purpose of this study was to evaluate the ef fect of calcium channel blockers on coronary vasomotion of angiographi cally smooth coronary arteries in hypercholesterolemic patients. Metho ds and Results-A total of 57 patients were included in the present ana lysis. Vasomotion of angiographically normal coronary arteries was eva luated in 37 control subjects (group 1) without and 20 patients (group 2) with calcium blocker administration before physical exercise. Both groups were subdivided into subgroup A (normal cholesterol values: le ss than or equal to 5.5 mmol/L or 212 mg%) and subgroup B (elevated ch olesterol values: >5.5 mmol/L or 212 mg%). Coronary luminal area at re st and during exercise was assessed by biplane quantitative coronary a ngiography. The normal vessels showed a significant increase in corona ry luminal area during exercise in subgroup A (n=13) with normal chole sterol values (31%; P<.05) but not in subgroup B (n=24; 13%; P=NS). In contrast, all patients in group 2 showed similar vasodilation during exercise, namely, 22% (P<.05) in subgroups A (n=8) and B (n=12) (P<.05 ). Independent of the actual cholesterol level, the stenotic lesions s howed coronary vasoconstriction during exercise in group 1 but vasodil ation in group 2 after pretreatment with calcium antagonists. Conclusi ons-Coronary vasomotor response to exercise is inversely related to ac tual serum cholesterol level in angiographically normal vessels. Admin istration of calcium antagonists normalizes exercise-induced vasodilat ion and thus eliminates cholesterol-induced abnormal vasomotion, proba bly by a direct effect on the smooth muscles of the vasculature.