Specific Coronary Hemodynamic Effects of Nisoldipine and Other Vasoactive Drugs

Abstract

The specific coronary hemodynamic effects of different vasoactive drugs were studied using a randomized, double-blind protocol in the "normal" contralateral artery after performing single-vessel coronary angioplasty. The intracoronary administration of 50 micrograms of nisoldipine resulted in an increase in epicardial diameter (+19%; p = 0.0001) and in coronary blood flow (+47%; p = 0.003), but the flow reserve decreased (-20%; p = 0.001). In placebo-treated patients, all parameters proved to be very stable and no significant changes were found. In a second study, 500 micrograms of diltiazem i.c. was administered to 20 patients, who were first randomized to pretreatment with either placebo (n = 10) or isosorbide dinitrate (0.5 micrograms/kg/min infusion; n = 10). There were increases in epicardial diameter (+10%; p = 0.0001) and coronary flow (+30%; p = 0.0001) in all patients. These changes were comparable in patients pretreated with placebo or nitrates but the reduction in coronary flow reserve was only significant in patients pretreated with placebo (+19%; p = 0.0008). In a third study, the hemodynamic effects of the intracoronary application of SIN-1 (500 micrograms), the active metabolite of molsidomine, were studied. There was a consistent increase in epicardial diameter (+26%; p < 0.0001) but the response at the microvascular level was heterogeneous and characterized by a trend to increased blood flow (+25%; p = 0.11) and decreased coronary vascular resistance (-18%; p = 0.09).(ABSTRACT TRUNCATED AT 250 WORDS)