DOUBLE-BLIND COMPARISON OF THE ACUTE EFFECTS OF 2 RELEVANT DOSES OF ORAL NICORANDIL ON CENTRAL HEMODYNAMICS, LEFT-VENTRICULAR FUNCTION, ANDMYOCARDIAL-CONTRACTILITY

Nicorandil is a nicotinamide derivative with potent vasodilator proper ties. Oral and sublingual administration of this compound in patients with coronary artery disease resulted in a predominant reduction of af terload and a small decrease in left ventricular preload. The effects of nicorandil in different doses on contractile left ventricular (LV) function, however, are not well defined. The aim of the present study was to assess the effects of nicorandil on hemodynamics, left ventricu lar volume and function, as well as the LV contractility index dP/dt m easured by Millar-tip manometers, A total of 16 patients with coronary artery disease were included in this study, After diagnostic coronary angiography and ventriculography, the patients randomly received eith er 10 or 20 mg of oral nicorandil. The hemodynamic parameters, cardiac output, and LV end-diastolic and systolic pressures were determined a fter 15, 30, and 60 minutes, and a second angiogram was performed 60 m inutes after administration. The predominant effect was a decrease in the mean aortic pressure with a concomitant decrease in the peripheral arterial resistance. Clinically relevant changes in aortic pressure, systemic vascular resistance, and rate-pressure product, however, were documented only after oral administration of 20 mg nicorandil, as opp osed to minimal changes in the 10 mg group. LV volume and cardiac outp ut were not changed significantly. LV contractility remained unchanged during the observation period. The hemodynamic profile of this compou nd is dose-dependent afterload reduction without a change in contracti lity. Because there was no concomitant increase in heart rate, calcula ted oxygen consumption was reduced, especially in the higher dose grou p.