Use of invasive ergometric exercise to assess the hemodynamic response to nicardipine

Abstract

The calcium antagonists are potent vasodilators. This physiologic property suggests that these agents have a potential role in the treatment of patients with hypertension and congestive heart failure. Although the clinical response to calcium antagonism in hypertension is promising, the response in patients with congestive heart failure is less than hoped for; this is due to the fact that this class of agents may induce a hemodynamically important degree of negative inotropic effect. To test the hemodynamic response to nicardipine, a second-generation dihydropyridine, the hemodynamic response to maximal ergometric exercise was evaluated in a group of patients with moderate to severe chronic congestive heart failure. One week of nicardipine therapy was associated with a significant reversal of vasoconstriction at rest and during peak exercise with a secondary increase of cardiac index, and a decrease in pulmonary wedge pressure. The reversal of vasoconstriction was associated with a decrease in mean arterial pressure, with no change in the heart rate. There was no change in oxygen consumption or carbon dioxide production; however, there was a decrease in arteriovenous oxygen difference, consistent with a reduction of oxygen extraction. This short-term study identified the potent vasodilator properties of nicardipine in patients with chronic congestive heart failure; a hemodynamically significant negative inotropic effect could not be identified. Although the use of calcium antagonists for the treatment of congestive heart failure may have a limited role, this study nonetheless suggests that nicardipine may have a favorable vasodilator effect without an overt negative inotropic effect. This would be of considerable advantage in the treatment of hypertension, when compared with β-adrenergic blocking agents.