Calcium antagonists in hypertension: from hemodynamics to outcomes.

Hypertension, by definition, is a hemodynamic disorder. A high cardiac output and a normal systemic vascular resistance characterize the young hypertensive patient. As hypertension progresses, resistance becomes progressively elevated and cardiac output returns to normal. The elderly patient with hypertension has very high systemic vascular resistance and low cardiac output. Antihypertensive drugs should not only lower arterial pressure but also bring other hemodynamic parameters as well as functional and structural changes of the cardiovascular system back to normal. With the notable exception of the classic beta-blockers, all antihypertensive drug classes, including the vasodilating beta-blockers, increase or maintain cardiac output and lower systemic vascular resistance. Calcium antagonists, although a very heterogeneous group, have been shown to have a similar effect on systemic hemodynamics. Initially, the short-acting agents (even verapamil) produce a reflex increase in heart rate and cardiac output with a decrease in systemic vascular resistance. This reflexive cardiac acceleration is not seen with the extended-release or longer-acting formulations, which usually maintain cardiac output and decrease systemic resistance. Lercanidipine is a novel calcium antagonist that has been shown to differ from other dihydropyridines in that the incidence of vasodilatory edema for any given decrease in blood pressure is less pronounced. Whereas all dihydropyridine calcium antagonists dilate the afferent arteriole in the kidney, preclinical studies have shown that lercanidipine also produces dilation of the efferent vessel. Similar balanced pre- and postcapillary vasodilation may be an explanation for the lower incidence of vasodilatory edema seen clinically with lercanidipine. These micro- and macrovascular features make lercanidipine an attractive new member in the arsenal of the powerful dihydropyridine calcium antagonists.