Comparison of two calcium blockers on hemodynamics, left ventricular mass,and coronary vasodilatory in advanced hypertension

Dihydropyridine acid nondihydropyridine calcium channel blockers (CCB) diff er in pharmacologic characteristics. Few clinical studies distinguish effec ts of CCB as monotherapy. We conducted a comprehensive comparison of two CC B on patients with moderate to severe hypertension. Thirty patients with pr etreatment diastolic blood pressures greater than or equal to 100 mm HE wer e randomly assigned to either nifedipine-GITS or verapamil-SR. Dose titrati on achieved a diastolic blood pressure of less than or equal to 95 mm Hg or a decrease of greater than or equal to 15 mm Hg over 4 weeks. Clinic blood pressure (BP), 24-h ambulatory BP, exercise BP, left ventricular mass, sys tolic and diastolic function by echocardiography, and coronary flow reserve by split-dose thallium-201 imaging with adenosine were assessed at baselin e, end of titration, 3 months and 6 months of treatment. Plasma renin activ ity, atrial natriuretic peptide, norepinephrine, and epinephrine were assay ed. Both drugs caused similar reductions in clinic and 24-h ambulatory BP a nd similar reductions in left ventricular mass index. Compared to nifedipin e-GITS, verapamil-SR produced a significantly lower resting and peak exerci se heart rate. Nifedipine-GITS elicited a lower peak exercise systolic BP. At end titration nifedipine-GITS produced lower plasma atrial natriuretic p eptide levels, no longer apparent by 6 months. Plasma norepinephrine was lo wer with verapamil-SR, also at end titration and at 3 months, but not at 6 months. Plasma epinephrine and plasma renin activity were unchanged by eith er drug. There was no difference for systolic or diastolic left ventricular function or coronary flow reserve between the two treatments. Once daily n ifedipine-GITS and verapamil-SR are equally effective for reduction of arte rial pressure in moderate to severe hypertension. Differences in their hemo dynamic profiles and neurohormonal responses are consistent with preclinica l pharmacologic characteristics. The clinical implications of their similar ities and differences remain to be fully evaluated in outcome studies. (C) 2001 American Journal of Hypertension, Ltd.