Antihypertensive efficacy of telmisartan vs ramipril over the 24-h dosing period, including the critical early morning hours: a pooled analysis of the PRISMA I and II randomized trials.

Cardiovascular risk is subject to circadian variation, with peak morning incidence of myocardial infarction and stroke correlating with the early morning blood pressure (BP) surge (EMBPS). Ideally, antihypertensive therapy should maintain control of BP throughout the 24-h dosing cycle. In two sister studies, Prospective, Randomized Investigation of the Safety and efficacy of Micardis vs Ramipril Using ABPM (ambulatory BP monitoring) (PRISMA) I and II, BP control was compared in patients with essential hypertension (24-h mean baseline ambulatory BP approximately 148/93 mm Hg) randomized to the angiotensin receptor blocker, telmisartan (80 mg; n=802), or the angiotensin-converting enzyme inhibitor, ramipril (5 or 10 mg; n=811), both dosed in the morning. The primary end point was the change from baseline in mean ambulatory systolic BP (SBP) and diastolic BP (DBP) during the final 6 h of the 24-h dosing cycle. The adjusted mean treatment differences in the last 6-h mean ambulatory SBP/DBP were -5.8/-4.2 mm Hg after 8 weeks and -4.1/-3.0 mm Hg after 14 weeks, in favour of telmisartan (P<0.0001 for all four comparisons). Secondary end point results, including the mean 24-h ambulatory BP monitoring, day- and night-time BP and 24-h BP load, also significantly favoured telmisartan (P<0.0001). Both treatments were well tolerated; adverse events, including cough, were less common with telmisartan. These findings suggest that telmisartan is more effective than ramipril throughout the 24-h period and during the EMBPS; this may be attributable to telmisartan's long duration of effect, which is sustained throughout the 24-h dosing period.