Antihypertensive efficacy of angiotensin receptor blockers as monotherapy as evaluated by ambulatory blood pressure monitoring: Ameta-Analysis

Aims: Angiotensin receptor blockers (ARBs) are available in different dosages and it is common clinical practice to uptitrate if blood pressure goal is not achieved with the initial dose. Data on the incremental antihypertensiv efficacy with uptitration are scarce. It is also unclear if antihypertensive efficacy of losartan is comparable with other ARBs. Methods and results: We systematically reviewed PubMed/EMBASE/Cochrane databases for all randomized clinical trials until December2012 reporting 24 h ambulatory blood pressure (ABP) for most commonly available ARBs in patients with hypertension. Reduction in ABP with ARBs was evaluated at 25% of the maximum (max) dose, 50% of the max dose, and at the max dose. Comparisonwas made between 24 h BP-Lowering effect of losartan 50 and 100 mg and other ARBs at 50% max dose and the max dose, respectively. Sixty-two studies enrolling 15 289 patients (mean age 56 years; 60% men) with a mean duration of 10weeks were included in the analysis. Overall, the dose-response curve with ARBs was shallow with decrease of 10.3/6.7 (systolic/diastolic), 11.7/7.6, and 13.0/8.3 mmHgwith 25% max dose, 50% max dose, and with the max dose of ARBs, respectively. Losartan in the dose of 50 mg lowered ABP lesswell than other ARBs at 50% max dose by 2.5 mmHg systolic (P < 0.0001) and 1.8 mmHg diastolic (P = 0.0003). Losartan 100 mg lowered ABP less well than other ARBs at max dose by 3.9 mm Hg systolic (P = 0.0002) and 2.2 mmHg diastolic (P = 0.002). Conclusion: In this comprehensive analysis of the antihypertensive efficacy of ARBs by 24 h ABP, we observed a shallow dose- response curve, and uptitration marginally enhanced the antihypertensive efficacy. Blood pressure reduction with losartan at starting dose and at max dose was consistently inferior to the other ARBs.