An effectiveness study comparing algorithm-based antihypertensive therapy with previous treatments using conventional and ambulatory blood pressure measurements.

Effectiveness trials in hypertension enable the efficacy and safety of new drugs to be compared with previous therapy. Since these open-label trials could inadvertently be influenced by observer bias, this study has used ambulatory blood pressure monitoring (ABPM) to provide a rigorous blinded end point to validate the study conclusions. The study was performed in 675 patients with stage 1 or 2 hypertension despite receiving single-agent or fixed-dose combination therapy. After baseline ABPM, the previous treatment was replaced by telmisartan 40 mg daily; if control (office blood pressure <140/90 mm Hg) was not achieved in 2 weeks, the dose was increased to 80 mg, and if necessary, a fixed combination with hydrochlorothiazide 12.5 mg was used after a further 4 weeks. ABPM was repeated after 4 weeks on final therapy. Overall, 50% of patients finished on monotherapy and 50% on combination therapy. By office measurements, there was a decrease (mean +/- SEM) of 16.8+/-0.5/10.3+/-0.3 mm Hg (p<0.001) when telmisartan-based treatment replaced previous treatment; by ABPM, the decrease was 8.2+/-0.4/5.0+/-0.2 mm Hg (p<0.001). The decreases were significant for comparisons with each of the prior drug classes. A treatment algorithm based on the angiotensin receptor blocker, telmisartan, was confirmed by the blinded end point of ABPM as an efficacious alternative to other antihypertensive regimens in clinical practice.