The Role of Baseline Blood Pressure in Guiding Treatment Choice

Abstract

Baseline blood pressure (BP) is a strong predictor of response to antihypertensive therapy and the patient's ability to reach BP goals. The objective of this study was to evaluate the role of baseline BP as a determinant of systolic BP (SBP) and treatment outcome to assist in the choice of initial therapy. This was a double-blind, placebo-controlled clinical trial (n = 1329) in patients with essential hypertension (mean sitting diastolic BP [DBP] > or = 95 mmHg and <110 mmHg) who were randomized to placebo, valsartan 160 mg, valsartan 320 mg, hydrochlorothiazide (HCTZ) 12.5 mg, HCTZ 25 mg, valsartan/HCTZ 160 mg/12.5 mg, valsartan/HCTZ 320 mg/12.5 mg or valsartan/HCTZ 320 mg/25 mg. Retrospective analyses were performed to determine mean BP at end of study and BP goal rates and to explore the relationship between baseline BP level and predicted final BP. The final SBP and DBP were lowest in the combination therapy groups across all baseline BPs and in subgroups of patients categorized by age (> or = 65 years, <65 years), race/ethnicity (White, Black, other), and severity of hypertension at baseline. The proportion of patients achieving the SBP goal of <140 mmHg was highest in the valsartan/HCTZ 320 mg/25 mg group; the overall SBP goal achievement rate was 85%, and 78% of participants with stage 2 hypertension achieved goal. By comparison, 59% of patients in the HCTZ 25 mg group and 52% in the valsartan 320 mg group achieved SBP goal. Initial combination therapy was associated with lower predicted final SBP and DBP at all baseline BP levels compared with monotherapy. Analysis of tolerability data revealed that the proportion of patients experiencing dizziness or discontinuing therapy due to adverse events was generally similar across treatment groups, whereas the BP-lowering efficacy was greatest in the groups receiving combination therapy. These secondary analyses suggest that characterizing the relationship between baseline SBP and achieved SBP can assist in the choice of initial therapy in a broad hypertensive population. Initial therapy with the combination of valsartan/HCTZ is more effective than monotherapy in lowering BP at all baseline BP levels, is consistent in this respect among all subgroups, and is well tolerated.