Influence of Baseline Diastolic Blood Pressure on Effects of Intensive Compared With Standard Blood Pressure Control.

BACKGROUND: In individuals with a low diastolic blood pressure (DBP), the potential benefits or risks of intensive systolic blood pressure (SBP) lowering are unclear. METHODS: SPRINT (Systolic Blood Pressure Intervention Trial) was a randomized controlled trial that compared the effects of intensive (target <120 mm Hg) and standard (target <140 mm Hg) SBP control in 9361 older adults with high blood pressure at increased risk of cardiovascular disease. The primary outcome was a composite of cardiovascular disease events. All-cause death and incident chronic kidney disease were secondary outcomes. This post hoc analysis examined whether the effects of the SBP intervention differed by baseline DBP. RESULTS: Mean baseline SBP and DBP were 139.7±15.6 and 78.1±11.9 mm Hg, respectively. Regardless of the randomized treatment, baseline DBP had a U-shaped association with the hazard of the primary cardiovascular disease outcome. However, the effects of the intensive SBP intervention on the primary outcome were not influenced by baseline DBP level (P for interaction=0.83). The primary outcome hazard ratio for intensive versus standard treatment was 0.78 (95% confidence interval, 0.57-1.07) in the lowest DBP quintile (mean baseline DBP, 61±5 mm Hg) and 0.74 (95% confidence interval, 0.61-0.90) in the upper 4 DBP quintiles (mean baseline DBP, 82±9 mm Hg), with an interaction P value of 0.78. Results were similar for all-cause death and kidney events. CONCLUSIONS: Low baseline DBP was associated with increased risk of cardiovascular disease events, but there was no evidence that the benefit of the intensive SBP lowering differed by baseline DBP. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01206062.

Success and predictors of blood pressure control in diverse North American settings: the antihypertensive and lipid-lowering treatment to prevent heart attack trial (ALLHAT).

CONTEXT: Blood pressure control (<140/90 mm Hg) rates for hypertension fall far short of the US national goal of 50% or more. Achievable control rates in varied practice settings and geographic regions and factors that predict improved blood pressure control are not well identified. OBJECTIVE: To determine the success and predictors of blood pressure control in a large hypertension trial involving a multiethnic population in diverse practice settings. DESIGN: The Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial is a randomized, double-blind, active-controlled clinical trial with a mean follow-up of 4.9 years. Participant enrollment began in February 1994 and follow-up was completed in March 2002. SETTING: A total of 623 centers in the United States, Canada, and the Caribbean. PARTICIPANTS: A total of 33,357 participants (aged > or =55 years) with hypertension and at least one other coronary heart disease risk factor. INTERVENTIONS: Participants were randomly assigned to receive (double-blind) chlorthalidone, 12.5-25 mg/d (n=15,255), amlodipine 2.5-10 mg/d (n=9048), or lisinopril 10-40 mg/d (n=9054) after other medication was discontinued. Doses were increased within these ranges and additional drugs from other classes were added as needed to achieve blood pressure control (<140/90 mm Hg). MAIN OUTCOME MEASURES: The outcome measures for this report are systolic and diastolic blood pressure, the proportion of participants achieving blood pressure control (<140/90 mm Hg), and the number of drugs required to achieve control in all three groups combined. RESULTS: Mean age was 67 years, 47% were women, 35% black, 36% diabetic; 90% were on antihypertensive drug treatment at entry. At the first of two pre-randomization visits, blood pressure was <140/90 mm Hg in only 27.4% of participants. After 5 years of follow-up, the percent controlled improved to 66%. Systolic blood pressure was <140 mm Hg in 67% of participants, diastolic blood pressure was <90 mm Hg in 92%, the mean number of drugs prescribed was 2.0+/-1.0, and the percent on > or =2 drugs was 63%. Blood pressure control varied by geographic regions, practice settings, and demographic and clinical characteristics of participants. CONCLUSIONS: These data demonstrate that blood pressure may be controlled in two thirds of a multiethnic hypertensive population in diverse practice settings. Systolic blood pressure is more difficult to control than diastolic blood pressure, and at least two antihypertensive medications are required for most patients to achieve blood pressure control. It is likely that the majority of people with hypertension could achieve a blood pressure <140/90 mm Hg with the antihypertensive medications available today.