Evidence to Maintain the Systolic Blood Pressure Treatment Threshold at 140 mm Hg for Stroke Prevention: The Northern Manhattan Study

Abstract

In 2014, the Eighth Joint National Committee revised the target maximum systolic blood pressure (SBP) from 140 to 150 mm Hg in patients aged ≥60 years without diabetes mellitus or chronic kidney disease. The evidence from cohort studies supporting this change was sparse, particularly among US minority populations. In the Northern Manhattan Study, 1750 participants aged ≥60 years and free of stroke, diabetes mellitus, and chronic kidney disease had SBP measured at baseline and were annually followed up for incident stroke. Mean age at baseline was 72±8 years, 63% were women, 48% Hispanic, 25% non-Hispanic white, and 25% non-Hispanic black. Among all participants, 40% were on antihypertensive medications; 43% had SBP <140 mm Hg, 20% had 140 to 149 mm Hg, and 37% had ≥150 mm Hg. Over a median follow-up of 13 years, 182 participants developed stroke. The crude stroke incidence was greater among individuals with SBP≥150 mm Hg (10.8 per 1000 person-years) and SBP 140 to 149 (12.3) than among those with SBP<140 (6.2). After adjusting for demographics, vascular risk factors, diastolic BP, and medication use, participants with SBP 140 to 149 mm Hg had an increased risk of stroke (hazard ratio, 1.7; 95% confidence interval, 1.2-2.6) compared with those with SBP <140 mm Hg. The increased stroke risk was most notable among Hispanics and non-Hispanic blacks. Raising the SBP threshold from 140 to 150 mm Hg as a new target for hypertension treatment in older individuals without diabetes mellitus or chronic kidney disease could have a detrimental effect on stroke risk reduction, especially among minority US populations.

Keywords: blood pressure; cardiovascular diseases; continental population groups; epidemiology; stroke.

Figure 1

Kaplan-Meier curves of stroke risk for systolic blood pressure (SBP) in persons aged 60 years or older without diabetes mellitus or chronic kidney disease. Kaplan-Meier curves were constructed by SBP levels at <140, 140-149 and ≥ 150 mmHg and compared with Log-Rank test, NOMAS (Northern Manhattan Study), 1993-2014.

Figure 2

Multivariable-adjusted hazards ratio of stroke for systolic blood pressure 140-149 verse <140 mmHg, overall or by race-ethnicity, sex and age, in persons aged 60 years or older without diabetes mellitus or chronic kidney disease at baseline for all (A), for those without diastolic blood pressure ≥ 90 mmHg (B), and for those without antihypertensive medication use (C). The model was adjusted for age, waist circumference, smoking, moderate alcohol drinking, physical activity, and history of myocardial infarction, atrial fibrillation and coronary artery disease, and applicable, for sex, race-ethnicity, antihypertensive medication use, and diastolic blood pressure, NOMAS (Northern Manhattan Study), 1993-2014.