Abstract and Introduction
Objectives: To estimate outcomes according to attained blood pressure (BP) in the oldest adults treated for hypertension in routine family practice.
Design: Cohort analysis of primary care inpatient and death certificate data for individuals with hypertension.
Setting: Primary care practices in England (Clinical Practice Research Datalink).
Participants: Individuals aged 80 and older taking antihypertensive medication and free of dementia, cancer, coronary heart disease, stroke, heart failure, and end-stage renal failure at baseline.
Measurements: Outcomes were mortality, cardiovascular events, and fragility fractures. Systolic BP (SBP) was grouped in 10-mmHg increments from less than 125 to 185 mmHg or more (reference 145–154 mmHg).
Results: Myocardial infarction hazards increased linearly with increasing SBP, and stroke hazards increased for SBP of 145 mmHg or greater, although lowest mortality was in individuals with SBP of 135 to 154 mmHg. Mortality of the 13.1% of patients with SBP less than 135 mmHg was higher than that of the reference group (Cox hazard ratio=1.25, 95% confidence interval=1.19–1.31; equating to one extra death per 12.6 participants). This difference in mortality was consistent over short- and long-term follow-up; adjusting for diastolic BP did not change the risk. Incident heart failure rates were higher in those with SBP less than 125 mmHg than in the reference group.
Conclusion: In routine primary care, SBP less than 135 mmHg was associated with greater mortality in the oldest adults with hypertension and free of selected potentially confounding comorbidities. Although important confounders were accounted for, observational studies cannot exclude residual confounding. More work is needed to establish whether unplanned SBPs less than 135 mmHg in older adults with hypertension may be a useful clinical sign of poor prognosis, perhaps requiring clinical review of overall care.
Hypertension is the most common chronic condition in older people, yet there is debate about treatment targets and longer-term adverse event rates, especially in the oldest adults. Current guidelines for adults aged 80 and older recommend upper systolic blood pressure (SBP) treatment targets varying from 150 mmHg[2–5] to 140 mmHg. Although there is accumulating evidence on the efficacy of antihypertensive treatment in older adults from randomized trials, less information is available on the overall prognosis for the oldest adults with hypertension treated under current guidelines, especially over the long term.
The current study used electronic medical record data from a large, nationally representative population registered with primary care practices in England in the Clinical Practice Research Datalink (CPRD) database to estimate overall prognosis according to attained SBP in the oldest adults in routine family practice, working under national guidance to achieve a SBP less than 150 mmHg. Associations between attained SBP and all-cause mortality, cardiovascular events, and fragility fractures were estimated in older adults undergoing treatment for hypertension. The goal was to estimate prognosis in individuals without comorbidities who might require specialized treatment or bias results (aiming to minimize confounding); thus, participants were free of dementia, recent cancer, stroke, heart failure, coronary heart disease, or end-stage renal failure at baseline. An extensive set of sensitivity analyses was also performed to examine the effects of suggested additional confounders.
J Am Geriatr Soc. 2017;65(5):995-1003. © 2017 Blackwell Publishing