Is lower systolic blood pressure associated with better outcomes in older patients who take anti-hypertension medications?
In this small cohort study of patients older than 85 years, lower systolic blood pressure during treatment with antihypertensive medications is associated with higher death rates and greater cognitive decline. (Level of Evidence = 1b–)
These researchers assembled a cohort of 570 residents of Leiden in the Netherlands who turned 85 years of age between 1997 and 1999. They excluded people who died within three months of enrollment and those who had no blood pressure measurement at baseline. At baseline, and periodically over the course of five years of follow-up, the researchers collected all kinds of information: sociodemographics, medical diagnoses, medications, mental status, grip strength (as a proxy for frailty), blood pressure, and so forth. They assessed the main outcome—death from any cause—by using municipal records. Slightly fewer than one-half of the residents (44%) took antihypertensive medications at baseline; these patients were more likely to have other cardiovascular disorders than those not taking antihypertensive medications (62% vs. 36%). During the five years of follow-up, 263 participants (46%) died. For those taking antihypertensive medications, all-cause mortality was significantly higher with decreasing systolic blood pressure (hazard ratio = 1.29 per 10 mm Hg lower systolic blood pressure; 95% confidence interval, 1.15 to 1.46). For the residents who were not taking antihypertensive medications, there was no significant correlation between systolic blood pressure and all-cause mortality. The patients taking antihypertensives had more rapid cognitive decline with lower systolic blood pressure. Although many explanations for the differences in treatment thresholds are given by the various guidelines, one is how we value clinical trial vs. observational data. The guidelines that promulgate lower blood pressure targets are more likely to value observational data. The data from this study are subject to many of the biases inherent in cohort studies, but they should moderate the enthusiasm for lower blood pressure targets.
Study design: Cohort (prospective)
Funding source: Government
Reference:StreitSPoortvlietRKGusseklooJLower blood pressure during antihypertensive treatment is associated with higher all-cause mortality and accelerated cognitive decline in the oldest-old data from the Leiden 85-plus study. Age Ageing2018;47(4):545–550.