Abstract

IMPORTANCEClinical evidence supports the beneficial effects of lowering blood pressure (BP) levels in community-living, robust, hypertensive individuals older than 80 years.However, observational studies in frail elderly patients have shown no or even an inverse relationship between BP and morbidity and mortality.OBJECTIVE To assess all-cause mortality in institutionalized individuals older than 80 years according to systolic BP (SBP) levels and number of antihypertensive drugs. DESIGN, SETTING, AND PARTICIPANTSThis longitudinal study included elderly residents of nursing homes.The interaction between low (<130 mm Hg) SBP and the presence of combination antihypertensive treatment on 2-year all-cause mortality was analyzed.A total of 1127 women and men older than 80 years (mean, 87.6 years; 78.1% women) living in nursing homes in France and Italy were recruited, examined, and monitored for 2 years.Blood pressure was measured with assisted self-measurements in the nursing home during 3 consecutive days (mean, 18 measurements).Patients with an SBP less than 130 mm Hg who were receiving combination antihypertensive treatment were compared with all other participants.MAIN OUTCOMES AND MEASURES All-cause mortality over a 2-year follow-up period.RESULTS A significant interaction was found between low SBP and treatment with 2 or more BP-lowering agents, resulting in a higher risk of mortality (unadjusted hazard ratio [HR], 1.81; 95% CI, 1.36-2.41);adjusted HR, 1.78; 95% CI, 1.34-2.37;both P < .001) in patients with low SBP who were receiving multiple BP medicines compared with the other participants.Three sensitivity analyses confirmed the significant excess of risk: propensity score-matched subsets (unadjusted HR, 1.97; 95% CI, 1.32-2.93;P < .001;adjusted HR, 2.05; 95% CI, 1.37-3.06;P < .001),adjustment for cardiovascular comorbidities (HR, 1.73; 95% CI, 1.29-2.32;P < .001),and exclusion of patients without a history of hypertension who were receiving BP-lowering agents (unadjusted HR, 1.82; 95% CI, 1.33-2.48;P < .001;adjusted HR, 1.76; 95% CI, 1.28-2.41;P < .001). CONCLUSIONS AND RELEVANCEThe findings of this study raise a cautionary note regarding the safety of using combination antihypertensive therapy in frail elderly patients with low SBP (<130 mm Hg).Dedicated, controlled interventional studies are warranted to assess the corresponding benefit to risk ratio in this growing population.