Low Blood Pressure, Comorbidities, and Ischemic Stroke Mortality in US Veterans

Background and Purpose: Low blood pressure (BP) is associated with higher stroke mortality, although the factors underlying this association have not been fully explored. We investigated prestroke BP and long-term mortality after ischemic stroke in a national sample of US veterans. Methods: Using a retrospective cohort study design of veterans hospitalized between 2002 and 2007 with a first ischemic stroke and with ≥1 outpatient BP measurements 1 to 18 months before admission, we defined 6 categories each of average prestroke systolic BP (SBP) and diastolic BP, and 7 categories of pulse pressure. Patients were followed-up to 12 years for primary outcomes of all-cause and cardiovascular mortality. We used Cox models to relate prestroke BP indices to mortality and stratified analyses by the presence of preexisting comorbidities (smoking, myocardial infarction, heart failure, atrial fibrillation/flutter, cancer, and dementia), race and ethnicity. Results: Of 29 690 eligible veterans with stroke (mean±SD age 67±12 years, 98% men, 67% White), 2989 (10%) had average prestroke SBP Conclusions: Compared with normotension, low prestroke BP was associated with mortality after stroke, particularly among patients with at least one comorbidity.