Low Systolic Blood Pressure Levels Linked With Risk of Recurrent Stroke
Very low–normal, high, or very high systolic blood pressure levels are associated with an increased risk of recurrent stroke in patients with recent noncardioembolic ischemic stroke, researchers reported in the November 16 issue of JAMA.
Bruce Ovbiagele, MD, MSc, of the Department of Neurosciences at the University of California, San Diego, and colleagues conducted a post-hoc observational analysis of the Prevention Regimen for Effectively Avoiding Second Strokes (PROFESS) study, a five-year, multicenter trial of 20,330 patients 50 or older with recent noncardioembolic ischemic stroke. Patients were enrolled in 695 centers in 35 countries. Participants were followed for a mean of 2.5 years, with the first recurrence of any type of stroke as the primary outcome and a composite of stroke, myocardial infarction, or death from vascular causes as the secondary outcome.
The researchers found a recurrent stroke rate of 8.0% for the very low–normal systolic blood pressure group (less than 120 mm Hg), 7.2% for the low-normal group (120 to less than 130 mm Hg), 6.8% for the high-normal group (130 to less than 140 mm Hg), 8.7% for the high group (140 to less than 150 mm Hg), and 14.1% for the very high group (150 mm Hg or greater).
Compared with patients in the high-normal systolic blood pressure group, those in the very low–normal group, the high group, and the very high group showed a greater risk of recurrent stroke. Furthermore, patients in the very low–normal, low-normal, high, and very high systolic blood pressure groups showed a higher risk of secondary outcome compared with patients in the high-normal group.
The investigators also found that, for both primary and secondary outcomes, the J-shaped relationship between blood pressure and outcome was greatest during the first 180 days following the index ischemic stroke.
“Our results indicate that there may indeed be thresholds of benefit or harm with regard to short-term to longer-term systolic blood pressure levels after a recent noncardioembolic ischemic stroke, and imply that clinicians regularly caring for stroke patients in the outpatient setting may need to be vigilant about how low a given patient’s blood pressure is within the normal range to promote favorable outcomes,” Dr. Ovbiagele and colleagues commented.
Ovbiagele B, Diener HC, Yusuf S, et al. Level of systolic blood pressure within the normal range and risk of recurrent stroke. JAMA. 2011;306(19):2137-2144.