Background and Purpose- Every year in the United States, almost 185 000 ischemic strokes occur in patients with a prior stroke. Recurrent stroke has significantly higher morbidity and mortality. Among modifiable risk factors for recurrent stroke, hypertension is the most prevalent. Reducing systolic blood pressure is standard of care for secondary stroke prevention. Recent literature suggests that increased blood pressure variability (BPV) is associated with primary stroke, although studies have not convincingly shown that it is associated with recurrent stroke, which was the goal of this analysis. Methods- We conducted a secondary analysis of 17 916 patients in the PRoFESS (Prevention Regimen for Effectively Avoiding Second Strokes) trial, which is the largest trial of patients with potential recurrent stroke. We calculated BPV and evaluated its effect on recurrent stroke (composite and stratified by ischemic or hemorrhagic stroke), major cardiovascular events (death from cardiovascular causes, recurrent stroke, myocardial infarction, or new or worsening heart failure), and all-cause death. Results- Both systolic and diastolic BPV were associated with recurrent stroke, major cardiovascular events, and all-cause death. The association with stroke was significant for ischemic, but not hemorrhagic, stroke. For every 10-point increase in BPV (systolic SD, range =0-54.2), the hazard ratio for a recurrent ischemic stroke was 1.15 (95% CI, 1.02-1.32; P=0.02), for major cardiovascular events was 1.19 (95% CI, 1.09-1.31; P<0.001), and for all-cause death was 1.24 (95% CI, 1.10-1.39; P<0.001). Conclusions- Our study adds to the growing body of literature suggesting that BPV is an important and potentially modifiable risk factor for ischemic stroke, cardiovascular events, and all-cause death. Specifically, it is the first study to demonstrate that increased BPV is associated with recurrent ischemic stroke and that diastolic BPV can be as important as systolic BPV. Future work should focus on evaluating whether actively reducing BPV, using widely available and inexpensive antihypertensive medications, reduces the risk of cardiovascular disease.
Keywords: blood pressure; heart failure; hypertension; myocardial infarction; renal insufficiency.