By Matthew E. Fink, MD
Louis and Gertrude Feil Professor and Chair, Department of Neurology, Associate Dean for Clinical Affairs, NYP/Weill Cornell Medical College
Dr. Fink reports no financial relationships relevant to this field of study.
SOURCE: Kitagawa K, Yamamoto Y, Arima H, et. al, for the Recurrent Stroke Prevention Clinical Outcome (RESPECT) Study Group. Effect of standard vs intensive blood pressure control on the risk of recurrent stroke: A randomized clinical trial and meta-analysis. JAMA Neurol 2019;76:1309-1318.
High blood pressure is the most prevalent and important risk factor for stroke. Great efforts have been made to reduce blood pressure (BP) for both primary and secondary stroke prevention. In clinical trials of primary prevention of all cardiovascular events, which includes stroke, lower BP seems to be better in all patients. A systolic BP of < 115 mmHg has been recommended as a target. However, after a stroke, there continues to be controversy and debate over the ideal target BP.
Kitagawa et al randomized 1,280 patients who already had suffered an ischemic or hemorrhagic stroke into two BP treatment arms — standard therapy, defined as BP control with a target lower than 140/90 mmHg, and an intensive treatment arm, with a target lower than 120/80 mmHg. The primary outcome measure was stroke recurrence.
This study was performed in Japan, and it ended early. Of the 1,263 enrolled patients, the mean age was 67.2 years, and 69.4% were male. Almost all patients (99.5%) completed a mean follow-up of 3.9 years, with a mean blood pressure at baseline that was 145.4/83.6 mmHg. In the standard group, throughout overall follow-up, mean BP was 133.2/77.7 mmHg. In the intensive treatment group, the mean BP was 126.7/77.4 mmHg. When comparing the rate of recurrent stroke between the two groups, there was a nonsignificant rate reduction in the intensive group compared to the standard group.
The investigators then pooled their data with findings from three previous randomized, controlled trials in a meta-analysis, and stated that with this larger group, the risk ratio favored intensive BP control (relative risk, 0.78; P = 0.02). The authors concluded intensive BP-lowering tended to reduce stroke recurrence and recommended a target BP that is < 130/80 mmHg for secondary stroke prevention.
However, there are problems with the recommendation from Kitagawa et al. They excluded patients 85 years of age and older, and this was a large cohort of stroke patients. The authors showed a significant difference only after conducting a meta-analysis and pooling data from other studies. This was not part of their initial research plan. They terminated the study early before any firm conclusions could be drawn. At this time, we do not have evidence to support a firm recommendation for optimal BP management for secondary stroke prevention.