Intensive Blood Pressure Lowering Is Likely to Reduce Stroke Recurrence

Craig Anderson, MD, PhD,The George Institute for Global Health, University of New South Wales

Craig Anderson, MD, PhD

According to results of a meta-analysis, a blood pressure target of less than 130/80 mm Hg is likely to be beneficial in reducing stroke recurrence.

Researchers aimed to assess the optimum blood pressure target in secondary stroke prevention, testing the hypothesis that intensive lowering of systolic and diastolic blood pressure less than 120 mm Hg and 80 mm Hg, respectively, reduces the rates of stroke recurrence compared with a standard lowering regimen.

“The work by Kitagawa et al. provides support for the recent move of many hypertension guidelines across the world to recommend lower BP targets in high-risk patient populations (ie, BP levels <130/85 mm Hg),” Craig Anderson, MD, PhD, of the George Institute for Global Health, University of New South Wales, wrote in an accompanying editorial.¹ “Globally, just under half of the total BP-attributable disease burden occurs in people with systolic BP less than 140 mm Hg, and most CV events occur in individuals who have had a previous event. Therefore, any recommendations for the initiation, intensification, and control of BP-lowering treatment for high-risk patients has substantial clinical and public health importance.”

In the Recurrent Stroke Prevention Clinical Outcome (RESPECT) Study, investigators randomized 1263 patients from 140 hospitals in Japan 1:1 to 2 blood pressure control groups with targets of either less than 140/90 mm Hg (the standard treatment group [n=630]) or less than 120/80 mm Hg (the intensive treatment group [n=633]). Mean blood pressure at baseline was 145.4/83.6 mm Hg. The independent data and safety monitoring committee recommended continuation of research at the first interim analysis on August 14, 2016; however, because of slow recruitment and a lack of funding, the committee stopped enrollment December 31, 2016, before reaching the planned sample size of 2000.

Eligible participants had the following characteristics: age 50&shy;—85, independent ambulation, systolic blood pressure of 130 to 180 mm Hg or diastolic blood pressure of 80 to 110 mm Hg on a regimen of 0&shy;–3 antihypertensive medications, and history of stroke within the previous 3 years.

The intensive treatment group received multidrug therapy with a blood pressure target less than 120/80 mm Hg, and the standard treatment group received the same therapy with blood pressure targets less than 140/90 mm Hg or less than 130/80 mm Hg for participants with diabetes, chronic kidney disease, or history of myocardial infarction. Participants received treatment orally every 4 weeks for 24 weeks at a maximum during the titration period.

The primary endpoint was recurrent stroke including ischemic stroke and intracerebral hemorrhage; secondary endpoints included reductions in ischemic stroke, subtype of ischemic stroke, composite cardiovascular events, all-cause death, and the composite of all-cause death, nonfatal stroke, and nonfatal myocardial infarction.

The study showed that lowering blood pressure to a target goal of less than 120/80 mm Hg compared to the standard goal resulted in nonsignificant reductions in all strokes, which were consistent among all subgroups. When this finding was pooled with the results of prior trials of intensive blood pressure control for secondary stroke prevention in an updated meta-analysis, investigators reported a reduction of 22% in stroke recurrence in those randomized to intensive blood pressure treatment.

Throughout the follow-up period, the mean blood pressure was 133.2/77.7 (95% CI, 132.5-133.8/77.1-78.4) mm Hg in the standard group and 126.7/77.4 (95% CI, 125.9-127.2/73.8-75.0) mm Hg in the intensive group. Investigators reported that 91 first recurrent strokes occurred. Nonsignificant rate reductions were seen for recurrent stroke in the intensive group compared with the standard group (P&thinsp; =.15).

The most frequent serious adverse effect in both groups was malignant neoplasm (5.08% in the standard treatment group and 3.63% in the intensive treatment group). One limitation of the study was that none of the individual studies demonstrated significant results for secondary stroke prevention; however, there was clear benefit in the meta-analysis.

REFERENCE

1. Anderson C. Challenges to Realizing Benefits From More Intensive Blood Pressure Control for Preventing Recurrent Stroke. JAMA Neurology. 2019. doi:10.1001/jamaneurol.2019.1668.

2. Kitagawa K, Yamamoto Y, Arima H, et al. Effect of Standard vs Intensive Blood Pressure Control on the Risk of Recurrent Stroke. JAMA Neurology. 2019. doi:10.1001/jamaneurol.2019.2167.