HONOLULU – according to research presented at the International Stroke Conference sponsored by the American Heart Association.
Combined with data from previous trials, these results support a target systolic blood pressure of less than 130 mm Hg and a diastolic blood pressure of less than 80 mm Hg for secondary stroke prevention, said Kazuo Kitagawa, MD, PhD.
Lowering blood pressure reduces the risk of recurrent stroke, but investigators have not identified the best target blood pressure for this indication. The Secondary Prevention of Small Subcortical Strokes Trial (SPS3) examined the efficacy of intensive blood pressure treatment for secondary stroke prevention. The investigators randomized more than 3,000 patients with recent lacunar stroke to intensive or standard blood pressure treatment. Intensive treatment (a target systolic blood pressure of less than 130 mm Hg) conferred a nonsignificant reduction of the risk of recurrent stroke. A 2018 meta-analysis of SPS3 and two smaller randomized controlled trials also showed that intensive treatment did not significantly reduce the risk of recurrent stroke.
A new multicenter trial
Dr. Kitagawa, of Tokyo Women’s Medical University, and colleagues conducted a new trial to evaluate whether intensive blood pressure reduction significantly reduced the risk of recurrent stroke, compared with standard treatment (a systolic target of less than 140 mm Hg and a diastolic target of less than 90 mm Hg). Between 2010 and 2016, they enrolled patients with a history of stroke within the previous 3 years at 140 hospitals in Japan. Participants were randomized to standard blood pressure treatment or intensive blood pressure treatment (defined in this study as a systolic target of less than 120 mm Hg and a diastolic target of less than 80 mm Hg). The primary end point was recurrent stroke.
Both treatment regimens were based on stepwise multidrug rationing. Step 1 was an angiotensin II receptor blockade (ARB), step 2 was the addition of diuretics, step 3 was the addition of calcium channel blockers, step 4 was an increase of the ARB, step 5 was increase of the calcium channel blocker, and step 6 was the addition of spironolactone.
This trial was stopped at the end of 2016 because of slow recruitment and funding cessation. Investigators randomized 1,280 patients out of a planned 2,000. Seventeen patients were excluded from analysis. At baseline, participants’ mean age was 67 years, and mean systolic blood pressure was 145 mm Hg. The qualifying event was ischemic stroke for 85% of patients and intracerebral hemorrhage for 15%. Mean follow-up duration was 3.9 years.
Intensive treatment reduced blood pressure
At 1 year, the mean systolic blood pressure was 132.0 mm Hg in the standard-treatment group and 123.7 mm Hg in the intensive-treatment group. Mean diastolic blood pressure was 77.5 mm Hg in the standard-treatment group and 72.8 mm Hg in the intensive-treatment group. The investigators observed a significant difference in blood pressure between the groups throughout the study period.