International Stroke Conference 2012: Clopidogrel/aspirin not effective for prevention of recurrent stroke

March 1, 2012

The antiplatelet arm of The Secondary Prevention of Small Subcortical Stroke (SPS3) study was halted in July 2011 due to reasons of safety and futility, according to principal investigator Oscar R. Benavente, MD, FRCP (C), professor of neurology at Canada's University of British Columbia in Vancouver, British Columbia.

The antiplatelet arm of The Secondary Prevention of Small Subcortical Stroke (SPS3) study was halted in July 2011 due to reasons of safety and futility, according to principal investigator Oscar R. Benavente, MD, FRCP (C), professor of neurology at Canada's University of British Columbia in Vancouver, British Columbia.

He presented the preliminary results of the trial at the International Stroke Conference 2012 in New Orleans.

Dr Benavente and researchers are looking for effective strategies to reduce recurrent stroke, cognitive decline, and major vascular events. Small subcortical strokes occur when blood flow in the small arteries to the subcortical areas of the brain get blocked. Although they account for more than a quarter of brain infarcts and are the most common cause of vascular dementia, no clinical trial has focused on this subtype, he said.

Results indicated that dual antiplatelet therapy was not more effective than aspirin alone. Annual risk for recurrent stroke for patients in the aspirin-only group was 2.7% versus 2.5% for patients in the dual therapy group. Compared with the aspirin-only group, the risk of bleeding nearly doubled for patients assigned to dual therapy.

Similarly, the annual risk of death for patients assigned to dual therapy was much higher than that for patients taking aspirin alone (2.1% versus 1.4%). This was surprising and Dr Benavente said they are continuing to analyze this finding.

"Certainly these results do not support the use of combination therapy of aspirin plus clopidigrel for long-term secondary stroke prevention in patients with lacunar strokes," he said.

The blood pressure arm of the trial, in which the investigators are examining whether blood pressure control may be associated with fewer recurrent strokes, is continuing. Patients with hypertension have been randomly assigned to 1 of 2 groups of blood pressure controls: below 130 mmHg of systolic pressure or between 130 mmHg and 149 mmHg. Dr Benavente said the trial will be completed in April and delayed results are expected later this summer.