MONTREAL – The optimal length for dual antiplatelet therapy in patients who have just had a mild stroke or transient ischemic attack is 21 days, a duration of combined treatment that maximized protection against major ischemic events while minimizing the extra risk for a major hemorrhage, according to a prespecified analysis of data from the POINT trial.
The new, prespecified analysis looked at outcomes on a week-by-week basis over the course of 90 days of treatment, and showed that during the first 21 days the rate of major ischemic events was 5.6% among patients on aspirin only and 3.6% among those on DAPT, a statistically significant 35% relative cut in these adverse outcomes by using DAPT,, reported at the World Stroke Congress. During the subsequent 69 days on treatment, the incidence of major ischemic events was roughly 1% in both arms of the study, showing that after 3 weeks the incremental benefit from DAPT disappeared, said Dr. Elm, a biostatistician at the Medical University of South Carolina, Charleston.
In contrast, the doubled rate of major hemorrhages (mostly reversible gastrointestinal bleeds) with DAPT, compared with aspirin alone, occurred at a relatively uniform rate throughout the 90 days of treatment, meaning that limiting DAPT to just 21 days could prevent many of the excess hemorrhages.
“These results suggest that limiting clopidogrel plus aspirin use to 21 days may maximize benefit and reduce risk,” Dr. Elm said, especially in light of the findings confirming the efficacy of 21 days of DAPT following a minor stroke or TIA that had been reported several years ago in the New Engl J Med. 2013 Jul 4;).
Although the new finding from the POINT results came in a secondary analysis, it’s statistically legitimate and should be taken into account when writing treatment guidelines, she said, emphasizing that “this is a very important analysis that is not just hypothesis generating.”
Another finding from the new analysis was that a large number of major ischemic events, and hence a large number of the events prevented by DAPT, occurred in the first 2 days following the index event, a finding made possible because the POINT investigators enrolled patients and started treatment within 12 hours of the qualifying events.
“It’s better to start treatment early,” Dr. Elm noted, but she also highlighted that major ischemic events continued to accumulate during days 3-21, suggesting that patients could still benefit from DAPT even if treatment did not start until 24 or 48 hours after their index event.
POINT received no commercial funding aside from study drugs supplied by Sanofi. Dr. Elm reported no disclosures.
SOURCE: World Stroke Congress, Late-breaking session.