Abstract 3081: CHARISMA (long-term dual anti-platelet therapy): The Impact of Risk Status, Prior History, and Proximity to Recent Cardiovascular Events
Background: In CHARISMA 15,603 patients, all treated with aspirin (A), were randomized to clopidogrel (C) or placebo (P), over a median of 28 months (primary endpoint: CV death, MI or stroke 6.8% C vs 7.3% p=ns). The hypothesis for this analysis is that the baseline risk status of the patients and proximity to a recent cardiovascular event influence the response to dual anti-platelet therapy. Patients with symptomatic CAD, CVD or PAD and all those with a history of CV events were included in this analysis (n=13,434).
Results: CV death/MI/ stroke occurred in 7.0% C vs 7.8% P (RR 0.79, 95% CI 0.80–1.02, p=ns), consistent with the primary endpoint of the trial. CV outcomes were also assessed according to quartiles of baseline CV risk. Only in the quartile with the greatest CV risk was there a strong trend for reduced rates of CV events with C. The incidence of severe bleeds (3.1% C vs 3.2% P) and ICH (1.0%C vs 1.0%P) was similar in this quartile, but moderate bleeds were more frequent (4.2%C vs 2.6%P, p=0.02). Proximity to a recent CV event (MI/stroke) was associated with significant benefit with C. For those randomized within 6 months of MI or stroke, the frequency further MI/stroke or death was 8.2% C vs 10.8% P (HR 0.76, 95%CI 0.59 – 0.98, p=0.034). In those patients who had a documented prior vascular event or with confirmed PAD (n=9478) the risk of death/MI/stroke was 7.3%C vs 8.8%P (HR 0.83, 95% CI 0.72– 0.96, p=0.01).
Commencing therapy within 6 months of a stroke or MI there is evidence of a benefit with clopidogrel treatment on rates of future death/MI/stroke.
Analysis of higher risk groups, including those with clear evidence of vascular disease and recent vascular events, suggests the potential for greater benefit when clopidogrel is added to aspirin.