Abstract 16616: Impact of Demographics and Risk Factors in PRoFESS: Focus on US Patients
Introduction: The Prevention Regimen for Effectively Avoiding Secondary Strokes (PRoFESS) trial randomized 20,332 pts within 120 days of a stroke to either a fixed-dose combination of aspirin and extended-release dipyridamole (ASA-ERDP) or clopidogrel. After a mean duration of 2.5 years, both groups had a similar rate of recurrent stroke, though the trial did not meet its prespecified endpoint.
Objective: The US represents a heterogeneous population in a unique healthcare market with distinct patterns of care. US health authorities have expressed interest in outcomes for US pts in cardiovascular outcome trials.
Methods: We undertook a post hoc analysis of primary, secondary, and tertiary outcomes for each anti-platelet treatment arm in the US population, vs the population of non-US pts as a comparator. Relative risk ratios (with 95% CI) were calculated. Treatment by country (US vs non-US) interaction P-values were calculated using the Cox proportional hazards model.
Conclusions: Consistent trends toward a statistical interaction in all endpoints explored suggest that a different treatment effect is present between ASA-ERDP and clopidogrel in the US vs non-US countries. Differences in baseline demographics and risk factors will be explored.
- © 2011 by American Heart Association, Inc.