Abstract TP156: Re-analysis of the SAPPHIRE and CREST Trials Using Weighted Composite Endpoints
Background: Composite endpoints were used in the Carotid Revascularization Endarterectomy Versus Stenting Trial (CREST) and Stenting and Angioplasty with Protection in Patients at High Risk for Endarterectomy (SAPPHIRE) trials to compare outcomes between those who underwent carotid artery stent (CAS) placement and those who underwent carotid endarterectomy (CEA) for treatment of carotid artery disease (CAD). However, using composite endpoints assumes that each individual outcome is of equal clinical importance.
Objective: To determine if there was a difference in effectiveness between CAS and CEA in treating CAD if weighted composite endpoints were used in the two randomized trials.
Methods: Long-term results were examined for each trial (3 years for SAPPHIRE and 4 years for CREST). Each outcome was given a weighted measure based on a point system [death=5; major stroke=4; minor stroke=2; and myocardial infarction=1]. Study populations were amplified by using a constant coefficient (sum of all points=12). Results were then compared between the CAS and CEA groups to determine statistical significance.
Results: At 3 years, there were a total of 56 and 67 adverse outcomes in the CAS and CEA groups, respectively, in the SAPPHIRE trial. At 4 years, there were a total of 215 and 190 adverse outcomes in the CAS and CEA groups, respectively, in the CREST trial. Based on weighted composite endpoints, the CAS group had a significantly lower rate of adverse outcomes compared to the CEA group in the SAPPHIRE trial (p<0.0001) but a significantly higher rate of adverse outcomes in the CREST trial (p<0.0001).
Conclusion: With the use of weighted composite endpoints, one can provide more clinically relevant information by discriminating among adverse outcomes and describing differences with greater discriminatory power. Based on weighted composite endpoints, there is clear superiority of CAS over CEA in the SAPPHIRE trial, but the converse is true of results from the CREST trial.
- © 2012 by American Heart Association, Inc.