Abstract 3686: Stroke, TIA, Amaurosis Fugax, or No Symptoms as Predictors of Outcomes in the Carotid Revascularization Endarterectomy versus Stenting Trial
Background In previous carotid revascularization trials, stroke as a qualifying symptom has had the greatest importance as a predictor of subsequent outcomes. However, the importance of stroke, TIA, amaurosis fugax, and asymptomatic status has not been analyzed together and comparatively as predictors of outcome for carotid stenosis in a randomized clinical trial (RCT).
Methods Qualifying events were analyzed for the 1321 symptomatic patients in the Carotid Revascularization Endarterectomy versus Stenting Trial (CREST) and were modeled as predictors of the primary outcome (stroke, myocardial infarction, and death during a 30-day peri-procedural period, or ipsilateral stroke over the follow-up period out to 4 years); the potential predictive value was also tested for the outcome of stroke and death. The model included other potential predictors such as age, sex, and treatment.
Results The distribution of pre-randomization qualifying events among symptomatic patients in CREST was 572 strokes, 550 TIA, and 199 amaurosis fugax. Relative to symptomatic patients qualifying for the study with stroke, the risk of subsequent primary endpoint was 15% lower for those qualifying with TIA (HR=0.85; 95% CI = 0.57 - 1.28), 36% lower for those qualifying with amaurosis fugax (HR=0.64; 95% CI = 0.3 - 1.23), and 48% lower for asymptomatic patients (HR=0.52; 95% CI = 0.35 - 0.76). The risk of stroke or death was 11% lower for TIA (HR=0.89; 95% CI = 0.57 - 1.40), 18% lower for amaurosis fugax (HR=0.82; 95% CI = 0.42 - 1.60), and 57% lower for asymptomatic patients (HR=0.43; 95% CI = 0.28 - 0.67) when compared to symptomatic patients qualifying with stroke. The risk for patients with stroke or TIA did not differ significantly, and the risk for asymptomatic patients and patients with amaurosis fugax did not differ significantly.
Conclusion Outcomes in patients with carotid disease were predicted in descending order by stroke, TIA, amaurosis fugax, and asymptomatic status in a large RCT. Asymptomatic status and amaurosis fugax have a comparatively benign prognosis. Better understanding of these predictors may help in determining who will benefit from carotid revascularization and how quickly they may benefit given the perioperative risks.
- © 2012 by American Heart Association, Inc.