Randomized Comparison of Synchronous CABG and Carotid Endarterectomy vs. Isolated CABG in Patients with Asymptomatic Carotid Stenosis: The CABACS Trial

Abstract

High-grade carotid artery stenosis is present in 6-8% of patients undergoing coronary artery bypass graft surgery. Many cardiovascular surgeons advocate staged or synchronous carotid endarterectomy to reduce the high perioperative and long-term risk of stroke associated with multivessel disease. However, no randomized trial has assessed whether a combined synchronous or staged carotid endarterectomy confers any benefit compared with isolated coronary artery bypass grafting in these patients. The objective of this study is to compare the safety and efficacy of isolated coronary artery bypass grafting vs. synchronous coronary artery bypass grafting and carotid endarterectomy in patients with asymptomatic high-grade carotid artery stenosis. Coronary Artery Bypass graft surgery in patients with Asymptomatic Carotid Stenosis (CABACS) is a randomized, controlled, open, multicenter, group sequential trial with two parallel arms and outcome adjudication by blinded observers. Patients with asymptomatic high-grade carotid stenosis scheduled for elective coronary artery bypass grafting will be assigned to either isolated coronary artery bypass grafting or synchronous coronary artery bypass grafting and carotid endarterectomy by 1 : 1 block-stratified randomization with three different stratification factors (age, gender, modified Rankin scale). The trial started in December 2010 aiming at recruiting 1160 patients in 25 to 30 German cardiovascular centers. The composite primary efficacy end point is the number of strokes and deaths from any cause (whatever occurs first) within 30 days after operation. A 4·5% absolute difference (4% compared to 8·5%) in the 30-day rate of the above end points can be detected with >80% power. The results of this trial are expected to provide a basis for defining an evidence-based standard and will have a wide impact on managing this disease.