Ischemia targeted coronary revascularization improves five-year survival following carotid endarterectomy.

Abstract

Objectives: Long-term survival following carotid endarterectomy (CEA) is limited by adverse cardiac events with 5% annual mortality. We sought to determine whether diagnosis of silent coronary ischemia together with elective ischemia-targeted coronary revascularization can reduce death and myocardial infarction (MI) and improve long-term survival of patients following CEA.

Methods: Observational cohort study of patients with no cardiac history or coronary symptoms undergoing elective CEA. Patients enrolled in a prospective study of pre-operative cardiac evaluation using coronary CT-derived fractional flow reserve (FFR_CT) to detect silent (asymptomatic) coronary ischemia together with elective post-operative ischemia-targeted coronary revascularization were compared to matched Controls with standard pre-operative cardiac evaluation and no elective coronary revascularization. Lesion-specific coronary ischemia was defined as FFR_CT ≤0.80 distal to >30% stenosis with severe ischemia defined as FFR_CT ≤0.75. Endpoints included all-cause death, cardiac death, MI, stroke and MACE (major adverse cardiovascular events = cardiovascular (CV) death, MI or stroke) during 5-year follow-up.

Results: FFR_CT (n=100) and Control (N=100) cohorts were well matched with no significant differences in age, gender, comorbidities or indications for CEA. Asymptomatic lesion-specific coronary ischemia (FFR_CT ≤0.80) was present in 57% of FFR_CT patients, with severe ischemia in 44%, and left main ischemia in 7%; 43% had no coronary ischemia (FFR_CT >0.80). The status of coronary ischemia was unknown in Controls. CEA was performed successfully in both cohorts with no deaths or neurologic events and all patients received optimal post-operative medical therapy. Elective ischemia-targeted coronary revascularization was performed in 33% of FFR_CT patients within 3 months of CEA. Controls had no elective coronary revascularization. During 5-year follow up, compared to Control, the FFR_CT group had fewer all-cause deaths (11% vs 24%, hazard ratio [HR] 0.37, 95% confidence interval [CI] 0.17-0.77, P=.016); fewer cardiac deaths (3% vs 13%, HR 0.15, 95% CI 0.03-0.69, P=.009); fewer MIs (3% vs 21%, HR 0.07, 95% CI 0.02-0.31, P<.001) and fewer MACE events (10% vs 33%, HR 0.21, 95% CI 0.10-0.44, P<.001) with no difference in stroke. There were no cardiac deaths or MIs among patients with no coronary ischemia (FFR_CT >0.80). Annual mortality in FFR_CT was 2.2% per year compared to 4.8% per year in Control.

Conclusions: Diagnosis of silent coronary ischemia together with elective ischemia-targeted coronary revascularization following CEA reduced the 5-year risk of all-cause death, cardiac death, MI and MACE by more than 50% and improved survival (89%) compared to patients receiving standard cardiac evaluation and care (76%).