SS05 - Coronary Revascularization of Patients with Silent Coronary Ischemia May Reduce the Risk of Myocardial Infarction and Cardiovascular Death Following Carotid Endarterectomy

Objectives: Coronary events are the primary cause of death following carotid endarterectomy (CEA). We sought to determine whether selective coronary revascularization of CEA patients with silent coronary ischemia can reduce adverse cardiac events following endarterectomy compared to patients receiving standard cardiac evaluation and care.

Methods: Two group comparison of patients with no cardiac history or coronary symptoms undergoing elective CEA: Group I: patients enrolled in a prospective IRB-approved study of pre-op non-invasive cardiac evaluation using coronary CT-derived fractional flow reserve (FFRCT) to identify unsuspected (silent) coronary ischemia with selective post-op coronary revascularization; Group II: concurrent matched Controls with standard pre-op cardiac evaluation and no post-op coronary revascularization. In Group I, lesion-specific coronary ischemia was defined as FFRCT≤0.80 with FFRCT ≤0.75 indicating severe ischemia. The status of coronary ischemia was unknown in Group II. Endpoints included cardiovascular (CV) death, cardiac death, myocardial infarction (MI), stroke and all-cause death through 3-year follow up.

Results: Group I (n=100) and Group II (n=100) patients were similar in regard to age, gender (65% vs 62% male), co-morbidities (hypertension 86% vs 82%; dyslipidemia 35% vs 26%; diabetes 10% vs 14%; smoking history 34% vs 30%) and indication for CEA. Coronary CT scans in Group I, showed extensive calcification with ≥50% stenosis in 46% of patients. FFRCT analysis revealed silent coronary ischemia in 57% of patients with left main in 7% and multivessel ischemia in 28%. Severe coronary ischemia was present in 44% of patients. After CEA, both groups had guideline-directed medical care. In Group I patients with silent ischemia were selected for coronary angiography 1-3 months post-CEA with elective coronary revascularization in 33 patients (27 PCI; 6 CABG). Group II patients had no coronary revascularization. Median follow up was 2.8 and 2.7 years in Group I and II, respectively. Results are shown on Table I. At 3 years, the rates of MI, cardiac death and CV death were significantly lower in Group I compared to Group II (p < 0.05). There were no significant differences in stroke or all-cause death. Kaplan-Meier estimate of CV death in the two groups during 3 years follow-up is shown in Fig 1.

Conclusions: Diagnosis of silent coronary ischemia with selective coronary revascularization following CEA significantly reduced CV death, cardiac death and MI during 3 follow up compared to standard cardiac evaluation and care. Prospective, controlled studies are indicated to further evaluate the role of FFRCT -guided coronary revascularization in CEA patients.