Coronary revascularization of patients with silent coronary ischemia may reduce the risk of myocardial infarction and cardiovascular death after carotid endarterectomy

Abstract

Background: Major adverse cardiac events (MACEs) are the primary cause of death after carotid endarterectomy (CEA). We sought to determine whether selective coronary revascularization of CEA patients with asymptomatic coronary ischemia can reduce the risk of MACEs, myocardial infarction (MI), and cardiac death after endarterectomy compared with CEA patients receiving standard cardiac evaluation and care.

Methods: Two groups of patients with no cardiac history or symptoms undergoing elective CEA were compared. Group I: patients enrolled in a prospective study of noninvasive preoperative cardiac evaluation using coronary computed tomography (CT)-derived fractional flow reserve (FFR_CT) to detect asymptomatic (silent) coronary ischemia with selective postoperative coronary revascularization. Group II: matched Control patients with standard preoperative cardiac evaluation and no postoperative coronary revascularization. Lesion-specific coronary ischemia in group I was defined as FFR_CT ≤ 0.80 distal to coronary stenosis with severe ischemia defined as FFR_CT ≤ 0.75. End points included MACEs, cardiac death, MI, cardiovascular (CV) death, stroke, and all-cause death through 3-year follow-up.

Results: Group I (n = 100) and group II (n = 100) patients were similar in age (68 vs 67 years), gender (65% vs 62% male), comorbidities, and indications for CEA (53% vs 48% symptomatic carotid stenosis). In group I, FFR_CT analysis revealed lesion-specific coronary ischemia in 57% of patients, severe coronary ischemia in 44%, left main ischemia in 7%, and multivessel ischemia in 28%. The status of coronary ischemia in group II was unknown. CEA was performed without complications in both groups, and all patients received optimal postoperative medical therapy. In group I, elective coronary revascularization was performed in 33 patients (27 percutaneous coronary intervention; 6 coronary artery bypass grafting) 1 to 3 months after CEA. Group II patients had no elective coronary revascularization. During 3-year follow-up, compared with group II, group I patients had fewer MACEs (4% vs 17%, hazard ratio [HR]: 0.21 [95% confidence interval (CI): 0.07-0.63], P = .004), fewer cardiac deaths (2% vs 9%, HR: 0.20 [95% CI: 0.04-0.95], P = .030), fewer MIs (3% vs 17%, HR: 0.16 [95% CI: 0.05-0.54], P = .001), and fewer CV deaths (2% vs 12%, HR: 0.16 [95% CI: 0.004-0.07], P = .009). There were no significant differences in the rates of stroke or all-cause death.

Conclusions: Preoperative diagnosis of silent coronary ischemia with selective coronary revascularization after CEA may reduce the risk of MACEs, cardiac death, MI, and CV death during 3-year follow-up compared with CEA patients receiving standard cardiac evaluation and care.

Keywords: Cardiac death; Carotid endarterectomy; Coronary CT-derived fractional flow reserve; Coronary revascularization; Myocardial infarction; Silent coronary ischemia.