Carotid Disease and CABG
Abstract & Commentary
By Michael H. Crawford, MD
Source: Van der Heyden J, et al. Staged carotid angioplasty and stenting followed by cardiac surgery in patients with severe asymptomatic carotid artery stenosis: Early and long-term results. Circulation. 2007;116:2036-2042.
The management of patients with significant carotid artery disease, who need coronary artery bypass surgery (CABG), especially if the carotid disease is asymptomatic, is controversial. In the absence of randomized trials, this report of carotid artery stenting followed by CABG in 356 patients with severe asymptomatic carotid disease is of interest. Asymptomatic was defined as no ipsilateral cerebral event in 4 months, and significant carotid disease was defined as > 80% luminal diameter reduction. Exclusion criteria included severe diffuse carotid atherosclerosis, chronic total occlusions, and long preocclusive lesions (sting sign). The primary end point was death and stroke for 30 days post CABG; secondary end points included myocardial infarction (MI). CABG was scheduled 14 to 30 days post carotid stenting, and aspirin and clopidogrel were discontinued 5 days before surgery, if possible.
Carotid stenting was successful in 98% of the patients. Death or stroke occurred in 5%; MI in 2%. Distal protection devices were used in 40% of patients. Periprocedure events were less within distal protection (2.2 vs 3.8%), but the difference was not statistically significant (P = .50). Between carotid stenting and CABG (mean 22 days), there was one death due to arrhythmias, 2 MIs, 5 episodes of unstable angina, 5 ipsilateral strokes (one severe), and 8 transient ischemic attacks. In the 3% of patients who had non-fatal cerebral events following CABG, carotid duplex ultrasound showed good stent apposition without in-stent restenosis or thrombosis. One patient died of cerebral hemorrhage. Van der Heyden et al concluded that the favorable periprocedural and 30-day results of carotid stenting in asymptomatic carotid stenosis patients before CABG suggest that this may be an attractive alternative treatment for patients with combined carotid and coronary artery disease.
Management of the patients with concomitant carotid and coronary artery disease is challenging, and there is no clearly preferable approach. Much debate in the past has revolved around when to do carotid endarterectomy (CEA): before, with, or after CABG. After CABG never gained much traction in the past because of the risk of going into cardiopulmonary bypass with significant carotid disease. Older data suggest about a 15% stroke rate with CABG when carotid lesions are > 80%. However, with off-pump surgery, this tactic could be more acceptable. Most of the debate has centered around CEA before or with CABG. Non-randomized experience shows an average MI rate of 3.6% for synchronous surgery and 6.5% for staged procedures, but this difference could be explained by selection biases; sicker patients were selected for a staged approach. The carotid stenting followed by CABG approach would seem competitive based on this study, where the MI rate was 2% and the death or stroke rate was 5%. Only a randomized trial could effectively answer this question, but may never be done.
The long-term survival for up to 5 years in this study was 76%, and freedom from death or stroke was 71%. These data are pretty good for patients with significant carotid and coronary disease. Interestingly, survival was better in women (84%). Also, age > 80 years was associated with a higher risk of a cerebral event. Repeat stenting or CEA was infrequent, and in those with cerebral events, no restenosis or thrombosis was observed in the stented site. These data are certainly encouraging.
The major issue with applying this management approach is timing. Carotid stenting should be followed with aspirin and clopidogrel indefinitely, but this increases the risk of bleeding with CABG. In lieu of these data, Van der Heyden et al devised their approach as follows: if delaying CABG was not feasible (one third of patients), they operated on antiplatelet drugs; in the other two-thirds, CABG was delayed; 14-30 days in half and > 30 days in the rest. Using this approach, no stent thrombosis or increase in bleeding was observed. They believed that a delay of 2-3 weeks was best, if possible. Although not a randomized trial, this formable experience suggests that carotid stenting followed by CABG in < 30 days is a viable option to CEA either before or with CABG.