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Among patients who are diagnosed with coexisting severe carotid disease while undergoing evaluation for open heart surgery, both carotid artery stenting (CAS) followed by surgery and concomitant carotid endarterectomy (CEA) plus surgery offer superior outcomes to CEA followed by surgery. Long-term results, however, strongly favor staged CAS/surgery, according to an observational study of all 3 approaches published online July 31, 2013, ahead of print in the Journal of the American College of Cardiology.
Researchers led by Mehdi H. Shishehbor, DO, MPH, of the Cleveland Clinic (Cleveland, OH), reviewed outcomes of 350 patients who received carotid revascularization within 90 days of planned open heart surgery at the Cleveland Clinic from January 1997 to August 2009. Most patients (81%) had asymptomatic carotid disease. Procedures included 45 staged CEA/surgeries (12.9%), 195 combined CEA/surgeries (55.7%), and 110 staged CAS/surgeries (31.4%), and all but 27 (8%) involved CABG vs. other types of cardiac surgery such as isolated valve or aortic repair.
Early MI, Late Mortality Differ Among Approaches
For staged procedures, the median intervals between carotid revascularization and surgery were 14 days for CEA and 47 days for CAS. Three inter-staged deaths occurred with CEA and 6 with CAS (P= 0.77). Patients in the staged CEA/surgery group had a higher MI rate during the gap between procedures than did those in the staged CAS/surgery group (24% vs. 3%; P < 0.001), though stroke rates were similar (2% vs. 1%; P = 0.51).
At 30 days, the composite rate of all-cause death, stroke, and MI (primary endpoint) was higher for staged CEA/surgery than for the other 2 strategies, driven primarily by increased rates of MI. The same pattern held true out to 1 year. Beyond 1 year, however, staged CAS/surgery offered the lowest mortality rate, resulting in better overall outcomes (table 1).
Table 1. Outcomes by Treatment Strategy
Staged CEA/Surgery(n = 45)
Combined CEA/Surgery(n = 195)
Staged CAS/Surgery(n = 110)
To 1 YearCompositeDeathStrokeMI
Beyond 1 YearCompositeDeathStrokeMI
Propensity matching to adjust for baseline differences again showed similar likelihood of the primary composite for staged CAS/surgery and combined CEA/surgery within the first year, with staged CEA/surgery resulting in higher MI risk. After 1 year, staged CAS/surgery was associated with fewer adverse events compared with both staged CEA/surgery (adjusted HR 0.33; 95% CI 0.15-0.77; P = 0.01) and combined CEA/surgery (adjusted HR 0.35; 95% CI 0.18-0.70; P = 0.003). There were no differences in mortality among the 3 groups during either time period.
“[A]vailable literature and the findings of our study demonstrate a consistent pattern in favor of the staged [CAS/surgery] strategy in this population,” the researchers comment, adding that only 3% of US patients with concomitant severe carotid and coronary artery disease undergo such treatment.
One argument on behalf of the combined CEA/surgery approach is an urgent need to revascularize the coronaries, they explain, since the staged CAS/surgery approach requires a delay to allow for dual antiplatelet therapy. But approximately 75% of combined CEA/surgery procedures are performed electively, meaning that urgent revascularization is not an issue.
“Based on the findings of the study, we believe staged [CAS/surgery] should be considered as a first-line strategy if the 3-4 week delay to [open heart surgery] is clinically acceptable,” Dr. Shishehbor and colleagues advise.
Staged CEA/surgery, however, “should be avoided if possible,” they conclude, citing the strategy’s “substantial risk of inter-stage MI.”
CAS Reimbursement an Obstacle
In an editorial accompanying the paper, Ehtisham Mahmud, MD, and Ryan Reeves, MD, both of the University of California, San Diego (La Jolla, CA), pointed out that 2 aspects of the study might have slightly biased results against CAS. Only 82% of CAS procedures involved embolic protection and nearly all CAS patients received universal neurologic monitoring, meaning that the observed stroke rates for the procedure might be inflated.
While Drs. Mahmud and Ryan agreed that staged CEA/surgery “should be avoided,” they noted a barrier to CAS: the fact that in the United States, reimbursement for the endovascular procedure is limited to symptomatic, high-risk patients.
“In standard risk or asymptomatic high-risk patients, enrollment in post-marketing registries is required,” the editorial authors explain. “As patients requiring carotid revascularization prior to [open heart surgery] are recognized as a high-risk cohort, the symptomatic status of the patient should not be a factor for reimbursement in this cohort. . . . These patients should either undergo combined [CEA/surgery] or be offered the option of CAS prior to [open heart surgery] based on medical criteria, not reimbursement issues.”
In a telephone interview with TCTMD, Dr. Shishehbor observed that the combined CEA/surgery approach is currently favored by many clinicians because of concerns over the delay between CAS and surgery. Centers for Medicare and Medicaid Services “only pays for carotid stenting if the patient is enrolled in one of the [manufacturer-sponsored] carotid registries,” whose protocols specify that patients must remain on dual antiplatelet therapy for approximately 1 month, he explained.
Moreover, “the level of expertise to perform carotid stenting is not as widespread as it is for carotid endarterectomy,” Dr. Shishehbor noted, adding that in lieu of randomized trial data supporting 1 strategy over another, physicians “have basically decided which approach they like and have really stuck with it.”
Several Factors Drive Clinical Practice
In the future, decision-making might change if, for example, dual antiplatelet therapy was not mandatory after CAS. Several small Italian studies have supported the idea of hybrid CAS/surgery, Dr. Shishehbor reported.
CAS or CEA is performed before open heart surgery specifically because carotid disease raises the risk of stroke during the latter procedure, he added. Substituting PCI for CABG would change the equation as PCI does not involve a similar stroke risk. “A lot of things have to be taken into consideration. If you look at the heart itself, maybe it’s better for the patient to have open heart surgery [such as] bypass. But when you put it in the context of carotid disease, maybe the patient is better off getting a stent,” Dr. Shishehbor said.
Many patients with asymptomatic severe carotid disease might also do just as well with medical management as with carotid revascularization if CABG is performed carefully to minimize stroke risk, he suggested. “Then in the future, in the next 2 or 3 months after the operation, you could consider them for carotid stenting or endarterectomy.”
Patients who underwent staged CAS/surgery had more prior strokes and carotid revascularization procedures, and their open heart surgeries tended to be more complex procedures.
In the staged CEA/surgery group, open heart surgery was performed as early as possible after CEA. Staged CAS/surgery patients were placed on mandatory dual antiplatelet therapy for 3 to 4 weeks unless worsening symptoms required earlier intervention; clopidogrel was stopped 5 days before open heart surgery in most cases.
2. Mahmud E, Reeves R. Carotid revascularization prior to open heart surgery: The data driven treatment strategy [editorial]. J Am Coll Cardiol. 2013;Epub ahead of print.