Management of coexisting coronary artery and asymptomatic carotid artery disease: report of a series of patients treated with coronary bypass alone

Is carotid artery disease responsible for perioperative strokes after coronary artery bypass surgery?

The coronary and extracranial carotid vascular beds are often simultaneously affected by significant atherosclerotic disease, and stroke is one of the potential major complications of coronary artery surgery. As a result, there is no shortage of reports in the vascular surgery literature describing simultaneous coronary and carotid artery revascularizations. Generally, these reports have found this combination of operations safe, but have stopped short of proving that it is necessary. Intuitively, simultaneous carotid endarterectomy and coronary artery bypass surgery could be justified if most perioperative strokes were the result of a significant carotid stenosis, either directly or indirectly. At first glance this appears to be a fairly straightforward issue; however, much of the evidence on both sides of the argument is circumstantial. One significant problem in analyzing outcome by choice of treatment in patients presenting with both coronary and carotid disease is the multiple potential causes of stroke in coronary bypass patients, which include hemorrhage and atheroemboli from aortic atheromas during clamping. But this controversial subject is now open to discussion, and our debaters have been given the challenge to clarify the evidence to justify their claims.

Combined carotid endarterectomy and coronary artery bypass grafting in patients with asymptomatic high-grade stenoses: An analysis of 758 procedures

PURPOSE

Surgical treatment of hemodynamically significant carotid artery stenoses has been well documented, especially in the asymptomatic patient. However, in those patients presenting with hemodynamically significant asymptomatic carotid artery disease who are to undergo cardiac surgery, optimal treatment remains controversial. In this study, we analyze our experience with patients who underwent synchronous carotid endarterectomy (CEA) and coronary artery bypass graft procedures (CABG) for hemodynamically significant (>70%) asymptomatic carotid artery stenosis and coronary artery disease (CAD).

METHODS

Demographics and outcomes of all patients undergoing synchronous CEA/CABG for asymptomatic carotid stenosis between April 1980 and January 2005 were reviewed from our vascular registry and patient charts. We included patients who underwent standard patching of their carotid artery and those undergoing eversion CEA. All neurologic events within the first 30 days that persisted >24 hours were considered a stroke. For purposes of comparison, we also reviewed outcomes for patients undergoing synchronous CEA/CABG for symptomatic carotid stenosis.

RESULTS

Asymptomatic carotid artery stenosis (>70%) was the indication in 702 patients (276 women and 426 men) undergoing 758 CEAs. In the asymptomatic group, 22 patients, of which 21 succumbed to cardiac dysfunction, and one died from a hemorrhagic stroke. The overall mortality rate was 3.1%. Seven permanent nonfatal neurologic deficits occurred in this series (1 woman, 6 men). The combined stroke mortality was 4.3%. This compares to a 30-day stroke mortality of 6.1% in 132 symptomatic combined CEA/CABG patients. The difference in stroke mortality in women compared with men was not significant.

CONCLUSION

In this experience, patients presenting with hemodynamically significant (>70%) asymptomatic carotid artery stenosis can undergo synchronous CEA/CABG with low morbidity and mortality.

An audit tool for assessing the appropriateness of carotid endarterectomy

Background

To update appropriateness ratings for carotid endarterectomy using the best clinical evidence and to develop a tool to audit the procedure's use.

Methods

A nine-member expert panel drawn from all the Canadian Specialist societies that are involved in the care of patients with carotid artery disease, used the RAND Appropriateness Methodology to rate scenarios where carotid endarterectomy may be performed. A 9-point rating scale was used that permits the categorization of the use of carotid endarterectomy as appropriate, uncertain, or inappropriate. A descriptive analysis was undertaken of the final results of the panel meeting. A database and code were then developed to rate all carotid endarterectomies performed in a Western Canadian Health region from 1997 to 2001.

Results

All scenarios for severe symptomatic stenosis (70–99%) were determined to be appropriate. The ratings for moderate symptomatic stenosis (50–69%) ranged from appropriate to inappropriate. It was never considered appropriate to perform endarterectomy for mild stenosis (0–49%) or for chronic occlusions. Endarterectomy for asymptomatic carotid disease was thought to be of uncertain benefit at best. The majority of indications for the combination of endarterectomy either prior to, or at time of coronary artery bypass grafting were inappropriate. The audit tool classified 98.0% of all cases.

Conclusions

These expert panel ratings, based on the best evidence currently available, provide a comprehensive and updated guide to appropriate use of carotid endarterectomy. The resulting audit tool can be downloaded by readers from the Internet and immediately used for hospital audits of carotid endarterectomy appropriateness.

Treatment of combined coronary and carotid artery disease

PURPOSE OF REVIEW

The purpose of this review is to evaluate the current indications and results of treatment of combined coronary and carotid disease. Synchronous carotid stenosis in patients with coronary artery disease poses a management challenge in patients with advanced atherosclerosis.

RECENT FINDINGS

Recent case series continue to demonstrate concomitant coronary and carotid disease with significant carotid stenosis greater than 70% in approximately 8% of patients evaluated for coronary artery bypass grafting. Surgical management options include staged operations addressing the carotid stenosis first, reverse staged operations addressing the coronary disease first, and combined synchronous operations addressing both territories during the same anesthetic. Recent reports demonstrate safety and acceptable risks with each operative approach. Lower trends in stroke rates were noted following staged procedures when compared with combined procedures. However, several metaanalyses showed no significant difference in rates of combined morbidity and mortality for all three strategies. Total morbidity and mortality risks for combined disease tended to be higher than for isolated coronary artery bypass grafting or carotid endarterectomy procedures performed for disease in a single vascular territory.

SUMMARY

Despite a large volume of data present in the literature, the treatment indications and surgical options remain controversial. We currently advocate treatment of symptomatic territory first in favor of staged procedures and reserve combined procedures for patients with critical stenosis or symptoms in both territories.

Carotid artery disease and stroke during coronary artery bypass: a critical review of the literature

OBJECTIVES

to determine the role of carotid artery disease in the pathophysiology of stroke after coronary artery bypass (CABG).

DESIGN

systematic review of the literature.

RESULTS

the risk of stroke after CABG was 2% and remained unchanged between 1970-2000. Two-thirds occurred after day 1 and 23% died. 91% of screened CABG patients had no significant carotid disease and had a <2% risk of peri-operative stroke. Stroke risk increased to 3% in predominantly asymptomatic patients with a unilateral 50-99% stenosis, 5% in those with bilateral 50-99% stenoses and 7-11% in patients with carotid occlusion. Significant predictive factors for post-CABG stroke included; (i) carotid bruit (OR 3.6, 95% CI 2.8-4.6), (ii) prior stroke/TIA (OR 3.6, 95% CI 2.7-4.9) and (iii) severe carotid stenosis/occlusion (OR 4.3, 95% CI 3.2-5.7). However, the systematic review indicated that 50% of stroke sufferers did not have significant carotid disease and 60% of territorial infarctions on CT scan/autopsy could not be attributed to carotid disease alone.

CONCLUSIONS

carotid disease is an important aetiological factor in the pathophysiology of post-CABG stroke. However, even assuming that prophylactic carotid endarterectomy carried no additional risk, it could only ever prevent about 40-50% of procedural strokes.

In search of tools to aid logical thinking and communicating about medical decision making

To have real-time impact on medical decision making, decision analysts need a wide variety of tools to aid logical thinking and communication. Decision models provide a formal framework to integrate evidence and values, but they are commonly perceived as complex and difficult to understand by those unfamiliar with the methods, especially in the context of clinical decision making. The theory of constraints, introduced by Eliyahu Goldratt in the business world, provides a set of tools for logical thinking and communication that could potentially be useful in medical decision making. The author used the concept of a conflict resolution diagram to analyze the decision to perform carotid endarterectomy prior to coronary artery bypass grafting in a patient with both symptomatic coronary and asymptomatic carotid artery disease. The method enabled clinicians to visualize and analyze the issues, identify and discuss the underlying assumptions, search for the best available evidence, and use the evidence to make a well-founded decision. The method also facilitated communication among those involved in the care of the patient. Techniques from fields other than decision analysis can potentially expand the repertoire of tools available to support medical decision making and to facilitate communication in decision consults.

Combined Surgery for cardiac and carotid disease: management and results of a rational approach

OBJECTIVES

The aim of the present study was to apply a rational plan for simultaneous cardiac and carotid surgery in high-risk patients.

MATERIALS AND METHODS

A consecutive series of 89 patients with coexisting severe cardiac and carotid disease were operated on during a 5-year period with routinary carotid shunting, moderate hypothermia and balanced anaesthesia. The combined surgical procedures were coronary artery by-pass grafts (CABG) + carotid endarterectomy (CEA) in 81 patients, CABG + CEA + aortic valve replacement (AVR) in four patients, and four cases of CEA + AVR. RESSULTS: Two deaths (2%), three acute myocardial infarctions (3%) and one (1%) major stroke occurred in five patients during the perioperative (30 days) period for a combined rate of death and/or disabling stroke of 3%. There were five reversible neurological deficits. Carotid and aortic mean clamping times were 9 and 60 min respectively. Patients were discharged after a mean length of stay in Intensive Care Unit (ICU) of 131 h and 7 days of hospitalisation post-ICU.

CONCLUSIONS

Based on our results, combined interventions of CEA and CABG can be performed with an acceptable morbidity and mortality when severe carotid stenosis is associated with advanced, symptomatic cardiac disease. The management of these patients needs careful and appropriate pre-intra and post-operative assessment and timing aimed to reduce the ischaemic injuries, both cardiac and cerebral, especially during CBP time.