Carotid endarterectomy (CEA) and carotid artery stenting (CAS) are both effective treatments for carotid artery stenosis. However, atherosclerotic disease is a chronic progressive multivessel disease that mostly affects medium and large arteries in the body, and both carotid and coronary arteries are medium-sized myoelastic arteries in the body circulation system. This article reviews the existing treatment options for carotid artery combined with coronary artery stenosis, referring to the relevant literature in recent years, with the aim of providing some reference value for the treatment of this combined disease.
I. Prevalence and current problems
The incidence of combined carotid and coronary artery lesions is on the rise with the change in lifestyle and the increase in the proportion of the aging population. According to statistics, the incidence of simultaneous lesions in both vessels is about 1.7-12% [1], while HuhJ.etal. pointed out that about 8% of patients requiring coronary artery bypass graft (CABG) surgery have combined carotid stenosis >70% [2]. On the other hand, up to 66%-77% of patients with carotid stenosis have concomitant coronary artery disease [3,4]. Although the prevalence of carotid combined with coronary stenosis varies across the literature, it is certain that the degree of coronary stenosis is positively correlated with carotid intimal thickening, plaque detection rate and lesion nature, and the rate of carotid atheromatous plaque detection increases significantly as the degree of coronary stenosis increases [5], suggesting that carotid atherosclerotic lesions are consistent with the development of coronary atherosclerotic lesions.
Cardiovascular disease is a common disease that seriously affects human health and quality of life. The question of how to intervene in the treatment of patients with carotid stenosis combined with coronary artery disease has been a difficult problem for clinicians. If carotid stenosis is treated directly, patients are at a significantly increased risk of postoperative myocardial infarction; however, the degree of carotid stenosis is also positively associated with the risk of stroke after CABG. The risk of stroke after CABG is approximately 2% due to the presence of carotid stenosis (<50%); the risk increases twofold when unilateral carotid stenosis is ≥50%, triples in the case of bilateral carotid stenosis, and even increases to 12% in the case of one-sided carotid obstruction [6]. Therefore, it is particularly important to clarify the treatment strategy for combined carotid and coronary lesions in order to reduce postoperative complications in patients.
II. Treatment options and influencing factors
The main perioperative complications include ischemic stroke, transient ischemic attack, myocardial infarction, and death. Regardless of the treatment measures taken, the primary goal is to reduce the incidence of perioperative complications as well as to prolong the survival time of patients and to improve the quality of survival as much as possible. Most agree that the risk of complications is significantly higher when managing carotid stenosis and coronary artery disease together than when treating any single disease. Current treatment options include concurrent or staged management of carotid stenosis and coronary stenosis, which are subdivided into concurrent or staged CEA-CABG, CABG-CEA, and concurrent or staged CAS-CABG, in addition to non-extracorporeal CABG, which is considered a safe and effective technique. However, the current guidelines on CABG, CEA, and CAS do not give the most optimal treatment strategy [7-10].
2.1, Carotid endarterectomy with coronary artery bypass grafting
CEA and CABG can be performed simultaneously or in two steps, with CEA followed by CABG, or vice versa. Compared to CABG alone, the risk of complications is significantly higher with simultaneous CEA-CABG [11]; however, current surgical guidelines still recommend staged or concurrent CEA to reduce the perioperative complication rate (IIa/C) in people with symptomatic carotid stenosis or asymptomatic carotid stenosis R80% who also require CABG [7]. However, it is important to note that the strategy of revascularization must be individualized [8].
In a recent Meta-analysis, the authors counted a total of 41,901 patients treated with carotid and coronary interventions in 53 publications (2000-2009), and concurrent and staged CEA-CABG was the most used treatment strategy, with a total of 40,681 cases, of which 34,555 cases were treated with concurrent CEA-CABG and 6126 cases. In this analysis, the mortality rates for concurrent or staged CEA-CABG were 5.1% and 6%, respectively, which were not statistically significant; however, the stroke rate was significantly higher in the former than in the latter (3.8% vs. 0.2%) [12]. Another study showed that when CEA and CABG were performed simultaneously, patients had the highest mortality rate of 4.6%, while if CEA and CABG were completed in stages, they could trigger a high incidence of myocardial infarction (6.5%), although the incidence of stroke and death was the lowest (6.1%) [13]. In contrast, GiulioIlluminatietal [14] concluded that in unilateral asymptomatic carotid stenosis combined with coronary stenosis, CEA performed before or simultaneously with CABG can be effective in preventing the occurrence of postoperative stroke. They randomly divided 185 patients with similar underlying characteristics and unilateral carotid stenosis >70% without cerebral ischemic symptoms into two groups: 94 patients in group A received concurrent or staged CEA-CABG, while group B was treated with reverse-staged surgery. one patient in group A died of postoperative heart failure, and no stroke occurred within 90 days after surgery. The incidence of stroke, myocardial infarction, and death at 30 days postoperatively was approximately 10.2-11.5% for either staged or concurrent surgery [13]. Therefore, simultaneous or staged CEA-CABG is a safe and effective treatment strategy, and the different complication rates can be attributed to the different criteria for patient selection.
Another strategy is the “reverse staging” approach, in which coronary artery bypass grafting is given first and then carotid endarterectomy is performed. This approach significantly reduces the incidence of perioperative myocardial infarction (0.9%), but inevitably increases the incidence of perioperative stroke (5.8%) [13]. Although some studies have shown that this regimen can also work well, most scholars do not support it because delayed CEA is positively associated with the incidence of postoperative stroke in patients [14]. In the randomized controlled study of GiulioIlluminatietal, 91 patients underwent reverse-staged CEA-CABG with an interval ranging from 1-3 months between the two procedures, although there was one postoperative death, however, a total of seven cases of ipsilateral ischemic stroke occurred 90 days after CABG, three of which occurred immediately after CABG, so we can assume that reverse-staged CEA- CABG is not a safe and effective strategy.
2.2. Carotid artery stenting with coronary artery bypass grafting
In recent years, carotid artery stenting (CAS) has also been widely used in the treatment of carotid artery combined with coronary stenosis because it is safe, effective and less invasive, especially in patients with high risk of surgery, such as diabetes, hypertension, unstable angina, peripheral vascular disease, smoking and advanced age, and even superior to staged or concurrent CEA-CABG [15]. Currently, the most used protocol is CAS first, followed by a period of “dual antiplatelet therapy” and then coronary artery intervention. However, the interval between CAS and CABG varies from one week to two months, and in Ziada,
K.M.etat. in a comparative study on staged CAS-CABG versus combined CEA-CABG, the mean interval between CAS and CABG was 39 days (±22 days) [16], while in VanderHeyden,J.etal. in an analysis of staged CAS-CABG, the mean interval was 22 days [17]; also, for The choice of “antiplatelet therapy” is also controversial, as in both studies, all patients received oral aspirin and clopidogrel before receiving CAS, on the other hand, Ziada,K.M. suggested that “dual anti” therapy should be continued for 2-3 weeks after CAS, only after CABG. On the other hand, Ziada,K.M. suggested that “dual anti” therapy should be continued for 2-3 weeks after CAS, with discontinuation of clopidogrel only before CABG, while VanderHeyden,J. discontinued all antiplatelet agents before CABG. Antiplatelet therapy plays an irreplaceable role in this regimen, as it not only increases the risk of perioperative bleeding, but likewise leads to severe myocardial infarction (3%) [12]. Although current antiplatelet treatment options are controversial, CAS-CABG remains a safe and effective, if not optimal, treatment for some patients.I. Velissaris [15] retrospectively analyzed a total of 70 patients with symptomatic carotid stenosis R60% and asymptomatic carotid stenosis R70% from 2003-2008, all of whom were suitable and received The results showed only one case of small contralateral infarct and no case of death or myocardial infarction 30 days after the procedure, which is a strong evidence that CAS-CABG can also be used for carotid stenosis combined with coronary artery stenosis.
The treatment of bilateral carotid artery stenosis combined with coronary artery disease is a complex problem that needs to be solved. CAS is first performed on one side of the carotid artery, and then CEA and CABG are performed on the opposite side at a later stage. According to ShichinoheHetal.[18], in two patients who underwent CEA and CAS for severe stenosis on both sides of the carotid artery, none of them developed perioperative complications. Therefore, the organic combination of CEA, CAS and CABG is a valuable optional option for complex carotid artery combined with coronary artery disease.
In order to reduce the adverse effects of CAS, two important factors deserve our attention: first, CAS is not applicable to all severe carotid stenoses. Second, the use of cerebral protection devices can effectively reduce the incidence of cerebrovascular infarction due to dislodged emboli. In addition, the impact of CAS surgery on the patient’s cardiac function should be fully considered, because stimulation of the carotid sinus occurs after release of the carotid stent and during post-dilatation, which may lead to persistent hypotension resulting in inadequate coronary blood supply and inducing thrombus formation in the coronary stent. Therefore, clinicians should fully consider the selection of CAS stent, the degree of post-dilatation, and the management of postoperative hypotension.
2.3 Combined application of carotid and coronary stenting
The possibility of simultaneous or staged percutaneous carotid and coronary intervention (CAS-PCI) has only been reported in a few publications, and the selection of patients is very cautious and strict. shawlFAetal.[20] first reported five patients who underwent combined carotid and coronary intervention in 1996, and concluded that in for patients who are critically ill and unfit for surgery, this option can be considered This option, however, needs to be further investigated. Other retrospective analyses have also shown that CAS-PCI is a safe and effective treatment measure when the patient’s condition is adequately evaluated [21-23]. Therefore, CAS-PCI should only be considered when the patient is contraindicated or at great risk for surgery, and its safety and long-term effectiveness require extensive in-depth studies.
2.4 Other influencing factors
Increasingly, experts are beginning to note that in addition to the presence of carotid stenosis, which increases the incidence of perioperative stroke, atherosclerotic embolism of the aortic arch is a very important separate influence, and that CEA, CAS, or CABG may themselves contribute to the development of ischemic stroke and coronary syndromes. In fact, no surgical strategy is perfect and cannot solve all problems, which requires more attention to some details. The consequences of dislodging atherosclerotic plaque emboli due to inexperience or insufficient technical ability of the surgeon are unthinkable; and atrial fibrillation, etc. caused by surgical operation should also be avoided by the clinical doctor. In addition, the establishment of extracorporeal circulation can cause hemodynamic changes, blood coagulation and disturbances in the self-regulation of the cardiovascular system, and the longer its duration, the higher the chance of postoperative complications [12,14,24]; therefore, if conditions allow, performing non-extracorporeal CABG is the best choice. In the case of simultaneous, non-extracorporeal CEA-CABG, the chances of stroke and death of the patient are only 0.4% and 2.3%, respectively [12]. At the same time, Ricotta, J.J. et al. pointed out that the patient’s own intrinsic factors are also crucial in influencing postoperative complications [25]. For example, the degree of carotid and coronary artery disease, the ejection fraction of the heart, the history of myocardial infarction, transient ischemic attack and stroke, the presence of chronic obstructive pulmonary disease, diabetes mellitus, hepatic and renal insufficiency, and even the patient’s age, gender and smoking status can have a different impact on the patient’s prognosis. Its comparison of 744 patients who received single CABG versus 744 CEA-CABG, respectively, while excluding differences in risk factors, noted that CEA did not additionally increase the risk of various postoperative complications in patients, with rates of stroke, myocardial infarction, and death of 5.0% vs 5.1%, 1.1% vs 0.54%, and 3.9% vs 4.4%, respectively.
III. Conclusion
In conclusion, no treatment strategy is perfect for carotid combined coronary artery stenosis.CAS-CABG seems to better reduce complication rates, improve patient prognosis, and could be an alternative to CEA-CABG. However, CAS-CABG is not yet widely available and no clear indications have been proposed, so there is not enough evidence to show that CAS is superior to CEA, not to mention that the level of expertise varies among study centers, the patient enrollment criteria are different, and they do not reach exactly the same conclusions. In this case, it is difficult to compare the different treatment options, let alone prescribe exact guidelines, so it is important to individualize the treatment of patients when dealing with this complex condition, taking into account all factors and choosing the most favorable treatment option for the patient. With the development of medicine and the emergence of new technologies, only a multicenter randomized controlled study with a larger sample size will make it possible to make persuasive guideline recommendations on the current treatment strategy and completely solve the problem of high perioperative complication rates that plague us.