Discussion
Cardiovascular operators have not yet reached a definitive consensus regarding the best treatment strategy in the presence of co-existing coronary artery and/or valve disease and extra-cranial carotid lesions amenable of operative repair.2 During the last decade there have not been systematic high-level evidence published, and two randomized clinical trials failed to establish which should be the recommended treatment strategy due to lack of adequate power and/or because of slow enrollment.3-16 Still a pending matter of debate, we believe that the choice to perform a single stage intervention may still be reasonable based on our institutional experience, especially in the presence of a homogeneous treatment protocol among the centers involved.10 The 3.9% postoperative mortality rate at 30-days observed in our cohort is acceptable considering the magnitude of intervention and the high-risk profile of the cohort: it is in line with the mean 5.1% in-hospital mortality reported in the larger cohort of the National Inpatient Sample analysis of isolated coronary artery bypass grafting, as well as not significantly inferior to the 3.8% reported for the staged treatment of the concomitant diseases.7,8,18-20
One modality for optimizing risk assessment is to use a predictive score but, currently, there are no mortality predictive scoring systems for single stage CVS and CEA.8,14,21,22 The predictors identified in our series are reliable since they have been associated with mortality in other experiences. When it comes to the carotid revascularization component of this complex clinical scenario, the risk of neurologic complications has been correlated to the clinical relevance of the carotid stenosis, namely a history of stroke.15,22,23 While there is no unquestionable evidence that the majority of patients undergoing coronary artery bypass grafting may benefit from CEA, high-grade extra-cranial carotid artery stenosis poses a higher risk of stroke than patients without carotid disease.1,2,23 The fact that stroke rate was lowest at 1.9% in the staged group of the vast cohort of the National Inpatient Sample may support this observation. Furthermore, most of the strokes have been mechanistically unrelated to pre-existing carotid artery occlusive disease.1,2,18 For the sake of comparability, the 1.3% rate found in our experience is favorable in comparison with the 2.8% reported in a recent meta-analysis by Ursoet al .24 in patients undergoing isolated coronary artery bypass grafting, and like the 2.5% in those undergoing isolated percutaneous coronary intervention with drug-eluting stents. Also, in our experience we did not observe a difference in occurrence of new strokes between patients who had symptomatic or asymptomatic carotid lesions. Taking into consideration that the recent clinical practice guidelines of the European Society for Vascular Surgery (ESVS) reported that CEA should be considered in patients with a history of stroke, and considering the favorable data in our cohort, we consider single stage CVS and CEA safe and effective in selected high-risk patients.10
Considering that outcomes in patients undergoing carotid artery stenting (CAS) markedly improved in recent years, CAS has been proposed as an alternative strategy for carotid lesions, as transcatheter aortic valve implantation for valve disease. In the cohort of the National Inpatient Sample, the staged approach with CAS preceding coronary-artery bypass grafting showed the lowest risk of mortality. However, CAS was associated with highest risk of stroke, and a higher risk of stroke and higher interstage risk of myocardial infarction for a total number of staged CAS-first strategy that was twenty times fewer than single stage coronary-artery bypass grafting and CEA.4 Thus, in these patients with concomitant diseases there is minimal reasonable evidence to widely support a CAS-first strategy.7,9,11