Drug-eluting stent or coronary artery bypass graft surgery in hemodialysis patients?

Abstract

The article by Baek and coworkers [1] published in this issue of the Journal of Nephrology provides valuable clinical information regarding the clinical outcome of surgical and endovascular myocardial revascularization procedures in patients with chronic kidney disease (CKD) in chronic hemodialysis. Both coronary artery bypass grafts (CABG) and percutaneous coronary interventions (PCI) were performed under elective conditions and using standard techniques as available in a time period between 1999 and 2006; this included an internal thoracic artery in surgical candidates, off-pump surgery in a minority of cases (17 %) and implantation of drug-eluting stents (DES) in patients treated with PCI. The study analyzed a population of 110 patients, 66 treated with CABG with at least one internal thoracic artery in 97 % of cases, and 44 treated with PCI and implantation of either rapamycin or paclitaxel DES in approximately 80 and 20 % of patients, respectively. Allocation of patients to CABG or PCI was a decision taken by the interventional cardiologist. Given some obvious baseline differences between the two groups, a propensitive score analysis was performed to normalize for some of such differences. Indeed, CABG patients had significantly more severe coronary artery disease, as well as some other worse comorbidities, although these did not reach statistical significance. At a mean follow-up period of 53.8 months the survival rate free of major adverse cardiac and cerebral events was better in the CABG group (HR 3.334, 95 % CI 1.482–7.498, p = 0.004); however, the overall survival did not diverge significantly even after propensitive score adjustment (HR 1.638, 95 %CI 0.555–4.839, p = 0.372). The authors therefore conclude that CABG represents a better treatment strategy compared to PCI with DES for patients in chronic hemodialysis. Publication of long-term clinical outcome of myocardial revascularization procedures in patients with advanced CKD is most welcomed since evidence of safety and efficacy in this population are scarce and often contradictory. Indeed, patients with advanced CKD are always excluded form trials testing myocardial revascularization options [2], likely because of the strong correlation that exists between heart and kidneys in determining patients survival, independently of the revascularization treatment [3]. Despite this major limitation of the available evidence, the Guidelines for Myocardial Revascularization of the European Society of Cardiology (ESC) issued in 2010 provided clear recommendations for the revascularization treatment of patients with CKD [4]. Basically, CABG was recommended as a preferred strategy compared to PCI in patients with multivessel coronary disease, moderate renal dysfunction and good general conditions with reasonable life expectancy, since the operative risk is low, and the long-term benefits of surgery appear evident with a longer follow-up [5]. On the contrary, patients with severe or end-stage CKD may derive less benefit from surgery given its most invasive nature. Indeed, a higher peri-procedural mortality and morbidity reduces the net clinical benefit and advantages of surgery at the long-term, and in the end, such a fragile population may benefit most from the less invasive PCI attempt, despite a higher recurrence of ischemic events requiring more re-interventions at the long-term [4]. F. Ribichini C. Vassanelli Department of Medicine, University of Verona, Verona, Italy