Safety and efficacy concerns regarding elective coronary artery surgery in patients with prior coronary stents.

Safety and efficacy concerns regarding elective coronary artery surgery in patients with prior coronary stents Recent data have raised concerns about the safety of drug-eluting stents. 1 Stents are used in over 70% of percutaneous coronary interventions (PCIs) because they reduce the risk of acute major complications of PCI and long-term restenosis. Despite the low procedural morbidity afforded by stent-ing, coronary artery bypass graft (CABG) surgery offers significantly greater freedom from angina, repeat revascularization, myo-cardial infarction, stroke, and death in the treatment of multivessel ischaemic heart disease. 2 Stenting has, however, become first line treatment in increasing numbers of patients that are surgical candidates. Many of these patients eventually require coronary artery surgery: in the UK over 5% of patients undergoing CABG have a history of previous PCI. 3 Surgeons suspect that prior stenting may have a negative impact on outcome after elective coronary surgery for several reasons. In-stent restenosis is associated with a higher risk of early venous graft failure. 4 The presence of coronary stents means that grafts are anastomozed more dis-tally, and endarterectomy may be required. Anti-platelet medication adds to increased morbidity and potential mortality, resulting from excess post-operative bleeding, and stopping this medication has been associated with stent thrombosis in off-pump CABG patients. Pathophysiological processes associated with stenting may adversely affect surgical outcomes. 5 Stenting causes prolonged endo-thelial dysfunction and local and systemic inflammatory syndromes, more profound than after balloon angioplasty, because of persistent radial mechanical strain, vessel wall rupture, and the presence of an intra-vascular foreign body. The local inflamma-tory response is stimulated by disruption of the coronary endothelium, and is characterized by a florid macrophage response that does not occur after balloon angioplasty. Six months after PCI endothelium-dependent vasomotor function has been shown to be more abnormal in stented coronaries compared with those undergoing balloon angio-plasty. Two years after stenting a chronic inflammatory response surrounds the stent, characterized by non-occlusive mural thrombi. Drug-eluting stents induce this inflammatory response, most prominently at the edges of the stent, but also where endothelialization is delayed leaving the intima exposed to metal within the stent. Troponin release is higher in patients receiving stents compared with those undergoing angioplasty alone, and is associated with increased peri-procedural mortality, rates of myocardial infarction, and repeat revascularization. UK data suggest that patients with previous PCI had higher mortality after CABG than patients without prior PCI, even when patients undergoing salvage CABG for …