Clinical and procedural predictors of suboptimal outcome after the treatment of drug-eluting stent restenosis in the unprotected distal left main stem: The Milan and New-Tokyo (MITO) registry

Background: Few data are available regarding the optimal revascularization strategy for unprotected distal left main coronary artery (UDLM) in-stent restenosis (ISR). Methods and Results: Between April 2002 and December 2008, UDLM-ISR following drug-eluting stent (DES) implantation occurred in 92 of 474 patients (19.4%). Of these, 8 (8.7%) who underwent a coronary artery bypass graft (CABG) were excluded, and the remaining 84 (91.3%) who underwent percutaneous coronary intervention (PCI) (43 plain old balloon angioplasty [POBA] and 41 DES) were analyzed to assess the feasibility of PCI for UDLM-ISR. The overall cardiac death, myocardial infarction (MI), and major adverse cardiac events during the follow-up period (median, 24 months) occurred in 4, 2, and 31 patients, respectively. Repeat target lesion revascularization (TLR) occurred in 28 patients. The incidence of repeat TLR was higher following PCI with POBA than with DES (hazard ratio [HR], 2.79; 95% CI, 1.23-6.34; P=0.014). On Cox regression analysis, the independent predictors of repeat TLR were treatment with POBA (HR, 3.29; 95% CI, 1.41-7.69; P=0.006) and EuroSCORE (European System for Cardiac Operative Risk Evaluation) >6 (HR, 2.53; 95% CI, 1.02-6.28; P=0.045). More complex lesions requiring a 2-stent strategy were associated with a higher occurrence of TLR for restenosis of the left circumflex coronary artery ostium (LCX-ISR) (HR, 2.51; 95% CI, 1.59-3.97; P=0.001) as well as repeat TLR for recurrent LCX-ISR (HR, 4.32; 95% CI, 0.97-19.20; P=0.05) compared to a 1-stent strategy. No cardiac death at 2 years occurred in patients with LCX-ISR. Conclusions: UDLM restenosis is better treated with DES than with POBA. The rate of recurrent ISR following repeat PCI was high, whereas the rates of MI and death were relatively low. Complex lesions requiring a 2-stent strategy had a higher recurrence rate at the ostial LCX but without an associated increased risk of MI and death.