1997;96: 3867 72. 34. Biondi-Zoccai GG, Lotrionte M, Moretti C, et al. A collaborative sys- tematic review and meta-analysis on 1278 patients undergoing percuta- neous drug-eluting stenting for unprotected left main coronary artery disease. Am Heart J. 2008;155:274 83. 35. Boudriot E, Thiele H, Walther T, et al. Randomized comparison of percutaneous coronary intervention with sirolimus-eluting stents versus coronary artery bypass grafting in unprotected left main stem stenosis. J Am Coll Cardiol. 2011;57:538 45. 36. Brener SJ, Galla JM, Bryant RI, et al. Comparison of percutaneous versus surgical revascularization of severe unprotected left main coronary stenosis in matched patients. Am J Cardiol. 2008;101:169 72. 37. Chieffo A, Magni V, Latib A, et al. 5-year outcomes following percu- taneous coronary intervention with drug-eluting stent implantation versus coronary artery bypass graft for unprotected left main coronary artery lesions: the Milan experience. J Am Coll Cardiol Intv. 2010;3: 595 601. 38. Chieffo A, Morici N, Maisano F, et al. Percutaneous treatment with drug-eluting stent implantation versus bypass surgery for unprotected left main stenosis: a single-center experience. Circulation. 2006;113: 2542 7. 39. Lee MS, Kapoor N, Jamal F, et al. Comparison of coronary artery bypass surgery with percutaneous coronary intervention with drug- eluting stents for unprotected left main coronary artery disease. J Am Coll Cardiol. 2006;47:864 70. 40. Makikallio TH, Niemela M, Kervinen K, et al. Coronary angioplasty in drug eluting stent era for the treatment of unprotected left main stenosis compared to coronary artery bypass grafting. Ann Med. 2008;40: 437 43. Levine et al 2011 ACCF/AHA/SCAI PCI Guideline e621 41. Naik H, White AJ, Chakravarty T, et al. A meta-analysis of 3,773 patients treated with percutaneous coronary intervention or surgery for unprotected left main coronary artery stenosis. J Am Coll Cardiol Intv. 2009;2:739 47. 42. Palmerini T, Marzocchi A, Marrozzini C, et al. 