Secrets of Success in Unprotected Left Main Intervention: Patient and Lesion Selection
- Volume 19 - Issue 9 - September, 2007
- Posted on: 8/1/08
- 0 Comments
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Despite advances in percutaneous coronary intervention techniques over the last two decades, the unprotected left main has largely remained the domain of cardiovascular surgery. The subset of patients with left main disease in the Collaborative Study in Coronary Artery Surgery (CASS) study demonstrated superior outcomes with bypass surgery as compared with medical therapy.1 While percutaneous intervention of the unprotected left main artery has been reported as early as in the late 1980s, initial results with balloon angioplasty of the left main were poor, with 1-year mortality approaching 30%.2 Coronary stenting clearly improved both acute results and restenosis rates as compared to balloon angioplasty, however, repeat revascularization rates remained high at 25–30%.3–8 With the advent of drug-eluting stents (DES), clinical restenosis rates have significantly dropped for most lesion types,9–13 but similar restenosis rates and clinical outcomes have not been consistently noted with unprotected left main stenting.14–25
In this issue of the Journal, Vecchio et al have described the safety, feasibility and mid-term outcomes of patients undergoing DES implantation for unprotected left main coronary artery (LMCA) stenosis.26 The study enrolled 114 consecutive patients with de novo unprotected LMCA stenosis, and after successful PCI with DES in all enrolled patients (35% sirolimus and 65% paclitaxel stents), followed them over a mean period of 17.1 ± 9.1 months. The primary endpoint of the study was the occurrence of major adverse cardiovascular events (MACE). The inclusion criteria were symptomatic LMCA disease or documented myocardial ischemia and angiographic documentation of ≥ 50% stenosis. It should be noted, however, that patients were preselected based on “suitable” anatomy for stenting, patient’s and physician’s preference for PCI and contraindications to surgery. The mean age was 75 years. Seventy-four percent of the enrolled patients were males and 29% had diabetes. Only 30% of the cases were elective for stable angina, whereas the remainder was urgent or emergent. The majority of patients in this study with non-ostial left main disease had distal/bifurcation disease as compared to mid-portion left main stenosis (61% vs. 9%).
Debulking coronary procedures were used in only 1.8% of the patients and intravascular ultrasound (IVUS) guidance in 7.9%. Intra-aortic balloon pump support was needed in 28% of patients. The mean stent diameter was 3.1 ± 0.3 mm, with an average of 1.2 ± 0.4 stents per lesion. Direct stenting was performed in 11.4% and postdilatation performed in 55.3% of patients. A variety of strategies were used in bifurcation lesions, with provisional T-stenting being the most common (63%). Final kissing-balloon inflations in distal lesions were performed in 94% of those patients. All patients received heparin to achieve an activated clotting time (ACT) > 250 seconds, however glycoprotein IIb/IIIa inhibitors were used in 40% of patients and their use was left to the physician’s discretion. All patients received aspirin 100 mg/day indefinitely, a loading dose of clopidogrel, followed by 75 mg/day for at least 9 months.