Background: Cardiac surgery is the standard treatment for unprotected left main disease (ULM). Drug-eluting stent (DES) implantation has been recently reported in patients with ULM but with unclear results. We systematically reviewed outcomes of percutaneous DES implantation in ULM.
Methods: Several databases were searched for clinical studies reporting on > or = 20 patients and > or = 6-month follow-up. The primary end point was major adverse cardiovascular events (MACEs; ie, death, myocardial infarction, or target vessel revascularization [TVR]) at the longest follow-up. Incidence and adjusted risk estimates were pooled with generic inverse variance random-effect methods (95% CIs).
Results: From 823 initial citations, 16 studies were included (1278 patients, median follow-up 10 months). Eight were uncontrolled registries, 5 nonrandomized comparisons between DES and bare-metal stents and 3 nonrandomized comparisons between DES and CABG, with no properly randomized trial. Meta-analysis for DES-based PCI showed, at the longest follow-up, rates of 16.5% (11.7%-21.3%) MACE, 5.5% (3.4%-7.7%) death, and 6.5% (3.7%-9.2%) TVR. Comparison of DES versus bare-metal stent disclosed adjusted odds ratios for MACE of 0.34 (0.16-0.71), and DES versus CABG showed adjusted odds ratios for MACE plus stroke of 0.46 (0.24-0.90). Meta-regression showed that disease location predicted MACE (P = .001) and TVR (P = .020), whereas high-risk features predicted death (P = .027).
Conclusions: Clinical studies report apparently favorable early and midterm results in selected patients with ULM. However, given their limitations in validity and the inherent risk for DES thrombosis, results from randomized trials are still needed to definitely establish the role of DES implantation instead of the reference treatment, surgery.