Evidence-based treatment of unprotected left main disease: a critical review of the literature.

Bypass surgery is currently the standard therapy for unprotected left main (UPLM) disease because it has been shown in randomized, long-term follow-up trials to reduce mortality compared with medical treatment. Early data in treating UPLM disease with bare metal stents has shown a high rate of restenosis and major adverse events. With the advent of drug-eluting stents (DES), stenting for treatment of UPLM disease has recently gained more acceptance among interventional cardiologists. DES have been shown to be superior to bare metal stents in reducing restenosis after treatment of UPLM disease. Also, observational and small randomized studies have shown promising short-term outcomes with the use of DES compared with bypass surgery. Furthermore, ostial left main (LM) stenting with DES appears to have superior outcome when compared with stenting of the distal LM at the bifurcation. These studies, however, are small, with significant selection biases and with limited follow-up. Large randomized trials are currently being performed to compare LM stenting with DES versus bypass surgery. UPLM stenting at this time needs to be reserved for high-risk surgical patients until more conclusive data about its safety and effectiveness become available from large randomized trials.