Validation of bifurcation DEFINITION criteria and comparison of stenting strategies in true left main bifurcation lesions.

There are controversies on optimal stenting strategy regarding true left main (LM) bifurcation lesions. The present study compared 1- and 2-stenting strategy for patients with true LM bifurcation lesions as differentiated by DEFINITION criteria. 928 patients with true LM bifurcation lesions (Medina 1,1,1 or 0,1,1) treated with DES were enrolled consecutively. 297 (32.0%) patients were identified as complex LM bifurcation, and 631 (68.0%) patients into simple LM bifurcation group according to DEFINTION criteria. Patients in complex vs. simple LM bifurcation group had significantly higher major adverse cardiac event (MACE, including cardiac death, myocardial infarction [MI] and ischemia-driven target vessel revascularization) rate at 30 days (7.8% vs. 4.0%, p = 0.01), 1 year (10.3% vs. 6.4%, p = 0.04), and numerically at 3 years (14.2% vs. 10.1%, p = 0.07), which was mainly driven by increased MI. Moreover, patients in the 2-stent strategy group had strong trend towards lower incidence of cardiac death in both complex LM bifurcation group (2.0% vs. 5.9%, p = 0.08) and simple LM bifurcation group (1.9% vs. 4.5%, p = 0.07). In conclusion, the complex bifurcation lesion criteria established in DEFINITION study was able to risk-stratify LM bifurcation patients. Two-stent technique yielded numerically lower 3-year cardiac mortality regardless of LM bifurcation complexity.