Long-term Clinical Outcomes Following Drug-eluting Stent Implantation for Unprotected Distal Trifurcation Left Main Disease: the Milan-New Tokyo (MITO) Registry

Background: Unprotected distal left main trifurcation (ULMT) lesion represents a challenge for interventional cardiologists with the potential for peri-procedural complications and adverse events at follow-up especially when the main branch and the side branches are concomitantly diseased.

Methods: A retrospective cohort analysis was performed on consecutive patients with ULMT stenosis who electively underwent percutaneous coronary intervention (PCI) with drug-eluting stent (DES) implantation in order to assess the technical feasibility and long-term outcomes according to the disease distribution in the trifurcation branches (true vs. non-true ULMT). Primary endpoint of the study was a composite of major adverse cardiovascular events (MACE) defined as cardiac-death, myocardial infarction (MI), and target lesion revascularization (TLR) during follow-up.

Results: Eighty-four patients underwent PCI with DES for ULMT disease during the study period (40 true trifurcation and 44 non-true trifurcation). Angiographic and procedural success were obtained in 94% and 92.8% of cases. At 3-years follow-up, the occurrence of MACE was significantly higher in patients with true ULMT than in those with non-true ULMT (HR 2.801 [confidence interval; CI 1.164-7.896], P = 0.025) due to a higher TLR rate (HR 3.032 [CI 1.164-7.896], P = 0.023). No episodes of late and very late definite/probable stent thrombosis (ST) occurred. On multivariable analysis, a true-ULMT lesion was the only independent predictor of MACE (HR 2.344 [C.I. 1.006-5.461], P = 0.049).

Conclusions: PCI with DES for ULMT stenosis is feasible with a high procedural success rate and no definite/probable ST reported at follow-up. A true trifurcation lesion is associated with enhanced risk of MACE mainly driven by TLR.