Fork in the road: Are all bifurcations created equal?

The TRYTON study evaluated routine side branch (SB) stenting with a novel bare metal stent (BMS) designed for true bifurcation lesions (Medina 1,1,1; 1,0,1; 0,1,1) and compared it to a strategy of balloon angioplasty with provisional stenting. It failed to meet the primary endpoint of non-inferiority in target vessel failure mainly driven by peri-procedural myocardial infarction (MI) with elevated CK-MB 3× the upper limit of normal. In this substudy, 41% of patients who had a SB diameter 2.25 mm were evaluated and the new stent was found to be non-inferior in the primary outcome of target vessel failure with no difference in post-procedural MI. This substudy suggests that appropriately sized SB stents with TRYTON may be useful when the SB is2.25 mm in diameter. However, further studies could evaluate routine use of FFR for SBs; drug eluting versions of the stent as well as stents designed for vessels 2.25 mm in diameter which are frequently felt to be clinically larger when not subjected to core lab analysis.