Effect of Side Branch Predilation in Coronary Bifurcation Stenting With the Provisional Approach - Results From the COBIS (Coronary Bifurcation Stenting) II Registry.

Background: Whether side branch (SB) predilation before main vessel (MV) stenting is beneficial is uncertain, so we investigated the effects of SB predilation on procedural and long-term outcomes in coronary bifurcation lesions treated using the provisional approach.

Methods and results: A total of 1,083 patients with true bifurcation lesions undergoing percutaneous coronary intervention were evaluated. The primary outcome was a major adverse cardiovascular event (MACE): cardiac death, myocardial infarction, or target lesion revascularization. SB predilation was performed in 437 (40.4%) patients. Abrupt (10.5% vs. 11.3%; P=0.76) or final SB occlusion (2.7% vs. 3.9%; P=0.41) showed no differences between the predilation and non-predilation groups. The rates of angiographic success (69.1% vs. 52.9%, P<0.001) and SB stent implantation (69.1% vs. 52.9%, P<0.001) were significantly higher in the predilation group. During a median follow-up of 36 months, we found no significant difference between the groups in the rate of MACE (9.4% vs. 11.5%; P=0.67) in a propensity score-matched population. In subgroup analysis, patients with minimal luminal diameter of the parent vessel ≤1 mm benefited from SB predilation in terms of preventing abrupt SB occlusion (P for interaction=0.04).

Conclusions: For the treatment of true bifurcation lesions, SB predilation improved acute angiographic and procedural outcomes, but could not improve long-term clinical outcomes. It may benefit patients with severe stenosis in the parent vessel.