Provisional stenting with side branch rescue stenting is associated with increased 3-year target lesion failure in patients with acute coronary syndrome and coronary bifurcation lesions.

Background: Provisional stenting (PS) is the main treatment for a majority of coronary bifurcation lesion and includes PS with 1-stent and PS with 2-stent. However, the treatment difference between PS with 1-stent and with 2-stent remains unclear in patients with the acute coronary syndrome (ACS) and coronary bifurcation lesions. Materials and methods: Overall, 820 ACS patients with Medina 1,1,1 or 0,1,1 coronary bifurcation lesion who had completed 3-year follow-up were included and assigned to the PS with 1-stent (n = 519) or the PS with 2-stent (n = 301) according to the use of final stenting technique. The primary endpoint was the target lesion failure (TLF) at 3 years since stenting procedures. Results: At 3-year follow-up, TLF occurred in 85 (16.4%) patients in the PS with 1-stent group and 69 (22.9%) in the PS with 2-stent group (hazard ratio [HR] 1.52, 95% confidence interval [CI] 1.06-2.17, p = 0.021), mainly driven by a higher rate of target lesion revascularization (TLR) in the PS with 2-stent group (13.0% vs. 8.3%, HR 1.65, 95% CI 1.04-2.61, p = 0.033). Complex bifurcations, side branch (SB) pretreatment, intravascular imaging guidance, and hyperlipidemia were the four predictors for 3-year TLF. SB pretreatment was associated with increased 3-year TLR, leading to an extremely higher 3-year TLF. Conclusion: Provisional with 2-stent for patients with ACS is associated with a higher rate of 3-year TLF, mainly due to increased requirement of revascularization. SB pretreatment should be avoided for simple bifurcation lesion.