Stepwise Provisional versus Planned Double Stenting Strategies in Treating Unprotected Left Main Distal Bifurcation Lesions: A Systematic Review and Meta-Analysis Comprising 11,672 Patients

Background: Provisional stenting is the preferred strategy for non-left main bifurcation lesions. However, its superiority over planned double stenting for unprotected left main distal bifurcation (UPLMB) lesions remains unclear. Previous studies have reported conflicting results. Methods: Randomised controlled trials (RCTs) and observational studies comparing the outcomes of provisional stenting to planned double stenting for UPLMB lesions were identified. The primary endpoint was major adverse cardiac events (MACE). The secondary endpoints were myocardial infarction (MI), target vessel revascularisation (TVR), target lesion revascularisation (TLR), all -cause death, cardiac death and stent thrombosis (ST). Aggregated odds ratios (OR) and 95% confidence intervals were calculated. A sensitivity analysis was conducted if I2 was >50% or p < 0.01. Publication bias analysis was considered if more than 10 studies were enrolled. Results: Two RCTs and 19 observational studies comprising 11,672 patients were enrolled. Provisional stenting had a significantly lower incidence of MACE, mainly driven by TLR and TVR. Double stenting had a significantly lower incidence of cardiac death. In addition, patients undergoing provisional stenting had a lower tendency towards the occurrence of MI, while patients undergoing double stenting had a lower tendency towards all-cause death and ST. Conclusions: A provisional stenting strategy was associated with lower MACE, TVR and TLR but higher cardiac death. Further investigation is needed through RCTs to assess which strategy performs better.