Ostial stent coverage in LMCA PCI: impact on long-term outcomes

Abstract Background Percutaneous coronary intervention (PCI) has emerged as the preferred strategy for treating selected cases of left main coronary artery (LMCA) stenosis. Although considerable attention in LMCA PCI has focused on bifurcation management, the clinical significance of ostial stent coverage has remained underexplored, despite its potential impact on outcomes. Purpose This study evaluated the impact of ostial LMCA stent coverage on long-term outcomes and identified additional predictive factors. Methods A total of 175 consecutive patients with unprotected LMCA disease who underwent de novo single-stent deployment at our institution between 2012 and 2024 were retrospectively analysed, including only those discharged alive. The LMCA ostium was defined on intravascular ultrasound (IVUS) as the area where the tunica media of the proximal LMCA was disrupted. Patients were categorised into uncovered and covered groups based on the presence of stent struts at the ostium. Ostial LMCA stent coverage, stent selection, and kissing balloon technique use were at the operator's discretion. Composite major adverse cardiovascular events (MACE), defined as all-cause mortality, myocardial infarction, and clinically driven target lesion revascularisation (TLR), were assessed over three years. IVUS-derived parameters included uncovered ostial lumen area, residual plaque burden, uncovered length, stent protrusion length, and proximal stent cross-sectional area. Results Of the 175 patients, 98 comprised the uncovered group (Group 1) and 77 the covered group (Group 2). During follow-up, composite MACE did not differ significantly between groups, whilst TLR was lower in Group 2 without reaching statistical significance. TLR occurred in 15 cases: seven around the LMCA ostium and eight at the bifurcation. All TLR around the LMCA ostium occurred in Group 1 (log-rank P = 0.03), whilst bifurcation TLR occurred in five cases in Group 1 and three in Group 2 (P = 0.82). In Group 1, residual plaque burden ≥44% at the proximal LMCA was the strongest predictor of TLR. No other IVUS-derived metrics significantly predicted MACE or its components. When stratified by stent type, everolimus-eluting stent (EES) deployment was significantly associated with lower composite MACE and TLR compared to other stents (log-rank P = 0.002 and P = 0.005, respectively), whilst newer drug-eluting stents did not impact MACE or TLR when compared to earlier-generation stents. In multivariable Cox analysis of procedure-related factors, EES deployment demonstrated the strongest association with reduced composite MACE and TLR. No cases of stent fracture were observed. Conclusions EES deployment was significantly associated with a lower incidence of composite MACE and TLR following de novo single-stent PCI to unprotected LMCA over three years. Furthermore, ostial LMCA stent coverage demonstrated potential benefits in reducing TLR, suggesting a role in long-term outcomes.LMCA ostium definition Characteristics and outcomes