Impact of Side Branch Occlusion on Patient Outcomes After Bifurcation Percutaneous Coronary Intervention

The outcomes and characteristics of patients with side branch occlusion (SBO) after bifurcation percutaneous coronary intervention (PCI) have received limited study.

We compared the procedural characteristics and outcomes of patients with and without SBO among 933 provisional bifurcation PCIs performed in 803 patients at six centers between 2014 and 2024.

The prevalence of SBO was 13% (n = 121). SBO patients had lower rates of hypertension, prior coronary artery bypass graft surgery (CABG), and prior PCI but higher angiographic complexity, with higher prevalence of left anterior descending artery stenoses, smaller side branch diameter and more severe side branch diameter stenoses. SBO patients were more likely to convert from provisional to two-stent strategies (24.8% vs 6.0%, p < 0.001), and to require plaque modification (39.7% vs 17.5%, p < 0.001) and side branch percutaneous transluminal coronary angioplasty (PTCA) (25.6% vs 12.9%, p < 0.001). SBO patients had lower technical (78.5% vs 96.2%, p < 0.001) and procedural (73.5% vs 92.2%, p < 0.001) success and similar in-hospital major adverse cardiovascular events (MACE), but higher dissection rates (7.1% vs 2.0%, p = 0.007). Patients with untreated SBO had similar in-hospital MACE with untreated SBO patients. During a median follow-up of 1,095 days patients with treated SBO (83.9%, n = 94) had lower follow-up MACE (hazard ratio [HR]: 0.29, 95% confidence intervals [CI]: 0.10, 0.84, p = 0.023) and mortality (HR: 0.22, CI: 0.065, 0.755, p = 0.016) compared with patients with untreated SBO.

SBO occurs in 13% of provisional PCIs. SBO patients had more complex coronary lesions and worse follow-up clinical outcomes if the SBO was left untreated.