Predictive Factors and Clinical Outcomes of Stent Malapposition in Calcified Lesions After PCI: A Retrospective Observational Study Based on OCT Assessment

Background: Stent malapposition (SM) remains a significant challenge in percutaneous coronary intervention (PCI), particularly in cases involving calcified coronary lesions. However, the predictors of SM and their relationship with clinical outcomes remains unclear. This study aims to identify the predictors of SM through optical coherence tomography (OCT) and assess its impact on clinical outcomes. Methods: In this single-center, retrospective observational study, we analyzed 384 patients who underwent PCI with OCT imaging for calcified coronary lesions between January 2019 and December 2023. Patients were divided into two groups based on post-PCI OCT findings: the SM group (n = 142) and non-SM group (n = 242). We compared calcium characteristics, procedural parameters, and clinical outcomes between the two groups. Results: The SM group exhibited more severe calcium characteristics, including a larger calcium arc (295.8° ± 58.4° vs 248.6° ± 62.3°, p < 0.001), greater thickness (1.12 ± 0.31 mm vs 0.89 ± 0.28 mm, p < 0.001), and longer length (18.6 ± 7.2 mm vs 12.8 ± 6.4 mm, p < 0.001). Multivariate analysis identified calcium arc >270° (odds ratio (OR) 2.84, 95% CI 1.86–4.32, p < 0.001), calcium thickness >1.0 mm (OR 2.16, 95% CI 1.42–3.28, p = 0.001), and diabetes mellitus (OR 1.68, 95% CI 1.12–2.52, p = 0.012) as independent predictors of SM. Over a median follow-up of 18.6 months, the SM group had higher rates of major adverse cardiovascular events (15.5% vs 8.7%, p = 0.04), primarily driven by increased target lesion revascularization (8.5% vs 4.1%, p = 0.03). Conclusions: Specific calcium characteristics and diabetes mellitus are strong predictors of stent malapposition in calcified coronary lesions. The presence of stent malapposition is associated with worse clinical outcomes, highlighting the importance of optimal lesion preparation and stent deployment strategies in high-risk lesions.