Introduction: Stent thrombosis (ST) is a rare but serious complication associated with high morbidity and mortality. Its pathophysiology is complex and influenced by the timing of occurrence, treatment adherence, and underlying clinical factors.
Methods: This prospective, single-centre observational study included patients with a confirmed diagnosis of ST between 2013 and 2022. We analysed clinical characteristics, in-hospital mortality, and adverse events during follow-up. A composite endpoint was used, including cardiovascular death, recurrent myocardial infarction, recurrent ST, or new revascularisation.
Results: A total of 142 patients were included, with a mean age of 65.8 years and predominance of males (84.8%). Early ST (<30 days post-implantation) occurred in 38% and late ST (>30 days) in 62%. Dyslipidaemia was the most common cardiovascular risk factor (65.7%), significantly higher in late ST (75.7% vs. 48.7%, p=0.009). The initial clinical presentation was mainly ST- segment elevation myocardial infarction in 81.9%, with most patients classified as Killip-Kimball class I (73%).
Issues with antiplatelet therapy prior to ST were observed in 16 patients (6 without an identifiable mechanical cause and 10 with one). A prothrombotic state was identified in 8 patients, including stage IV malignancy, thrombotic thrombocytopenic purpura, and cardiogenic shock. Discontinuation of antiplatelet therapy and a history of malignancy were strong predictors of ST, with odds ratios of 26.8 (95% CI: 8.4–85.4) and 17.5 (95% CI: 4.7–65.3), respectively.
In-hospital mortality was 9.2%, with no significant differences based on ST type. Independent predictors of mortality included Killip-Kimball class IV at admission (OR 9.5; 95% CI: 2.3–41.1; p=0.002) and renal failure (OR 14.8; 95% CI: 3.38–79.6; p=0.001).
During a mean follow-up of 5.9 ± 2.8 years, 18.9% of patients experienced the composite adverse outcome. Renal failure (HR 6.9; 95% CI: 1.4–26.1; p=0.016) and reduced ejection fraction (HR 0.91; 95% CI: 0.82–0.99; p=0.02) were significant predictors of adverse events.
Conclusion: Patients with ST exhibit distinct clinical profiles based on timing of presentation and generally have a poor prognosis. Renal failure, Killip-Kimball class IV, and reduced ejection fraction were key predictors of in-hospital mortality and long-term adverse outcomes. Importantly, interruption or non-adherence to antiplatelet therapy significantly increases the risk of ST, underscoring the critical role of maintaining appropriate antiplatelet treatment to improve patient outcomes.