Clinical and Procedural Characteristics and In-Hospital Outcomes of Stent Thrombosis Following Primary Percutaneous Coronary Intervention (PCI)

Introduction Early stent thrombosis (ST) (≤30 days) following primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI) remains a rare but serious complication. Despite advances in stent technology and antithrombotic therapy, this condition continues to be associated with high morbidity and mortality, particularly in resource-limited settings where local data are scarce. Purpose The purpose of this study is to evaluate the clinical characteristics, procedural factors, and in-hospital outcomes of patients with early stent thrombosis and to compare these findings with matched controls without stent thrombosis in a tertiary care cardiac center in Peshawar, Pakistan. Materials and methods This retrospective observational study included adult patients undergoing primary PCI who developed acute stent thrombosis (AST) (≤24 hours) or subacute stent thrombosis (24 hours to 30 days) during the same hospitalization. Data were collected from medical records, catheterization laboratory reports, and electronic hospital systems using a structured questionnaire. SPSS version 27.0 (IBM Corp., Armonk, NY) was used for statistical analysis, with comparisons made between cases and matched controls. Results A total of 80 patients with early stent thrombosis and 160 matched controls were analyzed. The majority were men (62/80, 77.5%). Common baseline cardiovascular risk factors included diabetes mellitus (28/80, 35%), hypertension (42/80, 52.5%), dyslipidemia (34/80, 42.5%), smoking (26/80, 32.5%), and prior coronary artery disease (12/80, 15%). Acute stent thrombosis occurred predominantly within 24 hours post-PCI (16/80, 20%). Procedural characteristics, including stent type, vascular access, and adjunctive therapies, were largely similar between sexes. Repeat PCI was the primary management strategy (62/80, 77.5%), and while most patients survived to discharge, a subset experienced serious in-hospital complications: heart failure (18/80, 22.5%), recurrent ischemia (10/80, 12.5%), arrhythmias (12/80, 15%), acute kidney injury (8/80, 10%), or bleeding events (6/80, 7.5%). Procedural factors associated with early stent thrombosis included high thrombus burden, suboptimal stent expansion, overlapping stents, and reduced post-procedural thrombolysis in myocardial infarction (TIMI) flow. Conclusion Early stent thrombosis after primary PCI remains an uncommon but potentially life-threatening complication with substantial in-hospital morbidity. Timely recognition and prompt intervention, primarily through repeat PCI, are essential to improve outcomes. These findings highlight the need for larger, multicenter studies to identify modifiable patient- and procedure-related risk factors, particularly in local populations, to enhance prevention and management strategies for early stent thrombosis.