Subacute stent thrombosis following coronary angioplasty: incidence and risk factors

BACKGROUND: Subacute stent thrombosis was a significant complication in the early years of coronary stenting, often leading to myocardial infarction, need for urgent surgery or even death. The introduction of intracoronary ultrasound enabled the identification and proper treatment of the main causes of stent thrombosis, reducing the rate of this complication to 1%. AIM: To identify risk factors of subacute stent thrombosis. METHODS: Data concerning 845 procedures with a single stent implantation in patients with stable or unstable angina, undergoing this procedure between 1998 and 2000, were analysed. RESULTS: Subacute stent thrombosis occurred in 13 (1.54%) patients. Risk factors for this complication included urgent procedures (so-called bailout stenting), improper pre-treatment with drugs ("ad hoc" procedures), dissection uncovered by stent, and poor final result of procedure (higher degree of residual stenosis). The majority of these patients developed myocardial infarction in spite of the fact that the patency of stented vessel was quickly achieved in all but one patient. CONCLUSIONS: Urgent stenting, improper drug pre-treatment and suboptimal result of the procedure are the risk factors of subacute stent thrombosis.