OBJECTIVETo determine risk factors and evaluate the efficacy of emergent PCI for acute or subacute coronary in-stent thrombosis.

METHODSBaseline and follow-up data of 6977 patients who underwent stent implantation in our institution between January 2000 and May 2006 were analyzed.

RESULTSOf 6977 patients, acute or subacute coronary in-stent thrombosis was confirmed in 52 (0.75%) patients by coronary angiogram. The in-stent thrombosis occurred between 30 minutes to 20 days post PCI (mean 3.6 +/- 4.2 days). Predictive factors for in-stent thrombosis showed by multivariate analysis were AMI, B2/C type lesions, multi-vessel diseases, heart failure and target lesions on left anterior descending artery (LAD). Among these 52 patients, 43 presented recurrent chest pain or ST elevation AMI, 6 suffered from cardiac arrests, 1 manifested hypotension and 2 showed no typical clinical symptoms and were diagnosed during scheduled PCI for other diseased vessels. Emergent coronary angiogram evidenced total thrombotic occlusion in 48 patients and 70% - 95% thrombotic stenosis in 4 patients. All 52 patients were treated with emergent PCI. Forty-seven patients survived and 5 patients died (mortality 9.6%).

CONCLUSIONThe risk of developing in-stent thrombosis was higher in patients with AMI, B2/C type lesions, multi-vessel diseases, heart failure and target lesions on LAD. Emergent PCI is the most effective method for treating in-stent thrombosis and should be carried out as early as possible in order to improve outcomes of this severe complication post stenting.