Clinical characteristics, angiographic findings, and one-year outcome of 101 consecutive stent thrombosis cases in British Columbia.

BACKGROUND: Stent thrombosis (ST) is rare, but is associated with significant morbidity and mortality.

METHODS: We analyzed data from the British Columbia (BC) Registry from April 2011-January 2012.

RESULTS: 101 ST cases were reported and verified. Based on timing, ST was considered early (≤30days) in 35.6%, late (>30days-1year) in 17.8% and very late (>1year) in 46.5%. The majority (68.5%) presented with STEMI, and the remaining with non-STEMI (31.5%). Most vessels were functionally occluded (TIM1 flow grade ≤1 in 67.1%). Thrombus burden was high (TIMI thrombus grade ≥4 in 77.2%). Aspiration thrombectomy was performed in 41% of cases. New stents were implanted in 62.4% cases. Intra-coronary imaging was low (11%). At the original stent implantation, STEMI was the clinical presentation in 39.6%, the lesion was complex in 62.1%, and thrombus was visualized in 23.0%. Prognosis after ST was unfavorable with high mortality (11.9% at 30days and 16.8% at one year), and further revascularization (5.0% repeat PCI and 6.9% coronary artery bypass graft surgery). Early ST was associated with worse clinical outcome compared to late/very late ST: 30-day mortality at 22.2% versus 6.2% (p=0.02), and 1-year mortality at 27.8% versus 10.8% (p=0.05).

CONCLUSIONS: In this prospective registry from BC, all ST presented with myocardial infarction, and the majority was treated with emergency PCI. Additional stents were commonly implanted with infrequent use of intracoronary imaging. Mortality rate was higher for early ST in comparison with late/very late ST. A comprehensive approach should be developed to treat this difficult complication.