Prevalence, Correlation and Clinical Outcome of Intra‐Procedural Stent Thrombosis in Patients Undergoing Primary Percutaneous Coronary Intervention for Acute Coronary Syndrome

OBJECTIVES: To assess the occurrence, correlation, and clinical outcome of intraprocedural stent thrombosis (IPST) in patients undergoing primary percutaneous coronary intervention (PCI) in the setting of acute coronary syndromes (ACSs). BACKGROUND: Stent thrombosis (ST), a rare complication of PCI, is more common in the setting of ACS. It is not known whether IPST carries the same prognosis as postprocedural ST. METHODS: This retrospective study comprised a review of 1,901 consecutive ACS patients who received primary PCI in our center from January 2006 to January 2011. IPST was defined as new, reappearing or increased thrombus within the deployed stent before the index PCI procedure was completed. All angiograms were independently reviewed frame by frame for the incidence of IPST. Patients with and without IPST were compared with respect to clinical characteristics, angiographic parameters, and major adverse cardiac events (MACEs) at 30 days and 1-year follow-up. RESULTS: Overall, there were 23 cases of IPST detected, thus, the prevalence of IPST was 1.2%. There were no significant differences in baseline clinical characteristics between the 2 groups. Patients with compared to those without IPST had significantly more bifurcation lesions involved, and more thrombus burden at baseline. IPST group compared to no IPST group had more MACEs on 30 days (26.1% vs. 8.7%, P = 0.01) and 1-year follow-up (30.4% vs. 14.4%, P = 0.02). CONCLUSIONS: IPST was a rare complication of PCI in the setting of ACS. It correlated with lesion morphology, presence of thrombus at baseline and was more likely to cause MACEs in 30 days and 1-year follow-up.