Abstract 4550: Mechanisms of Non-Fatal Acute Myocardial Infarction Late After Stent Implantation: The Relative Impact of Disease Progression, Stent Restenosis and Stent Thrombosis
Objectives The purpose of this study was to assess the cause of non-fatal acute myocardial infarction (AMI) after stent implantation.
Background The impact of disease progression, restenosis and stent thrombosis as responsible mechanisms of AMI after stent implantation is not clear.
Methods and Results In a retrospective observational study, out of 3936 patients with stent implantation, 76 cases of AMI at least one month following the procedure were identified. By detailed comparison of post AMI with the initial PCI angiogram the mechanism of AMI was analysed. Disease progression and stent related problems were considered responsible for AMI in 36 (47.4%) and 37 (48.7%) of cases respectively. The later consisted of 31 (40.8%) and 6 (7.9%) stent thrombosis attributed AMIs. The AMI mechanism could be either stent related or disease progression (non-identifiable culprit lesion) in 3 cases (3.9%). DES had been used in 30.6% of disease progression and 35.1% of the stent failure AMIs (50% of stent thrombosis cases). The median time from PCI to AMI was 32.5, 31 and 9 months for disease progression, restenosis and stent thrombosis group respectively. STEMI occurred in 33.3% of the disease progression and in 21.6% of the stent failure cases (16.1% restenosis and 50% stent thrombosis).
Conclusions In a “real world” population, late after stent implantation, a patient has an equal probability to have suffered a nonfatal AMI from either stent failure or disease progression. This emphasizes the need for continuous research effort equally addressed to both stent therapy and deceleration of disease progression.