ACUTE MYOCARDIAL INFARCTION TREATED WITH PRIMARY PERCUTANEOUS CORONARY INTERVENTION IN PATIENTS WITH PRIOR CORONARY ARTERY BYPASS GRAFTING AT A SINGLE CENTRE IN CANADA

Abstract

Due to an aging population, there is an increase in the number of patients undergoing coronary artery bypass grafting (CABG) presenting with ST-segment elevation myocardial infarction (STEMI). Despite this, there is a lack of data in this high-risk patient population. The purpose of the study is to characterize the baseline characteristics, culprit lesions and outcomes of patients with previous CABG and STEMI. We retrospectively reviewed a database of all patients undergoing emergency percutaneous coronary intervention (PCI) of which 95.8% of patients had electrocardiographic evidence of STEMI at a single-centre in British Columbia between January 2009 and December 2013. There were 94 (2.9%) patients with a prior history of CABG in a total of 3231 patients. The prior CABG group was significantly older and had a significantly greater incidence of hypertension, dyslipidemia, diabetes, previous MI, previous heart failure, and previous PCI. There was a significantly greater length of stay in the CABG population, but no difference when comparing in hospital mortality. The infarct-related vessel in the CABG group was a bypass graft in 44 patients (48.9%), native coronary artery in 36 patients (40.0%), was not identifiable in 10 patients (11.1%) and 4 patients had missing data. We further stratified previous CABG patients by the time between emergency PCI and index CABG. There were 79 patients (84.0%) who had CABG more than five years from emergency PCI. There were no significant differences in baseline characteristics, culprit lesions and 30-day mortality between CABG more than five years and less than five years from emergency PCI. Emergency PCI for STEMI after previous CABG is associated with more comorbidities when compared with patients that did not undergo previous CABG. However, there were similar outcomes in short-term mortality. Furthermore, there were no significant differences in baseline characteristics and short-term mortality between the timing from initial CABG to emergency PCI. Further data analysis is needed to characterize longer-term outcomes.