Heightened Risk of Cardiac Events Following Percutaneous Coronary Intervention for Cocaine-Associated Myocardial Infarction

INTRODUCTION:

Several works have suggested heightened risk for cardiac events in cocaine users following percutaneous coronary intervention (PCI). Such studies have generally been performed in small, poorly defined samples and have not utilised optimal control groups. We aimed to define the short-term risk for death or recurrent myocardial infarction (MI) when PCI was performed for myocardial infarction in subjects presenting with urine toxicology positive for cocaine in relation to subjects testing negative for cocaine use.

MATERIAL AND METHODS:

Our institutional electronic health record (EHR) was queried for all subjects with urine toxicology performed for cocaine exposure within 5 days before or after having elevated troponin-T assay between 1/1/08 and 12/31/13. Query results were cross-referenced with our institutional cardiology database to identify the sample who had PCI on the same admission as the cocaine test. Subsequent readmission for MI was assessed from the EHR, and deaths were identified from the National Death Index.

RESULTS:

PCI had been performed in 380 subjects who tested negative for cocaine and 44 subjects who tested positive. In the cocaine-positive group, incidences of death or MI at 30 days and 1 year were 18% and 23%, respectively. Those who tested positive for cocaine had increased odds (odds ratio (OR) = 2.3, 95% confidence interval (CI): 1.0-5.1, p = 0.04) for death or MI at 30 days post PCI, after adjustment for age, sex, prior MI, and comorbidity index. Although the odds for events 1-year post PCI were not increased (OR = 2.0, 95% CI: 0.9-4.3), the p-value approached significance in this small sample (p = 0.09).

CONCLUSIONS:

This retrospective study suggests that PCI performed in cocaine-associated myocardial infarction comes with a high 30-day and one-year risk. Further prospective studies are needed to better define this risk and to lend insight into better management strategies.