Acute stent thrombosis in the setting of cocaine abuse following percutaneous coronary intervention

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.

Cocaine-induced very late stent thrombosis

Cocaine misuse is a known cause of acute coronary syndrome (ACS). Management of these patients has always been a challenge due to medication compliance and eventual risk of stent thrombosis. However, even cocaine misusers who are compliant with dual antiplatelet therapy have been reported to have stent thrombosis. All cases of cocaine-induced stent thrombosis reported in the literature have occurred within first year of stent placement (acute, subacute or late). We report a first case of very late stent thrombosis in a 54-year-old active cocaine misuser who presented with ST segment elevation myocardial infarction, which was successfully managed with percutaneous transluminal coronary angioplasty. A review of all the reported cases of cocaine-induced stent thrombosis is also discussed. Given the high mortality associated with stent thrombosis, treatment option for cocaine misusers presenting with ACS should be conservative when possible. If percutaneous coronary intervention is needed, bare metal stent should be preferred.

Cocaine-induced coronary thrombosis: what is the optimal treatment strategy

Arterial thrombosis and especially coronary thrombosis are known complications of cocaine abuse. We report three cases of severe life-threatening coronary arterial thrombosis manifesting as acute coronary syndromes. Thrombosis occurred predominantly in the proximal coronary tree with spontaneous distal embolization. The thrombotic occlusions were frequently not superimposed on flow-limiting atherosclerotic lesions. Treatment of these patients with thrombolytic, antithrombotic and anti-platelet therapy resulted in thrombus and symptom resolution. While stenting these vessels can be successfully executed and may be required in some cases of ST-elevation myocardial infarction, it may expose these patients to the risk of stent thrombosis, which is reported to be significantly higher than the risk of the general population.