Definition
• Cocaine-induced angina is caused by multiple cardiovascular effects of cocaine, including increased HR, BP, contractility, & end-systolic wall stress (from sympathomimetic effects) which all lead to increased myocardial demands as well as cocaine-induced coronary arterial vasoconstriction resulting in decreased O2 supply
• Acute thrombosis of coronary arteries after cocaine use can also occur & use has been a/w premature coronary atherosclerosis
• Overall incidence of cocaine-associated MI is 0.7–6% of those presenting w/ CP after ingestion (Acad Emerg Med 2000;36:469; COCHPA, Acad Emerg Med 1994;1:330)
History
• CP (pressure-like) that may be a/w dyspnea, anxiety, palpitations, diaphoresis, dizziness, or nausea
• Sxs typically occur w/i 3 h of ingestion, but cocaine metabolites may persist up to 24 h to cause delayed or recurrent vasoconstriction
• RF for cocaine-induced MI: Male gender, current smoker, nonwhite
Evaluation
• Similar to ACS (see above)
• Urine toxicology: Usually detects the cocaine metabolite benzoylecgonine which has a urine t1/2 of 6–8 h, & can be detected for up to 24–48 h after use (range 16–66 h)
• Chronic cocaine users may have cocaine detectable in urine for weeks after last ingestion
Treatment
• Pts should be treated similarly to possible ACS (see “routine medical therapies” above)
• IV BZD
• Antihypertensives: IV NGT, sodium nitroprusside, or phentolamine; avoid BBs as an unopposed α-adrenergic effect can lead to worsening coronary vasoconstriction & BP
• STEMI: Early PCI
• Drug-abuse counseling
Disposition
• EDOU if sxs controlled & cardiac markers negative
• Admit to cardiac unit if +cardiac markers or ongoing CP
Pearls
• Cx: Arrhythmia & heart failure (∼90% occur w/i 12 h of presentation)
• Ventricular tachyarrhythmias immediately after cocaine use result from the local anesthetic (sodium channel) effect on the myocardium & may respond to sodium bicarbonate therapy in addition to standard therapies (ie, lidocaine)
• Cocaine-associated CP may be caused not only by myocardial ischemia but also by aortic dissection, thus maintain high index of suspicion
Guideline: McCord J, Jneid H, Hollander JE. Management of cocaine-associated chest pain and myocardial infarction: A scientific statement from the American Heart Association Acute Cardiac Care Committee of the Council on Cardiology. Circulation. 2008;117:1897–1907.