New guidelines for the management of cocaine chest pain

March 20, 2008 By Benjamin A. Olenchock, M.D. Ph.D. [mailto:bolenchock@partners.org]

The American Heart Association has published a review of cocaine chest pain and evidence-based recommendations to help physicians manage this common problem. The guidelines are available at http://circ.ahajournals.org/cgi/reprint/CIRCULATIONAHA.107.188950v1.

In the acute setting, patients presenting with chest pain after using cocaine should be treated like any other patient being evaluated for a possible acute coronary syndrome, with a few differences. First, the guidelines recommend that all suitable patients receive a benzodiazepine. Additionally, the guidelines recommend avoiding beta-blockers. In experimental models, beta-blockers cause increased alpha-adrenergic tone, exacerbating coronary vasospasm, decreasing coronary blood flow and causing increased mortality. Even labetalol, which has alpha- and beta-blocking activities, has been shown to increase mortality in animal models of cocaine toxicity. Along with aspirin and benzodiazepines, nitroglycerin should be considered a first line treatment for hypertensive patients with chest pain after cocaine use. Further evidence from cardiac catheterization studies suggests that verapamil and the alpha adrenergic receptor antagonist phentolamine have beneficial effects on coronary blood flow during cocaine toxicity.

Cocaine leads to more emergency department visits than any other illicit drug – almost 450,000 visits in 2005. Forty percent of these patients complain of chest discomfort, and an estimated 1-6% will have a myocardial infarction. Despite these large numbers of patients, well-controlled clinical studies of the benefits and risks of different interventions are lacking. The AHA guidelines remain largely based expert opinion and experimental animal models. Beta-blockers, regardless of their alpha- vs. beta-adrenergic receptor specificity, received a class III-C recommendation, i.e. expert opinion / small studies suggest potential harm. This recommendation contrasts with the current practice of many emergency department physicians. In areas of limited data such as this, dominant personalities and anecdotal experience often dictate local practice. If adopted, the new guidelines have the potential to significantly change current practice.