Outcomes of beta blocker use in cocaine-associated chest pain: a meta-analysis

Objectives Beta blockers (beta-blockers) remain a standard therapy in the early treatment of acute coronary syndromes. However, beta-blocker therapy in patients with cocaine-associated chest pain (CACP) continues to be an area of debate due to the potential risk of unopposed a-adrenergic stimulation and coronary vasospasm. Therefore, we performed a systematic review and meta-analysis of available studies to compare outcomes of beta-blocker versus no beta-blocker use among patients with CACP. Methods We searched the MEDLINE and EMBASE databases through September 2016 using the keywords 'beta blocker', 'cocaine' and commonly used beta-blockers ('atenolol', 'bisoprolol', 'carvedilol', 'esmolol', 'metoprolol' and 'propranolol') to identify studies evaluating beta-blocker use among patients with CACP. We specifically focused on studies comparing outcomes between beta-blocker versus no beta-blocker usage in patients with CACP. Studies without a comparison between beta-blocker and no beta-blocker use were excluded. Outcomes of interest included non-fatal myocardial infarction (MI) and all-cause mortality. Quantitative data synthesis was performed using a random-effects model and heterogeneity was assessed using Q and I-2 statistics. Results A total of five studies evaluating 1794 subjects were included. Overall, there was no significant difference on MI in patients with CACP on beta-blocker versus no beta-blocker (OR 1.36, 95% CI 0.68 to 2.75; p=0.39). Similarly, there was no significant difference in all-cause mortality in patients on beta-blocker versus no beta-blocker (OR 0.68, 95% CI 0.26 to 1.79; p=0.43). Conclusions In patients presenting with acute chest pain and underlying cocaine, beta-blocker use does not appear to be associated with an increased risk of MI or all-cause mortality.