Abstract 3464: Beta Blockers Reduce the Risk of MI and Death following Cocaine Use: a Multivariate Analysis
INTRODUCTION: Beta-blockers, once recommended for the treatment of cocaine toxicity, are now considered contraindicated as their use has been associated with coronary artery spasm when given to active cocaine users. However, no clinical series have ever been published regarding their safety or effect on important clinical outcomes. They have, on the other hand, been shown to have a clear mortality benefit in patients with myocardial infarction (MI) or systolic dysfunction, both conditions occurring more frequently in cocaine abusers.
HYPOTHESIS: Beta blockers are safe when given to patients following cocaine ingestion.
METHODS: We conducted a retrospective cohort study at a single academic municipal hospital. The cohort consisted of 363 consecutive telemetry, intensive care, and coronary care unit admissions over a 5-year period (329 individual patients) during which the patients had tested positive for cocaine by urine toxicology. Fifteen patients were excluded because they had been prescribed beta-blockers as outpatients without documented beta-blocker use during hospitalization. Primary outcome measures were MI (assessed in a subset of the overall cohort who had had troponin I measured - 310 admissions total - and defined by cardiac symptoms plus one or more measurements of troponin I ≥0.10, and/or significant ST elevations in two contiguous leads by EKG) and in-hospital mortality.
RESULTS: Beta-blockers were given in 60 of 348 admissions. Forty (66%) received beta-selective agents, 13 (21%) received mixed alpha/beta blockers, and 8 (13%) received both. By univariate analysis, the incidence of MI following administration of beta-blocker was significantly lower than without treatment (6.06% vs. 25.99%, p=0.03). Only one of 17 deaths occurred in a patient who had received beta-blockade (incidence 1.67% vs. 5.56%, p=0.24). Multivariate analysis showed that beta-blockers significantly reduced the risk of MI (OR: 0.09; 95% CI: 0.02, 0.48; p<0.01), and death (OR: 0.10: 95% CI: 0.01, 0.80; p=0.03) after adjusting for traditional CVD risk factors.
CONCLUSION: Beta blockade reduces the risk of MI and possibly death following cocaine ingestion. Further study is warranted.