Azithromycin and Risk of Cardiovascular Death: A Meta-Analytic Review of Observational Studies

Recent evidence, though conflicting, suggests an association between azithromycin use and cardiovascular death. We conducted a systematic review and meta-analysis to evaluate the effect of azithromycin on risk of death. Multiple databases were searched. Authors independently screened and extracted the data from studies. Primary outcome of interest was risk of death (cardiovascular and/or noncardiovascular). Subgroup analyses were conducted to explore the source of a possible heterogeneity. Random effects model meta-analysis and hazards ratio (HR) were used to pool the data and calculate the overall effect estimate, respectively. Eight hundred twenty-eight citations, identified with 5 cohort studies that involved 2,246,178 episodes of azithromycin use, met our inclusion criteria. Azithromycin use was not associated with higher risk of death from any cause, HR = 0.99 [confidence interval (CI), 0.82-1.19], I-2 = 54%, or cardiovascular cause, HR = 1.15 (CI, 0.66-2.00), I-2 = 64%, but there was a moderate degree of heterogeneity. Subgroup analyses have shown no increased risk of death with azithromycin use in younger population with zero degree of heterogeneity, HR = 0.85 (CI, 0.66-1.09), I-2 = 0%. However, current use of azithromycin (within 1-5 days of therapy) was associated with a higher risk of death among older population with mild degree of heterogeneity, HR = 1.64 (CI, 1.23-2.19), I-2 = 4%. In summary, azithromycin use was not associated with higher risk of death particularly in younger population. Nevertheless, older population might be at higher risk of death with current use of azithromycin, and an alternative therapy should probably be considered.