Abacavir Use and Risk for Myocardial Infarction and Cardiovascular Events: Pooled Analysis of Data From Clinical Trials

Background. Some observational studies and randomized controlled trials (RCTs) have suggested an association between abacavir (ABC) use and myocardial infarction (MI), whereas others have not. Methods. This pooled analysis of 66 phase II-IV RCTs estimates exposure-adjusted incidence rates (IRs) and relative rates (RRs) of MI and cardiovascular events (CVEs) in participants receiving ABC- and non-ABC-containing combination antiretroviral therapy (cART). The primary analysis of MI included ABC-randomized trials with 48-week follow-up. Sensitivity analyses of MI and CVEs included non-ABC-randomized and <48-week follow-up trials. Results. In 66 clinical trials, 13 119 adults (75% male, aged 18-85 years) were on ABC-containing cART and 7350 were not. Exposure-adjusted I R for MI was 1.5 per 1000 person-years (PY; 95% confidence interval [Cl], 0.67-3.34) in the ABC-exposed group and 2.18 per 1000 PY (95% CI, 1.09-4.40) in the unexposed group. The IR for CVEs was 2.9 per 1000 PY (95% CI, 2.09-4.02) in the exposed group and 4.69 per 1000 PY (95% CI, 3.40-6.47) in the unexposed group with studies of >= 48 weeks of follow-up, with an RR of 0.62 (95% CI, 0.39-0.98). The inclusion of nonrandomized and shorter-duration trials did not significantly change the RR for MI or coronary artery disease. Conclusions. This pooled analysis found comparable IRs for MI and CVEs among ABC-exposed and -unexposed participants, suggesting no increased risk for MI or CVEs following ABC exposure in a clinical trial population. Modifiable risk factors for MI and CVEs should be addressed when prescribing ART.