Immune Checkpoint Inhibitors and Cardiotoxicity: A Comparative Meta-Analysis of Observational Studies and Randomized Controlled Trials.

BACKGROUND

Immune checkpoint inhibitors (ICIs) have uncommon associations with cardiotoxicity, yet these cardiotoxic effects are associated with high mortality. An accurate assessment of risk for cardiotoxicity is essential for clinical decision-making, but data from randomized controlled trials often differ from real-world observational studies.

METHODS AND RESULTS

A systematic search of PubMed, Embase, Cochrane Library, and Scopus was performed, including phase II and III randomized controlled trials (RCTs) and observational studies (OSs) reporting myocarditis or pericardial disease, myocardial infarction, or stroke with an immunotherapy. Odds ratios (ORs) were used to pool results between ICIs and other cancer therapy in RCTs and OSs. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline was followed. In total, 54 RCTs (N=38 264) and 24 OSs (N=12 561 455) were included. In RCTs, ICI use resulted in higher risk of myocarditis (OR, 3.55 [95% CI, 2.10-5.98]), pericardial disease (OR, 2.73 [95% CI, 1.57-4.77]), and myocardial infarction (OR, 1.83 [95% CI, 1.03-3.25]), compared with non-ICI (placebo or chemotherapy). In OSs, ICI use was not associated with myocarditis, pericardial disease, or myocardial infarction compared with controls; however, combination ICIs demonstrated higher risk of myocarditis compared with single ICI use (OR, 3.07 [95% CI, 1.28-7.39]). Stroke risk was not increased with use of ICIs in RCTs.

CONCLUSIONS

We demonstrated increased risk of ICI myocarditis, pericardial disease, and myocardial infarction in RCTs but not OSs. Results of this study suggest there are differences between ICI cardiotoxicity risk, possibly suggesting differences in diagnoses and management, in clinical trials versus the OSs.