Systematic review: cardiotoxicity of immune checkpoint inhibitors

Abstract

According to the results of a systematic review and meta-analysis reported in the European Journal of Cancer, treatment with immune checkpoint inhibitors (ICIs) as single or combination regimens is not associated with an increased risk of cardiotoxicity. The review searched PubMed, MEDLINE, Embase databases and conference proceedings to identify randomised controlled trials published in English which involved treatment of any solid tumours. There were 66 studies involving 34 664 patients which compared ICIs with other treatments, and 14 studies involving 673 patients which compared dual-agent and single-agent ICI treatment. For cardiac events overall, the pooled incidence for ICIs versus other treatments was 3.78% vs 3.40% (relative risk [RR] 1.14; 95% CI 0.88, 1.48; p=0.326). There were no significant between-group differences according to severity grade of the adverse event (AE). For myocarditis, the incidence was 0.12% vs 0.01% (RR 1.11; 0.64, 1.92; p=0.701). When comparing dual versus single IC therapy, the pooled incidence of cardiac AEs was 2.87% vs 0.4% (RR 1.91; 0.52, 7.01; p=0.329), with no significant differences according to severity grade. For myocarditis, the incidence was 0.17% vs 0.00% (RR 1.10; 3.87; p=0.881). In subgroup analyses, there were no significant between-group differences by tumour type, disease setting, line of therapy, of type of ICI. In sensitivity analyses, the authors note that the pooled RR estimates were stable, with only minimal fluctuations when excluding each study sequentially . Although the risk of cardiotoxicity is not apparently increased by ICI therapy, which the authors note is reassuring for patients , they add that the population included in clinical trials is generally highly selected, so it is also necessary to assess the cardiac toxicities of ICI in real-world patients, who tend to experience more AEs that those included in clinical trials .