A retrospective cohort study on the cardiotoxicity incidence rates of immune checkpoint inhibitors for oncology patients.

Background: This present study investigated the incidence rates of cardiotoxicity among cancer patients treated with immune checkpoint inhibitors (ICIs) plus other anticancer drugs.

Methods: This was a retrospective hospital-based cohort study using the medical records and the Cancer Registry records from the Taipei Veterans General Hospital. We enrolled patients diagnosed with cancer between 2011 and 2017, who were over 20 years old and had received ICI therapy, including pembrolizumab, nivolumab, atezolizumab, and ipilimumab. Cardiotoxicity was defined by the diagnosis of myocarditis, pericarditis, arrhythmia, heart failure, and Takotsubo syndrome.

Results: We identified 407 patients who were eligible to participate in this study. We defined the three treatment groups as follows: ICI therapy, ICI combined with chemotherapy, and ICI combined with targeted therapy. Using ICI therapy as a reference group, the cardiotoxicity risk was not significantly higher compared to the ICI combined with chemotherapy group (adjusted hazard ratio 2.1, 95% confidence interval 0.2-21.1, p = 0.528] or to the ICI combined with targeted therapy group (adjusted hazard ratio 1.2, 95% confidence interval 0.1-9.2, p = 0.883). The total incidence rate of cardiotoxicity was 3.6 of 100 person-years, indicating an average incidence time of 1.0 ± 1.3 years (median: 0.5 years; range: 0.1-4.7 years) for 18 cardiotoxicity patients.

Conclusion: The incidence rate of ICI-related cardiotoxicity is low. Combination of ICI with either chemotherapy or targeted therapy might not significantly increase the risk of cardiotoxicities among cancer patients. Nevertheless, it is recommend being careful in patients treated high-risk cardiotoxicity medications to avoid drug-related cardiotoxicity with a combination of ICI therapy.