Cardiovascular and venous thromboembolism risks in cancer patients treated with immune checkpoint inhibitors compared to non-users- a multi-center retrospective study

Background: Immune Checkpoint Inhibitors (ICIs) have revolutionized cancer therapy. This study examines the cardiovascular risks of ICIs compared to non-ICI therapies. Methods: Utilizing the Chang Gung Research Database (CGRD) of Taiwan, this retrospective study analyzed 188,225 cancer patients, with 1,737 undergoing ICI treatment from January 1, 2008, to June 30, 2021. Through 1:1 propensity score matching (PSM), we compared specific outcomes between patients treated with ICIs and those who were not. The analysis also accounted for the competing risk of mortality in assessing the results after PSM. The observation period spanned from this index date to whichever came first: the date of the specific outcomes, the last follow-up recorded, or the end date of the study on June 30, 2022. Results: The study found no significant increase in the risk of cardiac death, non-fatal myocardial infarction, heart failure hospitalization, deep vein thrombosis, or pulmonary embolism in patients treated with ICIs as compared to those receiving non-ICI therapy. Interestingly, ICI treatment was linked to a lower risk of non-fatal stroke (0.27% per year vs. 0.46% per year; subdistribution hazard ratio = 0.59; 95% confidence interval = 0.35–0.98; P = 0.0430). Furthermore, subgroup analysis revealed that the ICI group had a decreased risk of cardiac death in patients with cancers other than head and neck cancer, and a reduced risk of stroke among diabetic patients. Conclusions: ICIs do not significantly elevate the risk of cardiovascular events in cancer patients and may lower the stroke risk, underscoring the need for additional prospective studies to clarify these findings.