Real-world incidence of thrombosis and cardiovascular adverse events associated with immune checkpoint inhibitors in a Hispanic population: A retrospective single-center study.

Abstract

e14622 Background: Immune checkpoint inhibitors (ICIs) targeting PD-1, PD-L1, and CTLA-4 have revolutionized cancer treatment. However, emerging evidence suggests that ICIs may accelerate atherosclerosis, increasing the risk of cardiovascular events (CVE), including major adverse cardiovascular events (MACE) and thrombosis (Drobni et al., 2020). Understanding the incidence, timing, and risk factors for CVEs in Hispanic populations—who remain underrepresented in clinical studies—is critical for optimizing patient outcomes. Methods: We conducted a single-center retrospective cohort study of patients treated with ICIs in Bogotá, Colombia, between 2014 and 2024. We report CVE, including MACE and thrombosis among patients receiving PD-1, PD-L1, and CTLA-4 inhibitors. Incidence rate of CVAEs was calculated per 1,000 person-years. Time to event was assessed using Kaplan-Meier analysis, while Cox proportional hazards models were used to identify risk factors for thrombosis and CVE development, incorporating known cardiovascular risk factors, including age, sex, smoking status, history of diabetes, and dyslipidemia. Results: Among the 208 patients analyzed, the estimated incidence rates per 1,000 person-years was 83.31 (95% CI: 47.68–118.94) for MACE, and 121.55 (95% CI: 77.31–165.79) for thrombosis. The median time to event was 77 days [IQR: 38–393] for thrombosis and 110 days [IQR: 60–353] for MACE. Kaplan-Meier analysis revealed significant differences in AE-free survival for thrombosis (Log-rank test p < 0.01). Thrombosis-free survival was significantly lower among patients receiving PD-1+CTLA-4 inhibitors compared to PD-L1 inhibitors (1-year thrombosis-free survival: 79.0%, 95% CI: 60.2%–94.2% vs. 94.2%, 95% CI: 85.4%–94.2%; p = 0.0088). However, no significant differences were observed in MACE-free survival across treatment groups (p = 0.4346). Cox proportional hazards models did not identify statistically significant risk modifiers of AEs across ICI subgroups or combination therapies. Conclusions: This study underscores the high incidence of thrombosis and MACE in Hispanic patients treated with ICIs, highlighting the elevated thrombotic risk in those receiving combination therapy with PD-1 and CTLA-4 inhibitors. Interestingly, the median time to onset of immune-related adverse events occurred prior to the median time to thrombosis, potentially indicating a temporal relationship in which inflammation may serve as a precursor to thrombotic events. These findings underscore the need to investigate ethnic differences in atherosclerosis susceptibility and ICI-associated cardiovascular toxicity and reinforce the importance of integrating cardiovascular risk assessment into survivorship care.