Troponin Screening and Major Cardiovascular Adverse Events During Immune Checkpoint Inhibitor Therapy.

Background: Troponin monitoring is recommended for the early detection of immune checkpoint inhibitor (ICI)-associated myocarditis, but its utility as a universal screening tool for all cardiovascular (CV) toxic effects in patients with cancer treated with ICIs remains uncertain. Objective: To evaluate whether systematic troponin screening is associated with reduced major adverse CV events (MACEs) and mortality in patients receiving ICI therapy for cancer. Design, Setting, and Participants: This retrospective, multicenter cohort study assessed adults treated with ICIs between January 1, 2017, and December 31, 2022, at 2 tertiary oncology centers. Patients undergoing systematic troponin screening (≥2 measurements during the first trimester of ICI therapy not prompted by symptoms) were compared with those undergoing clinical assessment without screening. Cross-sectional follow-up was undertaken between June 1, 2023, and June 30, 2024. Exposure: ICI therapy for solid cancer. Main Outcomes and Measures: The primary outcomes included adjudicated MACEs (ICI-associated myocarditis, acute coronary syndrome, heart failure requiring hospitalization, sudden cardiac death, and CV death). Multivariate Cox proportional hazards regression, Fine-Gray competing risk models, and propensity score matching were applied, with death from cancer considered a competing risk. Results: Of 859 patients (mean [SD] age, 70.1 [10.8] years; 517 [60.2%] male; 585 [68.1%] with lung cancer), 40 (4.7%) developed MACEs, including 6 (0.7%) with ICI-associated myocarditis; 484 (56.3%) died at a median follow-up of 3.3 (IQR, 1.3-7.2) months, mainly from cancer (436 [90.1%]). Routine troponin screening was associated with lower mortality combined with MACEs in multivariable models (hazard ratio, 0.56 [95% CI, 0.45-0.70]) (P < .001) but was not associated with MACEs after competitive risk analysis (hazard ratio, 0.56 [95% CI, 0.20-1.55]) (P = .27) or in a propensity score-matched cohort of 354 patients (hazard ratio, 0.49 [95% CI, 0.20-1.24]) (P = .13). Conclusions and Relevance: In this cohort study, systematic troponin screening was not associated with MACEs in an older population with metastatic solid cancer after competitive risk analysis or propensity score matching. These findings suggest that the benefits of universal troponin monitoring are questionable among unselected patients with cancer who are receiving ICIs; further investigation is needed to determine whether risk-adapted screening improves outcomes while avoiding unnecessary interruptions of treatment.