Cardiac Troponin Screening and Clinical Outcomes in Patients Receiving Immunotherapy

BACKGROUND: Immune checkpoint inhibitors (ICIs) are associated with cardiotoxicities such as myocarditis. However, data on the implementation and outcomes of cardiac biomarker screening remain limited. OBJECTIVES: The aim of this study was to examine the impact of cardiac troponin I (cTnI) surveillance integrated with symptom-based triaging in patients receiving immunotherapy. METHODS: A single-center retrospective cohort study was conducted among adults who underwent routine serial cTnI monitoring during immunotherapy between January 2019 and October 2021. For patients with elevated cTnI, clinical presentation, management, and outcomes were analyzed. Major adverse cardiac events included arrhythmia, myocarditis, heart failure, acute coronary syndrome, stroke, and pericardial effusion. Patients were followed for 24 months from their first ICI dose. RESULTS: Among 428 patients (mean age 67.1 ± 13.9 years, 60.3% men), 42 (9.8%) had elevated cTnI detected through monitoring. Compared with symptomatic patients, asymptomatic patients more often underwent outpatient evaluation (88.0% vs 17.6%; P < 0.001) and continued immunotherapy (68.0% vs 35.3%; P < 0.001), whereas symptomatic patients more often underwent myocarditis-specific diagnostics such as cardiac magnetic resonance imaging (58.8% vs 8.0%; P = 0.001) and received immunosuppression (47.1% vs 8.0%; P = 0.008). The cumulative incidence of major adverse cardiac events at 1.5 years following cTnI elevation was 19.0% (95% CI: 7.0%-31.1%) and was significantly higher in symptomatic vs asymptomatic patients (subdistribution HR: 18.9; 95% CI: 2.2-162.5; P = 0.008). Symptomatic patients had a significantly higher risk for all-cause mortality at 2-year follow-up (HR: 3.24; 95% CI: 1.06-9.94; P = 0.04). In total, 6 patients were diagnosed with myocarditis, with no cardiac-related deaths. CONCLUSIONS: cTnI surveillance integrated with symptom-based triaging can facilitate early intervention and treatment of cardiotoxicities such as myocarditis.