Abstract 12425: Troponin Kinetics and Cardiovascular Events in Patients With Myocarditis After Immune Checkpoint Inhibitors Use

Abstract

Introduction: Immune checkpoint inhibitors (ICI) leverage the immune system against cancer. Myocarditis is an uncommon but serious complication of ICI use. There are limited data on the utility of serum troponin levels in this setting. We assessed whether troponin values measured at different time points during admission have prognostic significance. Hypothesis: Baseline (admission), peak and inter-value trajectory (slope) of high-sensitivity cardiac Troponin T (hs-cTnT) levels predict cardiovascular events in ICI-myocarditis. Methods: A retrospective cohort of all patients admitted with ICI-myocarditis in a single integrated academic network was performed. Troponin measures were included from the 24 hours preceding admission until time of event/censoring. Optimal threshold values for baseline, peak hs-cTnT, and slope changes were obtained through ROC curves (Youden index). Major adverse cardiac event (MACE) was defined as a composite of cardiogenic shock, cardiac arrest, complete heart block and cardiac death. Results: A total of 980 hs-cTnT measures from 63 patients were identified (figure 1). Over a median follow-up period of 16 days, 24 events occurred. A higher baseline (>1248 ng/l, HR: 3.75, 95% CI: 1.57–9.00, p= 0.003) (figure 2) and peak hs-cTnT (>1959 ng/l, HR: 3.66, 95% CI: 1.49–8.98, p= 0.01) were associated with MACE adjusted for age and left ventricular ejection fraction (LVEF). Additional optimal threshold hs-cTnT values based on LVEF were also identified. For those with an LVEF < 50%, a baseline value >265 ng/l (HR: 4.9, 95% CI: 1.5-15.8, p< 0.01) and for those with an LVEF >50%, a baseline value >780 ng/l (HR: 3.6, 95% CI: 1.03-12.4, p=0.04) were associated with MACE. The hs-cTnT trajectory slope changes (baseline-to-peak, slope in first 24 hours, slope in first 48 hours) were not associated with events. Conclusion: Baseline and peak hs-cTnT during admission for ICI-related myocarditis associated with MACE. Cutoff values may vary by LVEF strata.