Background: Serial troponin monitoring is used during immune checkpoint inhibitor (ICI) therapy, but guidelines do not specify whether high-sensitivity cardiac troponin I (hs-cTnI) or T (hs-cTnT) should be measured. Unlike cardiac-specific hs-cTnI, hs-cTnT can rise from noncardiac sources.
Objective: To determine the prevalence and temporal stability of hs-cTnT/hs-cTnI discordance, identify clinical correlates, and evaluate prognostic implications in ambulatory ICI-treated patients.
Methods: In this prospective single-center cohort, patients starting ICI therapy underwent paired hs-cTnT (Roche Elecsys) and hs-cTnI (Siemens Atellica) measurements in the same banked samples at baseline and one month. Patients with adjudicated ICI-associated myocarditis or myositis were excluded by design.
Results: Among 433 patients with paired baseline measurements, hs-cTnT was elevated in 37.9% and hs-cTnI in 1.8%; 158 (36.5%) were discordant (elevated hs-cTnT, normal hs-cTnI), and 267 (61.7%) had normal levels of both (κ = 0.036). Among 329 patients with paired data at baseline and one month, discordance prevalence was unchanged (38.3% vs 38.0%; McNemar P > 0.99). Independent correlates were older age, male sex, and chronic kidney disease (all P < 0.05). Over a median follow-up of 30.1 months (reverse Kaplan-Meier), elevated hs-cTnT was associated with all-cause mortality (adjusted HR: 1.35; 95% CI: 1.00–1.81; P = 0.048); only 8 of 231 deaths (3.5%) were cardiac.
Conclusions: In ambulatory ICI-treated cancer patients, over one-third had elevated hs-cTnT with normal hs-cTnI: a stable, nonspecific pattern present before ICI exposure and consistent with noncardiac sources rather than acute cardiac injury. hs-cTnI is the more cardiac-specific assay; paired baseline measurement of both troponins may help contextualize later elevations when myocarditis is suspected.
JACC CardioOncology Editor-in-Chief and CME Editor
Bonnie Ky, MD, MSCE, FACC
Author
Salim S. Hayek, MD
Important Dates
Date of Release: October 20, 2026
Term of Approval/Date of CME/MOC Expiration: October 19, 2027