BACKGROUND Global circumferential strain (GCS) and global radial strain (GRS) are
reduced with cytotoxic chemotherapy. There are limited data on the effect of immune
checkpoint inhibitor (ICI) myocarditis on GCS and GRS. OBJECTIVES This study aimed
to detail the role of GCS and GRS in ICI myocarditis. METHODS In this retrospective
study, GCS and GRS from 75 cases of patients with ICI myocarditis and 50 ICI-treated
patients without myocarditis (controls) were compared. Pre-ICI GCS and GRS were available
for 12 cases and 50 controls. Measurements were performed in a core laboratory blinded
to group and time. Major adverse cardiovascular events (MACEs) were defined as a composite
of cardiogenic shock, cardiac arrest, complete heart block, and cardiac death. RESULTS
Cases and controls were similar in age (66 +/- 15 years vs 63 +/- 12 years; P = 0.20),
sex (male: 73% vs 61%; P = 0.20) and cancer type (P = 0.08). Pre-ICI GCS and GRS were
also similar (GCS: 22.6% +/- 3.4% vs 23.5% +/- 3.8%; P = 0.14; GRS: 45.5% +/- 6.2%
vs 43.6% +/- 8.8%; P = 0.24). Overall, 56% (n = 42) of patients with myocarditis presented
with preserved left ventricular ejection fraction (LVEF). GCS and GRS were lower in
myocarditis compared with on-ICI controls (GCS: 17.5% +/- 4.2% vs 23.6% +/- 3.0%;
P < 0.001; GRS: 28.6% +/- 6.7% vs 47.0% +/- 7.4%; P < 0.001). Over a median follow-up
of 30 days, 28 cardiovascular events occurred. A GCS (HR: 4.9 [95% CI: 1.6-15.0];
P = 0.005) and GRS (HR: 3.9 [95% CI: 1.4-10.8]; P = 0.008) below the median was associated
with an increased event rate. In receiveroperating characteristic (ROC) curves, GCS
(AUC: 0.80 [95% CI: 0.70-0.91]) and GRS (AUC: 0.76 [95% CI: 0.64-0.88]) showed better
performance than cardiac troponin T (cTnT) (AUC: 0.70 [95% CI: 0.58-0.82]), LVEF (AUC:
0.69 [95% CI: 0.56- 0.81]), and age (AUC: 0.54 [95% CI: 0.40-0.68]). Net reclassification
index and integrated discrimination improvement demonstrated incremental prognostic
utility of GRS over LVEF (P = 0.04) and GCS over cTnT (P = 0.002). CONCLUSIONS GCS
and GRS are lower in ICI myocarditis, and the magnitude of reduction has prognostic
significance. (J Am Coll Cardiol Img 2022;15:1883-1896) (c) 2022 the American College
of Cardiology Foundation. Published by Elsevier. All rights reserved.
