Global circumferential and radial strain among patients with immune checkpoint inhibitor myocarditis

Abstract

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 ¼ 0.20), sex (male: 73% vs 61%; P ¼ 0.20) and cancer type (P ¼ 0.08). Pre-ICI GCS and GRS were also similar (GCS: 22.6% 3.4% vs 23.5% 3.8%; P ¼ 0.14; GRS: 45.5% 6.2% vs 43.6% 8.8%; P ¼ 0.24). Overall, 56% (n ¼ 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 ¼ 0.005) and GRS (HR: 3.9 [95% CI: 1.4-10.8]; P ¼ 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 ¼ 0.04) and GCS over cTnT (P ¼ 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) © 2022 the American College of Cardiology Foundation. Published by Elsevier. All rights reserved.