Cardiac MRI Features and Prognostic Value in Immune Checkpoint Inhibitor–induced Myocarditis

Abstract

I mmune checkpoint inhibitor (ICI)-induced myocarditis (ICI-M) is one of the most serious immunotherapy-related toxicities (1)(2)(3)(4). By reactivating the immune response against a tumor, ICIs can lead to numerous immune-related adverse events, including ICI-M. Although this cardiovascular event is uncommon, the case fatality rate is high, at approximately 30%-50%, and early administration of corticosteroids is required to improve the prognosis (5-7). We need better knowledge of the features of this emerging cardiovascular disease to modify the management of patients.Endomyocardial biopsy (EMB) is the reference standard for the diagnosis of myocarditis but is not systematically used because of its potential complications and low sensitivity (8). Cardiac MRI is now considered the best noninvasive imaging modality for the diagnosis of non-ICI-induced myocarditis based on the updated 2018 Lake Louise (2018-LL) criteria, which help identify myocardial abnormalities, including global or regional nonischemic injury and edema (9). In addition, cardiac MRI has prognostic value based on late gadolinium enhancement (LGE) presence, localization, and pattern (10-12). Very little data exist on cardiac MRI findings and their predictive value in ICI-M. Recently, two retrospective studies investigated the Background: Cardiac MRI features are not well-defined in immune checkpoint inhibitor (ICI)-induced myocarditis (ICI-M), a severe complication of ICI therapy in patients with cancer. Purpose:To analyze the cardiac MRI features of ICI-M and to explore their prognostic value in major adverse cardiovascular events (MACE). Materials and Methods:In this retrospective study from May 2017 to January 2020, cardiac MRI findings (including late gadolinium enhancement [LGE], T1 and T2 mapping, and extracellular volume fraction [ECV] z scores) of patients with ICI-M were compared with those of patients with cancer scheduled to receive ICI therapy (pre-ICI group) and patients with viral myocarditis. As a secondary objective, the potential value of cardiac MRI for predicting MACE in patients with ICI-M by using Cox proportional hazards models was explored.Results: Thirty-three patients with ICI-M (mean age 6 standard deviation, 68 years 6 14; 23 men) were compared with 21 patients scheduled to receive to ICI therapy (mean age, 65 years 6 14; 14 men) and 85 patients with viral myocarditis (mean age, 32 years 6 13; 67 men). Compared with the pre-ICI group, patients with ICI-M showed higher global native T1, ECV, and T2 z scores (0.03 6 0.85 vs 1.79 6 1.93 [P , .001]; 1.34 6 0.57 vs 2.59 6 1.97 [P = .03]; and 20.76 6 1.41 vs 0.88 6 1.96 [P = .002], respectively), and LGE was more frequently observed (27 of 33 patients [82%] vs two of 21 [10%]; P , .001). LGE was less frequent in patients with ICI-M than those with viral myocarditis (27 of 33 patients [82%] vs 85 of 85 [100%]; P , .001) but was more likely to involve the septal segments (16 of 33 patients [48%] vs 25 of 85 [29%]; P , .001) and midwall layer (11 of 33 patients [33%] vs two of 85...

What Is the Evidence of the Diagnostic Criteria and Screening of Immune Checkpoint Inhibitor–Induced Myocarditis?

“…The lower rate of LGE and the lower sensitivity of the 2018-LL criteria in ICI-M than in viral myocarditis was confirmed in a recent study. 8 Several hypotheses may explain these results, including lack of standardization of CMR protocols and ICI-M definition, small sample size of biopsy-proven cases, and the early initiation of corticosteroid therapy, which may have affected the diagnostic performance of CMR. 7 Finally, CMR results may be influenced by the patient characteristics.…”

Immune myocarditis related to sintilimab treatment in a patient with advanced lung adenocarcinoma: A case report

“…Cardiac magnetic resonance (CMR) has evolved as an standard noninvasive tool for the diagnosis and evaluation of myocarditis. Late gadolinium enhancement (LGE) is associated with a poor prognosis in patients with ICI-induced myocarditis ( 12 ). Myocardial biopsy and CMR are often not available in the setting of an acute presentation.…”

Clinical Manifestations, Monitoring, and Prognosis: A Review of Cardiotoxicity After Antitumor Strategy

“…In a recent study, although the global LGE was less frequent in patients with ICI-myocarditis than those with viral myocarditis, septal and midwall layer LGE was more common. Septal LGE was the only CMR predictor of MACE at 1 year after adjustment for peak troponin (84).…”