Prospective serial cardiovascular magnetic resonance imaging of immune checkpoint inhibitor myocarditis correlates...

Limited prospective data exist on the utility of serial cardiovascular magnetic resonance (CMR) imaging in immune checkpoint inhibitor (ICI) myocarditis.

To evaluate serial changes in CMR parameters and outcomes in patients with ICI myocarditis.

Patients were enrolled into two arms as follows: 1) ICI myocarditis (ICI exposure with development of cardiac symptoms and abnormal cardiac biomarkers) or 2) pre-ICI control (patients planned to receive ICI therapy). Both cohorts received CMR imaging at the time of enrollment and upon follow-up at 8-12 weeks. CMR parameters were associated with adverse cardiovascular events (ACE).

Sixty-two patients were enrolled (N=52 in ICI myocarditis cohort; N=10 in pre-ICI control cohort). In those with ICI myocarditis, upon presentation, 38% of patients had a reduced LVEF (defined as < 57%) with a mean LVEF of 58% (SD ±12). LV global longitudinal strain (GLS) by feature tracking (FT) CMR was abnormal in 81% of patients (defined as > -18%) with a mean GLS -10% (SD ± 5). Eighty-five percent met at least one Lake Louise Criteria (LLC). Decreased LVEF at enrollment was associated with ACE (r= -0.437, p=0.002), as was increased CMR FT GLS and global circumferential strain (r=0.387, p=0.008 and r=0.439, p=0.002, respectively). Worse left atrial (LA) ejection fraction by CMR correlated with arrhythmia (r= -0.467, p=0.051), and presence of LA LGE correlated with heart failure (r=0.866, p=0.012). Abnormal LA strain parameters, including contraction strain (r=0.611, p=0.007) and reservoir strain (r=0.543, p=0.005) on follow-up, CMR were associated with death in those with ICI myocarditis.

Baseline and serial CMR parameters are associated with incident ACE. Serial CMR evaluation may further risk-stratify ICI myocarditis patients.