Diagnostic Value of the International Society of Cardio-Oncology Definition for Suspected Immune Checkpoint Inhibitor-Associated Myocarditis

Adverse myocardial and vascular side effects of immune checkpoint inhibitors: a prospective multimodal cardiovascular assessment

BACKGROUND

Immune checkpoint inhibitors (ICIs) can induce cardiovascular toxicities.

OBJECTIVES

To prospectively assess the incidence of major cardiovascular events (MACE) on ICIs in solid cancer patients: myocarditis, pericarditis, acute coronary syndrome, heart failure, high-degree conduction abnormalities or sustained ventricular arrhythmias, or cardiovascular death at 6 weeks (early MACE), including asymptomatic clinical changes by an independent adjudication committee using current recommended diagnostic criteria. The secondary objective was the incidence of the above-mentioned events adding atrial fibrillation (AF) at 6 months (late MACE).

RESULTS

Participants underwent pre-ICIs and repeated multimodality cardiac imaging (echocardiogram, cardiac magnetic resonance (CMR)), serum biomarkers (ultrasensitive troponin I), and rhythm surveillance (ambulatory ECG monitoring) at 6 weeks and 6 months. Forty-nine patients (38 (77.6%) male; mean age 64.3 (SD 11.0) years old) were included (June 2020-December 2021). Early MACE were observed in 9 (18.4%) patients at mean 40.1 (SD 5.9) days, with heart failure (HF) in 5 (10.2%), ventricular arrhythmias, or new conduction disorders in 4 (8.2%) patients. History of AF (HR 4.49 (CI 1.11-18.14), P = 0.035) predicted early MACE. At 6 months follow-up, 18 MACE were observed in 15/49 (31%) patients, with 6 (12.2%) HF events, 5 (10.2%) significant ventricular arrhythmias, or conduction disorders, and 4 (8.2%) AF. There was a significant decline in LVEF (P < 0.001) in patients with no MACE (P = 0.003) or HF (P = 0.0028). Higher creatinine at inclusion (HR 0.99 [0.98-1.00], P = 0.006) predicted HF on multivariate analysis. There were no significant T1 or T2 mapping changes in our study cohort on repeated CMR.

CONCLUSIONS

Cardiotoxicity on ICIs is more frequent than previously described when using a thorough detection strategy, consisting mainly in HF and asymptomatic rhythm disorders.

Immune Checkpoint Inhibitors and Their Cardiovascular Adverse Effects

Immune checkpoint inhibitors (ICIs) have reshaped and have become a well-established treatment modality for multiple advanced-stage malignancies. ICIs block the immune system regulatory checkpoints, namely CTLA-4 and PD-1/PDL1, which provokes excess immune response against self-antigens. Immune modulation with ICIs can result in diverse immune-related adverse events targeting organ systems. Several cases of ICI-related cardiotoxicity were reported, while the actual incidence was likely underestimated due to heterogeneous clinical presentation. These include, but are not limited to, myocarditis, pericarditis, atherosclerosis, and arrhythmia. EKG, Troponin, Echocardiogram (TTE), and Cardiac MRI (CMRI) are indispensable diagnostic tools to aid in the management of cardiac adverse effects. Herein, we review the ICI-mediated cardiovascular adverse events, diagnosis, treatment strategies, and reintroduction of ICIs post-cardiotoxicity.