Introduction
There have been incident reports of cardiac-related adverse events (CrAE) from immune checkpoint inhibitors (ICPI); however, the true incidence and subsequent management of these potential side effects have not been defined. It is therefore important to study ICPI related cardiac dysfunction to assist in monitoring and surveillance of these patients.
Methods
63 patients who received nivolumab and pembrolizumab at Stratton VAMC Albany between January 2015 to December 2018 were studied. Retrospective chart review was done to identify the CrAE up to two-year post-therapy completion or discontinuation. Naranjo score was used to assess drug-related side effect. IRB approval was obtained.
Results
CrAE were defined as new onset arrythmia identified on electrocardiogram, evidence of cardiomyopathy on echocardiogram, an acute coronary event, and hospitalizations from primary cardiac disorder following ICPI administration. Of the 63 patients, 6 patients developed CrAE. Our review showed 3 patients developed new arrythmias including 1 with atrial fibrillation, and 2 with atrial flutter. There was 1 case each of new heart failure with reduced ejection fraction and pericarditis with pericardial tamponade. 1 patient developed acute coronary syndrome in addition to complete heart block. Of the 6 patients, 2 had elevated brain natriuretic peptide (BNP) prior to onset of CrAE. Elevated markers including BNP and troponin-I were also seen in 13 patients with preexisting heart conditions without CrAE. Duration of therapy was variable for all patients with CrAE. Therapy was continued for 3 patients without recurrence of CrAE. Therapy was permanently discontinued in the patient who developed pericardial effusion (grade IV toxicity). The remaining 2 patients had additional concurrent immune-related toxicities that required discontinuation of therapy. Our analysis showed 25/63 patients with pre-existing cardiac conditions (including arrhythmia, heart failure or coronary artery disease) who did not develop new CrAE; however 6 of these patients required hospitalization for exacerbation related to these pre-existing conditions.
Conclusions
CrAE can occur with ICPIs, and vigilance is required in high-risk patient including those with pre-existing cardiac comorbidity. Further studies are required to establish if baseline screening EKG and echocardiogram should be obtained for all patients starting ICPI.