Abstract 12534: Incidence of Cardiotoxicity After Immune Checkpoint Inhibitor Therapy

Abstract

Introduction: Immune checkpoint inhibitors (ICI) have transformed care for cancer patients but can lead to immune-mediated toxicities in multiple organ systems. Cardiovascular toxicities are thought to be infrequent, but existing data likely underestimate this. We utilized Medicare claims data to define the incidence of cardiotoxicity after ICI therapy at a population level. Methods: We identified all fee-for-service beneficiaries who received an ICI, including CTLA-4 inhibitors, PD-1 inhibitors or PD-L1 inhibitors, between March 2011 through December 2018 using 100% Medicare Parts A and B. Demographic information, preexisting cardiac conditions, other comorbidities and cancer types were determined in the year prior to ICI exposure. Cardiac toxicities were identified using ICD-9/10 codes in the year after initial exposure. Results: In total, 40,676 patients were identified. Most (75%) received a PD-1 inhibitor and a significant minority (10%) received combination therapy. Across all ICI therapies, the incidence of myocarditis and related complications (ventricular arrhythmia, sudden cardiac death, heart block and cardiogenic shock) was 2.95% at one year. The incidence of acute decompensated heart failure was 10.76%, acute coronary syndrome 3.06% and death 1.92%. The highest incidence of myocarditis and associated cardiac diagnoses was seen with combination therapy (3.56%). Conclusions: Immune checkpoint inhibitors are associated with myocarditis and other serious cardiac toxicities. Results from our population level study suggest the incidence of cardiotoxicity after ICI exposure is likely higher than previously reported. The incidence of myocarditis and related complications is highest with combination therapy, as reported in prior studies.