Abstract 9361: The Effect of Immune Checkpoint Inhibitors on the Right Ventricle and Pulmonary Vasculature: Autopsy/Biopsy and Echocardiographic Data

Abstract

Introduction: Immune checkpoint inhibitors (ICI) have revolutionized cancer treatment but can lead to cardiovascular toxicities including myocarditis which can present as left ventricular dysfunction. Little is known about the effect of ICIs on the right ventricle (RV) and pulmonary vasculature. Methods: We identified six patients at our institution with ICI-induced myocarditis and right ventricular dysfunction. We also compared pulmonary pressure estimates or tricuspid regurgitant velocity measurements in two independent cohorts of patients who had pre- and post-ICI treatment echocardiography (echo) data. The first cohort included 13 unselected patients with renal cell carcinoma (RCC) or melanoma treated with an ICI at this institution. The second cohort included 31 patients from an international registry who met European Society of Cardiology criteria for ICI myocarditis. Echo parameters pre- and post-ICI were compared using the Wilcoxon signed rank test. Results: Biopsy and autopsy results from the six patient case series revealed lymphocytic myocarditis affecting the interventricular septum and right ventricle (Table 1). All patients with autopsies had RV dilation, and five of the six patients had RV dysfunction on imaging during their hospitalization. In the melanoma/RCC cohort, tricuspid regurgitation velocity was significantly increased post-ICI versus pre-ICI [mean 2.42, SD 0.51 m/s vs. mean 2.16, SD 0.48 m/s, p=0.03]. Right ventricular systolic pressure (RVSP) pre-ICI [mean 24.00, SD 8.26 mmHg] was decreased compared to post-ICI [mean 31.93, SD 12.93 mmHg, p=0.05]. In the second cohort, RVSP was significantly increased post-ICI [median: 30.5, IQR: 26.7-38] as compared to pre-ICI [median: 27.5, IQR: 24.6-35, p=0.03]. Conclusion: ICIs may negatively affect RV and pulmonary circulatory function. More research is needed to understand whether ICIs increase the risk of RV dysfunction and pulmonary vascular disease.