Background: Immune checkpoint inhibitors (ICIs) have uncommon associations with cardiotoxicity, yet these cardiotoxic effects are associated with high mortality. An accurate assessment of risk for cardiotoxicity is essential for clinical decision‐making, but data from randomized controlled trials often differ from real‐world observational studies. Methods and Results: A systematic search of PubMed, Embase, Cochrane Library, and Scopus was performed, including phase II and III randomized controlled trials (RCTs) and observational studies (OSs) reporting myocarditis or pericardial disease, myocardial infarction, or stroke with an immunotherapy. Odds ratios (ORs) were used to pool results between ICIs and other cancer therapy in RCTs and OSs. The Preferred Reporting Items for Systematic Reviews and Meta‐Analyses guideline was followed. In total, 54 RCTs (N=38 264) and 24 OSs (N=12 561 455) were included. In RCTs, ICI use resulted in higher risk of myocarditis (OR, 3.55 [95% CI, 2.10–5.98]), pericardial disease (OR, 2.73 [95% CI, 1.57–4.77]), and myocardial infarction (OR, 1.83 [95% CI, 1.03–3.25]), compared with non‐ICI (placebo or chemotherapy). In OSs, ICI use was not associated with myocarditis, pericardial disease, or myocardial infarction compared with controls; however, combination ICIs demonstrated higher risk of myocarditis compared with single ICI use (OR, 3.07 [95% CI, 1.28–7.39]). Stroke risk was not increased with use of ICIs in RCTs. Conclusions: We demonstrated increased risk of ICI myocarditis, pericardial disease, and myocardial infarction in RCTs but not OSs. Results of this study suggest there are differences between ICI cardiotoxicity risk, possibly suggesting differences in diagnoses and management, in clinical trials versus the OSs.

Introduction: Immune checkpoint inhibitors (ICIs) are associated with myocarditis, which is rare but has a high mortality. This study aimed to describe cases of ICI‐related myocarditis at the University of Iowa Hospitals & Clinics and, in doing so, provide valuable insights into patient characteristics, treatment, and outcomes.Methods: This single‐center observational registry included cases of ICI‐related myocarditis identified from 2009 to 2024. Data were collected retrospectively from electronic medical records and included demographics, cardiovascular risk factors, medications, and cancer characteristics. Between‐group comparisons for continuous data were conducted using unpaired Student's t‐tests or the Wilcoxon rank‐sum test. Categorical data were analyzed with Fisher's exact test.Results: Eighteen patients were included. The mean age was 74 ± 9.4 years with 61% being male. Compared to controls, patients with ICI‐related myocarditis had a significantly higher prevalence of coronary artery disease (36.8% vs. 7.5%, p = 0.01) and obstructive sleep apnea (33% vs. 10%, p = 0.03). They were less likely to have a normal sinus rhythm on baseline electrocardiogram (50% vs. 70%, p < 0.01) and more likely to suffer from a major adverse cardiac event (MACE) (38.9% vs. 2.5%, p < 0.01). Twelve (66.7%) of patients with ICI‐related myocarditis also had myasthenia gravis‐like overlap syndrome and 9 (50%) had myositis/rhabdomyolysis.Conclusions: ICI‐related myocarditis at a tertiary care center is rare with a calculated incidence of 0.48%. Despite this, the disease has a high incidence of MACE. Patients with pre‐existing cardiovascular disease are at higher risk of developing ICI‐related myocarditis. Careful cardiovascular monitoring in patients undergoing ICI therapy is warranted.

Background: Cardiac pseudoaneurysms are a potentially life-threatening pathology with a variety of non-specific clinical manifestations. This case series uniquely shares a collection of rare pathologies with differing preceding risk factors and presentations, with an emphasis on the utility of multi-modality imaging in diagnosis and management. Case summary: We present three cases of cardiac pseudoaneurysms. Case 1 is a 27-year-old woman with delayed presentation of a traumatic left ventricular pseudoaneurysm (LVP). Case 2 is a 73-year-old man with post-myocardial infarction LVP. Case 3 is a 38-year-old man with left ventricular outflow tract pseudoaneurysm after aortic valve replacement. Discussion: Cardiac pseudoaneurysms are rare and important to diagnose in a timely manner. Advances in non-invasive imaging modalities have improved our ability to distinguish pseudoaneurysms from other pathologies, leading to more timely management.