Bois, John P

Abstract Background Immune checkpoint inhibitors (ICIs) have revolutionized cancer treatment and are increasingly associated with cardiovascular toxicities, including myocarditis and accelerated atherosclerosis. While ICI myocarditis has received substantial attention, thrombotic complications remain underrecognized and may be difficult to distinguish from immune-mediated cardiac inflammation and cancer-related hypercoagulable state. We present a case of non-bacterial thrombotic endocarditis (NBTE) and myocardial microthrombi mimicking ICI myocarditis. Case summary A 76-year-old woman with metastatic adenosquamous lung carcinoma presented with progressive dyspnoea 3 weeks after initiating pembrolizumab. Pulmonary arterial and coronary imaging were unremarkable, but cardiac magnetic resonance imaging (MRI) showed late gadolinium enhancement (LGE) and myocardial oedema suggestive of ICI myocarditis. Chest computed tomography revealed inflammatory lung changes, and empirical corticosteroids were initiated with initial clinical improvement. One week later, brain MRI showed multifocal infarcts, and Doppler ultrasound identified bilateral lower extremity deep vein thromboses. Transoesophageal echocardiography showed thickened mitral and aortic valves with moderate regurgitation. Non-bacterial thrombotic endocarditis with embolic phenomena was suspected. Anticoagulation was escalated from apixaban to therapeutic enoxaparin, followed by warfarin. Despite initial stabilization, the patient died 2 months later. Post-mortem examination revealed fibrin-rich valvular vegetations consistent with NBTE, widespread intramyocardial thrombi, and no histopathologic evidence of myocarditis. Discussion This case underscores how microthrombotic complications of ICI therapy may closely mimic myocarditis on imaging. Nonspecific cardiac MRI findings, such as LGE and T2 signal elevation, can result from thrombotic or ischaemic injury alike. Histopathologic confirmation may be required for accurate diagnosis, as misclassification can lead to suboptimal treatment.

Abstract Background Cardiac masses encompass a broad differential, including benign tumours, malignancies, and pseudotumours. Accurate diagnosis requires integration of clinical context, patient characteristics, lesion location, and imaging features. In select cases, tissue characterization is necessary. We describe a case of a rapidly enlarging interatrial mass following transcatheter aortic valve implantation (TAVI). Case summary A 70-year-old man underwent TAVI for severe low-flow, low-gradient aortic stenosis. Preprocedural imaging revealed an incidental interatrial mass consistent with lipomatous hypertrophy of the atrial septum (LHAS). Six months later, the mass showed significant interval growth, raising concern for malignancy. Multimodality imaging, including cardiac magnetic resonance imaging and FDG positron emission tomography yielded indeterminate results. An echocardiography-guided biopsy was performed, and histopathologic analysis confirmed LHAS with intralesional haemorrhage likely incurred during the TAVI procedure. Discussion While LHAS is typically benign and stable or slowly progressive, rare cases may present with atypical features and rapid growth, mimicking malignant cardiac tumours. This case represents the first reported instance of LHAS with haemorrhagic expansion.

Abstract Aims Catheter ablation is commonly performed in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) for management of ventricular arrhythmias (VAs). The impact of catheter ablation on cardiac function is unknown. The aim is to assess the impact of catheter ablation for VAs on cardiac function in patients with ARVC. Methods and results This retrospective study included consecutive patients with ARVC who underwent catheter ablation for VAs. Cardiac and valvular functions were assessed on pre- and post-procedure cardiac imaging. The severities of tricuspid regurgitation, pulmonic regurgitation, right ventricular (RV) enlargement, and RV systolic dysfunction was graded as absent (=0), mild (=1), mild-moderate (=2), moderate (=3), moderate-severe (=4), or severe (=5). Thirty-four patients were included. Median age at the time of ablation was 49 [inter-quartile range (IQR), 23] years, and 10 (29%) patients were female. After a median follow-up of 1 (IQR, 0) day, 11 (34%) patients had worsening RV function, and 4 (12%) patients had worsening left ventricular ejection fraction (LVEF) >5%. Five (15%) patients required inotropic support. After a median follow-up of 6.5 (IQR, 6.4) months, 20 (59%) patients had repeat transthoracic echocardiograms. Among patients with worsening RV function post-ablation, one-sixth (17%) had improvement in the RV function at follow-up. In contrast, among patients who had an acute drop in LVEF post-ablation, two-thirds (67%) had improvement at follow-up. Conclusion Right ventricular dysfunction following catheter ablation in patients with ARVC is common, affecting one-third of patients. Patients undergoing catheter ablation of VAs should be counselled on the potential negative impact of ablation on cardiac function.

Heart failure with reduced ejection fraction (HFrEF) is a progressive clinical syndrome commonly associated with left ventricle dilatation and characterized by reduced cardiac output, secondary pulmonary and systemic venous congestion, and inadequate peripheral oxygen delivery. It is common yet complex and requires synthesis of evidence-based guidelines along with strong clinical acumen. The following is a review of an illustrative case that highlights the important clinical considerations in diagnosis, assessment, and management of HFrEF commonly encountered in practice. Explanations provided highlight of the relevant pathophysiology of HFrEF as well as detailed explanations of interpretation of examinations and both noninvasive and invasive assessment in heart failure. The example provided would hopefully serve as a potential point of reference for trainees as well as healthcare practitioners for patients with HFrEF.