Citations

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.

Case Description: Immune checkpoint inhibitors (ICIs) have transformed cancer therapy but are associated with immune-related adverse events, including cardiovascular toxicity. While ICI-myocarditis is rare but potentially fatal, thrombotic complications—such as venous thromboembolism, arterial occlusion, and non-bacterial thrombotic endocarditis (NBTE)—are underrecognized. These raise questions about the roles of malignancy-associated hypercoagulability versus ICI-induced effects. We present a case of NBTE and myocardial microthrombi mimicking ICI-myocarditis. A 76-year-old woman with metastatic adenosquamous lung cancer and recent DVT (on apixaban and aspirin) presented with worsening dyspnea three weeks after starting pembrolizumab (Image 1). One week earlier, CT pulmonary angiography and coronary angiography were unrevealing. On presentation, she was stable but had peripheral edema, a late diastolic murmur, and elevated hs troponin (706→657→656 ng/L). NT-proBNP was 11,500 pg/mL. Cardiac MRI showed mid-wall late gadolinium enhancement (LGE), myocardial edema, and elevated T2 values—findings concerning for ICI-myocarditis. She initially improved on intravenous methylprednisolone. A week later, brain MRI showed multifocal embolic infarcts. Doppler ultrasound revealed a new left-sided DVT. TEE showed no intracardiac thrombus but identified a thickened aortic valve with moderate-to-severe regurgitation, a thickened mitral A2 segment with moderate regurgitation, and a patent foramen ovale (PFO) with left-to-right shunting. Findings raised concern for NBTE with systemic embolism or paradoxical embolism. Anticoagulation was transitioned to heparin, then warfarin. She was discharged on oral prednisone without further cancer therapy. Two months later, she died suddenly. Autopsy revealed fibrin-rich vegetations on the mitral valve consistent with NBTE and thromboembolic infarcts in small myocardial arteries, without inflammatory infiltrates or myocardial scarring (Image 2 and 3). Conclusion: This case highlights NBTE and microthrombi as important mimics of ICI-myocarditis. Despite MRI features suggestive of inflammation, pathology confirmed ischemic injury. ICIs have been suggested to promote thrombosis through elevated factor VIII, von Willebrand factor, reduced protein S, and systemic inflammation. Clinicians should consider thrombotic mimics in ICI-treated patients with cardiac symptoms and abnormal imaging. Tissue diagnosis may be necessary to guide management.

Background: Disease-causative variants in LMNA -encoded lamin A/C cause the laminopathies, a heterogeneous group of diseases variably resulting in arrhythmogenic/dilated cardiomyopathy (ACM/DCM), lipodystrophy, muscular dystrophy, and progeria. The artificial intelligence (AI)-derived electrocardiographic age gap (AI-EAG), determined by the discrepancy between a patient’s artificial AI-enabled electrocardiogram (ECG) predicted biological age versus their chronological age, is accelerated in laminopathy. Thus, we sought to determine if the AI-EAG serves as a prognostic marker in patients with cardiac laminopathy. Methods: Retrospective analysis of 1,049 genotype-positive patients with genetic ACM/DCM was used to identify those with pathogenic/likely pathogenic (P/LP) variants in LMNA . After the exclusion of those who lacked a 12-lead ECG while in sinus rhythm, a previously trained AI-ECG age algorithm was used to determine the AI-EAG by subtracting the patient’s chronological age from the AI-ECG derived biological age. The AI-EAG was then correlated with a combined outcome of major ventricular arrhythmia [sudden cardiac arrest, sustained ventricular tachycardia, and appropriate implantable cardioverter-defibrillator shocks], heart transplantation, and cardiovascular death. Results: Overall, 147/1,049 (14%) patients with genetically-mediated ACM/DCM had a P/LP variant in LMNA . Of these, 80/147 (54%) LMNA variant-positive patients (52% female, mean chronological age 36 ± 15 years) had ECGs suitable for AI-EAG analysis. Most (52/80; 65%) had an AI-EAG >10 years with a mean AI-EAG of 17 ± 13 years. Of note, the AI-EAG was greater in those with a clinical cardiac phenotype (20 ± 14 vs. 13 ± 10 years; p = 0.011). As a continuous variable, an increased AI-EAG was associated with increased risk of the composite outcome at a median follow-up of 20 months (HR 1.036; 95% CI 1.004–1.068; p = 0.026) and AI-EAG > 10 and > 20 years were both associated with elevated risk (HR 4.272; 95% CI 1.388–13.147; p = 0.011 and HR 3.732; 95% CI 1.505–9.255; p = 0.004, respectively). Conclusion: In cardiac laminopathy, an increased AI-EAG was common and correlated with adverse cardiovascular outcomes. Non-invasive ascertainment of electrocardiographic aging by AI may provide a novel prognostic marker in cardiac laminopathy. Future studies are needed to validate this finding and further define the role of the AI-EAG in the risk-stratification of patients with cardiac laminopathy.

Background: Arrhythmogenic and dilated cardiomyopathies (ACM/DCM) are associated with adverse cardiovascular outcomes, including sudden death. Artificial intelligence (AI)-enabled electrocardiographic aging algorithms estimate biological age from 12-lead tracings and predict cardiovascular outcomes in the general population. However, their utility in genetic ACM/DCM has not been studied. Methods: Retrospective review of 1,045 genotype-positive ACM/DCM patients was used to identify those with a pathogenic/likely pathogenic variant in ClinGen-classified definitive/strong evidence ACM/DCM-susceptibility genes. Following exclusion of patients without a baseline ECG for analysis (e.g. paced rhythms), the AI-ECG age gap (AI-EAG) was calculated by subtracting chronological from AI-ECG age. Genes were grouped into functional categories: desmosomal ( PKP2, DSP, DSG2, DSC2, JUP ), nuclear envelope ( LMNA ), sarcomeric ( TTN, MYH7, TNNT2 ), cytoskeleton/Z-disc ( FLNC, DES, DMD, BAG3 ), and regulatory/ion channel ( PLN, RBM20, SCN5A ). Cardiac MRI data included left ventricular structure, function, and late gadolinium enhancement (LGE) presence and pattern. Mann-Whitney U was used for group comparisons; results are shown as median (IQR). Results: Overall, 824 patients (52.8% male; median age of 40.7 years, IQR 26.5–53.4; and median AI-EAG of 7.49 years, IQR 0.43–15.26) were included. DES variant-positive patients had the highest (19.98 years, IQR 9.66–23.21) and BAG3 variant-positive patients the lowest (–0.95 years, IQR -6.05–7.61) AI-EAGs. Among gene groups, nuclear envelope had the highest (15.12 years, IQR 6.79–25.17) and sarcomeric the lowest (5.75 years, IQR -0.69-14.01) AI-EAGs. Cardiac MRI was available for 538/824 (65%) of which 233/538 (43.3%) had LGE. No significant difference in AI-EAG was observed between LGE-positive and -negative patients (6.99 vs. 7.94 years; p=0.831). However, several LGE patterns were associated with significantly higher AI-EAGs: subepicardial (9.88 vs. 6.84; p=0.004), transmural (13.83 vs. 7.25; p=0.012), apical (12.89 vs. 7.17; p=0.002), and septal (8.91 vs. 7.19; p=0.016). Conclusion: AI-EAG varies by gene and functional group, possibly reflecting gene-specific myocardial remodeling. While certain LGE patterns were linked to increased biological aging, overall LGE status was not. These findings suggest AI-EAG may capture disease activity that is distinct from LGE and could serve as a complementary, non-invasive biomarker in genetic ACM/DCM.

ABSTRACT Background This study aims to assess how Watchman FLX (Boston Scientific) and Amplatzer Amulet (Abbott) devices for left atrial appendage occlusion (LAAO) impact the flow dynamics in the LA and the risk of device‐related thrombosis (DRT). Methods Flow simulations were carried out for 12 AF patients before and after undergoing LAAO. Six patients had Watchman FLX while the other six had Amulet devices, of which three in each group had DRT. The flow parameters investigated included the LA velocities, pressure, time averaged wall shear stress (TAWSS), oscillatory shear index (OSI), and relative residence time (RRT). Low TAWSS and high OSI and RRT are generally associated with flow stasis and thrombosis. Results LA flow dynamics differed significantly between the two groups. On average, after LAAO, the Amulet patients exhibited a 25% increase in TAWSS and 24% decrease in RRT while the Watchman FLX patients exhibited, on average, a 24% decrease in TAWSS and a 23% increase in RRT. Both populations experienced an increase in LA pressure (~10% for Amulet patients and 16% for Watchman FLX patients). Increased DRT volume seems to be correlated with low TAWSS and elevated RRT. Conclusion This preliminary study suggests that the Amulet device might be associated with improved LA flow dynamics and a potentially lower incidence of DRT compared with the Watchman. However, a larger clinical study is needed to confirm these findings.

Background Stroke remains a concern after transcatheter aortic valve replacement (TAVR). Several studies attempted to identify correlates of stroke but there remains a need for better predictors. Objective This study aims to characterize the aortic arch to identify potential correlates of stroke after TAVR using a patient cohort that includes cases with and without stroke. Methods A retrospective analysis was performed on 52 patients who underwent TAVR at Mayo Clinic and Maria Cecilia Hospital. Of these patients, 26 had a stroke after TAVR and 26 did not (control). Anatomical characterization was performed on each patient. Patient-specific 3D digital models of the ascending aorta, aortic arch, and calcium were created for each patient. Geometrical measurements, including cross-sectional areas, volumes, tortuosity, curvature, and length of the model were recorded. Results There was no significant difference in the various area measurements between the two groups, but the aortic arch cross-sectional area ratio (cerebral ostia cross-sectional areas/arch cross-sectional area) was significantly higher in the stroke group. Additionally, there was no significant difference in tortuosity, curvature, aortic volume, and length of the aorta. Aortic valve calcium score, aorta calcium, and aortic arch type (I, II, or III) were not significantly different between the groups. The prevalence of a bovine arch (BA) configuration was significantly higher in the stroke group (46% vs 8% control, p < 0.05). Conclusion Aortic arch cross-sectional area ratio and BA variant were the most significant correlates of stroke after TAVR.

Abstract Background The exclusion/occlusion of the left atrial appendage (LAA) is a treatment option for atrial fibrillation (AF) patients who are at high risk of stroke and high risk of bleeding. As the role of the LAA is not well understood or explored, this study aims to assess its role on flow dynamics in the left atrium. Methods Computational fluid dynamics (CFD) simulations were carried out for nine AF patients before and after LAA exclusion. The flow parameters investigated included the LA velocities, Time Averaged Wall Shear Stress (TAWSS), Oscillatory Shear Index (OSI), Relative Residence Time (RRT), and Pressure in the LA. Results This study shows that, on average, a decrease in TAWSS (1.82 ± 1.85 Pa to 1.27 ± 0.96 Pa, p < 0.05) and a slight increase in OSI (0.16 ± 0.10 to 0.17 ± 0.10, p < 0.05), RRT (1.87 ± 1.84 Pa −1 to 2.11 ± 1.78 Pa −1 , p < 0.05), and pressure (−19.2 ± 6.8 mmHg to −15.3 ± 8.3 mmHg, p < 0.05) were observed in the LA after the exclusion of the LAA, with a decrease in low‐magnitude velocities. Conclusion The exclusion of the LAA seems to be associated with changes in LA flow dynamics. Further studies are needed to elucidate the clinical implications of these changes.

Background Acute ischemic stroke complicates 2% to 3% of transcatheter aortic valve replacements (TAVRs). This study aimed to identify the aortic anatomic correlates in patients after TAVR stroke. Methods and Results This is a single‐center, retrospective study of patients who underwent TAVR at the Mayo Clinic between 2012 and 2022. The aortic arch morphology was determined via a manual review of the pre‐TAVR computed tomography images. An “a priori” approach was used to select the covariates for the following: (1) the logistic regression model assessing the association between a bovine arch and periprocedural stroke (defined as stroke within 7 days after TAVR); and (2) the Cox proportional hazards regression model assessing the association between a bovine arch and long‐term stroke after TAVR. A total of 2775 patients were included (59.6% men; 97.8% White race; mean±SD age, 79.3±8.4 years), of whom 495 (17.8%) had a bovine arch morphology. Fifty‐seven patients (1.7%) experienced a periprocedural stroke. The incidence of acute stroke was significantly higher among patients with a bovine arch compared with those with a nonbovine arch (3.6% versus 1.7%; P =0.01). After adjustment, a bovine arch was independently associated with increased periprocedural strokes (adjusted odds ratio, 2.16 [95% CI, 1.22–3.83]). At a median follow‐up of 2.7 years, the overall incidence of post‐TAVR stroke was 6.0% and was significantly higher in patients with a bovine arch even after adjusting for potential confounders (10.5% versus 5.0%; adjusted hazard ratio, 2.11 [95% CI, 1.51–2.93]; P <0.001). Conclusions A bovine arch anatomy is associated with a significantly higher risk of periprocedural and long‐term stroke after TAVR.