Hypertrophic cardiomyopathy-related left ventricular pseudoaneurysm: A case report.

Background: Myocardial infarction-related left ventricular pseudoaneurysm (LVP), covered by the adjacent pericardial or scar tissue, is a fatal sequela of left ventricular rupture. Whereas hypertrophic cardiomyopathy (HCM) may cause left ventricular true aneurysm. Differentiating LVP from left ventricular true aneurysm is crucial because their natural histories and treatment strategies are distinct. However, the incidence and management of HCM-related LVP remain unknown. Case presentation: An 88-year-old man was admitted to our hospital with sudden-onset chest pain. Upon initial examination, vital signs were stable, and a grade 4/6 systolic murmur was noted. An electrocardiogram revealed atrial fibrillation and poor R-wave progression without ST-T changes or negative T-waves. An echocardiography showed mild left ventricular hypertrophy, mid-ventricular obstruction with a significant intraventricular pressure gradient, left ventricular outflow tract obstruction, and a small left ventricular apical outpouching. Cardiac computed tomography angiography (CCTA) assisted in the diagnosis of LVP, and an accompanying pericardial effusion suggested impending cardiac rupture. Because the patient initially refused our proposed urgent surgery, medication was initiated with continuous hemodynamic monitoring in the intensive care unit; however, the patient's condition did not improve. During a semi-urgent surgical repair of the aneurysmal wall, LVP was observed and confirmed by pathology. Myocardial tissue adjacent to the pseudoaneurysm was consistent with that of HCM. Subsequently, a final diagnosis of HCM-related LVP was made. The postoperative course was notable for transient profound hypotension. Thereafter, the patient died of non-occlusive mesenteric ischemia on day 6. Conclusions: To our knowledge, this is the first reported case of HCM-related LVP mimicking impending cardiac rupture. Our case highlights the importance of considering HCM-related LVP in patients with left ventricular outpouching and CCTA in the LVP diagnosis. In further research, data on the appropriate management of HCM-related LVP should be accumulated.

Pro-Hemorrhagic Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy Associated with NOTCH3 p.R75P Mutation with Low Vascular NOTCH3 Aggregation Property.

OBJECTIVES: Intracerebral hemorrhage (ICH) and cerebral microbleeds (CMB) in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy are more common in East Asian populations than in people of white European ancestry. We hypothesized that the ethnic difference is explained by the East Asian-specific NOTCH3 p.R75P mutation. METHODS: This retrospective observational study included 118 patients with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy in Japanese and Korean cohorts. We investigated whether the p.R75P mutation is associated with symptomatic ICH and multiple CMB (>5) using quasi-Poisson regression models. We predicted the NOTCH3 extracellular domain protein structures in silico and graded NOTCH3 extracellular domain immunostaining in skin vessels of some patients, with subsequent comparisons between p.R75P and other conventional mutations. RESULTS: Among 63 Japanese patients (median age 55 years; 56% men), 15 had a p.R75P mutation, significantly associated with symptomatic ICH (adjusted relative risk 9.56, 95% CI 2.45-37.31), multiple CMB (3.00, 1.34-6.71), and absence of temporopolar lesions (4.91, 2.29-10.52) after adjustment for age, sex, hypertension, and antithrombotics. In the Korean cohort (n = 55; median age 55 years; 51% men), the p.R75P mutation (n = 13) was also associated with symptomatic ICH (8.11, 1.83-35.89), multiple CMB (1.90, 1.01-3.56), and absence of temporopolar lesions (2.32, 1.08-4.97). Structural analysis revealed solvent-exposed free cysteine thiols in conventional mutations, directly causing aggregation, whereas a stereochemically incompatible proline residue structure in p.R75P lowers correct disulfide bond formation probability, indirectly causing aggregation. Pathologically, the p.R75P mutation resulted in less vascular NOTCH3 extracellular domain accumulation than the other conventional mutations. INTERPRETATION: NOTCH3 p.R75P mutation is associated with hemorrhagic presentations, milder temporopolar lesions, and distinct mutant protein structure properties. ANN NEUROL 2024;95:1040-1054.

Pathological changes in the lenticulostriate artery indicate the mechanisms leading to intracranial hemorrhage in Moyamoya disease: a case report.

This case report details the pathological findings of a vessel wall identified as the bleeding point for intracranial hemorrhage associated with Moyamoya disease. A 29-year-old woman experienced intracranial hemorrhage unrelated to hyperperfusion following superficial temporal artery-middle cerebral artery bypass surgery. A pseudoaneurysm on the lenticulostriate artery (LSA) was identified as the causative vessel and subsequently excised. Examination of the excised pseudoaneurysm revealed a fragment of the LSA, with a disrupted internal elastic lamina and media degeneration. These pathological findings in a perforating artery, akin to the circle of Willis, provide insights into the underlying mechanisms of hemorrhage in Moyamoya disease.

18F-FDG PET/CT in left atrial undifferentiated pleomorphic sarcoma with osteosarcomatous differentiation.

Primary cardiac sarcomas are rare and sometimes difficult to discern from benign tumors and intracardiac thrombi. We describe the ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), and 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/CT findings in a case of left atrial undifferentiated pleomorphic sarcoma with osteosarcomatous differentiation, presenting with severe mitral regurgitation and pulmonary hypertension. The tumor presented as a broad-base mass protruding into the cardiac lumen, accompanied by punctate calcification-like high attenuation on CT. 18F-FDG PET/CT revealed high 18F-FDG uptake in the mass. Severe mitral regurgitation, a rare manifestation, was caused by tumor extension to the mitral valve leaflets and subvalvular tissue, which was best visualized on transesophageal echocardiography. This case illustrates the importance of multimodal diagnostic approaches including 18F-FDG PET/CT, which can facilitate accurate diagnosis and timely initiation of curative treatment, ultimately saving the patient's life. Learning objective: Firstly, cardiac sarcomas, particularly those with calcification/ossification, are rare and may mimic benign tumors and chronic intracardiac thrombi. Multimodal imaging approach, including 18F-FDG PET/CT, may be helpful in the accurate diagnosis of malignancies. Second, left atrial undifferentiated pleomorphic sarcoma has the potential to extensively spread along the endocardium and can extend to involve the valve leaflets, resulting in mitral regurgitation and pulmonary hypertension.

Can right ventricular endomyocardial biopsy predict left ventricular fibrosis beforehand in dilated cardiomyopathy?

AIMS: Myocardial fibrosis of the left ventricle (LV) is a prognostic factor in dilated cardiomyopathy (DCM). This study aims to evaluate whether fibrosis of right ventricular (RV) endomyocardial biopsy (EMB) can predict the degree of LV fibrosis beforehand in DCM. METHODS AND RESULTS: Fibrosis extent in 70 RV-EMB specimens of DCM diagnosis was compared with that in the whole cross-sectional LV of excised hearts in the same patients (52 explanted hearts for transplant and 18 autopsied hearts). The median interval between biopsy and excision was 4.1 (0.13-19.3) years. The fibrosis area ratio of the EMBs and excised hearts were evaluated via image analysis. The distribution of cardiovascular magnetic resonance-late gadolinium enhancement (LGE) in the intraventricular septum was classified into four quartile categories. The fibrosis area ratio in RV-EMB correlated significantly with that in the short-axis cut of the LV of excised hearts (r = 0.82, P < 0.0001) and with a diffuse pattern of LGE (r = 0.71, P = 0.003). In a multivariate model, after adjusting for the interval between biopsy performance and heart excision, the fibrosis area ratio in RV-EMB was associated with that in LV-excised heart (regression coefficient, 0.82; 95% confidence interval, 0.68-0.95; P < 0.0001). CONCLUSIONS: The fibrosis observed in RV-EMB positively correlated with the extent of fibrosis in the LV of excised hearts in patients with DCM. The study findings may help predict LV fibrosis, considered a prognostic factor of DCM through relatively accessible biopsy techniques.

Tenascin-C as a potential marker for immunohistopathology of doxorubicin-induced cardiomyopathy.

Aims: Doxorubicin is used in classical chemotherapy for several cancer types. Doxorubicin-induced cardiomyopathy (DOX-CM) is a critical issue among cancer patients. However, differentiating the diagnosis of DOX-CM from that of other cardiomyopathies is difficult. Therefore, in this study, we aimed to determine novel histopathological characteristics to diagnose DOX-CM. Methods and results: Twelve consecutive patients with DOX-CM who underwent cardiac histopathological examination in two medical centres were included. Twelve patients with dilated cardiomyopathy, who were matched with DOX-CM patients in terms of age, sex, and left ventricular ejection fraction, formed the control group. Another control group comprised five consecutive patients with cancer therapy-related cardiac dysfunction induced by tyrosine kinase inhibitors or vascular endothelial growth factor inhibitors were the controls. The positive area of tenascin-C, number of infiltrating macrophages, and presence of p62- and ubiquitin-positive cardiomyocytes were evaluated. Human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) were used for in vitro investigation. The myocardium exhibited significantly greater tenascin-C-positive area and macrophage number in the DOX-CM group than in the control groups (P < 0.01). The tenascin-C-positive area correlated with the number of both CD68- and CD163-positive cells (r = 0.748 and r = 0.656, respectively). Immunostaining for p62 was positive in 10 (83%) patients with DOX-CM. Furthermore, western blotting analysis revealed significant increase in tenascin-C levels in hiPSC-CMs upon doxorubicin treatment (P < 0.05). Conclusion: The combined histopathological assessment for tenascin-C, macrophages, and p62/ubiquitin may serve as a novel tool for the diagnosis of DOX-CM. Doxorubicin may directly affect the expression of tenascin-C in the myocardium.

A 5-year survivor of endarterectomy for sclerosing undifferentiated intimal sarcoma of the pulmonary artery: Importance of clinical suspicion and careful histologic evaluation.

We present a diagnostically challenging case of intimal sarcoma of the pulmonary artery (PA) due to the histologic finding of a sclerosing appearance with no appreciable spindle/pleomorphic cell proliferation. Initial endarterectomy specimens were composed of sclerosing extracellular matrix with a few bland cells, some recanalization, and fibrin thrombi, impeding the confirmation of intimal sarcoma as these findings were also consistent with chronic thromboembolic pulmonary hypertension. However, the patient experienced recurrence 5 years later, and the second endarterectomy specimens revealed more firm and solid mass and the proliferation of atypical spindle/pleomorphic cells within a myxomatous matrix in the distal PA, leading to the definitive diagnosis of undifferentiated intimal sarcoma of the PA. The archival specimens from the endarterectomy confirmed intense MDM2 expression by immunohistochemistry, suggesting its role as a potential diagnostic marker for intimal sarcoma. This case highlights that prominent sclerosing extracellular matrix with very few atypical cells should raise the possibility of intimal sarcoma of the PA and that high index of suspicion, generous sampling, and ancillary tests are critical for accurate diagnosis. In this case, the tumor was incidentally removed by endarterectomy, resulting in 5 years of survival.

Modeling Reduced Contractility and Stiffness Using iPSC-Derived Cardiomyocytes Generated From Female Becker Muscular Dystrophy Carrier.

Study investigators encountered a female Becker muscular dystrophy (BMD) carrier with advanced heart failure (HF) and identified a stop-gain variant in procollagen-lysine, 2-oxoglutarate 5-dioxygenase 3 (PLOD3) as a potential second-hit variant. Isogenic induced pluripotent stem cells (iPSCs) with dominant expression of WT-DMD, Δ45-48-DMD, or Δ45-48-DMD with corrected PLOD3 variant were established. Microforce testing using 3-dimensional self-organized tissue rings (SOTRs) generated from iPSC-derived cardiomyocytes (iPSC-CMs) demonstrated that correction of the heterozygous PLOD3 variant did not improve the reduced force, but it significantly recovered the reduced stiffness in Δ45-48-DMD SOTRs. Correction of the PLOD3 variant restored collagen synthesis in iPSC-CMs. Our findings revealed the pathogenesis underlying advanced HF in a female BMD carrier.

Transthyretin derived amyloid deposits in the atrium and the aortic valve: insights from multimodality evaluations and mid-term follow up.

BACKGROUND: Recent studies have reported atrial involvement and coexistence of aortic stenosis in transthyretin (ATTR) cardiac amyloidosis (CA). However, pathological reports of extraventricular ATTR amyloid deposits in atrial structures or heart valves are limited, and the clinical implications of ATTR amyloid deposits outside the ventricles are not fully elucidated. CASE PRESENTATION: We report 3 cases of extraventricular ATTR amyloid deposits confirmed in surgically resected aortic valves and left atrial structures, all of which were unlikely to have significant ATTR amyloidosis infiltrating the ventricles as determined by multimodality evaluation including 99mtechnetium-pyrophosphate scintigraphy, cardiac magnetic resonance, endomyocardial biopsy and their mid-term clinical course up to 5 years. These findings suggested that these were extraventricular ATTR amyloid deposits localized in the aortic valve and the left atrium. CONCLUSIONS: While long-term observation is required to fully clarify whether these extraventricular ATTR amyloid deposits are truly localized outside the ventricles or are early stages of ATTR-CA infiltrating the ventricles, our 3 cases with multimodality evaluations and mid-term follow up suggest the existence of extraventricular ATTR amyloid deposits localized in the aortic valve and left atrial structures.

Fulminant myocarditis in a young woman with mixed connective tissue disease: a case report.

Background: Although cardiac involvement is relatively common in mixed connective tissue disease (MCTD), few reports on MCTD-associated fulminant myocarditis are available. Case summary: A 22-year-old woman diagnosed with MCTD was admitted to our institution for cold-like symptoms and chest pain. Echocardiography revealed that the left ventricular ejection fraction (LVEF) had rapidly decreased from 50 to 20%. Because endomyocardial biopsy revealed no significant lymphocytic infiltration, immunosuppressant drugs were not started initially; however, steroid pulse therapy (methylprednisolone, one1000 mg/day) was initiated due to prolonged symptoms and unimproved haemodynamics. Despite strong immunosuppressant therapy, the LVEF did not improve, and severe mitral regurgitation appeared. Three days after steroid pulse therapy initiation, she experienced a sudden cardiac arrest; thus, venoarterial extracorporeal membrane oxygenation (VA-ECMO) and intra-aortic balloon pumping (IABP) were initiated. Subsequent immunosuppressant therapy was continued with prednisolone (100 mg/day) and intravenous cyclophosphamide (1000 mg). Six days after steroid therapy initiation, the LVEF improved to 40% and then recovered to near-normal levels. After successful weaning off of VA-ECMO and IABP, she was discharged. Thereafter, a detailed histopathological examination revealed multi-focal signs of ischaemic micro-circulatory injury and diffuse HLA-DR in the vascular endothelium, suggesting an autoimmune inflammatory response. Discussion: We report a rare case of fulminant myocarditis in a patient with MCTD who recovered with immunosuppressive treatment. Despite the absence of significant lymphocytic infiltration findings on histopathological examination, patients with MCTD may experience a dramatic clinical course. Although it is unclear whether myocarditis is triggered by viral infections, certain autoimmune mechanisms may lead to its development.

Tricaprin can prevent the development of AAA by attenuating aortic degeneration.

Medical therapeutic options to prevent rupture of abdominal aortic aneurysm (AAA), a critical event, must be developed. Moreover, further understanding of the process of AAA development and rupture is crucial. Previous studies have revealed that aortic hypoperfusion can induce the development of AAA, and we successfully developed a hypoperfusion-induced AAA animal model. In this study, we examined the effects of medium-chain triglycerides (MCTs), tricaprylin (C8-TG) and tricaprin (C10-TG), on hypoperfusion-induced AAA rat model. We estimated the effects of MCTs on aortic pathologies, mechanical properties of the aorta, and development of AAA. C10-TG, but not C8-TG, significantly suppressed AAA development and completely prevented the rupture. We observed that C10-TG prevented the development and rupture of AAA, but not C8-TG. Additionally, regression of AAA diameter was observed in the C10-TG group. Pathological analysis revealed C10-TG improved the hypoperfusion-induced increase in hypoxia-inducible factor-1α levels, medial smooth muscle cells (SMCs) loss, degeneration of aortic elastin and collagen fibers, and loss of aortic wall elasticity. In addition, regression of the formed AAA was observed by administration of C10-TG after AAA formation. C10-TG administration after AAA formation improved degeneration of AAA wall including degradation of aortic elastin and collagen fibers, stenosis of vasa vasorum, and loss of medial SMCs. These data suggest C10-TG can prevent AAA by attenuating aortic hypoperfusion and degeneration. Considering the clinical safety of C10-TG, C10-TG can be a promising AAA drug candidate.

A novel homozygous missense mutation in PNPLA2 in a patient manifesting primary triglyceride deposit cardiomyovasculopathy.

Primary triglyceride deposit cardiomyovasculopathy (P-TGCV), caused by a rare genetic mutation in PNPLA2 encoding adipose triglyceride lipase (ATGL), exhibits severe cardiomyocyte steatosis and heart failure. Here, we report the case of a 51-year-old man with P-TGCV homozygous for a novel PNPLA2 mutation (c.446C > G, P149R) in the catalytic domain of ATGL. Analyses of endomyocardial biopsy specimens and in vitro expression experiments showed mutant protein expression with conserved lipid binding, but reduced lipolytic activity, indicating mutation pathogenicity.

Steep increase in the number of transthyretin-positive cardiac biopsy cases in Japan: evidence obtained by the nation-wide pathology consultation for the typing diagnosis of amyloidosis.

BACKGROUND: In 2019, 2020 and 2022, the Japanese Government approved the use of tafamidis and two technetium-scintigraphies for transthyretin amyloid (ATTR) cardiomyopathy, and announced the patient criteria for tafamidis therapy. In 2018, we had started a nation-wide pathology consultation of amyloidosis. OBJECTIVE: To reveal the impact of approval of tafamidis and technetium-scintigraphy on the diagnosis of ATTR cardiomyopathy. METHODS: Ten institutes participated in this study on the pathology consultation of amyloidosis and shared rabbit polyclonal anti-κ116-133, anti-λ118-134, and anti-transthyretin115-124 antibodies. Proteomic analysis was performed when the typing diagnosis by immunohistochemistry was unavailable. RESULTS: Out of 5400 consultation cases received from April 2018 to July 2022, the type of amyloidosis by immunohistochemistry was determined in 4119 of the 4420 Congo-red positive cases. The incidences of AA, ALκ, ALλ, ATTR, Aß2M and others were 3.2, 11.3, 28.3, 54.9, 0.6 and 1.8%, respectively. Out of 2208 cardiac biopsy cases received, 1503 cases were ATTR positive. There were 4.0 and 4.9 times more total cases and ATTR-positive cases, respectively, in the last 12 months as compared to the first 12 months. CONCLUSIONS: The approval of tafamidis and technetium-scintigraphy raised the awareness of ATTR cardiomyopathy, leading to an upsurge in ATTR-positive cardiac biopsy cases.

COVID-19-associated myocardial injury: A case report.

Coronavirus disease 2019 (COVID-19) is often accompanied by pneumonia and can be fatal. We report a case of COVID-19-associated myocardial injury mimicking fulminant myocarditis. Endomyocardial biopsy revealed numerous von Willebrand factor-rich microthrombi with small myocardial necrotic areas, complement deposits in small vessels/microthrombi, and macrophage-predominant interstitial infiltration. These findings, distinct from those of typical lymphocytic myocarditis, show diffuse endothelial injury, complement activation, and activated macrophages as characteristic features of COVID-19-associated pathogenesis. Dysregulated serum cytokine profiles predicting severe/critical COVID-19-associated myocardial injury were also determined. This case emphasizes the occurrence of fatal cardiac manifestation with microthrombotic injury in the early stage of COVID-19.

Fulminant myocarditis with COVID-19 infection having normal C-reactive protein and serial magnetic resonance follow-up.

A 44-year-old woman who was quarantined for 5 days after the diagnosis of coronavirus disease of 2019 (COVID-19) was transferred to our hospital with the complaint of chest pain. The patient was unvaccinated. Electrocardiography revealed ST elevation in the lateral leads. Echocardiographic biventricular dysfunction with oedematous wall thickening was identified. Cardiac enzyme levels were elevated; however, C-reactive protein (CRP) levels, and the coronary angiogram were normal. The patient required mechanical circulatory support to stabilize haemodynamics and was treated with remdesivir, baricitinib, and intravenous methylprednisolone. She recovered after 13 days of mechanical support. Serial cardiac magnetic resonance imaging revealed acute myocardial oedema and subsequent fibrosis. An endomyocardial biopsy on admission showed mild interstitial inflammatory infiltrates with endomyocardial fibrous thickening and mild interstitial fibrosis of the myocardium. Normal CRP levels suggested minor involvement of interleukin (IL)-6, supporting the efficacy of baricitinib.

Early vascular responses to abluminal biodegradable polymer-coated versus circumferential durable polymer-coated newer-generation drug-eluting stents in humans: a pathological study.

BACKGROUND: Recent clinical studies are testing strategies for short (1-3 months) dual antiplatelet therapy following newer-generation drug-eluting stent (DES) placement. However, detailed biological responses to newer-generation DES remain unknown in humans. AIMS: We sought to evaluate early pathologic responses to abluminal biodegradable polymer-coated (BP-) DES compared with circumferential durable polymer-coated (DP-) DES in human autopsy cases. METHODS: The study included 38 coronary lesions with newer-generation DES implanted for <90 days (DP-DES=24, BP-DES=14) in 26 autopsy cases. The degree of strut coverage was defined as follows: grade 0 (bare), grade 1 (with fibrin or tissues/cells without endothelium), grade 2 (with single-layered endothelium), and grade 3 (with endothelium and underlying smooth muscle cell layers). RESULTS:  The duration following implantation was similar in DP- and BP-DES (median=20 vs 17 days). A total of 2,022 struts (DP-DES=1,297, BP-DES=725) were pathologically analysed. Focal grade 2 coverage was observed as early as 5 days after the implantation in both stents. The multilevel mixed-effects ordered logistic regression model demonstrated that BP-DES exhibited greater strut coverage compared with DP-DES (odds ratio [OR]: 3.64, 95% confidence interval [CI]: 1.37-9.67; p=0.009), which remained significant after adjustment for the duration following implantation and underlying tissue characteristics (OR: 2.74, 95% CI: 1.10-6.80; p=0.030). The predictive probability of grade 2 and 3 coverage was comparably limited at 30 days (DP-DES=17.1%, BP-DES=28.7%) and increased at 90 days (DP-DES=76.5%, BP-DES=86.6%). Both stents showed low inflammation and a similar degree of fibrin deposition. CONCLUSIONS: Single-layered endothelial coverage begins in the days after newer-generation DES placement, and BP-DES potentially exhibit faster strut coverage with smooth muscle cell infiltration than DP-DES in humans. Nevertheless, vessel healing remains suboptimal in both stents at 30 days.