Changes in Cardiac Function Following Fulminant Myocarditis.

BACKGROUND: The natural history of myocardial dysfunction in patients with fulminant myocarditis is poorly understood. This study aims to evaluate changes in cardiac function in patients with fulminant myocarditis using a nationwide registry in Japan. METHODS: This retrospective cohort study included patients with biopsy-proven fulminant myocarditis and available for left ventricular ejection fraction (LVEF). We described the LVEF on admission, at discharge, and 1 year after discharge. We divided patients into 2 groups based on LVEF at discharge (reduced ejection fraction of <50% or preserved ejection fraction of ≥50%) and analyzed changes in LVEF and prognosis according to groups. RESULTS: We included 214 patients (the median [first-third quartiles] age of the cohort was 48 [35-62] years, and 63 [38%] were female). Of 153 patients available for LVEF at 1 year, the median (first-third quartiles) LVEF increased from 33% (21-45%) on admission to 59% (49-64%) at discharge and further to 61% (55-66%) at 1 year. Of 153 patients, 45 (29%) and 22 (14%) had LVEF <50% at discharge and at 1 year, respectively. Comparisons between patients with LVEF <50% and those with LVEF ≥50% demonstrated that the former group had a higher adjusted probability of death or heart transplantation (hazard ratio, 8.19 [95% CI, 2.13-31.5]; P=0.002). CONCLUSIONS: Some patients with fulminant myocarditis had left ventricular dysfunction in the chronic phase. Patients with reduced left ventricular function at discharge had a worse prognosis than those with preserved left ventricular function. REGISTRATION: URL: https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000045352; Unique identifier: UMIN000039763.

Prognostic impact and predictors of persistent renal dysfunction in acute kidney injury after percutaneous coronary intervention for acute myocardial infarction.

This study aimed to evaluate the prognostic impact and predictors of persistent renal dysfunction in acute kidney injury (AKI) after an emergency percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI). A total of 877 patients who underwent emergency PCI for AMI were examined. AKI was defined as serum creatinine (SCr) ≥ 0.3 mg/dL or ≥ 50% from baseline within 48 h after PCI. Persistent AKI was defined as residual impairment of SCr ≥ 0.3 mg/dL or ≥ 50% from baseline 1 month after the procedure. The primary outcome was the composite endpoints of death, myocardial infarction, hospitalization for heart failure, stroke, and dialysis. AKI and persistent AKI were observed in 82 (9.4%) and 25 (2.9%) patients, respectively. Multivariate Cox proportional hazards analysis demonstrated that persistent AKI, but not transient AKI, was an independent predictor of primary outcome (hazard ratio, 4.99; 95% confidence interval, 2.30-10.8; P < 0.001). Age > 75 years, left ventricular ejection fraction < 40%, a high maximum creatinine phosphokinase MB level, and bleeding after PCI were independently associated with persistent AKI. Persistent AKI was independently associated with worse clinical outcomes in patients who underwent emergency PCI for AMI. Advanced age, poor cardiac function, large myocardial necrosis, and bleeding were predictors of persistent AKI.

Multisystemic Inflammation Influences Prognosis in Fulminant Lymphocytic Myocarditis.

BACKGROUND: Multisystem inflammatory syndrome (MIS) is a hyperinflammatory shock associated with cardiac dysfunction and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. However, there are no reports on using MIS criteria, such as multisystemic inflammation (MSI) in fulminant myocarditis, without SARS-CoV-2 infection. This study investigated the differences in clinical characteristics and course between patients with fulminant lymphocytic myocarditis (FLM) plus MSI and those without MSI.Methods and Results: This multicenter retrospective cohort study included 273 patients with FLM registered in the JROAD-DPC database between April 2014 and March 2017. We evaluated the presence of MSI using criteria modified from previously reported MIS criteria and compared the characteristics and risk of mortality or heart transplantation between FLM patients with MSI and without MSI. Of the 273 patients with FLM, 107 (39%) were diagnosed with MSI. The MSI group was younger (44 vs. 57 years; P<0.0001) and had more females (50% vs. 36%; P=0.0236), a higher incidence of pericardial effusion (58% vs. 40%; P=0.0073), and a lower 90-day mortality rate (19% vs. 33%; P=0.0185) than the non-MSI group. The risk of mortality at 90 days was lower in FLM patients aged <50 years with MSI aged <50 years than in those without MSI (P=0.0463). CONCLUSIONS: These results suggest that MSI may influence the prognosis of FLM, especially in patients aged <50 years.

Myocardial DNA Damage Predicts Heart Failure Outcome in Various Underlying Diseases.

BACKGROUND: Reliable predictors of treatment efficacy in heart failure have been long awaited. DNA damage has been implicated as a cause of heart failure. OBJECTIVES: The purpose of this study was to investigate the association of DNA damage in myocardial tissue with treatment response and prognosis of heart failure. METHODS: The authors performed immunostaining of DNA damage markers poly(ADP-ribose) (PAR) and γ-H2A.X in endomyocardial biopsy specimens from 175 patients with heart failure with reduced ejection fraction (HFrEF) of various underlying etiologies. They calculated the percentage of nuclei positive for each DNA damage marker (%PAR and %γ-H2A.X). The primary outcome was left ventricular reverse remodeling (LVRR) at 1 year, and the secondary outcome was a composite of cardiovascular death, heart transplantation, and ventricular assist device implantation. RESULTS: Patients who did not achieve LVRR after the optimization of medical therapies presented with significantly higher %PAR and %γ-H2A.X. The ROC analysis demonstrated good performance of both %PAR and %γ-H2A.X for predicting LVRR (AUCs: 0.867 and 0.855, respectively). There was a negative correlation between the mean proportion of DNA damage marker-positive nuclei and the probability of LVRR across different underlying diseases. In addition, patients with higher %PAR or %γ-H2A.X had more long-term clinical events (PAR HR: 1.63 [95% CI: 1.31-2.01]; P < 0.001; γ-H2A.X HR: 1.48 [95% CI: 1.27-1.72]; P < 0.001). CONCLUSIONS: DNA damage determines the consequences of human heart failure. Assessment of DNA damage is useful to predict treatment efficacy and prognosis of heart failure patients with various underlying etiologies.

Human leukocyte antigen-DQ risk heterodimeric haplotypes of left ventricular dysfunction in cardiac sarcoidosis: an autoimmune view of its role.

Cardiac sarcoidosis (CS) is the scarring of heart muscles by autoimmunity, leading to heart abnormalities and patients with sarcoidosis with cardiac involvements have poor prognoses. Due to the small number of patients, it is difficult to stratify all patients of CS by human leukocyte antigen (HLA) analysis. We focused on the structure of antigen-recognizing pockets in heterodimeric HLA-class II, in addition to DNA sequences, and extracted high-affinity combinations of antigenic epitopes from candidate autoantigen proteins and HLA. Four HLA heterodimer-haplotypes (DQA1*05:03/05:05/05:06/05:08-DQB1*03:01) were identified in 10 of 68 cases. Nine of the 10 patients had low left ventricular ejection fraction (< 50%). Fourteen amino-acid sequences constituting four HLA anchor pockets encoded by the HLA haplotypes were all common, suggesting DQA1*05:0X-DQB1*03:01 exhibit one group of heterodimeric haplotypes. The heterodimeric haplotypes recognized eight epitopes from different proteins. Assuming that autoimmune mechanisms might be activated by molecular mimicry, we searched for bacterial species having peptide sequences homologous to the eight epitopes. Within the peptide epitopes form the SLC25A4 and DSG2, high-homology sequences were found in Cutibacterium acnes and Mycobacterium tuberculosis, respectively. In this study, we detected the risk heterodimeric haplotypes of ventricular dysfunction in CS by searching for high-affinity HLA-class II and antigenic epitopes from candidate cardiac proteins.

Overexpression of GRK2 in vascular smooth muscle leads to inappropriate hypertension and acute heart failure as in clinical scenario 1.

Clinical scenario 1 (CS1) is acute heart failure (HF) characterized by transient systolic blood pressure (SBP) elevation and pulmonary congestion. Although it is managed by vasodilators, the molecular mechanism remains unclear. The sympathetic nervous system plays a key role in HF, and desensitization of cardiac ß-adrenergic receptor (AR) signaling due to G protein-coupled receptor kinase 2 (GRK2) upregulation is known. However, vascular ß-AR signaling that regulates cardiac afterload remains unelucidated in HF. We hypothesized that upregulation of vascular GRK2 leads to pathological conditions similar to CS1. GRK2 was overexpressed in vascular smooth muscle (VSM) of normal adult male mice by peritoneally injected adeno-associated viral vectors driven by the myosin heavy chain 11 promoter. Upregulation of GRK2 in VSM of GRK2 overexpressing mice augmented the absolute increase in SBP (+ 22.5 ± 4.3 mmHg vs. + 36.0 ± 4.0 mmHg, P < 0.01) and lung wet weight (4.28 ± 0.05 mg/g vs. 4.76 ± 0.15 mg/g, P < 0.01) by epinephrine as compared to those in control mice. Additionally, the expression of brain natriuretic peptide mRNA was doubled in GRK2 overexpressing mice as compared to that in control mice (P < 0.05). These findings were similar to CS1. GRK2 overexpression in VSM may cause inappropriate hypertension and HF, as in CS1.

Derivation and validation of a clinical predictive model of NT-proBNP ≥125 pg/mL to detect pre-heart failure.

BACKGROUND: Several guidelines recommend the measurement of N-terminal pro-B-type natriuretic peptide (NT-proBNP) to diagnose heart failure (HF); however, no screening criteria for measuring NT-proBNP in asymptomatic patients exist. We develop/validate a clinical prediction model for elevated NT-proBNP to support clinical outpatient decision-making. METHODS: In this multicenter cohort study, we used a derivation cohort (24 facilities) from 2017 to 2021 and a validation cohort at one facility from 2020 to 2021. Patients were aged ≥65 years with at least one risk factor of HF. The primary endpoint was NT-proBNP ≥125 pg/mL. The final model was selected using backward stepwise logistic regression analysis. Diagnostic performance was evaluated for sensitivity and specificity, the area under the curve (AUC), and calibration. In total, 1645 patients (derivation cohort, n = 837; validation cohort, n = 808) were included, of whom 378 (23.0 %) had NT-proBNP ≥125 pg/mL. Body mass index, age, systolic blood pressure, estimated glomerular filtration rate, cardiothoracic ratio, and heart disease were used as predictors and aggregated into a BASE-CH score of 0-11 points. RESULTS: Internal validation resulted in an AUC of 0.74 and an external validation AUC of 0.70. CONCLUSIONS: Based on available clinical and laboratory variables, we developed and validated a new risk score to predict NT-proBNP ≥125 pg/mL in patients at risk for HF or with pre-HF.

Heart failure with preserved ejection fraction phenogroup classification using machine learning.

AIMS: Heart failure (HF) with preserved ejection fraction (HFpEF) is a complex syndrome with a poor prognosis. Phenotyping is required to identify subtype-dependent treatment strategies. Phenotypes of Japanese HFpEF patients are not fully elucidated, whose obesity is much less than Western patients. This study aimed to reveal model-based phenomapping using unsupervised machine learning (ML) for HFpEF in Japanese patients. METHODS AND RESULTS: We studied 365 patients with HFpEF (left ventricular ejection fraction >50%) as a derivation cohort from the Nara Registry and Analyses for Heart Failure (NARA-HF), which registered patients with hospitalization by acute decompensated HF. We used unsupervised ML with a variational Bayesian-Gaussian mixture model (VBGMM) with common clinical variables. We also performed hierarchical clustering on the derivation cohort. We adopted 230 patients in the Japanese Heart Failure Syndrome with Preserved Ejection Fraction Registry as the validation cohort for VBGMM. The primary endpoint was defined as all-cause death and HF readmission within 5 years. Supervised ML was performed on the composite cohort of derivation and validation. The optimal number of clusters was three because of the probable distribution of VBGMM and the minimum Bayesian information criterion, and we stratified HFpEF into three phenogroups. Phenogroup 1 (n = 125) was older (mean age 78.9 ± 9.1 years) and predominantly male (57.6%), with the worst kidney function (mean estimated glomerular filtration rate 28.5 ± 9.7 mL/min/1.73 m2 ) and a high incidence of atherosclerotic factor. Phenogroup 2 (n = 200) had older individuals (mean age 78.8 ± 9.7 years), the lowest body mass index (BMI; 22.78 ± 3.94), and the highest incidence of women (57.5%) and atrial fibrillation (56.5%). Phenogroup 3 (n = 40) was the youngest (mean age 63.5 ± 11.2) and predominantly male (63.5 ± 11.2), with the highest BMI (27.46 ± 5.85) and a high incidence of left ventricular hypertrophy. We characterized these three phenogroups as atherosclerosis and chronic kidney disease, atrial fibrillation, and younger and left ventricular hypertrophy groups, respectively. At the primary endpoint, Phenogroup 1 demonstrated the worst prognosis (Phenogroups 1-3: 72.0% vs. 58.5% vs. 45%, P = 0.0036). We also successfully classified a derivation cohort into three similar phenogroups using VBGMM. Hierarchical and supervised clustering successfully showed the reproducibility of the three phenogroups. CONCLUSIONS: ML could successfully stratify Japanese HFpEF patients into three phenogroups (atherosclerosis and chronic kidney disease, atrial fibrillation, and younger and left ventricular hypertrophy groups).

New Classification for the Combined Assessment of the Fractional Excretion of Urea Nitrogen and Estimated Plasma Volume Status in Acute Heart Failure.

Background The fractional excretion of urea nitrogen (FEUN) has been used as a renal blood flow index related to cardiac output, and the estimated plasma volume status (ePVS) as a body fluid volume index. However, the usefulness of their combination in acute decompensated heart failure (HF) management is unclear. We investigated the effect of 4 hemodynamic categories according to the high and low FEUN and ePVS values at discharge on the long-term prognosis of patients with acute decompensated HF. Methods and Results Between April 2011 and December 2018, we retrospectively identified 466 patients with acute decompensated HF with FEUN and ePVS values at discharge. Primary end point was postdischarge all-cause death. Secondary end points were (1) the composite of all-cause death and HF readmission, and (2) HF readmission in a time-to-event analysis. The patients were divided into 4 groups according to the high/low FEUN (≥35%, <35%) and ePVS (>5.5%, ≤5.5%) values at discharge: high-FEUN/low-ePVS, high-FEUN/high-ePVS, low-FEUN/low-ePVS, and low-FEUN/high-ePVS groups. During a median follow-up period of 28.1 months, there were 173 all-cause deaths (37.1%), 83 cardiovascular deaths (17.8%), and 121 HF readmissions (26.0%). The Kaplan-Meier curve analysis showed that the high-FEUN/low-ePVS group had a better prognosis than the other groups (log-rank test, P<0.001). In the multivariable Cox regression analysis, the low-FEUN/high-ePVS group had a higher mortality than the high-FEUN/low-ePVS group (hazard ratio, 2.92 [95% CIs, 1.73-4.92; P<0.001]). Conclusions The new classification of the 4 hemodynamic profiles using the FEUN and ePVS values may play an important role in improving outcomes in patients with stable acute decompensated HF.

Prediction of optical coherence tomography-detected calcified nodules using coronary computed tomography angiography.

Diagnosis of calcified nodules (CNs) is critical in the proper management of coronary artery disease, but CNs can be detected only using intracoronary imaging modalities. This study aimed to investigate the ability of coronary computed tomography angiography (CCTA) in predicting CNs detected using optical coherence tomography (OCT). From 138 patients who underwent OCT-guided percutaneous coronary intervention (PCI) after CCTA evaluation, 141 PCI target vessels were retrospectively enrolled and classified into CN (12 vessels/11 patients; CNs in the PCI culprit lesion) and non-CN (129 vessels/127 patients; without CNs) groups based on the OCT analysis. Retrospective CCTA analysis revealed significantly higher coronary artery calcification score (CACS), calcified plaque volume (CPV), and maximum calcified plaque area (MCPA) of the target vessel in the CN group than in the non-CN group. Receiver operating characteristic curve indicated that CACS ≥ 162 (area under the ROC curve (AUC 0.76, sensitivity 83.3%, specificity 54.2%), CPV ≥ 20.1 mm3 (AUC 0.83, sensitivity 100%, specificity 57.3%), and MCPA ≥ 4.51 mm2 (AUC 0.87, sensitivity 91.7%, specificity 78.3%) were the best cutoff values for predicting CNs. MCPA showed the highest AUC among all the CCTA parameters. In conclusion, CCTA is useful for predicting OCT-detected CNs in PCI target vessels.

sFlt-1 in Chronic Kidney Disease: Friend or Foe?

Placental growth factor (PlGF) and its receptor, fms-like tyrosine kinase-1 (Flt-1), are important regulators involved in angiogenesis, atherogenesis, and inflammation. This review article focuses on the function of PlGF/Flt-1 signaling and its regulation by soluble Flt-1 (sFlt-1) in chronic kidney disease (CKD). Elevation of circulating sFlt-1 and downregulation of sFlt-1 in the vascular endothelium by uremic toxins and oxidative stress both exacerbate heart failure and atherosclerosis. Circulating sFlt-1 is inconsistent with sFlt-1 synthesis, because levels of matrix-bound sFlt-1 are much higher than those of circulating sFlt-1, as verified by a heparin loading test, and are drastically reduced in CKD.

Features and Outcomes of Histologically Proven Myocarditis With Fulminant Presentation.

BACKGROUND: Fulminant myocarditis presentation (FMP) is a rare and severe presentation of myocarditis. The natural history of FMP and its clinical features associated with poor outcomes are incompletely understood because there is a lack of generalizable evidence. METHODS: This multicenter retrospective cohort study included patients hospitalized with histologically proven myocarditis who underwent catecholamine or mechanical support from 235 cardiovascular training hospitals across Japan between April 2012 and March 2017. Clinical features and the prognostic predictors of death or heart transplantation within 90 days on the basis of clinical and pathologic findings were determined using the Kaplan-Meier method, log-rank test, and Cox regression analysis. RESULTS: This study included 344 patients with histologically proven FMP (median age, 54 years; 40% female). The median follow-up was 600 days (interquartile range, 36 to 1599 days) and the cumulative risk of death or heart transplantation at 90 days was 29% (n=98). Results from multivariable Cox regression analysis showed that older age, nonsinus rhythm, low left ventricular wall motion (<40%) on admission, and ventricular tachycardia or fibrillation on admission day were associated with worse 90-day survival. Severe histologic damage (damaged cardiomyocytes comprising ≥50% of the total cardiomyocytes) was associated with a worse 90-day prognosis in patients with lymphocytic myocarditis. CONCLUSIONS: The results from analyses of data from this multicenter registry demonstrated that patients with FMP are at a higher risk of death or heart transplantation in real-world settings. These observations inform which clinical and pathologic findings may be useful for prognostication in FMP. REGISTRATION: URL: https://www.umin.ac.jp/ctr; Unique identifier: UMIN000039763.

Histopathological and epigenetic changes in myocardium associated with cancer therapy-related cardiac dysfunction.

AIMS: Cancer therapy-related cardiac dysfunction (CTRCD) is commonly reported, but its histopathology, mechanisms, and risk factors are not known. We aimed to clarify the histopathology and mechanisms of CTRCD to identify risk factors. METHODS AND RESULTS: We performed myocardial histopathological studies on 13 endomyocardial biopsies from CTRCD patients, 35 autopsied cancer cases with or without cardiac dysfunction, and controls without cancer (10 biopsies and 9 autopsies). Cardiotoxicity risk scores were calculated based on medication; and patient-related risk factors, fibrosis, and cardiomyocyte changes were scored; and p53 and H3K27ac histone modification were evaluated by histological score (H-score). In the biopsy cases, all histopathological changes and the p53 evaluation were significantly higher in the CTRCD group than in the controls [p53 H-score; 63 (9.109) vs. 33 (5.099), P < 0.05]. In patients with a short time between drug and disease onset (<4.2 years), fibrosis and p53 positively correlated (r = 0.76, P < 0.05), and in those with late onset disease (>4.2 years), cellular abnormalities and p53 trended to a positive correlation and cardiotoxicity risk scores and p53 positively correlated (r = 0.95, P < 0.05). A year after biopsy, the short-term group had significant recovery of ejection fraction compared with the long-term group (P < 0.05). The CTRCD group had a significantly worse overall survival prognosis than the control group [hazard ratio 7.61 (95% confidence interval 1.30-44.6), P < 0.05]. Autopsy cases with cancer treatment also had a high grade of histopathological changes, with even more severe changes in patients with cardiac dysfunction, and had increased p53 and H3K27ac expression levels, compared with controls. H-scores of p53 and H3K27ac showed a positive correlation in the CTRCD group in biopsy cases (r = 0.62, P < 0.05) and a positive correlation in autopsy cases. CONCLUSIONS: Our results indicate distinct morphological characteristics in myocardial histopathology associated with CTRCD. p53 and H3K27ac histone modification could be sensitive markers of CTRCD and suggest a mechanistic involvement of epigenetic changes.

Transthyretin Amyloid Cardiomyopathy: Impact of Transthyretin Amyloid Deposition in Myocardium on Cardiac Morphology and Function.

BACKGROUND: Transthyretin (TTR) amyloid cardiomyopathy (ATTR-CM) is increasingly being recognized as a cause of left ventricular (LV) hypertrophy (LVH) and progressive heart failure in elderly patients. However, little is known about the cardiac morphology of ATTR-CM and the association between the degree of TTR amyloid deposition and cardiac dysfunction in these patients. METHODS: We studied 28 consecutive patients with ATTR-CM and analyzed the relationship between echocardiographic parameters and pathological features using endomyocardial biopsy samples. RESULTS: The cardiac geometries of patients with ATTR-CM were mainly classified as concentric LVH (96.4%). The relative wall thickness, a marker of LVH, tended to be positively correlated with the degree of non-cardiomyocyte area. The extent of TTR deposition was positively correlated with enlargement of the non-cardiomyocyte area, and these were positively correlated with LV diastolic dysfunction. Additionally, the extent of the area containing TTR was positively correlated with the percentage of cardiomyocyte nuclei stained for 8-hydroxy-2'deoxyguanosine, a marker of reactive oxygen species (ROS). ROS accumulation in cardiomyocytes was positively correlated with LV systolic dysfunction. CONCLUSION: Patients with ATTR-CM mainly displayed concentric LVH geometry. TTR amyloid deposition was associated with cardiac dysfunction via increased non-cardiomyocyte area and ROS accumulation in cardiomyocytes.

New Conversion Formula Between B-Type Natriuretic Peptide and N-Terminal-Pro-B-Type Natriuretic Peptide　- Analysis From a Multicenter Study.

BACKGROUND: Although B-type natriuretic peptide (BNP) and N-terminal (NT)-proBNP are commonly used markers of heart failure, a simple conversion formula between these peptides has not yet been developed for clinical use.Methods and Results: A total of 9,394 samples were obtained from Nara Medical University, Jichi Medical University, and Osaka University. We randomly selected 70% for a derivation set to investigate a conversion formula from BNP to NT-proBNP using estimated glomerular filtration rate (eGFR) and body mass index (BMI); the remaining 30% was used as the internal validation set and we used a cohort study from Nara Medical University as an external validation set. Multivariate linear regression analysis revealed a new conversion formula: log NT-proBNP = 1.21 + 1.03 × log BNP - 0.009 × BMI - 0.007 × eGFR (r2=0.900, P<0.0001). The correlation coefficients between the actual and converted values of log NT-proBNP in the internal and external validation sets were 0.942 (P<0.0001) and 0.891 (P<0.0001), respectively. We applied this formula to samples obtained from patients administered with sacubitril/valsartan. After treatment initiation, NT-proBNP levels decreased and actual BNP levels increased. However, the calculated BNP levels decreased roughly parallel to the NT-proBNP levels. CONCLUSIONS: This new and simple conversion formula of BNP and NT-proBNP with eGFR and BMI is potentially useful in clinical practice.

Functional Evaluation of Human Bioengineered Cardiac Tissue Using iPS Cells Derived from a Patient with Lamin Variant Dilated Cardiomyopathy.

Dilated cardiomyopathy (DCM) is caused by various gene variants and characterized by systolic dysfunction. Lamin variants have been reported to have a poor prognosis. Medical and device therapies are not sufficient to improve the prognosis of DCM with the lamin variants. Recently, induced pluripotent stem (iPS) cells have been used for research on genetic disorders. However, few studies have evaluated the contractile function of cardiac tissue with lamin variants. The aim of this study was to elucidate the function of cardiac cell sheet tissue derived from patients with lamin variant DCM. iPS cells were generated from a patient with lamin A/C (LMNA) -mutant DCM (LMNA p.R225X mutation). After cardiac differentiation and purification, cardiac cell sheets that were fabricated through cultivation on a temperature-responsive culture dish were transferred to the surface of the fibrin gel, and the contractile force was measured. The contractile force and maximum contraction velocity, but not the maximum relaxation velocity, were significantly decreased in cardiac cell sheet tissue with the lamin variant. A qRT-PCR analysis revealed that mRNA expression of some contractile proteins, cardiac transcription factors, Ca2+-handling genes, and ion channels were downregulated in cardiac tissue with the lamin variant.Human iPS-derived bioengineered cardiac tissue with the LMNA p.R225X mutation has the functional properties of systolic dysfunction and may be a promising tissue model for understanding the underlying mechanisms of DCM.

Incidence of epicardial connections between the right pulmonary vein carina and right atrium during catheter ablation of atrial fibrillation: A comparison between the conventional method and unipolar signal modification.

BACKGROUND: When performing an electrical isolation of ipsilateral pulmonary veins (PVs) for atrial fibrillation, physicians often need additional radiofrequency (RF) ablation in the carina region between the superior and inferior PVs to achieve a right PV isolation because of intercaval bundles between the right PVs and right atrium (RA). We compared the efficacy of a high-power and short-duration ablation guided by unipolar signal modification (UM) with the conventional method (CM) for ablating epicardial connections between the right PV carina and RA. METHODS: The study subjects consisted of patients who underwent an initial box isolation of atrial fibrillation from January 2015 to December 2019 at Nara Medical University Hospital. Among these patients, 94 and 65 patients who met the criteria were assigned to the CM and UM groups, respectively. We retrospectively analyzed the anterior ablation line of the right PV using an electroanatomical mapping system. Patients whose initial ablation line included the right PV carina were excluded. RESULTS: Six and seven patients were, respectively, excluded from the CM and UM groups. Among 88 CM group patients, 21 needed additional right PV carina ablation, while among 58 UM group patients, 30 needed additional right PV carina ablation (p = .001). No anatomical factors were associated with the additional right PV carina ablation. CONCLUSIONS: Compared to the CM group, a box isolation was less achievable without RF ablation at the right PV carina in the UM group. We should consider a long-duration ablation for epicardial connections between the right PV carina and RA.