RV1+RV3 Index to Differentiate Idiopathic Ventricular Arrhythmias Arising From Right Ventricular Outflow Tract and Aortic Sinus of Valsalva: A Multicenter Study.

BACKGROUND: This study aimed to investigate the predictive value of parameters of every precordial lead and their combinations in differentiating between idiopathic ventricular arrhythmias (IVAs) from the right ventricular outflow tract and aortic sinus of Valsalva (ASV). METHODS AND RESULTS: Between March 1, 2018, and December 1, 2021, consecutive patients receiving successful ablation of right ventricular outflow tract or ASV IVAs were enrolled. The amplitude and duration of the R wave and S wave were measured in every precordial lead during IVAs. These parameters were either summed, subtracted, multiplied, or divided to create different indexes. The index with the highest area under the curve to predict ASV IVAs was developed, compared with established indexes, and validated in an independent prospective multicenter cohort. A total of 150 patients (60 men; mean age, 45.3±16.4 years) were included in the derivation cohort. The RV1+RV3 index (summed R-wave amplitude in leads V1 and V3) had the highest area under the curve (0.942) among the established indexes. An RV1+RV3 index >1.3 mV could predict ASV IVAs with a sensitivity of 95% and a specificity of 83%. Its predictive performance was maintained in the validation cohort (N=109). In patients with V3 R/S transition, an RV1+RV3 index >1.3 mV could predict ASV IVAs, with an area under the curve of 0.892, 93% sensitivity, and 75% specificity. CONCLUSIONS: The RV1+RV3 index is a simple and novel criterion that accurately differentiates between right ventricular outflow tract and ASV IVAs. Its performance outperformed established indexes, making it a valuable tool in clinical practice.

Injectable and Conductive Nanomicelle Hydrogel with α-Tocopherol Encapsulation for Enhanced Myocardial Infarction Repair.

Substantial advancements have been achieved in the realm of cardiac tissue repair utilizing functional hydrogel materials. Additionally, drug-loaded hydrogels have emerged as a research hotspot for modulating adverse microenvironments and preventing left ventricular remodeling after myocardial infarction (MI), thereby fostering improved reparative outcomes. In this study, diacrylated Pluronic F127 micelles were used as macro-cross-linkers for the hydrogel, and the hydrophobic drug α-tocopherol (α-TOH) was loaded. Through the in situ synthesis of polydopamine (PDA) and the incorporation of conductive components, an injectable and highly compliant antioxidant/conductive composite FPDA hydrogel was constructed. The hydrogel exhibited exceptional stretchability, high toughness, good conductivity, cell affinity, and tissue adhesion. In a rabbit model, the material was surgically implanted onto the myocardial tissue, subsequent to the ligation of the left anterior descending coronary artery. Four weeks postimplantation, there was discernible functional recovery, manifesting as augmented fractional shortening and ejection fraction, alongside reduced infarcted areas. The findings of this investigation underscore the substantial utility of FPDA hydrogels given their proactive capacity to modulate the post-MI infarct microenvironment and thereby enhance the therapeutic outcomes of myocardial infarction.

A Simple Score to Predict New-onset Atrial Fibrillation After Ablation of Typical Atrial Flutter.

BACKGROUND: New-onset atrial fibrillation (NeAF) is common after cavotricuspid isthmus-dependent counterclockwise atrial flutter (CCW-AFL) ablation. This study aimed to investigate a simple predictive model of NeAF after CCW-AFL ablation. METHODS: From January 2013 to December 2017, consecutive patients receiving CCW-AFL ablation were enrolled from three centers. Clinical, echocardiographic, and electrocardiographic data were collected and followed. Patients from two centers and another center were assigned into the derivation and validation cohorts, respectively. In the derivation cohort, logistic regression was performed to evaluate the ability of parameters to discriminate those with and without NeAF. A score system was developed and then validated. RESULTS: Two hundred seventy-one patients (mean 59.7±13.6 age; 205 male) were analyzed. During follow-up (73.0±6.5 months), 107 patients (39.5%) had NeAF. 190 and 81 patients were detected in the derivation and validation cohorts, respectively. Hypertension, age ≥70 years, left atrial diameter ≥42 mm, P wave duration ≥120 ms and the negative component of flutter wave in lead II ≥120 ms were selected as the final parameters. A weighted score was used to develop the HAD-AF score ranging from 0 to 9. In the derivation cohort, area under the receiver operating characteristic curve (AUC) was 0.938 (95% CI 0.902-0.974), superior to those of currently used CHA2DS2-VASC (0.679, 95% CI 0.600-0.757) and HATCH scores (0.651, 95% CI 0.571-0.730) (P<0.001). Performance maintained in the validation cohort. CONCLUSIONS: 39.5% of patients developed NeAF in 6 years after CCW-AFL ablation. HAD-AF score can reliably identify patients likely to develop NeAF after CCW-AFL ablation.

Stretchable, Self-Rolled, Microfluidic Electronics Enable Conformable Neural Interfaces of Brain and Vagus Neuromodulation.

Implantable neuroelectronic interfaces have gained significant importance in long-term brain-computer interfacing and neuroscience therapy. However, due to the mechanical and geometrical mismatches between the electrode-nerve interfaces, personalized and compatible neural interfaces remain serious issues for peripheral neuromodulation. This study introduces the stretchable and flexible electronics class as a self-rolled neural interface for neurological diagnosis and modulation. These stretchable electronics are made from liquid metal-polymer conductors with a high resolution of 30 µm using microfluidic printing technology. They exhibit high conformability and stretchability (over 600% strain) during body movements and have good biocompatibility during long-term implantation (over 8 weeks). These stretchable electronics offer real-time monitoring of epileptiform activities with excellent conformability to soft brain tissue. The study also develops self-rolled microfluidic electrodes that tightly wind the deforming nerves with minimal constraint (160 µm in diameter). The in vivo signal recording of the vagus and sciatic nerve demonstrates the potential of self-rolled cuff electrodes for sciatic and vagus neural modulation by recording action potential and reducing heart rate. The findings of this study suggest that the robust, easy-to-use self-rolled microfluidic electrodes may provide useful tools for compatible neuroelectronics and neural modulation.

Radiomics features on computed tomography reflect thrombus histological age prior to endovascular treatment of acute ischemic stroke.

PURPOSE: To investigate the role of radiomics features in thrombus age identification and establish a CT-based radiomics model for predicting thrombus age of large vessel occlusion stroke patients. METHODS: We retrospectively reviewed patients with middle cerebral artery occlusion receiving mechanical thrombectomy from July 2020 to March 2022 at our center. The retrieved clots were stained with Hematoxylin and Eosin (H&E) and determined as fresh or older thrombi based on coagulation age. Clot-derived radiomics features were selected by least absolute shrinkage and selection operator (LASSO) regression analysis, by which selected radiomics features were integrated into the Rad-score via the corresponding coefficients. The prediction performance of Rad-score in thrombus age was evaluated with the area under the curve (AUC) of receiver operating characteristic (ROC) curve analysis. RESULTS: A total of 104 patients were included in our analysis, with 52 in training and 52 in validation cohort. Older thrombi were characterized with delayed procedure time, worse functional outcome and marginally associated with more attempts of device. We extracted 982 features from NCCT images. Following T test and LASSO analysis in training cohort, six radiomics features were selected, based on which the Rad-score was generated by the linear combination of features. The Rad-score showed satisfactory performance in distinguishing fresh with older thrombi, with the AUC of 0.873 (95 %CI: 0.777-0.956) and 0.773 (95 %CI: 0.636-0.910) in training and validation cohort, respectively. CONCLUSION: This study established and validated a CT-based radiomics model that could accurately differentiate fresh with older thrombi for stroke patients receiving mechanical thrombectomy.

Binary Colloidal Crystals Promote Cardiac Differentiation of Human Pluripotent Stem Cells via Nuclear Accumulation of SETDB1.

Biophysical cues can facilitate the cardiac differentiation of human pluripotent stem cells (hPSCs), yet the mechanism is far from established. One of the binary colloidal crystals, composed of 5 µm Si and 400 nm poly(methyl methacrylate) particles named 5PM, has been applied as a substrate for hPSCs cultivation and cardiac differentiation. In this study, cell nucleus, cytoskeleton, and epigenetic states of human induced pluripotent stem cells on the 5PM were analyzed using atomic force microscopy, molecular biology assays, and the assay for transposase-accessible chromatin sequencing (ATAC-seq). Cells were more spherical with stiffer cell nuclei on the 5PM compared to the flat control. ATAC-seq revealed that chromatin accessibility decreased on the 5PM, caused by the increased entry of histone lysine methyltransferase SETDB1 into the cell nuclei and the amplified level of histone H3K9me3 modification. Reducing cytoskeleton tension using a ROCK inhibitor attenuated the nuclear accumulation of SETDB1 on the 5PM, indicating that the effect is cytoskeleton-dependent. In addition, the knockdown of SETDB1 reversed the promotive effects of the 5PM on cardiac differentiation, demonstrating that biophysical cue-induced cytoskeletal tension, cell nucleus deformation, and then SETDB1 accumulation are critical outside-in signal transformations in cardiac differentiation. Human embryonic stem cells showed similar results, indicating that the biophysical impact of the 5PM surfaces on cardiac differentiation could be universal. These findings contribute to our understanding of material-assistant hPSC differentiation, which benefits materiobiology and stem cell bioengineering.

A nomogram for predicting thrombus composition in stroke patients with large vessel occlusion: combination of thrombus density and perviousness with clinical features.

PURPOSE: To establish a nomogram incorporating pretreatment imaging parameters and clinical characteristics for predicting the thrombus composition of acute ischemic stroke (AIS) with large vessel occlusion (LVO). METHODS: We retrospectively enrolled patients with occlusion of the Middle Cerebral Artery (MCA) who underwent Mechanical Thrombectomy (MT). Retrieved thrombi were stained with Hematoxylin and Eosin (H&E) and Martius Scarlet Blue (MSB). Thrombi are assigned to the Fibrin-rich or RBC-rich group based on the relative fractions of Red Blood Cells (RBC), fibrin, and platelet. The independent risk factors for Fibrin-rich clots were determined via univariate and multivariate logistic regression analysis and were then integrated to establish a nomogram. RESULTS: In total, 98 patients were included in this study. Patients with fibrin-rich clots had worse functional outcome [modified Rankin scale (mRS) 0-2, 34.7% vs 63.2%, p = 0.005], longer procedure time (76.8 min vs 50.8 min, p = 0.001), and increased maneuvers of MT (1.84 vs 1.46, p = 0.703) than those with RBC-rich clots. The independent risk factors for Fibrin-rich clots were lower perviousness measured by Non-Contrast Computer Tomography (NCCT) and CT Angiography (CTA), lower thrombus relative attenuation on NCCT, elevated Platelet-WBC ratio (PWR) of admission peripheral blood, and previous antithrombotic medication. The nomogram showed good discrimination with an area under the Receiver Operating Characteristic (ROC) curve (AUC) of 0.852 (95% CI: 0.778-0.926). The calibration curve and decision curve analysis also displayed satisfactory accuracy and clinical utility. CONCLUSION: This study has developed and internally validated an easy-to-use nomogram which can help predict clot composition and optimize therapeutic strategies for thrombectomy.

Unsupervised machine learning reveals epicardial adipose tissue subtypes with distinct atrial fibrosis profiles in patients with persistent atrial fibrillation: A prospective 2-center cohort study.

BACKGROUND: Epicardial adipose tissue (EAT) accumulation is associated with the progression of atrial fibrillation. However, the histological features of EATs are poorly defined and their correlation with atrial fibrosis is unclear. OBJECTIVE: The purpose of this study was to identify and characterize EAT subgroups in the persistent atrial fibrillation (PeAF) cohorts. METHODS: EATs and the corresponding left atrial appendage samples were obtained from patients with PeAF via surgical intervention. Adipocyte markers, that is, Uncoupling Protein 1, Transcription Factor 21, and CD137, were examined. On the basis of expression of adipocyte markers, patients with PeAF were categorized into subgroups by using unsupervised clustering analysis. Clinical characteristics, histological analyses, and outcomes were subsequently compared across the clusters. External validation was performed in a validation cohort. RESULTS: The ranking of feature importance revealed that the 3 adipocyte markers were the most relevant factors for atrial fibrosis compared with other clinical indicators. On the k-medoids analysis, patients with PeAF could be categorized into 3 clusters in the discovery cohort. The histological studies revealed that patients in cluster 1 exhibited statistically larger size of adipocytes in EATs and severe atrial fibrosis in left atrial appendages. Findings were replicated in the validation cohort, where severe atrial fibrosis was noted in cluster 1. Moreover, in the validation cohort, there was a high degree of overlap between the supervised classification results and the unsupervised cluster results from the k-medoids method. CONCLUSION: Machine learning-based cluster analysis could identify subtypes of patients with PeAF having distinct atrial fibrosis profiles. Additionally, EAT whitening (increased proportion of white adipocytes) may be involved in the process of atrial fibrosis.

Endovascular thrombectomy for acute ischemic stroke in elderly patients with atrial fibrillation.

BACKGROUND: To assess the clinical outcomes after endovascular thrombectomy (EVT) in elderly large vessel occlusion (LVO)-related acute ischemic stroke (AIS) patients with atrial fibrillation (AF). METHODS: Between January 2019 and December 2020, consecutive AF patients who received EVT due to anterior-circulation stroke were enrolled. The primary outcome was modified Rankin scale (mRS) score at 90 days. Secondary outcomes included all-cause mortality, the recanalization status after EVT (assessed using modified thrombolysis in cerebral infarction scale, mTICI) and any intracranial hemorrhage (ICH). A multivariate logistic regression model was performed to identify predictors of the functional outcome. RESULTS: A total of 148 eligible patients were finally enrolled. Among them, 42 were ≥ 80 years old. Compared to their younger counterparts, patients aged ≥80 years had lower likelihood of good functional outcome (mRS score 0-2) at 90 days (26.2% vs. 48.1%, P = 0.015), less satisfied recanalization (mTICI, 2b-3) (78.6% vs. 94.3%, P = 0.004) and higher all-cause mortality rate (35.7% vs. 14.2%, P = 0.003). A multivariable logistic regression analysis showed that age ≥ 80 years at baseline were the significant predictors for a poor functional outcome (OR: 3.72, 95% CI: 1.17-11.89, p = 0.027). Intravenous thrombolysis (IVT) prior to EVT and longer time intervals from onset of symptoms to EVT tended to be associated with poor functional outcome in patients ≥80 years old. CONCLUSIONS: Age ≥ 80 years was a significant predictor of unfavorable outcomes after EVT for AIS patients with AF. An increased risk of adverse events must be balanced against the benefit from EVT in elderly patients with AF.

Association Between Prior Anticoagulation and Thrombus Composition in Mechanical Thrombectomy Patients with Atrial Fibrillation.

PURPOSE: Anticoagulation (AC) is the main preventive strategy for ischemic stroke in atrial fibrillation (AF) patients. We aim to investigate the association of prior AC with thrombus composition and clinical outcome in AF patients with acute ischemic stroke (AIS). MATERIALS AND METHODS: From January 2019 to December 2020, consecutive AIS patients with AF treated with mechanical thrombectomy (MT) in our center were included in this analysis. Retrieved thrombi were stained with hematoxylin and eosin (H&E) and Martius Scarlet blue (MSB). The relative fractions of red blood cell (RBC), white blood cell (WBC), fibrin, and platelet were quantitatively analyzed. Procedural and clinical outcomes were compared between patients with and without prior AC. RESULTS: A total of 133 patients were enrolled in this study, with 39 in AC group and 94 in non-AC (NAC) group. Thrombi in AC group contained more fibrins (36% vs 20%, p<0.001), more platelets (36% vs 24%, p<0.001) and fewer RBCs (25% vs 54%, p<0.001). No difference was detected in terms of successful recanalization evaluated with modified Thrombolysis in Cerebral Infarction scale (mTICI 2b-3, 97% vs 86%, p=0.065), functional independence at 90 days with modified Rankin Score (mRS 0-2, 44% vs 33%, p=0.246). CONCLUSION: Thrombi retrieved from AF patients with prior AC contained more fibrins, more platelets and fewer RBCs compared with those of NAC patients. A trend of higher successful reperfusion rate was observed in AC patients but failed to reach statistical significance.

ECG Predictors for New-Onset Atrial Fibrillation Within a Year After Radiofrequency Ablation of Counterclockwise-Rotating Atrial Flutter.

Background: New-onset atrial fibrillation (AF) after ablation of typical atrial flutter (AFL) is not rare. This study aimed to investigate the predictive value of electrocardiographic parameters on new-onset AF post-typical AFL ablation. Methods: A total of 158 consecutive patients (79.1% males, mean age 57.8 ± 14.3 years) with typical AFL were enrolled between January 2012 and August 2017 in this single-center study. Patients with a history of AF before ablation were excluded. ECGs during sinus rhythm (SR) and AFL were collected. The duration of the negative component of flutter wave in lead II (DFNII), proportion of the DFNII of the total circle length of AFL (DFNII%), amplitude of the negative component of flutter wave in lead II (AFNII), duration (DPNV1), and amplitude (APNV1) of negative component of the P wave in lead V1, and P wave duration in lead II (DPII) during sinus rhythm were measured. Results: During a median follow-up of 26.9 ± 11.8 months, 22 cases (13.9%) developed new-onset AF. DFNII was significantly longer in patients with new-onset AF compared to patients without AF (114.7 ± 29.6 ms vs. 82.7 ± 12.8 ms, p < 0.0001). AFNII was significantly lower (0.118 ± 0.034 mV vs. 0.168 ± 0.051 mV, p < 0.0001), DPII (144.21 ± 23.77 ms vs. 111.46 ± 14.19 ms, p < 0.0001), and DPNV1 was significantly longer (81.07 ± 16.87 ms vs. 59.86 ± 14.42 ms, p < 0.0001) in patients with new-onset AF. In the multivariate analysis, DFNII [odds ratio (OR), 1.428; 95% CI, 1.039-1.962; p = 0.028] and DPII (OR, 1.429; 95% CI, 1.046-1.953; p = 0.025) were found to be independently associated with new-onset AF after typical AFL ablation. Conclusion: Parameters representing left atrial activation time under both the SR and AFL were independently associated with new-onset AF post-typical AFL ablation and may be useful in risk prediction, which needs to be confirmed by further prospective studies.