Data-driven classification of left atrial morphology and its predictive impact on atrial fibrillation catheter ablation.

INTRODUCTION: Various left atrial (LA) anatomical structures are correlated with postablative recurrence for atrial fibrillation (AF) patients. Comprehensively integrating anatomical structures, digitizing them, and implementing in-depth analysis, which may supply new insights, are needed. Thus, we aim to establish an interpretable model to identify AF patients' phenotypes according to LA anatomical morphology, using machine learning techniques. METHODS AND RESULTS: Five hundred and nine AF patients underwent first ablation treatment in three centers were included and were followed-up for postablative recurrent atrial arrhythmias. Data from 369 patients were regarded as training set, while data from another 140 patients, collected from different centers, were used as validation set. We manually measured 57 morphological parameters on enhanced computed tomography with three-dimensional reconstruction technique and implemented unsupervised learning accordingly. Three morphological groups were identified, with distinct prognosis according to Kaplan-Meier estimator (p < .001). Multivariable Cox model revealed that morphological grouping were independent predictors of 1-year recurrence (Group 1: HR = 3.00, 95% CI: 1.51-5.95, p = .002; Group 2: HR = 4.68, 95% CI: 2.40-9.11, p < .001; Group 3 as reference). Furthermore, external validation consistently demonstrated our findings. CONCLUSIONS: Our study illustrated the feasibility of employing unsupervised learning for the classification of LA morphology. By utilizing morphological grouping, we can effectively identify individuals at different risks of postablative recurrence and thereby assist in clinical decision-making.

Effect of obstructive sleep apnea on prognosis in patients with acute coronary syndromes with varying numbers of standard modifiable risk factors: insight from the OSA-ACS study.

BACKGROUND: Standard modifiable risk factors (SMuRFs) increase the risk of cardiovascular events in patients with acute coronary syndrome (ACS) and are also strongly associated with obstructive sleep apnea (OSA) in a bidirectional relationship. However, the association of OSA with recurrent cardiovascular events in ACS patients based on the number of SMuRFs remains unclear. Hence, we aimed to elucidate the prognostic implication of OSA in ACS patients stratified by the number of SMuRFs. METHODS: This was a post hoc analysis of the OSA-ACS study (NCT03362385), including 1927 patients admitted for ACS and undergoing portable sleep monitoring. OSA was defined as an apnea hypopnea index ≥ 15 events/h. The primary endpoint was major adverse cardiovascular and cerebrovascular event (MACCE) including cardiovascular death, myocardial infarction, stroke, hospitalization for unstable angina or heart failure, and ischemia-driven revascularization. Cox proportional hazards model and Kaplan-Meier analysis were used to investigated the relationship between OSA and subsequent cardiovascular events after patients were stratified by the number of SMuRFs. RESULTS: Among 1927 patients enrolled, 130 (6.7%) had no SMuRF, 1264 (65.6%) exhibited 1-2 SMuRFs and 533 (27.7%) presented 3-4 SMuRFs. With the increase of the number of SMuRFs, the proportion of OSA in ACS patients tended to increase (47.7% vs. 51.5% vs. 56.6%), but there was no significant difference between them (P = 0.08). After the stratification of ACS patients via SMuRF numbers and adjustment for confounding factors, fully adjusted Cox regression indicated that OSA increased the risk of MACCE (adjusted HR, 1.65; 95%CI, 1.06-2.57; P = 0.026) and ischemia-driven revascularization (adjusted HR, 2.18; 95%CI, 1.03-4.65; P = 0.042) in ACS patients with 3-4 SMuRFs. CONCLUSIONS: In hospitalized ACS patients, OSA is associated with an increased risk of MACCE and ischemia-driven revascularization among patients with 3-4 SMuRFs. Therefore, screening for OSA should be emphasized in ACS patients with 3-4 SMuRFs, and intervention trials should be prioritized in these high-risk patients.

Impact of carotid atherosclerosis on arrhythmia recurrence following atrial fibrillation catheter ablation.

BACKGROUND: It remains unclear whether carotid atherosclerosis (CAS) increases the atrial fibrillation (AF) recurrence rate after ablation. The aim was to assess the association between CAS, defined as carotid intima-media thickness (CIMT) ≥1 mm and or presence of carotid plaques, and AF recurrence rate after ablation. METHODS: We retrospectively collected patients who underwent carotid ultrasonography and AF ablation at the First Affiliated Hospital of Zhengzhou University. The AF recurrence was defined as documented atrial arrhythmias over 30 s on ECG or 24-h Holter monitoring after the first three months blanking period. Cox regression models were used to analyze the risk of AF recurrence. RESULTS: Overall, 385 patients were analyzed (mean age, 60.58±10.98 years old; female, 41.30%; persistent AF, 47.27%). After a follow-up of 1 year, 138 (35.84%) patients experienced recurrence, Kaplan-Meier analysis showed that patients with the presence of carotid plaques, CIMT ≥1 mm, and CAS had a higher risk of recurrence compared with the absence (all log-rank p < .05). In multivariate Cox regression analysis, CAS (HR 2.159, ±95% CI 1.320-3.532, p = .002), carotid plaque (HR 1.815, ±95%CI 1.160-2.841, p = .009), and CIMT ≥1 mm (HR 1.696, ±95%CI 1.192-2.413, p = .003) were independently associated with a higher risk of recurrence. In subgroup analysis, the association of CAS, carotid plaque, and AF recurrence rate was weaker in men than women. CONCLUSION: Carotid atherosclerosis, CIMT ≥1 mm, and carotid plaque were significantly associated with a higher AF recurrence rate after radiofrequency catheter ablation. They were all risk factors for the recurrence of AF.

Effect of Dapagliflozin on the Outcome of Radiofrequency Catheter Ablation in Patients with Type 2 Diabetes Mellitus and Atrial Fibrillation.

INTRODUCTION: Dapagliflozin, one of the sodium-glucose cotransporter-2 inhibitors, has been widely used for the treatment of type 2 diabetes mellitus (T2DM) and heart failure. In this study, we sought to determine the impact of dapagliflozin on the outcome of radiofrequency catheter ablation (RFCA) for patients with T2DM and atrial fibrillation (AF). METHODS: This retrospective study included patients who underwent AF ablation between January 2019 to February 2021 at the First Affiliated Hospital of Zhengzhou University. All patients had a history of T2DM and were divided into the dapagliflozin group (n = 79) and the control group (n = 247) according to whether the patients were treated with dapagliflozin after ablation. The definition of AF recurrence was documented atrial arrhythmias over 30 s after a 1-month blanking period. Cox regression models were used to analyze the risk of AF recurrence. RESULTS: Overall, 326 patients were analyzed (mean age, 63.7±10.0 years old; male, 58.9%; paroxysmal AF, 52.8%; recurrence rate, 40.8%). We found that hemoglobin A1c before ablation was higher in the dapagliflozin group than in the control group (7.7±1.4 vs. 7.3±1.2, P = 0.007). After a mean follow-up of 15.5±8.9 months, the dapagliflozin group had a lower recurrence rate than the control group (27.8% vs. 44.9%, P = 0.007). Treatment with dapagliflozin (HR 0.614, ±95%CI 0.387-0.974, P = 0.038) was associated with a lower risk of recurrence of atrial arrhythmias (ATa) after ablation in multivariable Cox regression models that adjusted for duration of AF, BMI, AF type, left atrial diameter (LAD), and eGFR. The Cox regression model that incorporated hemoglobin A1c and other antidiabetic agents also demonstrated a similar reduction in the risk of recurrent atrial arrhythmias with dapagliflozin treatment (HR 0.611, ±95% CI 0.379-0.985, P = 0.043). CONCLUSIONS: In patients with T2DM, treatment with dapagliflozin appears to be independently associated with a significant reduction in the risk of recurrent atrial arrhythmias after RFCA.

Nickel-Catalyzed Cross-Coupling of Acyl Chloride with Racemic α-Trifluoromethyl Bromide to Access Chiral α-Trifluoromethyl Ketones.

The nickel-catalyzed reductive cross-coupling reaction of acyl chloride with racemic secondary α-trifluoromethyl bromide has been developed. By this chemistry, a series of structurally interesting chiral α-CF3 carbonyl compounds could be accessed with great enantioselectivity and good functional group tolerance. The study of late-stage transformation indicated that this chemistry could be used as the robust method to prepare products that contain a bioactive motif. Furthermore, the importance of the α-trifluoromethyl group to this reaction has been illustrated by control experiments.

Result and technique consideration of radiofrequency catheter ablation of tachycardia in patients with dextrocardia.

BACKGROUND: Patients with tachycardia, in the context of pre-existing dextrocardia, could benefit from catheter ablation. However, anatomical complexities hinder effective conduct of this procedure. We aimed to retrospectively summarize the clinical characteristics and the safety and efficiency, and recommended the technique considerations. METHODS: Twenty-one cases from 19 patients with tachycardia and dextrocardia, who underwent catheter ablation between 2009 and 2021, were enrolled. All patients underwent echocardiography and computed tomography (CT) to confirm the anatomical malformations. Transseptal puncture was guided by fluoroscopy or intracardiac echocardiography when left atrial access was necessary and the ablation process was guided by three-dimensional (3D) mapping. RESULTS: Six cases exhibited situs solitus while nine cases exhibited situs inversus. Fourteen cases had atrial fibrillation, seven had atrial flutter, and two had atrioventricular reentrant tachycardia (AVRT); two cases had combined atrial fibrillation and atrial flutter. Acute success was achieved in 18 cases (85.7%, 18/21). The 3D mapping system was not employed in the three cases which failed. During long-term follow-up (20.71 ± 21.86 months), eight cases (72.7%, 8/11) of atrial fibrillation with dextrocardia successfully attained sinus rhythm. None of AVRT cases had recurrence. Half of the atrial flutter cases with dextrocardia, especially those with a history of surgical correction for cardiac malformations, underwent recurrence. One case had cardiac tamponade. CONCLUSIONS: Catheter ablation for tachycardia patients with dextrocardia is safe, efficient, and feasible. It is imperative to integrate echocardiography, cardiac computer tomography, and 3D mapping, and apply 3D reconstruction to facilitate the success of catheter ablation.

In situ sulfidation of porous sponge-like CuO/SiW11Co into Cu2S/SiW11Co as stabilized and efficient counter electrode for quantum dot-sensitized solar cells.

Quantum dot-sensitized solar cells (QDSSCs), which are cost-effective, facilely prepared and environmentally friendly, are regarded as a promising third-generation photovoltaic technology, although the conversion efficiency of QDSSCs is still far lower than the theoretical efficiency (44%). Furthermore, the traditional Cu2S/brass counter electrode (CE) is susceptible to continuous corrosion from the polysulfide electrolyte, reducing the stability and electrocatalytic activity of the CE, thereby affecting cell performance. To enhance the stability of the Cu2S CE and make full use of its excellent catalytic properties, we used eco-friendly polyoxometalates (K6SiW11O39Co(ii) (H2O), SiW11Co) and porous sponge-like CuO as precursors to prepare a novel SiW11Co-doped high-efficiency Cu2S/SiW11Co CE on FTO by adopting the method of in situ sulfidation in the electrolyte. Electrochemical analysis revealed that the novel Cu2S/2%-SiW11Co (Cu2S-2) CE exhibits extremely high stability and electrocatalytic performance compared with other electrodes. Meanwhile, adding an appropriate amount of SiW11Co can inhibit charge recombination and improve cell performance. The CdS/CdSe co-sensitized QDSSCs assembled with the novel Cu2S-2 CE obtained a power conversion efficiency (PCE) of 5.94%, which was 20% more efficient than QDSSCs based on Cu2S/brass CE (4.96%). The method reported here puts forth a new direction for the preparation of efficient Cu2S counter electrodes.

Lutein inhibits proliferation, invasion and migration of hypoxic breast cancer cells via downregulation of HES1.

An intratumoral hypoxic microenvironment is frequently observed in solid tumors, including breast cancer. Lutein, a plant-derived compound and non-vitamin A carotenoid, has been demonstrated to possess multiple protective properties including anti-inflammation, anti-oxidative stress and antitumor effects. The main objective of the present research was to elucidate the involvement of lutein in the production of reactive oxygen species (ROS) under hypoxia, the activation of hairy and enhancer of split 1 (HES1), and the proliferation, invasion and migration of breast cancer cells. The human breast cancer cell lines MDA­MB­157 and MCF­7 were exposed to hypoxic conditions and various concentrations of lutein. An MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay was performed to examine cell proliferation, and Annexin V-fluorescein isothiocyanate/propidium iodide staining was performed to analyze the apoptosis ratio. The levels of hypoxia inducible factor-1α (HIF­1α), NOTCH signaling molecules, HES1 and epithelial-mesenchymal transition (EMT)-associated factors were examined by reverse transcription-quantitative polymerase chain reaction and western blot analysis. Wound healing and Transwell invasion assays were used to detect the invasion and migration of breast cancer cells. Intracellular ROS levels were examined using 2,7-dichlorodihydrofluorescein-diacetate and flow cytometry. The results revealed that cell proliferation was inhibited by lutein in a dose-dependent manner, and the apoptosis ratio gradually increased with lutein treatment under hypoxia as evident from flow cytometry-based analysis. Exposure to lutein inhibited hypoxia-mediated activation of HIF­1α, NOTCH signaling and HES1 expression, and suppressed the hypoxia-induced expression of EMT-associated factors. Lutein markedly inhibited the invasion and migration of breast cancer cells under hypoxia. Hypoxia-induced production of ROS was also decreased by lutein. Furthermore, the ROS scavenger N­acetylcysteine also suppressed hypoxia inducible factor 1α and HES1 expression in breast cancer cells during hypoxia, but hydrogen peroxide (H2O2) levels were increased. Taken together, the results of the present study suggested that lutein may be a novel candidate for the chemoprevention of breast cancer. Furthermore, HES1 may be crucial in mediating the involvement of lutein in the suppression of hypoxia-driven ROS-induced breast cancer progression.