A preliminary study of minimal left atrial appendage occlusion using Watchman under the guidance of fluoroscopy.

BACKGROUND: Left atrial appendage occlusion (LAAO) has been considered an alternative treatment to prevent embolic stroke in patients with nonvalvular atrial fibrillation (NVAF). However, it carries a risk of general anesthesia or esophageal injury if guided by transesophageal echocardiography (TEE). AIMS: We aimed to investigate the feasibility and safety of minimal LAAO (MLAAO) using Watchman under fluoroscopy guidance alone in patients with NVAF. METHODS: A total of 249 consecutive patients with NVAF who underwent LAAO using the WATCHMAN device were divided into two groups: the Standard LAAO (SLAAO) group and the MLAAO group. Procedural characteristics and follow-up results were compared between the two groups. RESULTS: There was no statistically significant difference in the rate of successful device implantation (p > 0.05). Fluoroscopy time, radiation exposure dose, and contrast medium usage in the MLAAO group were higher than those in the SLAAO group (p < 0.001). The procedure time and hospitalization duration were significantly lower in the MLAAO group than those in the SLAAO group (p < 0.001). The occluder compression ratio, measured with fluoroscopy, was lower than that measured with TEE (17.63 ± 3.75% vs. 21.69 ± 4.26%, p < 0.001). Significant differences were observed between the SLAAO group and the MLAAO group (p < 0.05) in terms of oropharyngeal/esophageal injury, hypotension, and dysphagia. At 3 months after LAAO, the MLAAO group had a higher incidence of residual flow within 1-5 mm compared to the SLAAO group, although the difference was not statistically significant. CONCLUSION: MLAAO guided by fluoroscopy, instead of TEE, without general anesthesia simplifies the operational process and may be considered safe, effective, and feasible, especially for individuals who are unable to tolerate or unwilling to undergo TEE or general anesthesia.

Construction of atrial fibrillation-related circRNA/lncRNA-miRNA-mRNA regulatory network and analysis of potential biomarkers.

BACKGROUND: The specific pathogenesis of atrial fibrillation (AF) remains unclear. In this study, we examined the expression of differential messenger RNAs (mRNAs), circular RNAs (circRNAs), and long-stranded noncoding RNAs (lncRNAs) from human peripheral blood mononuclear cells to initially construct a circRNA/lncRNA-miRNA-mRNA ceRNA regulatory network to explore the pathogenesis of AF and to screen for potential biomarkers. METHODS: A total of four pairs of AF cases and healthy subjects were selected to detect differentially expressed mRNAs, circRNAs, and lncRNAs in peripheral blood mononuclear cells by microarray analysis. And 20 pairs of peripheral blood from AF patients and healthy subjects were selected for validation of mRNA, circRNA, and lncRNA by quantitative real-time PCR (qRT-PCR).The relevant ceRNA networks were constructed by GO and KEGG and correlation analysis. RESULTS: The results showed that compared with healthy subjects, there were 813 differentially expressed mRNAs (DEmRNAs) in peripheral blood monocytes of AF, including 445 upregulated genes and 368 downregulated genes, 120 differentially expressed circRNAs (DEcircRNAs), including 65 upregulated and 55 downregulated, 912 differentially expressed lncRNAs (DElncRNAs), including 531 upregulated and 381 downregulated lncRNAs. GO and KEGG analysis of DERNA revealed the biological processes and pathways involved in AF. Based on microarray data and predicted miRNAs, a ceRNA network containing 34 mRNAs, 212 circRNAs, 108 lncRNAs, and 38 miRNAs was constructed. CONCLUSION: We revealed a novel ceRNA network in AF and showed that downregulated XIST, circRNA_2773, and CADM1 were negatively correlated with miR-486-5p expression and had a potential targeting relationship with miR-486-5p.

Effects of freeze-thaw cycles on nutrient removal from bioretention cells.

There have been numerous summaries of the runoff purification characteristics of bioretention cells in warm climates. However, little has been done on the effects of freeze-thaw cycles (FTCs) that frequently occur in cold regions on bioretention cell performance. Three experimental columns were constructed to simulate the operation of the bioretention cell under the FTCs. The effects of FTCs on the nutrient removal efficiency of different filling bioretention cells were analyzed. The results showed that the ammonia nitrogen (NH4+-N) concentration in the effluent of the wood chip bioretention cell under the T3 conditions (WBCF) (2.35 mg/L) was significantly higher than that of the wood chip bioretention cell operating at room temperature (WBCR) (0.62 mg/L). The effluent NH4+-N concentration of aluminum sludge bioretention cell (ABCF) (0.096 mg/L) under the FTCs was lower than that of WBCF (0.91 mg/L). Under the T3 condition, the effluent nitrate nitrogen (NO3--N) and total nitrogen (TN) concentrations of WBCF (5.33 mg/L and 8.86 mg/L) were higher than those of WBCR (5 mg/L and 6.11 mg/L) at room temperature. Under FTCs conditions, both WBCF and ABCF had high NO3--N removal efficiency (up to 85.87% and 24.75%) at the initial stage of thawing of the filler, and the efficiency gradually decreased with the thawing of the filler. With the increase of FTCs, the NO3--N removal efficiency of WBCF gradually decreased (always higher than 13.6%), while the removal efficiency of ABCF fluctuated wildly (the removal efficiency was primarily negative). The total phosphorus (TP) concentration in the effluent of WBCF (0.11 mg/L) under the T3 conditions was lower than that of WBCR (0.02 mg/L) at room temperature, and the TP concentration of ABCF (0.021 mg/L) in the effluent under the FTCs was slightly lower than that of WBCF (0.031 mg/L). The FTCs have a more significant impact on removing nitrogen pollutants in runoff, but have little effect on phosphorus. Compared with aluminum sludge, wood chips are more suitable for efficient removal of nitrogen pollutants in runoff under the FTCs. The experimental conclusions can provide a reference for the construction of bioretention cells in cold regions.

Effects of Left Atrial Appendage Closure on Neuroendocrine Function in Patients with Nonvalvular Atrial Fibrillation.

BACKGROUND The left atrial appendage (LAA) is an organ with neuroendocrine function. It remains unclear whether left atrial appendage closure (LAAC) has physiological effects on neuroendocrine function in patients with nonvalvular atrial fibrillation (NVAF). In the present study, we aimed to investigate the effects of LAAC on neuroendocrine function in patients with NVAF. MATERIAL AND METHODS We enrolled 20 patients with NVAF treated by LAAC in Jiangsu Taizhou People's Hospital from October 2019 to October 2020. Blood samples were collected 1 day before LAAC and 12 months after LAAC. Plasma concentrations of adrenaline, aldosterone, pro-atrial natriuretic peptide (NT-proANP), and N-terminal pro-B-type natriuretic peptide (NT-proBNP) were measured. RESULTS LAAC was successfully performed in all patients, without serious complications. Compared with the preoperative levels, there was no significant difference in the levels of NT-proANP, NT-proBNP, and epinephrine at 12 months after LAAC (P>0.05). However, there was a significant decrease in aldosterone level at 12 months post-procedure (209.04±132.98 pg/ml) compared with pre-procedure baseline (279.08±166.88 pg/ml, P=0.04). There was no correlation between the compression rate of the occlusion and the reduction of aldosterone (Kendall's Tau-b=0.159, P=0.351). CONCLUSIONS LAAC can be safely and effectively performed in NVAF patients, and showed no significant effect on the adrenergic system and natriuretic peptides, but had an influence on the RAAS.

Influencing Factors of Recurrence of Nonvalvular Atrial Fibrillation after Radiofrequency Catheter Ablation and Construction of Clinical Nomogram Prediction Model.

Purpose: This study sought to investigate the predictive factors for atrial fibrillation (AF) recurrence in patients after radiofrequency ablation (RFCA) and construct a nomogram prediction model for providing precious information of ablative strategies. Methods: A total of 221 patients with AF who underwent RFCA were enrolled. Univariate and multivariate Cox regression were used to screen the predictors of recurrence. The receiver operating characteristic (ROC) curve and the Kaplan-Meier (K-M) curve were drawn to analyze the value of predictors. The nomogram model was further constructed to predict the recurrence of AF in patients after RFCA. Results: There were 59 cases of AF recurrence after RFCA. Monocyte count/high-density lipoprotein cholesterol (MHR), AF course (COURSE), coronary heart disease (CHD), and AF type (TYPE) were the independent risk factors for predicting AF recurrence after RFCA. Accordingly, a nomogram prediction model based on MHR, COURSE, CHD, and TYPE was constructed with a C-index of 0.818 (95% CI: 0.681∼0.954), while the C-index of verification was 0.802 (95% CI: 0.658∼0.946). Conclusions: Preoperative MHR, COURSE, CHD, and TYPE were independent risk factors for predicting recurrence of AF after RFCA. The nomogram model based on MHR, COURSE, CHD, and TYPE can be used to predict the recurrence of AF after RFCA accurately and individually.

Purification effect of bioretention with improved filler on runoff pollution under low temperature conditions.

In recent years, there have been a number of studies on bioretention during hot summer, with only few studies reported during low-temperature winters. The application of bioretention in cold areas still lacks effective guidance. In this study, runoff simulation experiments were conducted to explore the influence of wood chips filler and water treatment residue on the removal of runoff pollutants under different packing gradations and low temperature conditions. Under low temperature, nitrate nitrogen removal rate of wood chips filler decreased from 70% to 90% in autumn to -23%- 35% in winter, the total nitrogen removal rate decreased from 75 to 90% in autumn to 20%-50% in winter, the removal rate of ammonia nitrogen and total phosphorus exceeded 70% during the entire experiment. Water treatment residue filler maintained a high ammonia nitrogen and total phosphorus removal rate during the experiment, with the total phosphorus removal rate above 90% and ammonia nitrogen removal rate above 80%. The bioretention effluent concentration of nitrate and total nitrogen was higher than 7.3 mg/L and 8.5 mg/L, respectively, most of the time. However, at low temperature, the COD removal rate of the two fillers was 25%-50%, which was very poor. Therefore, wood chips filler was observed to be better suited for the removal of nitrate and total nitrogen from the runoff, while water treatment residue had a better effect on the removal of ammonia nitrogen and total phosphorus in winter. Thus, for the application of bioretention in northern China, appropriate fillers should be selected considering the water quality characteristics of the area.

Circulating Galectin-3 and Aldosterone for Predicting Atrial Fibrillation Recurrence after Radiofrequency Catheter Ablation.

Background: Circulating galectin-3 (Gal-3) and aldosterone (ALD) are involved in fibrosis and inflammation. However, their potential value as predictors of atrial fibrillation (AF) recurrence after radiofrequency catheter ablation (RFCA) is unknown or controversial. Therefore, the aim of this study was to assess the relationship between baseline Gal-3, ALD levels, and AF recurrence in patients performing RFCA. Methods: 153 consecutive patients undergoing RFCA were included. Gal-3 and ALD were measured at baseline. Univariate and multivariate Cox regressions were performed to determine the predictors of AF recurrence. Receiver operating characteristic (ROC) curve and Kaplan-Meier (K-M) curve were used to assess the value of predictors. Results: There were 35 (22.88%) cases of AF recurrence after RFCA. The recurrence group had significantly higher preoperative serum levels of Gal-3 and ALD than the nonrecurrence group. Univariate and multivariate analysis showed that Gal-3 (HR = 1.28, 95% CI: 1.04-1.56, p = 0.02) and ALD (OR = 1.02, 95% CI: 1.00-1.03, p < 0.03) were significantly associated with AF recurrence after RFCA. The area under the curve (AUC) of preoperative serum Gal-3, ALD, and 2 combined to predict the recurrence of AF patients after RFCA was 0.636, 0.798, and 0.893, respectively, while sensitivity was 65.32%, 71.69%, and 88.61%, respectively and specificity was 77.46%, 78.53%, and 86.0%, respectively. Patients with Gal-3 above the cutoff value of 14.57 pg/ml had higher frequent AF recurrence than the patients with Gal - 3 ≤ 14.57 pg/ml (35% vs. 12%, p < 0.001) during a follow-up. Meanwhile, patients with ALD above the cutoff value of 243.61 pg/ml also had a higher AF recurrence rate than those with ALD ≤ 243.61 pg/ml (37% vs. 11%, p < 0.001) during a follow-up. The recurrence rate in patients with Gal - 3 > 14.57 pg/ml + ALD > 243.61 pg/ml was higher than that in patients with baseline Gal - 3 > 14.57 pg/ml or ALD > 243.61 pg/ml and patients with Gal - 3 ≤ 14.57 pg/ml + ALD ≤ 243.61 pg/ml (57% vs. 14% vs. 9%, p < 0.01, respectively). Conclusion: AF recurrence after RFCA had higher baseline Gal-3 and ALD levels, and higher preoperative circulating Gal-3 and ALD levels were independent predictors of AF recurrence for patients undergoing RFCA, while combination of preoperative Gal-3 and ALD levels has higher prediction accuracy.

Safety and efficacy of different anticoagulation regimens after left atrial appendage occlusion.

BACKGROUND: This study examined the safety and efficacy of different anticoagulation regimens in patients with atrial fibrillation (AF) after left atrial appendage occlusion (LAAC) using the Watchman closure device. METHODS: AF patients who underwent LAAC using the Watchman closure device in the Department of Cardiology, Jiangsu Taizhou People's Hospital between March 2018 and November 2019 were retrospectively enrolled in this study. Patients were divided into two groups according to different postoperative anticoagulant regimens. One group was treated with anticoagulant therapy alone [oral anticoagulant (OAC)/new OAC (NOAC) group] and the other was given NOACs combined with single antiplatelet therapy (SPAT) (NOAC + SAPT group). The incidences of ischemic stroke/transient ischemic attack (TIA), major bleeding events, all-cause mortality, and device-related thrombosis (DRT) were recorded. Furthermore, multivariate regression was used to analyze the factors associated with the occurrence of early DRT. RESULTS: A total of 160 patients, including 42 (51%) females, with a mean age of 69.13±6.14 years were enrolled in this study. The mean CHA2DS2-VASc score was 3.66±1.11 and the mean HAS-BLED score was 4.16±0.82. During the postoperative follow-up period, there were no significant differences in the incidence of ischemic stroke/TIA [hazard ratio (HR) =0.616; 95% confidence interval (CI): 0.056 to 6.818; P=0.693], major bleeding events (HR =0.520; 95% CI: 0.047 to 5.764; P=0.594) nor all-cause mortality (HR =0.579; 95% CI: 0.052 to 6.394; P=0.656) between the two groups. However, the incidence of early DRT was higher in the OAC/NOAC group compared to the NOAC + SAPT group [odds ratio (OR) =0.120; 95% CI: 0.015 to 0.984; P=0.048]. Multivariate regression confirmed that atrial blood stasis (OR =11.367; 95% CI: 1.394 to 92.687; P=0.023) and peri-device leak (OR =9.337; 95% CI: 1.623 to 53.727; P=0.012) were independent predictors of early DRT. CONCLUSIONS: Short-term NOAC + SAPT after LAAC did not significantly increase the incidence of major bleeding events, ischemic stroke/TIA, nor all-cause mortality compared to OAC/NOAC therapy. Not only was NOAC + SAPT therapy found to be safe and effective in short-term follow-up, but it also lowered the risk of early DRT.

Correlation between Serum LP-PLA2 and sST2 Levels and the Condition of Patients with Acute Heart Failure and Their Prognostic Value.

Acute heart failure (AHF) occurs mostly in the elderly, which is a syndrome that occurs in the later stages of the development of cardiovascular disease. Due to the sharp decline in the patient's heart function, the patient has a high mortality rate and a poor prognosis, which seriously threaten the life safety of the elderly. Therefore, early diagnosis of AHF and timely treatment are extremely important. Lipoprotein-associated phospholipase A2 (LP-PLA2) is a newly discovered cardiovascular-specific inflammatory marker, which is closely related to the formation and progression of atherosclerotic plaque and the occurrence and development of coronary heart disease. Soluble growth stimulation expression gene 2 (sST2) protein is a protein produced under the induction of mechanical stress in cardiomyocytes. It can act as a decoy receptor to mediate the interleukin-33 (IL-33)/ST2 signaling pathway to bind to IL-33, thereby reducing the myocardial protective effect and leading to myocardial remodeling. The purpose of this study was to explore the serum LP-PLA2 and sST2 levels in AHF patients and to analyze their correlation with the disease and their prognostic value. The results showed that the levels of serum LP-PLA2 and sST2 were increased in AHF patients, and the levels of serum LP-PLA2 and sST2 in patients with adverse prognostic events were higher than those in patients without adverse prognostic events. The levels of serum LP-PLA2 and sST2 are closely related to the degree of patients' illness, among which the combined prediction of AHF patients with LP-PLA2 and sST2 has the highest value, which is worthy of promotion.

Removal characteristics of heavy metal ions in rainwater runoff by bioretention cell modified with biochar.

As a form of pollution source control and a low-impact development measure, bioretention is a convenient, economical, and effective method for the removal of heavy metals from stormwater runoff, which can adapt to the randomness and uncontrollability of non-point source pollution. However, few studies have assessed the performance of bioretention in the simultaneous removal of multiple heavy metals and the impact of heavy metal migration on the bioretention life cycle. In this study, the removal rates of various heavy metals: copper (Cu), zinc (Zn), lead (Pb), and cadmium (Cd), were enhanced using a biochar modified bioretention cell, as compared to the traditional sandy soil bioretention process. Following treatment with the biochar modified bioretention cell, the average concentrations of Cu, Zn, Pb, and Cd were 55%, 61%, 19.66%, and 36.43% lower than the traditional sandy soil bioretention effluent, respectively. These results show that biochar significantly improves the removal of heavy metals by the bioretention process, especially Cu and Zn. This study also evaluated the effect of biochar on the inhibition of heavy metal migration in the filler material, by sampling and analysing the filler and retained water at different filler depths, then repeating the filler leaching experiment after simulated rainfall. The content of heavy metals at a filler depth of 45 cm in the traditional sandy soil bioretention system, was significantly higher than in the biochar modified bioretention system, showing that biochar plays an important role in the inhibition of heavy metal migration.