Efficacy and safety of pulsed field ablation for accessory pathways: a pilot study.

AIMS: Radiofrequency ablation is used as a first-line therapy for accessory pathways (APs). However, data regarding the effects of pulsed field ablation (PFA) on APs are limited. We sought to evaluate the acute procedural and 6-month success and safety of PFA in a cohort of patients with APs. METHODS AND RESULTS: A focal contact force-sensing PFA catheter was used for patients with APs. Pulsed field ablation generator generated a bipolar and biphasic waveform (±1000 V) with a duration of 100 ms from the tip of the PFA catheter. A 100% acute procedural success was achieved in 10 conscious patients with APs (7 left anterolateral, 2 left inferolateral, and 1 right posteroseptal APs) including 6 (60%) patients after an initial application. The average total ablation time was 6.3 ± 4.9 s for 4.7 ± 1.8 ablation sites (ASs), including 3.1 ± 2.4 s at targets and 3.2 ± 2.9 s at 3.2 ± 2 bolus ASs. The mean skin-to-skin time was 59.3 ± 15.5 min, and PFA catheter dwell time was 29.4 ± 7.8 min. One patient encountered transient sinus arrest during PFA due to parasympathetic overexcitation. Sinus rhythm was restored in all patients without any significant adverse events during the short-term follow-up. CONCLUSION: Pulsed field ablation of APs was feasible, effective, and safe. Its efficiency was remarkable for its ultrarapid termination of AP conduction. Further studies are warranted to prove whether utilization of PFA with current parameters can extend to manifold AP ablation.

Visfatin aggravates transverse aortic constriction-induced cardiac remodelling by enhancing macrophage-mediated oxidative stress in mice.

Previous studies have reported that visfatin can regulate macrophage polarisation, which has been demonstrated to participate in cardiac remodelling. The aims of this study were to investigate whether visfatin participates in transverse aortic constriction (TAC)-induced cardiac remodelling by regulating macrophage polarisation. First, TAC surgery and angiotensin II (Ang II) infusion were used to establish a mouse cardiac remodelling model, visfatin expression was measured, and the results showed that TAC surgery or Ang II infusion increased visfatin expression in the serum and heart in mice, and phenylephrine or hydrogen peroxide promoted the release of visfatin from macrophages in vitro. All these effects were dose-dependently reduced by superoxide dismutase. Second, visfatin was administered to TAC mice to observe the effects of visfatin on cardiac remodelling. We found that visfatin increased the cross-sectional area of cardiomyocytes, aggravated cardiac fibrosis, exacerbated cardiac dysfunction, further regulated macrophage polarisation and aggravated oxidative stress in TAC mice. Finally, macrophages were depleted in TAC mice to investigate whether macrophages mediate the regulatory effect of visfatin on cardiac remodelling, and the results showed that the aggravating effects of visfatin on oxidative stress and cardiac remodelling were abrogated. Our study suggests that visfatin enhances cardiac remodelling by promoting macrophage polarisation and enhancing oxidative stress. Visfatin may be a potential target for the prevention and treatment of clinical cardiac remodelling.

Correlation between Serum Myosin Light Chain 4 Levels and Recurrence after Radiofrequency Ablation in Patients with Atrial Fibrillation.

Atrial fibrillation (AF) is the most common arrhythmia that is harmful to human health. This study aims to explore the relationship between myosin light chain 4 (MYL4) and AF recurrence after radiofrequency ablation (RFA). Patients with AF (n = 85) were enrolled, and healthy subjects (n = 90) with normal sinus rhythm and no previous history of AF were selected as controls. The serum levels of MYL4, transforming growth factor (TGF) -ß1, and procollagen type-I C-terminal propeptide (PICP) were determined. The correlation between MYL4 and atrial fibrosis remodeling indicators (TGF-ß1/PICP) and left atrial diameter (LAD) was analyzed. The influence of MYL4 on AF recurrence after RFA was evaluated, and the independent correlation between them was assessed. Patients with AF and the controls showed no significant differences in age, gender, body mass index, systolic blood pressure, diastolic blood pressure, left ventricular ejection fraction, triglycerides, total cholesterol, high-density lipoprotein, low-density lipoprotein, white blood cell count, neutrophil/lymphocyte ratio, brain natriuretic peptide, and history of smoking, drinking, hypertension, and diabetes (P > 0.05), but with increased LAD in patients with AF (P < 0.01). Serum MYL4 level was reduced in patients with AF (0.6 ± 0.2) compared with that of controls (0.1 ± 0.6) (P < 0.01), and it was negatively correlated with TGF-ß1, PICP, and LAD (r = -0.2389, P < 0.05; r = -0.5174, P < 0.01; r = -0.3191; P < 0.01). Low levels of MYL4 increased the risk of AF recurrence after RFA (χ2 = 16.64; P < 0.0001). A low MYL4 level in patients with AF showed a poorer prognosis. Serum MYL4 level and AF type were independent risk factors affecting AF recurrence after RFA.

Unipolar electrogram-guided radiofrequency catheter ablation in paroxysmal atrial fibrillation: electrogram patterns and outcomes.

BACKGROUND: Transmural lesions (TLs) are the crucial point for radiofrequency catheter ablation (RFCA) in atrial fibrillation (AF) patients. Previous studies have reported that complete positive unipolar electrogram (UP-EGM) after ablation is associated with transmural lesions. However, UP-EGM patterns may differ in different regions of continuous circular lesions (CCLs) around the pulmonary vein ostia after ablation. We aimed to analyze the different UP-EGM patterns in different CCL regions after ablation and the effectiveness of UP-EGM guided RFCA in paroxysmal atrial fibrillation (PAF). METHODS: A total of 43 patients with PAF (aged 59 ± 11 years; 65% male) were consecutively included. Pulmonary vein isolation was achieved by contiguous point-by-point RFCA. UP-EGM was recorded by the ablation catheter. Both CCLs were divided into six regions. Two points were randomly chosen from each region to analyze UP-EGM type after ablation. All the patients were followed for atrial arrhythmias recurrence. RESULTS: All pulmonary veins were isolated with complete bidirectional block. A total of 1032 RFCA points with complete positive UP-EGM were collected. UP-EGM morphology after ablation was divided into four different types defined as R, rR', Rr', and M. M patterns mostly appeared in anterosuperior (65%) and roof (49%) regions of left CCLs. In the remaining regions, the percentage of non-M patterns (R, rR', and Rr') ranged from 63% in posteroinferior regions of right CCLs to 88% in anteroinferior regions of right CCLs. After a mean follow-up time of 19 months, 37 (86%) patients remained in sinus rhythm. CONCLUSION: Most (72%) UP-EGM types after ablation are non-M patterns. Pulmonary vein isolation guided by UP-EGM with a complete positive pattern in PAF patients is reliable.

Comparison of dabigatran and warfarin used in patients with non-valvular atrial fibrillation: Meta-analysis of random control trial.

BACKGROUND: Dabigatran is a kind of oral anticoagulant and there was little review only about dabigatran and warfarin used in patients with atrial fibrillation. This meta-analysis only assesses the dabigatran and warfarin used in patients with atrial fibrillation. DESIGN: Cochrane Library, PubMed, Clinical Trials.gov, CNKI, and WanFang databases were searched. The primary endpoint was the incidence of stroke and the second endpoints were the incidence of bleeding and embolic events. RESULTS: Six RCTs and 20086 patients were included in our meta-analysis. No significant difference was obtained between 110 mg dabigatran and warfarin on the endpoint of stroke (risk ratio (RR), 0.90; 95% confidence interval [CI], 0.71-1.12; P = .34; I = 0%) and embolic events p (RR, 0.89; 95% CI, 0.71-1.12; P = .32; I = 0%). However, the 110 mg dabigatran associated lower incidence of bleeding (RR, 0.81; 95% CI, 0.69-0.95; P = .01; I = 0%) compare with warfarin. When compared with 150 mg dabigatran, warfarin associated with lower rate of stroke (RR, 0.96; 95% CI, 0.83-1.12; P = .62; I = 0%) and embolic events (RR, 0.67; 95% CI, 0.53-0.86; P = .001; I = 0%) but similar in the incidence of bleeding (RR, 0.67; 95% CI, 0.53-0.86; P = .001; I = 0%). CONCLUSION: No significant difference was obtained between 110 mg dabigatran and warfarin in the incidence of stroke and embolic events. However, the 110 mg dabigatran associated lower incidence of bleeding compare with warfarin. When compared with 150 mg dabigatran, warfarin associated with lower incidence of stroke and embolic events but similar in the incidence of bleeding.

ABCB1 C3435T polymorphism and response to clopidogrel treatment in coronary artery disease (CAD) patients: a meta-analysis.

BACKGROUND: A number of investigators have evaluated the association between the ABCB1 polymorphism and clopidogrel responding, but the results have been inconclusive. To examine the risk of high platelet activity and poor clinical outcomes associated with the ABCB1 C3435T polymorphism in CAD patients on clopidogrel, all available studies were included in the present meta-analysis. METHODS: We performed a systematic search of PubMed, Scopus and the Cochrane library database for eligible studies. Articles meeting the inclusion criteria were comprehensively reviewed, and the available data were accumulated by the meta-analysis. RESULTS: It was demonstrated that the ABCB1 C3435T variation was associated with the risk of early major adverse cardiovascular events (MACE) (T vs. C OR, 1.34; 95% CI, 1.10 to 1.62; P=0.003; TT vs. CC: OR, 1.77; 95% CI, 1.19 to 2.63; P=0.005; CT + TT vs.CC: OR, 1.48; 95% CI, 1.06 to 2.06; P=0.02) and the polymorphism was also associated with the risk of the long-term MACE in patients on clopidogrel LD 300 mg (T vs. C: OR, 1.28; 95% CI, 1.10 to 1.48; P=0.001; TT vs. CC: OR, 1.59; 95% CI, 1.19 to 2.13; P=0.002; CT + TT vs.CC: OR, 1.39; 95% CI, 1.08 to 1.79; P=0.01). The comparison of TT vs. CC was associated with a reduction in the outcome of bleeding (TT vs. CC: OR, 0.51; 95% CI, 0.40 to 0.66; P<0.00001). However, the association between ABCB1 C3435T polymorphism and platelet activity and other risk of poor clinical outcomes was not significant. CONCLUSIONS: The evidence from our meta-analysis indicated that the ABCB1 C3435T polymorphism might be a risk factor for the MACE in patients on clopidogrel LD 300 mg, and that TT homozygotes decreased the outcome of bleeding compared with CC homozygotes.