Impact of high-power short-duration atrial fibrillation ablation technique on the incidence of silent cerebral embolism: a prospective randomized controlled study.

BACKGROUND: High-power short-duration (HPSD) ablation strategy has emerged as a popular approach for treating atrial fibrillation (AF), with shorter ablation time. The utilized Smart Touch Surround Flow (STSF) catheter, with 56 holes around the electrode, lowers electrode-tissue temperature and thrombus risk. Thus, we conducted this prospective, randomized study to investigate if the HPSD strategy with STSF catheter in AF ablation procedures reduces the silent cerebral embolism (SCE) risk compared to the conventional approach with the Smart Touch (ST) catheter. METHODS: From June 2020 to September 2021, 100 AF patients were randomized 1:1 to the HPSD group using the STSF catheter (power set at 50 W) or the conventional group using the ST catheter (power set at 30 to 35 W). Pulmonary vein isolation was performed in all patients, with additional lesions at operator's discretion. High-resolution cerebral diffusion-weighted magnetic resonance imaging (hDWI) with slice thickness of 1 mm was performed before and 24-72 h after ablation. The incidence of new periprocedural SCE was defined as the primary outcome. Cognitive performance was assessed using the Montreal Cognitive Assessment (MoCA) test. RESULTS: All enrolled AF patients (median age 63, 60% male, 59% paroxysmal AF) underwent successful ablation. Post-procedural hDWI identified 106 lesions in 42 enrolled patients (42%), with 55 lesions in 22 patients (44%) in the HPSD group and 51 lesions in 20 patients (40%) in the conventional group (p = 0.685). No significant differences were observed between two groups regarding the average number of lesions (p = 0.751), maximum lesion diameter (p = 0.405), and total lesion volume per patient (p = 0.669). Persistent AF and CHA2DS2-VASc score were identified as SCE determinants during AF ablation procedure by multivariable regression analysis. No significant differences in MoCA scores were observed between patients with SCE and those without, both immediately post-procedure (p = 0.572) and at the 3-month follow-up (p = 0.743). CONCLUSIONS: Involving a small sample size of 100 AF patients, this study reveals a similar incidence of SCE in AF ablation procedures, comparing the HPSD strategy using the STSF catheter to the conventional approach with the ST catheter. TRIAL REGISTRATION: Clinicaltrials.gov: NCT04408716. AF = Atrial fibrillation, DWI = Diffusion-weighted magnetic resonance imaging, HPSD = High-power short-duration, ST = Smart Touch, STSF = Smart Touch Surround Flow.

Better CRT Response in Patients Who Underwent Atrioventricular Node Ablation or Upgrade From Pacemaker: A Nomogram to Predict CRT Response.

Background: Response rates for cardiac resynchronization therapy (CRT) in patients without intrinsic left bundle-branch block (LBBB) morphology are poor. Objective: We sought to develop a nomogram model to predict response to CRT in patients without intrinsic LBBB. Methods: We searched electronic health records for patients without intrinsic LBBB who underwent CRT at Mayo Clinic. Logistic regression and Cox proportional hazards regression analysis were performed for the odds of response to CRT and risk of death, respectively. Results were used to develop the nomogram model. Results: 761 patients without intrinsic LBBB were identified. Six months after CRT, 47.8% of patients demonstrated improvement of left ventricular ejection fraction by more than 5%. The 1-, 3-, and 5-year survival rates were 95.9, 82.4, and 66.70%, respectively. Patients with CRT upgrade from pacemaker [odds ratio (OR), 1.67 (95% CI, 1.05-2.66)] or atrioventricular node (AVN) ablation [OR, 1.69 (95% CI, 1.09-2.64)] had a greater odds of CRT response than those patients who had new implant, or who did not undergo AVN ablation. Patients with right bundle-branch block had a low response rate (39.2%). Patients undergoing AVN ablation had a lower mortality rate than those without ablation [hazard ratio, 0.65 (95% CI, 0.46-0.91)]. Eight clinical variables were automatically selected to build a nomogram model and predict CRT response. The model had an area under the receiver operating characteristic curve of 0.71 (95% CI, 0.63-0.78). Conclusions: Among patients without intrinsic LBBB undergoing CRT, upgrade from pacemaker and AVN ablation were favorable factors in achieving CRT response and better long-term outcomes.

Cardiac resynchronization therapy modulates peripheral sympathetic activity.

BACKGROUND: Heightened sympathetic nerve activity has been associated with poorer prognosis in patients with reduced left ventricular systolic function (ie, heart failure with reduced ejection fraction [HFrEF]). OBJECTIVE: The purpose of this study was to investigate the effects of cardiac resynchronization therapy (CRT) on sympathetic nerve activity, measured by average skin sympathetic nerve activity (aSKNA). METHODS: This prospective study enrolled 36 patients with HFrEF who received CRT. Ten patients who received an implantable cardioverter-defibrillator for primary prevention served as controls. Patient clinical data, echocardiographic variables, and aSKNA at baseline and 3-month follow-up were collected. RESULTS: CRT patients who exhibited wider QRS duration had higher aSKNA (1.52 ± 0.65 µV vs 0.97 ± 0.49 µV; P = .027) compared to the control group at baseline. In the CRT group, patients with QRS duration ≥150 ms had higher aSKNA than those with QRS duration <150 ms (1.67 ± 0.63 µV vs 1.19 ± 0.51 µV; P =.039). After CRT, left ventricular ejection fraction (LVEF) improved from 29.6% to 35.4% (P = .001). aSKNA decreased significantly (1.52 ± 0.65 µV vs 1.31 ± 0.63 µV; P = .018). Seventeen of the 36 CRT patients were CRT responders, with LVEF improvement ≥5% at 3-month follow-up. aSKNA significantly decreased from 1.47 to 1.15 µV (P = .003) in CRT responders but was unchanged in nonresponders (1.44 ± 0.69 to 1.37 ± 0.70; P = .61). After CRT, a significant reduction in aSKNA was associated with improvement in LVEF (r = 0.638; P = .001). CONCLUSION: CRT reduces elevated sympathetic activity in HFrEF patients, accompanied by improvement in systolic function at short-term follow-up. The reduction of sympathetic activity is mainly seen in CRT responders.

Experimental Study on the Effect of a Weifufang on Human Gastric Adenocarcinoma Cell Line BGC-823 Xenografts and PTEN Gene Expression in Nude Mice.

Background: This study aims at investigating the effect of the Weifufang, an effective prescription for the treatment of gastric cancer developed by the Traditional Chinese Medicine (TCM)/Combination of TCM and Western Medicine Department of the Hunan Cancer Hospital, on gastric cancer xenografts in nude mice and its effect on the PTEN gene; it also aims at exploring the possible tumor suppression mechanism. Methods: Nude mice with xenografts were treated with different concentrations of the Weifufang for 2 weeks, and changes in tumor volume were observed. The histopathology of the tumor was detected by hematoxylin and eosin staining; PTEN gene expression in tumor tissues was detected by immunohistochemistry (IHC) and western blot. Results: After 2 weeks of treatment, tumor inhibition rates in the 5-flourouracil (5-FU) group, and in the Weifufang low-, middle-, and high-dose groups were 30.67%, 19%, 49.52%, and 29.36%, respectively. The IOD of the PTEN gene was detected by IHC. The values in the water group, the 5-FU group, and the Weifufang low-, middle-, and high-dose groups were 0.013 ± 0.004, 0.085 ± 0.062, 0.041 ± 0.024, 0.128 ± 0.032, and 0.061 ± 0.052, respectively. Except for the 5-FU group, the differences between the gastric compound middle dose-group and the other groups were statistically significant (p < 0.05). Results of PTEN expression detection by western blot: The expression levels in the water group, 5-FU group, and the Weifufang low-, middle-, and high-dose groups were 0.2240 ± 0.0172, 0.4200 ± 0.0228, 0.2760 ± 0.0163, 0.3840 ± 0.0133, and 0.3040 ± 0.0211, respectively. Except for the 5-FU group, differences between the Weifufang middle-dose group and the other groups were statistically significant (p < 0.05). Conclusion: The Weifufang may inhibit the growth of gastric cancer xenografts by upregulating PTEN gene expression. The middle-dose group had the best effect.

Left cardiac sympathetic denervation reduces skin sympathetic nerve activity in patients with long QT syndrome.

BACKGROUND: Although left cardiac sympathetic denervation (LCSD) is an effective antiarrhythmic therapy for patients with long QT syndrome (LQTS), direct evidence of reduced sympathetic activity after LCSD in humans is limited. OBJECTIVE: The purpose of this study was to assess skin sympathetic nerve activity (SKNA) in patients with LQTS undergoing LCSD. METHODS: We prospectively enrolled 17 patients with LQTS who underwent LCSD between 2017 and 2019. SKNA recordings from the left arm (L-SKNA) and chest (C-SKNA) leads were performed before and after LCSD. Mean SKNA, burst activity, and nonburst activity of L-SKNA and C-SKNA were analyzed. RESULTS: The mean patient age was 21 ± 9 years (8 men 47%). The longest baseline corrected QT value was 497 ± 55 ms at rest and 531 ± 38 ms on exercise stress testing. Five patients (29.4%) had previous LQTS-triggered cardiac events including syncope, documented torsades de pointes, and ventricular fibrillation. In the 24 hours after LCSD, mean L-SKNA decreased from 1.25 ± 0.64 to 0.85 ± 0.33 µV (P = .005) and mean C-SKNA from 1.36 ± 0.67 to 1.05 ± 0.49 µV (P = .11). The frequency of episodes of SKNA bursts recorded from the left-arm lead (2.87 ± 1.61 bursts per minute vs 1.13 ± 0.99 bursts per minute; P < .001) and mean L-SKNA during burst (1.82 ± 0.79 µV vs 1.15 ± 0.44 µV; P < .001) and nonburst (1.09 ± 0.60 µV vs 0.75 ± 0.32 µV; P = .03) periods significantly decreased after LCSD, while the frequency of episodes of SKNA bursts recorded from the chest lead (P = .57) and mean C-SKNA during burst (P = .44) and nonburst (P = .10) periods did not change significantly. No arrhythmic events were documented after 11.9 months (range 3.0-22.2 months) of follow-up. CONCLUSION: LCSD provides an inhibitory effect on cardiac sympathetic activity by suppressing burst discharge as measured by SKNA.