Quantitative assessment of transient autonomic modulation after single-shot pulmonary vein isolation with pulsed-field ablation.

INTRODUCTION: Pulmonary vein isolation (PVI) with thermal energy is characterized by concomitant ablation of the surrounding ganglionated plexi (GP). Pulsed-field ablation (PFA) selectively targets the myocardium and seems associated with only negligible effects on the autonomic nervous system (ANS). However, little is known about the dynamic effects of PFA on the GP immediately after PVI. This study sought to investigate the degree and acute vagal modulation induced by the FarapulseTM PFA system during PVI compared with single-shot thermal ablation. METHODS: A total of 76 patients underwent first-time PVI with either FarapulseTM PFA (PFA group, n = 40) or cryoballoon ablation (thermal ablation group, n = 36) for paroxysmal atrial fibrillation (AF). The effect on the ANS in the two groups was assessed before and after PVI with extracardiac vagal stimulation (ECVS). To capture any transient effects of PFA on the ANS, in a subgroup of PFA patients ECVS was repeated at three predefined timepoints: (1) before PVI (T0); (2) immediately after PVI (T1); and (3) 10 min after the last energy application (T2). RESULTS: Despite similar baseline values, the vagal response induced by ECVS after PVI almost disappeared in the thermal ablation group but persisted in the PFA group (thermal group: 840 [706-1090] ms, p < .001 compared to baseline; PFA group: 11 466 [8720-12 293] ms, p = .70 compared to baseline). Intraprocedural vagal reactions (defined as RR increase >50%, transitory asystole, or atrioventricular block) occurred more frequently with PFA than thermal ablation (70% vs. 28%, p = .001). Moreover, heart rate 24 h post-PVI increased more with thermal ablation than with PFA (16.5 ± 9.0 vs. 2.6 ± 6.1 beats/min, p < .001). In the subgroup of PFA patients undergoing repeated ANS modulation assessment (n = 11), ECVS demonstrated that PFA determined a significant acute suppression of the vagal response immediately after PVI (p < .001 compared to baseline), which recovered almost completely within 10 min. CONCLUSION: PVI with the FarapulseTM PFA system is associated with only transitory and short-lasting vagal effects on the ANS which recover almost completely within a few minutes after ablation. The impact of this phenomenon on AF outcome needs to be further investigated.

Cost-effectiveness analysis of vagal nerve blocking for morbid obesity.

OBJECTIVES: To assess the lifetime cost-effectiveness of intermittent, reversible vagal nerve blocking (via the implantable weight loss device vBloc) therapy versus conventional therapy as treatment for patients who are class 2 obese with diabetes and for those who are class 3 obese with or without diabetes, who have found pharmacotherapy and behavioral therapies ineffective, but are not prepared or willing to undergo current bariatric surgical options. STUDY DESIGN: A cost-effectiveness model was designed to simulate weight loss, diabetes remission, and costs in patients with obesity undergoing vagal nerve blocking therapy versus conventional therapy. METHODS: The model compared 2 treatment arms, vagal nerve blocking therapy and conventional therapy, and for each treatment arm included 4 health states based on body mass index (BMI) class. Using Monte Carlo simulation, patients entered the model one at a time and could transition between health states by experiencing BMI change. The model focused on change in BMI and diabetes remission as predictors of healthcare costs, health-related quality of life, and survival. Inputs for vagal nerve blocking effectiveness were obtained from the ReCharge trial; however, remaining inputs were estimated from published literature. Incremental cost-effectiveness ratios (ICERs) were evaluated in terms of cost per quality-adjusted life-year (QALY) gained. RESULTS: ICERs for vagal nerve blocking versus conventional therapy in patients who were class 2 and class 3 obese were estimated to be $17,274 and $21,713 per QALY gained, respectively. Sensitivity analyses showed results to be robust to reasonable variation in model inputs, with the upper limit of ICERs remaining below $30,000 for all sensitivity analysis scenarios assessed. CONCLUSIONS: Vagal nerve blocking therapy provides a cost-effective alternative to conventional therapy in patients who are class 2 obese with diabetes and in those who are class 3 with or without diabetes.

Quality of life after total vs distal gastrectomy with Roux-en-Y reconstruction: Use of the Postgastrectomy Syndrome Assessment Scale-45.

AIM: To investigate the detrimental impact of loss of reservoir capacity by comparing total gastrectomy (TGRY) and distal gastrectomy with the same Roux-en-Y (DGRY) reconstruction. The study was conducted using an integrated questionnaire, the Postgastrectomy Syndrome Assessment Scale (PGSAS)-45, recently developed by the Japan Postgastrectomy Syndrome Working Party. METHODS: The PGSAS-45 comprises 8 items from the Short Form-8, 15 from the Gastrointestinal Symptom Rating Scale, and 22 newly selected items. Uni- and multivariate analysis was performed on 868 questionnaires completed by patients who underwent either TGRY (n = 393) or DGRY (n = 475) for stage I gastric cancer (52 institutions). Multivariate analysis weighed of six explanatory variables, including the type of gastrectomy (TGRY/DGRY), interval after surgery, age, gender, surgical approach (laparoscopic/open), and whether the celiac branch of the vagus nerve was preserved/divided on the quality of life (QOL). RESULTS: The patients who underwent TGRY experienced the poorer QOL compared to DGRY in the 15 of 19 main outcome measures of PGSAS-45. Moreover, multiple regression analysis indicated that the type of gastrectomy, TGRY, most strongly and broadly impaired the postoperative QOL among six explanatory variables. CONCLUSION: The results of the present study suggested that TGRY had a certain detrimental impact on the postoperative QOL, and the loss of reservoir capacity could be a major cause.

Association of vagus nerve severance and decreased risk of subsequent type 2 diabetes in peptic ulcer patients: An Asian population cohort study.

Vagus nerve may play a role in serum glucose modulation. The complicated peptic ulcer patients (with perforation or/and bleeding) who received surgical procedures with or without vagotomy provided 2 patient populations for studying the impact of vagus nerve integrity. We assessed the risk of developing type 2 diabetes in peptic ulcer patients without and with complications by surgical treatment received in a retrospective population study using the National Health Insurance database in Taiwan.A cohort of 163,385 patients with peptic ulcer and without Helicobacter pylori infection in 2000 to 2003 was established. A randomly selected cohort of 163,385 persons without peptic ulcer matched by age, sex, hypertension, hyperlipidemia, Charlson comorbidity index score, and index year was utilized for comparison. The risks of developing diabetes in both cohorts and in the complicated peptic ulcer patients who received truncal vagotomy or simple suture/hemostasis (SSH) were assessed at the end of 2011.The overall diabetes incidence was higher in patients with peptic ulcer than those without peptic ulcer (15.87 vs 12.60 per 1000 person-years) by an adjusted hazard ratio (aHR) of 1.43 (95% confidence interval [CI] = 1.40-1.47) based on the multivariable Cox proportional hazards regression analysis (competing risk). Comparing ulcer patients with truncal vagotomy and SSH or those without surgical treatment, the aHR was the lowest in the vagotomy group (0.48, 95% CI = 0.41-0.56).Peptic ulcer patients have an elevated risk of developing type 2 diabetes. Moreover, there were associations of vagus nerve severance and decreased risk of subsequent type 2 diabetes in complicated peptic ulcer patients.

Cost-benefit of vagus nerve stimulation for refractory epilepsy.

PURPOSE: Vagus nerve stimulation (VNS) is an established treatment for patients with medically refractory epilepsy who are unsuitable candidates for conventional epilepsy surgery. VNS requires an initial financial investment but apart from our own previous study there are no reports on cost-benefit published to date. The purpose of this paper is to assess prospectively the cost-benefit ratio of VNS in a series of patients with long term follow-up. METHODS: Our experience with VNS comprises 25 patients of whom 20 with sufficient follow-up will be further discussed. These 20 patients have a mean post-implantation follow-up of 26 months (range: 6-50 months). Mean age was 30 years (range: 12-45 years); mean duration of epilepsy 17 years (range: 5-35 years). We prospectively assessed seizure frequency, prescribed AEDs, number of hospital admission days and side effects and calculated the epilepsy related direct medical cost and compared this with pre-implantation data. RESULTS: Mean seizure frequency decreased from 14 seizures/month (range: 2-40) to 9 seizures/month (range: 0-30) (p = 0.0003). The mean yearly epilepsy related direct medical costs per patient dropped from 6,682 USD (range: 829-21,888 USD) to 3,635 USD (range: 684-12,486 USD) (p = 0.0046). The mean number of hospital admission days was reduced from 16 days/year (range: 0-60) to 4 days/year (range: 0-30) (p = 0.0029). CONCLUSION: VNS is an efficacious and cost-beneficial treatment for refractory partial seizures.