Background: Abstinence from alcohol is effective for reduction of atrial fibrillation (AF) burden. However, effects of alcohol abstinence on clinical outcomes of catheter ablation for AF remain unknown. We sought to assess association of alcohol consumption reduction with clinical outcomes of catheter ablation for AF. Methods: In this multicenter prospective observational study, consecutive patients undergoing catheter ablation for AF were enrolled. All patients were requested to limit alcohol consumption to <20 g/wk after the ablation. The primary end point was AF/atrial tachycardia (AT) recurrence-free survival without antiarrhythmic drugs beyond a 3-month blanking period. Percent reduction of alcohol consumption from baseline to 1-year postablation, if freed from AF/AT for 1-year, or to AF/AT recurrence was assessed. Univariate and multivariate Cox regression analyses were performed to assess the association of the percent reduction of alcohol consumption with AF/AT recurrence-free survival as well as to determine the cutoff value for the percent reduction of alcohol consumption that yielded the largest difference in AF/AT recurrence-free survival. Results: Of 3474 patients enrolled in this study, analysis was performed in 1720 patients who consumed alcohol regularly before ablation (64±10 years, male 88%, paroxysmal AF 55.9%, persistent AF 31.6%, longstanding persistent AF 12.5%). Median baseline alcohol consumption was 140 g/wk (interquartile range, 70–280 g). Alcohol consumption during 1-year follow-up decreased to a median of 70 g (interquartile range, 13–162 g; P <0.0001). Multivariate Cox regression analysis demonstrated that alcohol reduction of ≥1% from baseline to 1-year follow-up (median reduction, 75% [interquartile range, 45%–100%]) was associated with lower risk of AF/AT recurrence (hazard ratio, 0.630 [95% C, 0.518–0.768], P <0.001), compared with alcohol reduction of <1% (median, 0% [interquartile range, −20% to 0%]). Conclusions: This study suggests that abstinence from alcohol improves clinical outcomes of catheter ablation for AF.

Purpose: Diaphragm ultrasonography is used to identify causes of diaphragm dysfunction. However, its correlation with pulmonary function tests, including maximal inspiratory (MIP) and expiratory pressures (MEP), remains unclear. This study investigated this relationship by measuring diaphragm thickness, thickening fraction (TF), and excursion (DE) using ultrasonography, and their relationship to MIP and MEP. It also examined the influence of age, sex, height, and BMI on these measures. Methods: We recruited healthy Japanese volunteers and conducted pulmonary function tests and diaphragm ultrasonography in a seated position. Diaphragm ultrasonography was performed during quiet breathing (QB) and deep breathing (DB) to measure the diaphragm thickness, TF, and DE. A multivariate analysis was conducted, adjusting for age, sex, height, and BMI. Results: Between March 2022 and January 2023, 109 individuals (56 males) were included from three facilities. The mean (standard deviation) MIP and MEP [cmH2O] were 72.2 (24.6) and 96.9 (35.8), respectively. Thickness [mm] at the end of expiration was 1.7 (0.4), TF [%] was 50.0 (25.9) during QB and 110.7 (44.3) during DB, and DE [cm] was 1.7 (0.6) during QB and 4.4 (1.4) during DB. Multivariate analysis revealed that only DE (DB) had a statistically significant relationship with MIP and MEP (p = 0.021, p = 0.008). Sex, age, and BMI had a statistically significant influence on relationships between DE (DB) and MIP (p = 0.008, 0.048, and < 0.001, respectively). Conclusion: In healthy adults, DE (DB) has a relationship with MIP and MEP. Sex, age, and BMI, but not height, are influencing factors on this relationship.

BACKGROUND: The clinical outcome of pulmonary vein isolation (PVI) for persistent atrial fibrillation (AF) is suboptimal. Mapping studies have demonstrated atrial sites outside of the pulmonary veins displaying focal activation patterns during AF. We sought to determine whether adding catheter ablation of focal activation sites to PVI improves clinical outcomes of catheter ablation for persistent AF. METHODS: In this multicenter, randomized, single-blinded trial, we assigned patients with persistent AF to either PVI alone or to mapping-guided ablation of focal activation sites in addition to PVI in a 1:1 ratio. In the mapping-guided group, both atria were mapped after PVI using a Pentaray catheter (Biosense-Webster) and focal activation sites identified by CARTOFINDER (Biosense-Webster) were ablated. The primary end point was freedom from AF or atrial tachycardia without antiarrhythmic drugs beyond a 90-day blanking period. RESULTS: A total of 98 patients were assigned to the mapping-guided group and 102 to the PVI alone group. In the mapping-guided group, focal activation sites were identified at 2.6±0.3 and 2.5±0.2 sites per patient in the left and right atrium, respectively. Patients were followed up for 768.5 (interquartile range, 723.75–915.75) and 755.5 days (interquartile range, 728.5–913.75) in the mapping-guided ablation and the PVI alone groups, respectively. Freedom from AF/atrial tachycardia without antiarrhythmic drugs at 2-year follow-up was 66.8% and 75.2% in the mapping-guided ablation and the PVI alone groups, respectively (hazard ratio, 1.26 [95% CI, 0.76–2.10]; P =0.37). Adverse events occurred in 3 patients (3.0%) and none (0%) in the mapping-guided ablation and the PVI alone groups, respectively ( P =0.12). CONCLUSIONS: In patients with persistent AF, the addition of mapping-guided ablation of focal activation sites to PVI did not improve clinical outcomes compared with PVI alone. REGISTRATION: URL: https://center6.umin.ac.jp/cgi-open-bin/ctr/index.cgi?function=02 ; Unique identifier: UMIN000037569.

Introduction: Measurements of diaphragm function by ultrasonography are affected by body position, but reference values in the seated position have not been established for an Asian population. This study aimed to determine reference values for diaphragm thickness, thickening fraction, and dome excursion by ultrasonography and to investigate the effects of sex, height, and body mass index. Methods: Diaphragm ultrasonography was performed on 109 seated Japanese volunteers with normal respiratory function who were enrolled between March 2022 and January 2023. Thickness, thickening fraction, and excursion were measured. Reference values and the measurement success rate were calculated. Multivariate analysis adjusted for sex, height, and body mass index was performed. Results: The measurement success rate was better for thickness than for excursion. The mean (lower limit of normal) values on the right/left sides were as follows. During quiet breathing, thickness at end expiration(mm) was 1.7 (0.9)/1.6 (0.80), thickening fraction(%) was 50 (0.0)/52 (0.0), and excursion(cm) was 1.7 (0.5)/1.9 (0.5). During deep breathing, the thickening fraction was 111 (24)/107 (22), and the excursion was 4.4 (1.7)/4.1 (2.0). In multivariate analysis, body mass index was positively associated with thickness but not with the thickening fraction. Conclusion: The reference values in this study were smaller than those in previous reports from Europe. Considering that thickness is influenced by body mass index, using Western reference values in Asia, where the average body mass index is lower, might not be appropriate. The thickening fraction in deep breathing is unaffected by other items and can be used more universally.

Background/Objectives: The effects of ageing on the diaphragm are unclear. This study examined the association between ageing and diaphragm thickness, thickening fraction (TF), and diaphragm excursion (DE) as assessed by ultrasonography after adjusting for other factors. The relationship between these parameters and maximal inspiratory pressure (MIP) was also investigated. Methods: From 2022 to 2024, ambulatory and communicative adult volunteers and outpatients were recruited from four Japanese medical institutions. Each participant’s background factors (including height, weight, and underlying diseases) and pulmonary function test results were assessed. Diaphragm thickness, TF, and DE were evaluated using ultrasonography. Results: The study involved 230 individuals with a mean age of 55.5 years (older adults (65 years and over), n = 117; non-older adults, n = 113). In older adults, the diaphragm was thicker (2.1 vs. 1.7 mm, p < 0.001), and TF was lower (88.7% vs. 116.0%, p < 0.001), with no significant difference in DE. Multivariate linear regression analysis adjusted for sex, height, body mass index, and underlying diseases showed positive associations between age and diaphragm thickness (p = 0.001), but not with TF or DE. MIP was positively associated with DE (p < 0.001) but not with thickness or TF. Age was negatively associated with MIP, regardless of diaphragm thickness, TF, and DE (all p < 0.001). Conclusions: As the diaphragm thickens with age, neither thickness nor TF is associated with MIP; only DE is related to MIP. Additionally, ageing is negatively associated with MIP, independent of diaphragm thickness, TF, and DE. Diaphragm function should be assessed using DE rather than thickness or TF.