Does left atrial epicardial conduction time reflect atrial fibrosis and the risk of atrial fibrillation recurrence after thoracoscopic ablation? Post hoc analysis of the AFACT trial.

OBJECTIVES: To determine the association between left atrial epicardial conduction time (LAECT), fibrosis and atrial fibrillation (AF) recurrence after thoracoscopic surgical ablation of persistent AF. SETTING: Single tertiary care centre in the Netherlands. PARTICIPANTS: Patients with persistent AF from the randomised Atrial Fibrillation Ablation and Autonomic Modulation via Thoracoscopic Surgery (AFACT)-trial were included. Patients eligible for thoracoscopic AF ablation were included, full inclusion and exclusion criteria were previously published. All patients underwent thoracoscopic ablation, encompassing pulmonary vein isolation with an additional roof and trigone lesion. In patients with conduction block across the roof and trigone lesion, LAECT was measured. LAECT was defined as the time to local activation at one side of the roofline on pacing from the opposite side. Collagen fibre density was quantified from left atrial appendage histology. OUTCOME MEASURES: Primary outcome: AF recurrence during 2 years of follow-up. RESULTS: 121 patients were included, of whom 35(29%) were women, age was 60.4±7.8 and 51% (62) had at least one AF recurrence during 2 years of follow-up. LAECT was longer in patients with versus without AF recurrence (182±43 ms vs 147±29 ms, p<0.001). LAECT was longer in older patients, in patients with a higher body mass index (BMI) and in patients using class IC antiarrhythmic drugs. LAECT was shorter in patients with higher collagen fibre density. A previously failed catheter ablation, LAECT and BMI were independently associated with AF recurrence. CONCLUSION: LAECT is correlated with collagen fibre density and BMI and is independently associated with AF recurrence in patients with persistent AF. In these patients, LAECT appears to reflect substrate characteristics beyond clinical AF type and left atrial volume. TRIAL REGISTRATION NUMBER: NCT01091389.

Care and referral patterns in a large, dedicated nurse-led atrial fibrillation outpatient clinic.

INTRODUCTION: Atrial fibrillation (AF) is the most common arrhythmia and imposes a high burden on the healthcare system. A nurse-led AF outpatient clinic may alleviate the burden on the cardiology outpatient clinic by triaging patients who need care by a cardiologist or general practitioner (GP). However, care and referral patterns after initial assessment in a nurse-led AF outpatient clinic are unknown. We examined the proportion of AF patients assessed in a nurse-led clinic without outpatient follow-up by a cardiologist. METHODS: All patients with AF referred to our tertiary medical centre underwent cardiac work-up in the nurse-led AF outpatient clinic and were prospectively followed. Data on patient characteristics, rhythm monitoring and echocardiography were collected and described. Odds ratio (OR) for continuing care in the nurse-led AF outpatient clinic was calculated. RESULTS: From 2014 to 2018, 478 consecutive individual patients were referred to the nurse-led AF outpatient clinic. After the initial cardiac work-up, 139 patients (29.1%) remained under nurse-led care and 121 (25.3%) were referred to a cardiologist and 218 (45.6%) to a GP. Patients who remained under nurse-led care were significantly younger, were more symptomatic, more often had paroxysmal AF and had less comorbidities than the other two groups. After multivariable testing, CHA2DS2-VASc score ≥ 2 was associated with discontinued nurse-led care (OR 0.57, 95% confidence interval 0.34-0.95). CONCLUSION: After initial cardiac assessment in the nurse-led outpatient clinic, about half of the newly referred AF patients were referred back to their GP. This strategy may reduce the burden of AF patients on secondary or tertiary cardiology outpatient clinics.

Can we spice up our Christmas dinner? : Busting the myth of the 'Chinese restaurant syndrome'.

BACKGROUND: Monosodium glutamate (MSG), also referred to as Vetsin or E621, is a flavour enhancer frequently used in Asian cuisine and abundantly present in the famous Chinese dish Peking duck. MSG is notorious for triggering the onset of the so-called 'Chinese restaurant syndrome' (CRS), a complex of unpleasant symptoms, which might include flushing, sweating and the onset of atrial fibrillation (AF). This study aims to determine the effects of MSG on the occurrence of AF. METHODS: We conducted a placebo self-controlled single-arm study in the Academic Medical Centre in Amsterdam. We included paroxysmal AF patients who reported a consistent onset of AF upon MSG intake. During three admissions, participants were subsequently administered: placebo, 1.5 g and 3 g MSG. If AF was recorded after the dose of 1.5 g MSG, patients were given another placebo instead of 3 g MSG. The primary outcome was the onset of AF registered by 24-hour Holter monitoring. The secondary outcomes were any other arrhythmia and the onset of CRS defined as two or more symptoms of CRS after MSG intake. RESULTS: Six men participated in the study. Both 1.5 g and 3 g MSG were unrelated to CRS, arrhythmias or AF occurrence. CONCLUSION: Peking duck can be put on the Christmas menu without risking guests to be admitted to the emergency department with new episodes of AF.

Aldosterone Pathway Blockade to Prevent Atrial Fibrillation: A Systematic Review and Meta-Analysis.

BACKGROUND: Despite advances in therapeutic interventions AF remains a progressive and symptomatic disease. Therefore, novel therapeutic interventions targeting the underlying arrhythmogenic substrate for AF is needed. Atrial fibrosis is an important component of the arrhythmogenic substrate of AF and may be initiated by aldosterone binding to the mineralocorticoid receptor. We hypothesized that aldosterone pathway blockade with mineralocorticoid receptor antagonists (MRA) reduces atrial fibrosis, and thus AF. METHODS: We searched OVID MEDLINE, OVID EMBASE and the Cochrane Central Register of Controlled Trials from inception to June 10th, 2016 for randomized controlled trials (RCT) and observational studies addressing MRA and providing information on AF occurrence. Two independent reviewers selected and appraised the data. We performed random-effects meta-analyses. Summary odds ratios (OR) with 95% confidence intervals (CI) were calculated. RESULTS: We included 14 studies, 5 RCT and 9 observational cohorts, with a cumulative number of 5332 patients (male: 74.9%, age: 65.3years); 2397 (45.0%) received an MRA (spironolactone or eplerenone). During follow-up, 204 (8.5%) patients treated with MRAs, developed AF, compared to 547 (18.6%) patients, without MRA treatment. Meta-analyses showed a significant overall reduction of AF risk in MRA treated patients (OR: 0.48 CI: 0.38-0.60 p<0.001), including a reduction of new-onset AF (OR: 0.52 CI: 0.37-0.74 p<0.001) and recurrent AF (OR: 0.37 CI: 0.24-0.57 p<0.001), but not post-operative AF (POAF) (OR: 0.60 CI: 0.33-1.09 p=0.09). CONCLUSIONS: MRAs significantly reduce new-onset AF and recurrent AF, but not POAF. MRA treatment can be considered an additive therapeutic strategy in AF.

Fluorinated steroids do not improve outcome of isolated atrioventricular block.

INTRODUCTION: Congenital atrioventricular block (CAVB) is a rare disorder with a significant morbidity and mortality. Consensus regarding the prescription and efficacy of prenatal corticosteroids is lacking. This nationwide study was initiated to evaluate the effects of prenatal treatment with corticosteroids on the outcome of CAVB in The Netherlands. METHODS: All fetuses identified with isolated congenital AVB-II° or AVB-III° in any of the eight academic fetal heart centers of The Netherlands between 2003 and 2013 were included and reviewed. RESULTS: Fifty-six fetuses were included. Fourteen (25%) fetuses were treated with dexamethasone. We found no differences between the steroid-treated and untreated cases regarding in utero progression of the AVB (63% vs 67% respectively), survival to birth (86% vs 84%), pacemaker implantations (74% vs 58%) or long-term dilated cardiomyopathy (13% vs 17%). Steroid treated fetuses demonstrated more in utero growth restriction (38% vs 11%). CONCLUSION: No benefit from prenatal corticosteroid treatment was demonstrated for fetuses with isolated CAVB in this study. However, we found negative side effects. Our data provide no evidence to support the routine administration of corticosteroids for the treatment of fetal CAVB.