No antiarrhythmic effect of direct oral anticoagulants versus vitamin K antagonists in paroxysmal atrial fibrillation patients undergoing catheter ablation.

INTRODUCTION: Direct oral anticoagulants (DOACs) are superior to vitamin K antagonists (VKAs) for the prevention of stroke in atrial fibrillation (AF) patients with elevated stroke risk. Possible antiarrhythmic effects of DOACs have been discussed. We analyzed impact of DOAC treatment on recurrence-free survival after AF catheter ablation. METHODS: Two-hundred and thirty-nine consecutive patients (median age 57 [IQR 48-64] years, 26.4% female) undergoing ablation for paroxysmal AF were included into this study. 68.6% of them received DOACs (DOAC group), 31.4% VKA (VKA group). The primary outcome was arrhythmia-free one-year survival. RESULTS: DOAC patients had lower BMI, shorter history of AF, less arterial hypertension, less vascular disease, less use of antiarrhythmics and consequently lower CHA2DS2-VASc and HAS-BLED Scores. There was no difference in arrhythmia-free survival between DOAC and VKA groups (DOAC: 86.6%, VKA: 76.7%, p = 0.286). CONCLUSIONS: Despite baseline characteristics favouring a better outcome of DOAC patients, arrhythmia-free survival was similar in both groups. Consequently, DOAC treatment did not have clinically relevant antiarrhythmic properties in these patients.

Is there a difference in rhythm outcome between patients undergoing first line versus second line paroxysmal atrial fibrillation ablation?

BACKGROUND: Catheter ablation of atrial fibrillation (AF) is an established second line therapy for patients with symptomatic paroxysmal AF (PAF) and may be considered as a first line therapy in selected patients who are highly symptomatic, considering patient choice, benefit, and risk, according to recent guidelines. Our study investigated whether a first line vs. second line ablation approach may result in improved sinus rhythm maintenance after ablation. METHODS: A total of 153 patients undergoing pulmonary vein isolation for PAF were included in the study (age 55±12 years, 29% female). Seventy-nine patients underwent first line AF ablation and 74 patients underwent second line AF ablation after failed antiarrhythmic drug therapy. There was no significant difference in baseline characteristics such as age, history of AF, left atrial size or LVEF between groups. Success was defined as atrial tachyarrhythmia free survival during a 12-month follow-up by means of serial ECG Holter monitoring. RESULTS: There was no significant difference in cumulative arrhythmia-free survival between those patients who received AF ablation as a first or second line therapy. Single procedure success was 78% in the first line group vs. 81% in the second line group; multiple procedure success was 90 vs. 91%, (n.s.). Complication rate was 1.3% vs. 1.4% (n.s.). CONCLUSION: Success of AF ablation did not differ between patients who receive ablation as first vs. second line therapy. Based on these data, a trial of AAD therapy before AF ablation may be justified in most patients with symptomatic PAF eligible for rhythm control.

Arterial hypertension drives arrhythmia progression via specific structural remodeling in a porcine model of atrial fibrillation.

BACKGROUND: Arterial hypertension (HT) contributes to progression of atrial fibrillation (AF) via unknown mechanisms. OBJECTIVE: We aimed to characterize electrical and structural changes accounting for increased AF stability in a large animal model of rapid atrial pacing (RAP)-induced AF combined with desoxycorticosterone acetate (DOCA)-induced HT. METHODS: Eighteen pigs were instrumented with right atrial endocardial pacemaker leads and custom-made pacemakers to induce AF by continuous RAP (600 beats/min). DOCA pellets were subcutaneously implanted in a subgroup of 9 animals (AF+HT group); the other 9 animals served as controls (AF group). Final experiments included electrophysiology studies, endocardial electroanatomic mapping, and high-density mapping with epicardial multielectrode arrays. In addition, 3-dimensional computational modeling was performed. RESULTS: DOCA implantation led to secondary HT (median [interquartile range] aortic pressure 109.9 [100-137] mm Hg in AF+HT vs 82.2 [79-96] mm Hg in AF; P < .05), increased AF stability (55.6% vs 12.5% of animals with AF episodes lasting >1 hour; P < .05), concentric left ventricular hypertrophy, atrial dilatation (119 ± 31 cm2 in AF+HT vs 78 ± 23 cm2 in AF; P < .05), and fibrosis. Collagen accumulation in the AF+HT group was mainly found in non-intermyocyte areas (1.62 ± 0.38 cm3 in AF+HT vs 0.96 ± 0.3 cm3 in AF; P < .05). Left and right atrial effective refractory periods, action potential durations, endo- and epicardial conduction velocities, and measures of AF complexity were comparable between the 2 groups. A 3-dimensional computational model confirmed an increase in AF stability observed in the in vivo experiments associated with increased atrial size. CONCLUSION: In this model of secondary HT, higher AF stability after 2 weeks of RAP is mainly driven by atrial dilatation.