Atrial fibrillation (AF) affects over 33 million individuals worldwide1 and has a complex heritability.2 We conducted the largest meta-analysis of genome-wide association studies for AF to date, consisting of over half a million individuals including 65,446 with AF. In total, we identified 97 loci significantly associated with AF including 67 of which were novel in a combined-ancestry analysis, and 3 in a European specific analysis. We sought to identify AF-associated genes at the GWAS loci by performing RNA-sequencing and expression quantitative trait loci (eQTL) analyses in 101 left atrial samples, the most relevant tissue for AF. We also performed transcriptome-wide analyses that identified 57 AF-associated genes, 42 of which overlap with GWAS loci. The identified loci implicate genes enriched within cardiac developmental, electrophysiological, contractile and structural pathways. These results extend our understanding of the biological pathways underlying AF and may facilitate the development of therapeutics for AF.

BACKGROUNDPatients with recent-onset atrial fibrillation commonly undergo immediate restoration of sinus rhythm by pharmacologic or electrical cardioversion. However, whether immediate restoration of sinus rhythm is necessary is not known, since atrial fibrillation often terminates spontaneously. METHODSIn a multicenter, randomized, open-label, noninferiority trial, we randomly assigned patients with hemodynamically stable, recent-onset (<36 hours), symptomatic atrial fibrillation in the emergency department to be treated with a wait-and-see approach (delayed-cardioversion group) or early cardioversion. The wait-and-see approach involved initial treatment with rate-control medication only and delayed cardioversion if the atrial fibrillation did not resolve within 48 hours. The primary end point was the presence of sinus rhythm at 4 weeks. Noninferiority would be shown if the lower limit of the 95% confidence interval for the between-group difference in the primary end point in percentage points was more than −10. RESULTSThe presence of sinus rhythm at 4 weeks occurred in 193 of 212 patients (91%) in the delayed-cardioversion group and in 202 of 215 (94%) in the early-cardioversion group (between-group difference, −2.9 percentage points; 95% confidence interval [CI], −8.2 to 2.2; P = 0.005 for noninferiority). In the delayed-cardioversion group, conversion to sinus rhythm within 48 hours occurred spontaneously in 150 of 218 patients (69%) and after delayed cardioversion in 61 patients (28%). In the earlycardioversion group, conversion to sinus rhythm occurred spontaneously before the initiation of cardioversion in 36 of 219 patients (16%) and after cardioversion in 171 patients (78%). Among the patients who completed remote monitoring during 4 weeks of follow-up, a recurrence of atrial fibrillation occurred in 49 of 164 patients (30%) in the delayed-cardioversion group and in 50 of 171 (29%) in the earlycardioversion group. Within 4 weeks after randomization, cardiovascular complications occurred in 10 patients and 8 patients, respectively. CONCLUSIONSIn patients presenting to the emergency department with recent-onset, symptomatic atrial fibrillation, a wait-and-see approach was noninferior to early cardioversion in achieving a return to sinus rhythm at 4 weeks. (Funded by the Netherlands Organization for Health Research and Development and others; RACE 7 ACWAS ClinicalTrials.gov number, NCT02248753.

In 81 candidates for cardiac resynchronization therapy (CRT) we measured the area of the QRS complex (QRSAREA) using 3-dimensional vectorcardiography. QRSAREA was larger in echocardiographic responders than in non-responders and predicted CRT response better than QRS duration and than simple LBBB criteria. QRSAREA is a promising electrophysiological predictor of CRT response.

Aims Atrial fibrillation (AF) is a progressive disease, but identifying patients at risk for AF progression is challenging. We aimed to identify factors associated with AF progression. Methods and results Atrial fibrillation progression was assessed in 392 patients with recent-onset paroxysmal or persistent AF included in the prospective, observational, multicentre identification of a risk profile to guide atrial fibrillation (AF-RISK) study. Progression of AF was assessed by Holter monitoring and 2-week event recorder at baseline and 1-year follow-up. AF progression was defined as: (i) doubling in AF burden at 1 year compared to baseline with a minimum AF burden of 10% in paroxysmal AF; or (ii) transition from paroxysmal to persistent or permanent AF; or (iii) persistent to permanent AF. Age was 60 ± 11 years, 62% were men, and 83% had paroxysmal AF. At 1 year, 52 (13%) had AF progression (11% in paroxysmal; 26% in persistent AF). Multivariable logistic regression showed that left atrial volume [odds ratio (OR) per 10 mL 1.251, 95% confidence interval (CI) 1.078–1.450; P &lt; 0.001], N-terminal pro-B-type natriuretic peptide (NT-proBNP; OR per standard deviation increase 1.583, 95% CI 1.099–2.281; P = 0.014), and plasminogen activator inhibitor-1 (PAI-1; OR per standard deviation increase 0.660, 95% CI 0.472–0.921; P = 0.015) were associated with AF progression. In an additional follow-up of 1.9 (0.9–3.3) years patients with AF progression developed more cardiovascular events and all-cause mortality (12.4%/year vs. 2.3%/year, P &lt; 0.001). Conclusion Atrial fibrillation progression occurred in 13% of patients with recent-onset AF during 1-year follow-up. Left atrial volume, NT-proBNP, and PAI-1 were associated with AF progression. Patients with AF progression had a higher event rate. Trial registration number Clinicaltrials.gov NCT01510210.