Genetic variants associated with atrial fibrillationand long-term recurrence after catheter ablation for atrialfibrillation in Turkish patients

Genome-wide association studies reveal differences in genetic susceptibility between single events vs. recurrent events of atrial fibrillation and myocardial infarction: the HUNT study

Genetic research into atrial fibrillation (AF) and myocardial infarction (MI) has predominantly focused on comparing afflicted individuals with their healthy counterparts. However, this approach lacks granularity, thus overlooking subtleties within patient populations. In this study, we explore the distinction between AF and MI patients who experience only a single disease event and those experiencing recurrent events. Integrating hospital records, questionnaire data, clinical measurements, and genetic data from more than 500,000 HUNT and United Kingdom Biobank participants, we compare both clinical and genetic characteristics between the two groups using genome-wide association studies (GWAS) meta-analyses, phenome-wide association studies (PheWAS) analyses, and gene co-expression networks. We found that the two groups of patients differ in both clinical characteristics and genetic risks. More specifically, recurrent AF patients are significantly younger and have better baseline health, in terms of reduced cholesterol and blood pressure, than single AF patients. Also, the results of the GWAS meta-analysis indicate that recurrent AF patients seem to be at greater genetic risk for recurrent events. The PheWAS and gene co-expression network analyses highlight differences in the functions associated with the sets of single nucleotide polymorphisms (SNPs) and genes for the two groups. However, for MI patients, we found that those experiencing single events are significantly younger and have better baseline health than those with recurrent MI, yet they exhibit higher genetic risk. The GWAS meta-analysis mostly identifies genetic regions uniquely associated with single MI, and the PheWAS analysis and gene co-expression networks support the genetic differences between the single MI and recurrent MI groups. In conclusion, this work has identified novel genetic regions uniquely associated with single MI and related PheWAS analyses, as well as gene co-expression networks that support the genetic differences between the patient subgroups of single and recurrent occurrence for both MI and AF.

Pre-Procedural Right Atrial Diameter May Predict the Development of Typical Atrial Flutter in Patients Undergoing Catheter Ablation for Atrial Fibrillation

BACKGROUND

Some patients undergoing catheter ablation for atrial fibrillation may develop typical atrial flutter on follow-up, and a second procedure for typical atrial flutter is often required in such patients. In this study, we aimed to define the variables associated with the development of typical atrial flutter after ablation.

METHODS

One hundred fifty-nine patients who underwent catheter ablation for the first time due to atrial fibrillation and who did not have a previously documented atrial flutter were included in the study. Before ablation, baseline clinical features and echocardiographic parameters were recorded. At the 1st, 3rd, 6th, and 12th months after the procedure, and then annually, the patients were followed up for typical atrial flutter development.

RESULTS

At a mean follow-up of 34.0 (14.0-50.0) months, typical atrial flutter developed in 21 (13.2%) patients. During the follow-up, right atrial diameter was greater in those who developed typical atrial flutter than those who did not [39.0 (38.0-43.0) vs. 36.0 (34.0-39.0) mm, P <.001]. A multiple Cox regression analysis showed that the right atrial diameter was the only independent predictor of typical atrial flutter development (hazard ratio = 1.12, 95% CI: 1.02-1.23, P =.021). A receiver operating characteristic analysis showed that the best cutoff for the right atrial diameter was 38.5 mm to predict typical atrial flutter development (area under the curve = 0.77, 95% CI: 0.67-0.86, sensitivity = 62%, specificity = 75%, P <.001).

CONCLUSION

In patients undergoing catheter ablation for atrial fibrillation, a pre-procedural right atrial diameter measurement may predict typical atrial flutter development at follow-up. In particular, patients with a pre-procedural right atrial diameter ≥39 mm may be at a higher risk for developing typical atrial flutter in the future.

Gene Polymorphism and Recurrent Atrial Fibrillation after Catheter Ablation: A Comprehensive Review

Atrial fibrillation (AF) is one of the most common cardiac arrhythmias, but its pathogenesis is still poorly understood. Catheter ablation is one of the most effective treatments for AF, but recurrence after ablation remains a challenge. There has been much research into the association of AF recurrence with several factors, including genetics. Over the past decade or so, significant advances have been made in the genetic architecture of atrial fibrillation. Genome-wide association studies (GWAS) have identified over 100 loci for genetic variants associated with atrial fibrillation. However, there is relatively little information on the systematic assessment of the genes related to AF recurrence after ablation. In this review article, we highlight the value of genetic polymorphisms in atrial fibrillation recurrence after catheter ablation and their potential mechanisms in the recurrence process to enhance our understanding of atrial fibrillation recurrence and contribute to individualized treatment strategies for patients with AF.