Impact of Type-2 Diabetes Mellitus on the Outcomes of Catheter Ablation of Atrial Fibrillation (European Observational Multicentre Study)

The Influence of Risk Factor Modification on Atrial Fibrillation Outcomes and Their Impact on the Success of Catheter Ablation

The global prevalence of atrial fibrillation (AF) is growing with a significant increase in AF burden. The pathophysiology of AF is complex and exhibits a strong relationship with modifiable lifestyle AF risk factors, such as physical inactivity, smoking, obesity, and alcohol consumption, as well as co-morbidities, such as hypertension, diabetes mellitus, and cardiovascular disease. Current evidence suggests that cardiac rehabilitation and lifestyle risk factor modification can potentially lower the overall AF burden. Additionally, AF ablation can be an effective treatment for a rhythm control strategy, but reducing AF recurrences post-catheter ablation is paramount. Thus, addressing these modifiable lifestyle risk factors and co-morbidities is critical, as the recent 2024 European Society of Cardiology AF guidance update highlights. A comprehensive approach to treating these risk factors is essential, especially given the rising prevalence of AF. This article provides a state-of-the-art update on the evidence of addressing AF-related risk factors and co-morbidities, particularly in patients undergoing AF ablation.

Risk factors for the recurrence of atrial fibrillation after catheter ablation: a meta-analysis

BACKGROUND

The rate at which atrial fibrillation (AF) patients experience a return of symptoms after catheter ablation is significant, and there are multiple risk factors involved. This research intends to perform a meta-analysis to explore the risk factors connected to the recurrence of AF in patients following catheter ablation.

METHODS

The PubMed, Cochrane Library, WOS, Embase, SinoMed, CNKI, Wanfang, and VIP databases were explored for studies from January 1, 2000 to August 10, 2021, and research meeting the established inclusion requirements was chosen. Two authors separately gathered details regarding the study structure. The strength of the link between various risk factors and AF returning after CA was evaluated using odds ratios. All statistical evaluations were conducted with RevMan5.3 software.

RESULTS

In total, 44 articles and 62,674 patients were included. The OR for AF recurrence in patients with diabetes was 2.04 compared with the reference group (95% CI 1.51-2.76, p < 0.00001); that of lower left ventricular ejection fraction was 1.38 (95% CI 1.25-1.52, p < 0.00001); that of female was 1.34 (95% CI 1.18-1.52, p < 0.00001); that of increased age was 1.03 (95% CI 1.02-1.04, p < 0.00001); that of persistent AF was 1.72 (95% CI 1.58-1.87, p < 0.00001); that of AF duration over 2 years was 1.17 (95% CI 1.08-1.26, p < 0.00001); that of increased left atrial diameter (LAD) was 1.12 (95% CI 1.08-1.17, p < 0.00001); that of larger left atrial volume index (LAVi) was 1.02 (95% CI 1.01-1.03, p < 0.00001); that of higher hs-CRP was 1.19 (95% CI 1.04-1.36, p = 0.04); that of early recurrence (ER) was 3.22 (95% CI 2.74-3.77, p < 0.00001); and that of long ablation duration was 1.00 (95% CI 0.98-1.02, p = 0.72). Heterogeneity and slight publication bias were observed for each factor.

CONCLUSIONS

Evidence indicates that diabetes, low left ventricular ejection fraction, being female, older age, longer duration of atrial fibrillation, elevated high-sensitivity C-reactive protein levels, large left atrial dimension, large left atrial volume index, persistent atrial fibrillation, and exercise rehabilitation are factors that increase the chances of getting atrial fibrillation again after catheter ablation. However, the length of the ablation procedure does not relate to the recurrence of AF.

Dapagliflozin Mediates the Protective Effect against atrial fibrillation/atrial flutter and the Reduction in All-Cause Mortality Risk

OBJECTIVE

This study aimed to investigate the association between dapagliflozin and the incidence of atrial fibrillation (AF) and atrial flutter (AFL), along with its impact on all-cause mortality in patients with diabetes mellitus (DM).

MATERIAL AND METHODS

Adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, this meta-analysis conducted a comprehensive search across PubMed, Embase, and ClinicalTrials.gov databases up to June 2021. We focused on randomized controlled trials (RCTs) that compared dapagliflozin with a placebo. Trial sequential analysis (TSA) was utilized to assess the reliability of the findings. All statistical analyses were performed using Review Manager software.

RESULTS

The final analysis included nine studies, encompassing a total of 30,235 patients. The findings indicated a statistically significant reduction in the incidence of AF / AFL in the dapagliflozin group compared to the placebo group (relative risk (RR) = 0.73, 95 % confidence interval (CI) = 0.59 to 0.89, p=0.002), although this result was not corroborated by TSA. The occurrences of AF and all-cause mortality were also lower in the dapagliflozin group than in the placebo group (RR = 0.71, 95 % CI = 0.57 to 0.89, p=0.003 and RR = 0.90, 95 % CI = 0.82 to 0.98, p=0.02, respectively). However, TSA did not confirm these outcomes.

CONCLUSION

Dapagliflozin appears to offer a significant protective effect against AF / AFL and may reduce the risk of all-cause mortality in patients with DM. However, further research is needed to confirm these findings due to the lack of confirmation by TSA.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society, the Asia Pacific Heart Rhythm Society, and the Latin American Heart Rhythm Society.

The Role of P Wave Parameters in Predicting Pulmonary Vein Isolation Outcomes for Paroxysmal Atrial Fibrillation: An Observational Cohort Study

BACKGROUND

Pulmonary vein isolation (PVI) is an effective management method for paroxysmal atrial fibrillation (PAF). The P wave in the 12-lead electrocardiogram (ECG) represents atrial depolarisation. This study aims to utilise the P wave to predict PVI outcomes for PAF.

METHODS

This single-centre retrospective study aimed to predict PVI outcomes using P wave parameters. It included 211 consecutive patients with first PVI for PAF between 2018 and 2019 and targeted the pulmonary veins (PVs). Procedure success was defined by freedom of ECG-documented AF at 12 months. Digital 12-lead ECGs with 1-50 hertz bandpass filters were monitored before the procedure. Corrected P wave duration (PWDc), P wave amplitude (PWV), P wave dispersion (PWDisp), intra-atrial block (IAB), P wave area (PWA), and P wave terminal force in V1 (PTFV1) were measured before ablation and correlated with the outcomes.

RESULTS

Successful PVI occurred in 154 patients (73%). Demographics were similar between both arms. P wave parameters correlated with PVI failure included increased PWDc in all leads except for lead III, aVR, and V3, decreased PWV in lead I (hazard ratio [HR]: 0.7, 95% confidence interval [CI]: 0.53-0.95), lead II (HR: 0.45, 95% CI: 0.22-0.65), aVL (HR: 0.58, 95% CI: 0.22-0.98), and aVF (HR: 0.67, 95% CI: 0.58-0.87), decreased PWA in lead I (HR: 0.55, 95% CI: 0.21-0.76), lead II (HR: 0.48, 95% CI: 0.34-0.87), aVL (HR: 0.65, 95% CI: 0.45-0.96), and aVF (HR: 0.61, 95% CI: 0.32-0.89), and the presence of IAB (HR: 2, 95% CI: 1.4-4.2, p = 0.02). PWDisp and PTFV1 were not correlated with PVI outcome.

CONCLUSIONS

PWDc, PWA, PWV, and IAB are valuable predictors for PVI outcome for PAF at 12 months.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society, the Asia Pacific Heart Rhythm Society, and the Latin American Heart Rhythm Society.

The effect of non-insulin-based insulin resistance indices on the prediction of recurrence in patients with atrial fibrillation undergoing radiofrequency catheter ablation

BACKGROUND

Atrial fibrillation (AF) is acknowledged as a disease continuum. Despite catheter ablation being recommended as a primary therapy for AF, the high recurrence rates have tempered the initial enthusiasm. Insulin resistance (IR) has been established as an independent predictor for the onset of AF. However, the correlation between non-insulin-based IR indices and late AF recurrence in patients undergoing radiofrequency catheter ablation remains unknown.

METHODS

A retrospective cohort of 910 AF patients who underwent radiofrequency catheter ablation was included in the analysis. The primary endpoint was late AF recurrence during the follow-up period after a defined blank period. The relationship between non-insulin-based IR indices and the primary endpoint was assessed using multivariate Cox hazards regression models and restricted cubic splines (RCS). Additionally, the net reclassification improvement and integrated discrimination improvement index were calculated to further evaluate the additional predictive value of the four IR indices beyond established risk factors for the primary outcome.

RESULTS

During a median follow-up period of 12.00 months, 189 patients (20.77%) experienced late AF recurrence, which was more prevalent among patients with higher levels of IR. The multivariate Cox hazards regression analysis revealed a significant association between these IR indices and late AF recurrence. Among the four indices, METS-IR provided the most significant incremental effect on the basic model for predicting late AF recurrence. Multivariable-adjusted RCS curves illustrated a nonlinear correlation between METS-IR and late AF recurrence. In subgroup analysis, METS-IR exhibited a significant correlation with late AF recurrence in patients with diabetes mellitus (HR: 1.697, 95% CI 1.397 - 2.063, P < 0.001).

CONCLUSION

All the four non-insulin-based IR indices were significantly associated with late AF recurrence in patients undergoing radiofrequency catheter ablation. Addressing IR could potentially serve as a viable strategy for reducing the late AF recurrence rate.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society (HRS), the Asia Pacific HRS, and the Latin American HRS.

[Cluster Analysis and Ablation Success Rate in Atrial Fibrillation Patients Undergoing Catheter Ablation]

Objective

Atrial fibrillation (AF) is a disease of high heterogeneity, and the association between AF phenotypes and the outcome of different catheter ablation strategies remains unclear. Conventional classification of AF (e.g. according to duration, atrial size, and thromboembolism risk) fails to provide reference for the optimal stratification of the prognostic risks or to guide individualized treatment plan. In recent years, research on machine learning has found that cluster analysis, an unsupervised data-driven approach, can uncover the intrinsic structure of data and identify clusters of patients with pathophysiological similarity. It has been demonstrated that cluster analysis helps improve the characterization of AF phenotypes and provide valuable prognostic information. In our cohort of AF inpatients undergoing radiofrequency catheter ablation, we used unsupervised cluster analysis to identify patient subgroups, to compare them with previous studies, and to evaluate their association with different suitable ablation patterns and outcomes.

Methods

The participants were AF patients undergoing radiofrequency catheter ablation at West China Hospital between October 2015 and December 2017. All participants were aged 18 years or older. They underwent radiofrequency catheter ablation during their hospitalization. They completed the follow-up process under explicit informed consent. Patients with AF of a reversible cause, severe mitral stenosis or prosthetic heart valve, congenital heart disease, new-onset acute coronary syndrome within three months prior to the surgery, or a life expectancy less than 12 months were excluded according to the exclusion criteria. The cohort consisted of 1102 participants with paroxysmal or persistent/long-standing persistent AF. Data on 59 variables representing demographics, AF type, comorbidities, therapeutic history, vital signs, electrocardiographic and echocardiographic findings, and laboratory findings were collected. Overall, data for the variables were rarely missing (<5%), and multiple imputation was used for correction of missing data. Follow-up surveys were conducted through outpatient clinic visits or by telephone. Patients were scheduled for follow-up with 12-lead resting electrocardiography and 24-hours Holter monitoring at 3 months and 6 months after the ablation procedure. Early ablation success was defined as the absence of documented AF, atrial flutter, or atrial tachycardia >30 seconds at 6-month follow-up. Hierarchical clustering was performed on the 59 baseline variables. All characteristic variables were standardized to have a mean of zero and a standard deviation of one. Initially, each patient was regarded as a separate cluster, and the distance between these clusters was calculated. Then, the Ward minimum variance method of clustering was used to merge the pair of clusters with the minimum total variance. This process continued until all patients formed one whole cluster. The "NbClust" package in R software, capable of calculating various statistical indices, including pseudo t2 index, cubic clustering criterion, silhouette index etc, was applied to determine the optimal number of clusters. The most frequently chosen number of clusters by these indices was selected. A heatmap was generated to illustrate the clinical features of clusters, while a tree diagram was used to depict the clustering process and the heterogeneity among clusters. Ablation strategies were compared within each cluster regarding ablation efficacy.

Results

Five statistically driven clusters were identified: 1) the younger age cluster (n=404), characterized by the lowest prevalence of cardiovascular and cerebrovascular comorbidities but the highest prevalence of obstructive sleep apnea syndrome (14.4%); 2) a cluster of elderly adults with chronic diseases (n=438), the largest cluster, showing relatively higher rates of hypertension, diabetes, stroke, and chronic obstructive pulmonary disease; 3) a cluster with high prevalence of sinus node dysfunction (n=160), with patients showing the highest prevalence of sick sinus syndrome and pacemaker implantation; 4) the heart failure cluster (n=80), with the highest prevalence of heart failure (58.8%) and persistent/long-standing persistent AF (73.7%); 5) prior coronary artery revascularization cluster (n=20), with patients of the most advanced age (median: 69.0 years old) and predominantly male patients, all of whom had prior myocardial infarction and coronary artery revascularization. Patients in cluster 2 achieved higher early ablation success with pulmonary veins isolation alone compared to extensive ablation strategies (79.6% vs. 66.5%; odds ratio [OR]=1.97, 95% confidence interval [CI]: 1.28-3.03). Although extensive ablation strategies had a slightly higher success rate in the heart failure group, the difference was not statistically significant.

Conclusions

This study provided a unique classification of AF patients undergoing catheter ablation by cluster analysis. Age, chronic disease, sinus node dysfunction, heart failure and history of coronary artery revascularization contributed to the formation of the five clinically relevant subtypes. These subtypes showed differences in ablation success rates, highlighting the potential of cluster analysis in guiding individualized risk stratification and treatment decisions for AF patients.

Comprehensive atrial fibrillation burden and symptom reduction post-ablation: insights from DECAAF II

AIMS

Traditional atrial fibrillation (AF) recurrence after catheter ablation is reported as a binary outcome. However, a paradigm shift towards a more granular definition, considering arrhythmic or symptomatic burden, is emerging. We hypothesize that ablation reduces AF burden independently of conventional recurrence status in patients with persistent AF, correlating with symptom burden reduction.

METHODS AND RESULTS

Ninety-eight patients with persistent AF from the DECAAF II trial with pre-ablation follow-up were included. Patients recorded daily single-lead electrocardiogram (ECG) strips, defining AF burden as the proportion of AF days among total submitted ECG days. The primary outcome was atrial arrhythmia recurrence. The AF severity scale was administered pre-ablation and at 12 months post-ablation. At follow-up, 69 patients had atrial arrhythmia recurrence and 29 remained in sinus rhythm. These patients were categorized into a recurrence (n = 69) and a no-recurrence group (n = 29). Both groups had similar baseline characteristics, but recurrence patients were older (P = 0.005), had a higher prevalence of hyperlipidaemia (P = 0.007), and had a larger left atrial (LA) volume (P = 0.01). There was a reduction in AF burden in the recurrence group when compared with their pre-ablation burden (65 vs. 15%, P < 0.0001). Utah Stage 4 fibrosis and diabetes predicted less improvement in AF burden. The symptom severity score at 12 months post-ablation was significantly reduced compared with the pre-ablation score in the recurrence group, and there was a significant correlation between the reduction in symptom severity score and the reduction in AF burden (R = 0.39, P = 0.001).

CONCLUSION

Catheter ablation reduces AF burden, irrespective of arrhythmia recurrence post-procedure. There is a strong correlation between AF burden reduction and symptom improvement post-ablation. Notably, elevated LA fibrosis impedes AF burden decrease following catheter ablation.

Impact of atrial fibrillation phenotype and left atrial volume on outcome after pulmonary vein isolation

AIMS

Pulmonary vein isolation (PVI) is increasingly performed in patients with atrial fibrillation (AF). Both AF phenotype and left atrial (LA) volume have been shown to influence ablation outcome. The inter-relationship of the two is incompletely understood. We aimed to investigate the impact of AF phenotype vs. LA volume on outcome after PVI.

METHODS AND RESULTS

In a retrospective analysis of a prospective registry of patients undergoing a first PVI, the association of AF phenotype and LA volume index (LAVI) was assessed as well as their impact on AF recurrence during follow-up. Overall, 476 patients were enrolled (median age 63 years, 29% females, 65.8% paroxysmal AF). Obesity, hypertension, chronic kidney disease, and heart failure were all significantly more frequent in persistent AF. After 1 year, single-procedure, freedom from arrhythmia recurrence was 61.5%. Patients with paroxysmal AF had better outcomes compared with patients with persistent AF (65.6 vs. 52.7%, P = 0.003), as had patients with no/mild vs. moderate/severe LA dilation (LAVI <42 mL/m2 67.1% vs. LAVI ≥42 mL/m2 53%, P < 0.001). The combination of both parameters refined prediction of 1-year recurrence (P < 0.001). After adjustment for additional clinical risk factors in multivariable Cox proportional hazard analysis, both AF phenotype and LAVI ≥42 mL/m2 contributed significantly towards the prediction of 1-year recurrence.

CONCLUSION

Atrial fibrillation phenotype and LA volume are independent predictors of outcome after PVI. Persistent AF with no/mild LA dilation has a similar risk of recurrence as paroxysmal AF with a moderate/severe LA dilation and should be given similar priority for ablation.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society, the Asia Pacific Heart Rhythm Society, and the Latin American Heart Rhythm Society .

The Role of Risk Factor Modification in Atrial Fibrillation: Outcomes in Catheter Ablation

The management of atrial fibrillation has evolved significantly over the last ten years with advancements in medical and catheter ablation approaches, but these have limited success when used in isolation. Trends in the management of lifestyle modifications have surfaced, as it is now better understood that modifiable risk factors contribute significantly to the development and propagation of atrial fibrillation, as well as failure of treatment. International guidelines have integrated the role of lifestyle modification in the management of atrial fibrillation and specifically in the persistent form of atrial fibrillation; these guidelines must be addressed prior to considering catheter ablation. Effective risk factor modification is critical in increasing the likelihood of an arrhythmia-free survival following catheter ablation.

An effective prediction model based on XGBoost for the 12-month recurrence of AF patients after RFA

BACKGROUND

Atrial fibrillation (AF) is a common heart rhythm disorder that can lead to complications such as stroke and heart failure. Radiofrequency ablation (RFA) is a procedure used to treat AF, but it is not always successful in maintaining a normal heart rhythm. This study aimed to construct a clinical prediction model based on extreme gradient boosting (XGBoost) for AF recurrence 12 months after ablation.

METHODS

The 27-dimensional data of 359 patients with AF undergoing RFA in the First Affiliated Hospital of Soochow University from October 2018 to November 2021 were retrospectively analysed. We adopted the logistic regression, support vector machine (SVM), random forest (RF) and XGBoost methods to conduct the experiment. To evaluate the performance of the prediction, we used the area under the receiver operating characteristic curve (AUC), the area under the precision-recall curve (AP), and calibration curves of both the training and testing sets. Finally, Shapley additive explanations (SHAP) were utilized to explain the significance of the variables.

RESULTS

Of the 27-dimensional variables, ejection fraction (EF) of the left atrial appendage (LAA), N-terminal probrain natriuretic peptide (NT-proBNP), global peak longitudinal strain of the LAA (LAAGPLS), left atrial diameter (LAD), diabetes mellitus (DM) history, and female sex had a significant role in the predictive model. The experimental results demonstrated that XGBoost exhibited the best performance among these methods, and the accuracy, specificity, sensitivity, precision and F1 score (a measure of test accuracy) of XGBoost were 86.1%, 89.7%, 71.4%, 62.5% and 0.67, respectively. In addition, SHAP analysis also proved that the 6 parameters were decisive for the effect of the XGBoost-based prediction model.

CONCLUSIONS

We proposed an effective model based on XGBoost that can be used to predict the recurrence of AF patients after RFA. This prediction result can guide treatment decisions and help to optimize the management of AF.

Lifestyle changes in atrial fibrillation management and intervention

Atrial fibrillation (AF) is one of the most common arrhythmias in adults, and its continued rise in the United States is complicated by the increased incidence and prevalence of several AF risk factors, such as obesity, physical inactivity, hypertension, obstructive sleep apnea, diabetes mellitus, coronary artery disease, and alcohol, tobacco, or caffeine use. Lifestyle and risk factor modification has been proposed as an additional pillar of AF therapy, added to rhythm control, rate control, and anticoagulation, to reduce AF burden and risk. Although emerging evidence largely supports the integration of lifestyle and risk factor management in clinical practice, randomized clinical trials investigating the long-term sustainability and reproducibility of these benefits remain sparse. The purpose of this review is to discuss potentially reversible risk factors on AF, share evidence for the impact on AF by modification of these risk factors, and then provide an overview of the effects of reversing or managing these risk factors on the success of various AF management strategies, such as antithrombotic, rate control, and rhythm control therapies.

Cryoballoon pulmonary vein isolation for atrial fibrillation in obese patients: A non-inferiority analysis

Background

Patients with obesity are at higher risk of developing atrial fibrillation (AF) and benefit from radiofrequency ablation. Potentially, cryoballoon ablation (CBA) may be equally effective and safe in such patients.

Methods

We conducted a prospective, single-center study to investigate whether CBA for pulmonary vein isolation is as effective and safe in obese patients as it is in non-obese controls. Primary efficacy endpoint was recurrence of AF, atrial flutter or atrial tachycardia after a 90-day blanking period. Safety endpoints were death, stroke or procedure-associated complications. Conduction of a subgroup analysis regarding the impact of additional diabetes was predefined in case the primary efficacy endpoint was met. The study was event driven and powered for noninferiority.

Results

A total of 949 patients underwent CBA (251 obese with mean body-mass-index 33.5 ± 3 kg/m2 and 698 non-obese with mean body-mass-index 25.3 ± 3 kg/m2) during a 5-year recruitment period. Median follow-up was 15 months. The primary efficacy endpoint occurred in 78/251 obese and 247/698 non-obese patients (12-months Kaplan-Meier event-rate estimates, hazard ratio 0.79; 95% confidence interval [CI], 0.58 to 1.07; log-rank P = 0.0002 for noninferiority). No differences were observed in safety end point occurrence (P = 0.78). The occurrence of primary efficacy end point was found to be unaffected by the presence of diabetes in the prespecified subgroup analysis (log-rank P = 0.57).

Conclusion

CBA is effective and safe in obese and DM patients. Weighing the high cardiovascular risk of obese patients against a reduction of cardiovascular events by early rhythm control, CBA should be offered to this patient population.

Effect of Insulin Resistance on Recurrence after Radiofrequency Catheter Ablation in Patients with Atrial Fibrillation

BACKGROUND

Whether there are many risk factors for recurrence of atrial fibrillation (AF) after ablation is unclear. The aim of this study was to investigate the relationship between insulin resistance (IR) and AF recurrence in patients without diabetes who underwent catheter ablation.

METHODS

This retrospective study included patients who underwent AF ablation between 2018 and 2019 at the First Affiliated Hospital of Zhengzhou University. Homeostasis model assessment of insulin resistance (HOMA-IR) was calculated, and a value of ≥2.69 was defined as IR. The patients were divided into two groups (group 1 HOMA-IR < 2.69, n = 163; group 2 HOMA-IR ≥ 2.69, n = 69). AF recurrence was defined as the occurrence of atrial arrhythmias of more than 30 s after the first 3 months. Univariate and multivariable Cox regression models were used to analyse the risk of AF recurrence.

RESULTS

Overall, 232 patients were enrolled (mean age, 59.9 ± 10.2 years old; female, 37.5%; paroxysmal AF, 71.6%). We found that dyslipidaemia, antiarrhythmic drug use, fasting blood glucose and fasting insulin were significantly higher in the IR group (P < 0.05). During the follow-up 1 year after ablation, 62 (26.7%) patients experienced AF recurrence. After adjusting for traditional risk factors, multivariable analysis showed that the HOMA-IR value (HR 1.259, 95% CI 1.086-1.460, P = 0.002) and left atrial diameter (LAD; HR 1.043, 95% CI 1.005-1.083, P = 0.026) were independently associated with AF recurrence.

CONCLUSIONS

The present results provide evidence that IR patients are more likely to experience AF recurrence. Improving IR status may be a potential target for reducing the postoperative recurrence rate.

Surgical ablation for atrial fibrillation: impact of Diabetes Mellitus type 2

BACKGROUND

Diabetes mellitus (DM) type 2 is an independent risk factor for atrial fibrillation (AF). Surgical ablation or "maze procedure" is an option for patients with AF undergoing concomitant or isolated cardiac surgery. The aim of this study was to evaluate the impact of DM type 2 on early and long-term outcomes of patients following surgical AF ablation.

METHODS

We performed an observational cohort study in Israel's largest tertiary care center. All data of patients who underwent surgical AF ablation, between 2006 and 2021 were extracted from our departmental database. Patients were divided into Group I (non-diabetic patients) and Group II (DM type 2 patients). We compared the two groups with respect to freedom from recurrent atrial arrhythmia, and mortality rate.

RESULTS

The study population included 606 patients. Group I (non-DM patients), consisting of 484 patients, and Group II (DM type 2 patients), comprised 122 patients. Patients with DM were older, had more hypertension and incidence of cerebrovascular accident (CVA)/transient ischemic attack (TIA), higher EuroSCORE (p < .05 for all), and a longer bypass time-130 ± 40 vs. 122 ± 36 min (p = 0.028). The mean follow-up duration was 39.0 ± 22.7 months. Freedom from atrial fibrillation was similar between the non-DM and DM type 2 groups after a 1-year follow-up, 414 (88.2%) vs. 101 (87.1%) (p = 0.511), after a 3-year follow-up, 360 (86.3%) vs. 84 (79.9%) (p = 0.290) and after a 5-year follow-up, 226 (74.1%) vs. 55 (71.5%) (p = 0.622) respectively. Furthermore, 1- and 3-year mortality was similar between non-DM and DM type 2 groups, 2.5% vs. 4.9%, (p = 0.226) and 5.6% vs. 10.5% (p = 0.076) respectively. 5-year mortality was higher in Group II (DM type 2 patients) compared with Group I (non-DM patients), 11.1% vs. 23.4% (p = 0.009).

CONCLUSION

Surgical ablation had a high success rate, with freedom from recurrent atrial arrhythmia at 1- 3- and 5- years follow-up in both the DM type 2 and non-DM groups. Furthermore,1- and 3-year mortality after surgical ablation was also similar in both groups. However, 5-year mortality was higher in the DM type 2 group.

Predictors of outcome after catheter ablation for atrial fibrillation: Group analysis categorized by age and type of atrial fibrillation

BACKGROUND

The outcome of catheter ablation could probably differ among patients with atrial fibrillation (AF), depending on age and AF type. We aimed to investigate the difference in predictors of outcome after catheter ablation for AF among the patient categories divided by age and AF type.

METHODS AND RESULTS

A total of 396 patients with AF (mean age 65.69 ± 11.05 years, 111 women [28.0%]) who underwent catheter ablation from January 2018 to December 2019 were retrospectively analyzed. We divided the patients into four categories: patients with paroxysmal AF (PAF) or persistent AF (PeAF) who were 75 years or younger (≤75 years) or older than 75 years (>75 years). Kaplan-Meier survival analysis demonstrated that patients with PAF aged ≤75 years had the lowest AF recurrence among the four groups (log-rank test, p = .0103). In the patients with PAF aged ≤75 years (N = 186, 46.7%), significant factors associated with recurrence were female sex (p = .008) and diabetes (p = .042). In the patients with PeAF aged ≤75 years (N = 142, 35.9%), the only significant factor associated with no recurrence was medication with a renin-angiotensin system inhibitor (p = .044). In the patients with PAF aged >75 years (N = 53, 14.4%), diabetes was significantly associated with AF recurrence (p = .021). No significant parameters were found in the patients with PeAF aged >75 years (N = 15, 4.1%).

CONCLUSIONS

Our findings indicate that the risk factors for AF recurrence after catheter ablation differed by age and AF type.

Temporal trends in atrial fibrillation ablation procedures at an academic medical center: 2011-2021

INTRODUCTION

Radiofrequency ablation technology for treating atrial fibrillation (AF) has evolved rapidly over the past decade. We investigated the impact of technological and procedural advances on procedure times and ablation outcomes at a major academic medical center over a 10-year period.

METHODS

Clinical data was collected from patients who presented to NYU Langone Health between 2011 and 2021 for a first-time AF ablation. Time to redo AF ablation or direct current cardioversion (DCCV) for recurrent AF during a 3-year follow-up period was determined and correlated with ablation technology and practices, antiarrhythmic medications, and patient comorbid conditions.

RESULTS

From 2011 to 2021, the cardiac electrophysiology lab adopted irrigated-contact force ablation catheters, high-power short duration ablation lesions, steady-pacing, jet ventilation, and eliminated stepwise linear ablation for AF ablation. During this time the number of first time AF ablations increased from 403 to 1074, the percentage of patients requiring repeat AF-related intervention within 3-years of the index procedure dropped from 22% to 14%, mean procedure time decreased from 271 ± 65 to 135 ± 36 min, and mean annual major adverse event rate remained constant at 1.1 ± 0.5%. Patient comorbid conditions increased during this time period and antiarrhythmic use was unchanged.

CONCLUSION

Rates of redo-AF ablation or DCCV following an initial AF ablation at a single center decreased 36% over a 10-year period. Procedural and technological changes likely contributed to this improvement, despite increased AF related comorbidities.

The complex interplay between diabetes mellitus and atrial fibrillation

INTRODUCTION

: A growing body of evidence suggests that diabetes mellitus (DM) is associated with an increased risk of new-onset atrial fibrillation (AF) and contributes to suboptimal arrhythmia control and poor prognosis in patients with AF. The high prevalence of AF among patients with DM is primarily attributed to common risk factors, shared pathophysiological mechanisms, and associated atrial remodeling and autonomic dysfunction.

AREAS COVERED

: This comprehensive review covers the current data on the role of DM in the development and prognosis of AF. In addition, we review the impact of anti-DM medications on AF prevention and the role of anticoagulation in patients with coexisting DM and AF.

EXPERT OPINION

: DM is independently associated with new-onset AF, and the coexistence of these two conditions contributes to poor outcomes, from reduced quality of life to increased risks of thromboembolic events, heart failure, and mortality. Despite this strong link, the current evidence is insufficient to recommend routine screening for AF in patients with DM. Although some observations exist on preventing AF with anti-DM medications, randomized controlled trials are warranted to explore the proposed benefits of novel anti-DM medicines in reducing the risk of incident AF.

Lifestyle Modification and Atrial Fibrillation: Critical Care for Successful Ablation

Management of atrial fibrillation (AF) requires a comprehensive approach due to the limited success of medical or procedural approaches in isolation. Multiple modifiable risk factors contribute to the development and progression of the underlying substrate, with a heightened risk of progression evident with inadequate risk factor management. With increased mortality, stroke, heart failure and healthcare utilisation linked to AF, international guidelines now strongly support risk factor modification as a critical pillar of AF care due to evidence demonstrating the efficacy of this approach. Effective lifestyle management is key to arrest and reverse the progression of AF, in addition to increasing the likelihood of freedom from arrhythmia following catheter ablation.

Glycemic control and atrial fibrillation: an intricate relationship, yet under investigation

Atrial fibrillation (AF) and diabetes mellitus (DM) constitute two major closely inter-related chronic cardiovascular disorders whose concurrent prevalence rates are steadily increasing. Although, the pathogenic mechanisms behind the AF and DM comorbidity are still vague, it is now clear that DM precipitates AF occurrence. DM also affects the clinical course of established AF; it is associated with significant increase in the incidence of stroke, AF recurrence, and cardiovascular mortality. The impact of DM on AF management and prognosis has been adequately investigated. However, evidence on the relative impact of glycemic control using glycated hemoglobin levels is scarce. This review assesses up-to-date literature on the association between DM and AF. It also highlights the usefulness of glycated hemoglobin measurement for the prediction of AF and AF-related adverse events. Additionally, this review evaluates current anti-hyperglycemic treatment in the context of AF, and discusses AF-related decision-making in comorbid DM. Finally, it quotes significant remaining questions and sets some future strategies with the potential to effectively deal with this prevalent comorbidity.

Medical therapies for prevention of cardiovascular and renal events in patients with atrial fibrillation and diabetes mellitus

Atrial fibrillation (AF), type 2 diabetes mellitus (DM), and chronic kidney disease (CKD) are three global epidemics with significant effects on morbidity and mortality. Diabetes is a risk factor for AF, and a risk factor for thromboembolism, comorbidity, and mortality when AF is present. The pathophysiology of diabetes-related AF and interrelationships with cardiovascular events and renal events is not fully understood but is in part related to structural, electrical, electromechanical, and autonomic remodelling. The current practice guidelines offer limited recommendations on the management of patients with AF (or risk of AF) and diabetes with its own heterogeneity for the prevention of cardiovascular and renal events. This document discusses possible clinical approaches for these patients. In the last decade, there have been major improvements for the prevention of stroke in AF patients with direct oral anticoagulants, which are preferable to vitamin K antagonists for stroke prevention in DM. Because of the increased risk rate for several cardiovascular adverse events in diabetic patients, a similar relative risk reduction generally translates into greater absolute risk reduction in the diabetic population. Recent trials with non-insulin diabetes drugs using glucagon-like peptide-1 agonists and sodium-glucose cotransporter-2 inhibitors showed a significant reduction for the risk of major adverse cardiovascular events in patients with type 2 DM. Sodium-glucose cotransporter-2 inhibitors also showed a large reduction in hospitalization for heart failure and renal events, which need to be more completely evaluated in patients with AF. Mechanisms, risks, and optimal management of AF patients with DM who have or are under risk of developing heart failure or CKD are also discussed in this document. The benefits of medical therapies for these patients still need to be put into perspective, and gaps in evidence on some of these issues are likely to be addressed in future years.

The prognostic significance of left atrial appendage peak flow velocity in the recurrence of persistent atrial fibrillation following first radiofrequency catheter ablation

Background

Atrial fibrillation (AF) relapse following radiofrequency catheter ablation (RFCA) for persistent atrial fibrillation (PeAF) continues to be a concern. This study establishes a connection between left atrial appendage peak flow velocity (LAAV) and recurrence of AF in individuals having PeAF following first RFCA.

Methods

We retrospectively studied 164 successive PeAF patients who had first RFCA between January 2018 and December 2019. Before the ablation, the LAAV was recorded using transesophageal echocardiography (TEE). The demographic and clinical data of the individuals were gathered. Participants were monitored at regular intervals to monitor for recurrence of AF. We employed Cox proportional hazards regression to determine if LAAV, as well as other clinical indicators, were predictive of AF recurrence in follow-up.

Results

In this study, AF relapse was seen in 43 patients (26.2%) following a median follow-up of 15 [interquartile range (IQR): 12–18] months. It was shown that the LAAV was decreased in individuals who had recurrences of AF (0.36±0.05 vs. 0.45±0.17 m/s, P=0.004). Using Kaplan-Meier analysis, it was discovered that the low LAAV (0.37 m/s) group had a poorer event-free survival rate compared to the high LAAV (>0.37 m/s) group (17.6 vs. 21.2 months, log-rank P=0.002) group. Based on the results of the multivariate Cox regression analysis, a LAAV of fewer than 0.37 m/s [hazard ratio (HR): 2.32; 95% confidence interval (CI): 1.177–4.227; P=0.014] was shown to be an independent predictor of AF recurrence following RFCA.

Conclusions

A low LAAV is associated with AF relapse, and it is a predictor of AF relapse following the first RFCA for PeAF. This discovery may be useful in the optimization of treatment strategies and the care of patients with PeAF.

Predictive value of the cardio-ankle vascular index for recurrence of atrial fibrillation after catheter ablation

BACKGROUND

The predictive value of the cardio-ankle vascular index (CAVI) for estimating the efficacy outcome of catheter ablation (CA) in atrial fibrillation (AF) patients is unclear. We aimed to examine the predictive performance of the CAVI for recurrences of atrial arrhythmias after CA.

METHODS

We enrolled a total of 193 patients with AF (paroxysmal 126 and non-paroxysmal 67) who underwent initial CA procedures at our institute, and CAVI measurements were conducted between January 2016 and March 2017. We evaluated recurrences of atrial arrhythmias after the first CA procedure as a clinical outcome. The CAVI value was assessed and the enrolled patients were divided according to the optimal CAVI value cut-off point (9.5) in the atrial arrhythmia recurrence group.

RESULTS

During a mean follow-up of 31.3 (17.5-43.0) months, 74 (32.5%; PaAF 41 and 49.3%; non-PaAF 33) patients had recurrences of atrial arrhythmias. The recurrence ratio of atrial arrhythmias was significantly higher in patients with a high CAVI (≥9.5) than those with a low CAVI (<9.5) (log rank test; p = 0.018). A univariate analysis showed the association between higher CAVI values and recurrences of atrial arrhythmias (p = 0.072). Multivariate analyses using a Cox proportional hazard model after adjusting for other clinical factors revealed that the CAVI value was determined to be a significant predictive factor of a recurrence of atrial arrhythmias after CA (Hazard ratio: 1.44, 95% confidence interval: 1.17-1.78, p < 0.01).

CONCLUSIONS

The CAVI was significantly associated with a recurrence of atrial arrhythmias after CA in AF patients.

Catheter ablation of atrial fibrillation in patients with hypertrophic cardiomyopathy: a European observational multicentre study

AIMS

Atrial fibrillation (AF) is common in hypertrophic cardiomyopathy (HCM). Data on the efficacy of catheter ablation of AF in HCM patients are sparse.

METHODS AND RESULTS

Observational multicentre study in 137 HCM patients (mean age 55.0 ± 13.4, 29.1% female; 225 ablation procedures). We investigated (i) the efficacy of catheter ablation for AF beyond the initial 12 months; (ii) the available risk scores, stratification schemes and genotype as potential predictors of arrhythmia relapse, and (iii) the impact of cryoballoon vs. radiofrequency in procedural outcomes. Mean follow-up was 43.8 ± 37.0 months. Recurrences after the initial 12-month period post-ablation were frequent, and 24 months after the index procedure, nearly all patients with persistent AF had relapsed, and only 40% of those with paroxysmal AF remained free from arrhythmia recurrence. The APPLE score demonstrated a modest discriminative capacity for AF relapse post-ablation (c-statistic 0.63, 95% CI 0.52-0.75; P = 0.022), while the risk stratification schemes for sudden death did not. On multivariable analysis, left atrium diameter and LV apical aneurysm were independent predictors of recurrence. Fifty-eight patients were genotyped; arrhythmia-free survival was similar among subjects with different gene mutations. Rate of procedural complications was high (9.3%), although reducing over time. Outcome for cryoballoon and radiofrequency ablation was comparable.

CONCLUSION

Very late AF relapses post-ablation is common in HCM patients, especially in those with persistent AF. Left atrium size, LV apical aneurysm, and the APPLE score might contribute to identify subjects at higher risk of arrhythmia recurrence. First-time cryoballoon is comparable with radiofrequency ablation.

Approach to recurrence of atrial fibrillation after catheter ablation

Atrial fibrillation (AF) is the most commonly observed sustained rhythm disorder during adult ages. Since it has been shown that the ectopic beat initiating AF is usually caused by pulmonary veins, AF ablation has become the mainstay of therapy worldwide. Cryoballoon and radiofrequency ablation are the most commonly used methods in today's technologies. However, despite technological advances, the success of a single procedure in AF ablation is still limited and multiple procedures may be required for the majority of patients. In cases in which a redo ablation is required, pulmonary vein isolation is still the main target, but non-pulmonary vein targets should also be considered in AF episodes that continue despite multiple ablations. Many issues are still unclear as to which energy to choose in the first procedure, and what ablation strategy will be utilized when a redo ablation is required. The studies on this subject are very limited but, it still seems feasible and a rational approach to utilize a customized treatment strategy in each specific patient subgroup.

Predictors of recurrent atrial fibrillation following catheter ablation

INTRODUCTION

Atrial fibrillation (AF) is a complex and multi-factorial rhythm disorder. Catheter ablation is widely used for the management of AF. However, it is limited by relapse of the arrhythmia necessitating repeat procedures.

AREAS COVERED

This review aims to discuss the predictors of post-ablation recurrent AF including age, gender, genetic predisposition, AF type and duration, comorbidities, lifestyle factors, echocardiographic parameters of heart chambers, left atrial fibrosis and ablation strategies and targets. An extensive literature search was undertaken on PubMed and Google Scholar to obtain full texts of relevant AF-related articles.

EXPERT OPINION

Maintenance of stable sinus rhythm is the main intended outcome of AF ablation. Therefore, it is very crucial to identify the risk factors that may influence the ablation success. Most of these predictors such as comorbidities, ablation strategy and targets and lifestyle factors are either reversible or modifiable. Thus, not only the awareness of these known risk factors by both patients and their physicians but also future research to identify the unknown predictors are critical to optimize care in this multi-faceted morbidity.

First experience of POLARx™ versus Arctic Front Advance™: An early technology comparison

INTRODUCTION

Cryoballoon ablation is an established technique to achieve pulmonary vein isolation in patients with atrial fibrillation (AF). Recently, a new manufacturer of cryoballoon achieved regulatory CE marking (POLARx™; Boston Scientific). We describe our early experience of using this new market entrant of the technology and describe procedural aspects in comparison to the incumbent Medtronic Arctic Front Advance™.

METHODS

We assessed the first 40 AF ablations performed with the POLARx catheter at the Barts Heart Centre. These patients were compared with a contemporaneous series of patients undergoing ablation by the same operators using the Arctic Front Advance. Procedural metrics were prospectively recorded.

RESULTS

A total of four operators undertook 40 cases using the POLARx catheter, compared with 40 cases using the Arctic Front Advance. Procedure times (60.0 vs. 60.0 min) were similar between the two technologies, however left atrial dwell time (35.0 vs 39.0 min) and fluoroscopy times (3.3 vs. 5.2 min) were higher with the POLARx. Measured nadir and isolation balloon temperatures were significantly lower with POLARx. Almost all veins were isolated with a median freezing time of 16.0 (POLARx) versus 15.0 (Arctic Front Advance) min. The rate of procedural complications was low in both groups.

CONCLUSION

The POLARx cryoballoon is effective for pulmonary vein isolation. Measured isolation and nadir temperatures are lower compared with the predicate Arctic Front Advance catheter. The technology appears similar in acute efficacy and has a short learning curve, but formal dosing studies may be required to prove equivalence of efficacy.

Atrial Fibrillation (Part 1): Pathophysiology, Risk Factors, and Therapeutic Basis

A fibrilação atrial é a arritmia sustentada mais comum na prática clínica com predileção pelas faixas etárias mais avançadas. Com o envelhecimento populacional, as projeções para as próximas décadas são alarmantes. Além de sua importância epidemiológica, a fibrilação atrial é destacada por suas repercussões clínicas, incluindo fenômenos tromboembólicos, hospitalizações e maior taxa de mortalidade. Seu mecanismo fisiopatológico é complexo, envolvendo uma associação de fatores hemodinâmicos, estruturais, eletrofisiológicos e autonômicos. Desde os anos 1990, o estudo Framingham em análises multivariadas já demonstrou que, além da idade, a presença de hipertensão, diabetes, insuficiência cardíaca e doença valvar é preditor independente dessa normalidade do ritmo. Entretanto, recentemente, vários outros fatores de risco estão sendo implicados no aumento do número de casos de fibrilação atrial, tais como sedentarismo, obesidade, anormalidades do sono, tabagismo e uso excessivo de álcool. Além disso, as mudanças na qualidade de vida apontam para uma redução na recorrência de fibrilação atrial, tornando-se uma nova estratégia para o tratamento de excelência dessa arritmia cardíaca. A abordagem terapêutica envolve um amplo conhecimento do estado de saúde e hábitos do paciente, e compreende quatro pilares principais: mudança de hábitos de vida e tratamento rigoroso de fatores de risco; prevenção de eventos tromboembólicos; controle da frequência; e controle do ritmo. Pela dimensão de fatores envolvidos no cuidado ao paciente portador de fibrilação atrial, ações integradas com equipes multiprofissionais estão associadas aos melhores resultados clínicos.

A novel predictive model for late recurrence after catheter ablation for atrial fibrillation using left appendage volume measured by cardiac computed tomography

Larger left atrial appendage (LAA) volume is associated with a higher risk of late recurrence (LR) in patients undergoing radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF). However, it is unclear whether LAA volume predicts LR, independent of established risk factors. We sought to evaluate the value of LAA volume in predicting LR after RFCA for AF and to develop a score prediction model including LAA volume for these patients. We retrospectively studied 992 patients who underwent RFCA for AF and cardiac computed tomography before RFCA at a single center. At 3 years after RFCA, 362 patients (36.5 %) experienced recurrence. The multivariate Cox regression model showed that age ≥ 75 years (10 points), non-paroxysmal AF (9 points), diabetes mellitus (4 points), left atrial volume index (1 point per 10 ml/m² rounded to the nearest integer), and the second (4.7 to < 7 ml/m²; 4 points) and third (≥ 7 ml/m²; 5 points) tertiles of the LAA volume index were independent risk factors LR. The above-mentioned risk factors were included in the integrated score model, and the C-index of the proposed score model was 0.715 (95 % confidence interval [CI] 0.679-0.752). LAA volume is an independent predictor of LR and the predictive model including LAA volume showed good discrimination power. These findings provide evidence for the inclusion of LAA volume in the risk stratification for AF recurrence in patients undergoing RFCA for AF.

Diabetes and Endocrine Disorders (Hyperthyroidism/Hypothyroidism) as Risk Factors for Atrial Fibrillation

Risk factors including cardiometabolic and endocrine disorders have a significant impact on atrial remodeling causing atrial fibrillation (AF). Diabetes mellitus and hyperthyroidism are strong independent risk factors for AF and worsen outcomes of rhythm control strategies. An early diagnosis and intervention for these risk factors combined with rhythm control strategies may improve the overall cardiovascular mortality and morbidity. This review summarizes the current state of knowledge about the AF risk factors diabetes mellitus and thyroid disease, and discusses the impact of the modification of these risk factors on primary and secondary prevention of AF.

Predictors of Recurrence after Catheter Ablation of Paroxysmal Atrial Fibrillation in Different Follow-Up Periods

Background and objectives: Pulmonary vein (PV) reconnection is a major reason for recurrence after catheter ablation of paroxysmal atrial fibrillation (PAF). However, the timing of the recurrence varies between patients, and recurrence >1 year after ablation is not uncommon. We sought to elucidate the characteristics of atrial fibrillation (AF) that recurred in different follow-up periods. Materials and Methods: Study subjects comprised 151 consecutive patients undergoing initial catheter ablation of PAF. Left atrial volume index (LAVi) and atrial/brain natriuretic peptide (ANP/BNP) levels were systematically measured annually over 3 years until AF recurred. Results: Study subjects were classified into four groups: non-recurrence group (n = 84), and short-term- (within 1 year) (n = 30), mid-term- (1–3 years) (n = 26), and long-term-recurrence group (>3 years) (n = 11). The short-term-recurrence group was characterized by a higher prevalence of diabetes mellitus (hazard ratio 2.639 (95% confidence interval, 1.174–5.932), p = 0.019 by the Cox method), frequent AF episodes (≥1/week) before ablation (4.038 (1.545–10.557), p = 0.004), and higher BNP level at baseline (per 10 pg/mL) (1.054 (1.029–1.081), p < 0.0001). The mid-term-recurrence group was associated with higher BNP level (1.163 (1.070–1.265), p = 0.0004), larger LAVi (mL/m²) (1.033 (1.007–1.060), p = 0.013), and longer AF cycle length at baseline (per 10 ms) (1.194 (1.058–1.348), p = 0.004). In the long-term-recurrence group, the ANP and BNP levels were low throughout follow-up, as with those in the non-recurrence group, and AF cycle length was shorter (0.694 (0.522–0.924), p = 0.012) than those in the other recurrence groups. Conclusions: Distinct characteristics of AF were found according to the time to first recurrence after PAF ablation. The presence of secondary factors beyond PV reconnections could be considered as mechanisms for the recurrence of PAF in each follow-up period.

Catheter ablation of atrial fibrillation in patients with diabetes mellitus

BACKGROUND

Diabetes mellitus (DM) is an independent risk factor for atrial fibrillation (AF). Few studies have compared clinical outcomes after catheter ablation between patients with and those without DM.

OBJECTIVE

The purpose of this study was to compare AF ablation outcomes in patients with and those without DM.

METHODS

We performed a retrospective analysis of 351 consecutive patients who underwent first-time AF ablation. Clinical outcomes included freedom from recurrent atrial arrhythmia, symptom burden (Mayo AF Symptom Inventory score), cardiovascular and all-cause hospitalizations, and periprocedural complications.

RESULTS

Patients with DM (n = 65) were older, had a higher body mass index, more persistent AF, more hypertension, and larger left atrial diameter (P <.05 for all). Median (Q1, Q3) total radiofrequency duration [64.0 (43.6, 81.4) minutes vs 54.3 (39.2, 76.4) minutes; P = .132] and periprocedural complications (P = .868) did not differ between patients with and those without DM. After a median follow-up of 29.5 months, arrhythmia recurrence was significantly higher in the DM group compared to the no-DM group after adjustment for baseline differences (adjusted hazard ratio [HR] 2.24; 95% confidence [CI] 1.42-3.55; P = .001). There was a nonsignificant trend toward higher AF recurrence with worse glycemic levels (HR 1.29; 95% CI 0.99-1.69; P = .064).

CONCLUSION

Although safety outcomes associated with AF ablation were similar between patients with and those without DM, arrhythmia-free survival was significantly lower among patients with DM. Poor glycemic control seems to an important risk factor for AF recurrence.