Markers of oxidative stress after ablation of atrial fibrillation are associated with inflammation, delivered radiofrequency energy and early recurrence of atrial fibrillation

Beyond Pulmonary Vein Reconnection: Exploring the Dynamic Pathophysiology of Atrial Fibrillation Recurrence After Catheter Ablation

Atrial fibrillation (Afib) recurrence after catheter ablation (CA) remains a significant clinical challenge, driven by a complex and dynamic interplay of structural, electrical, and autonomic mechanisms. While pulmonary vein isolation (PVI) is the cornerstone of CA, recurrence rates remain substantial, highlighting the need to understand the evolving pathophysiology beyond PV reconnection. Post-ablation changes, including inflammation, edema, oxidative stress, and ischemia, create a transient proarrhythmic state that may contribute to early recurrence. Over time, atrial remodeling, fibrosis, and residual autonomic activity further sustain arrhythmogenicity. Additionally, epicardial adipose tissue promotes atrial myopathy, accelerating disease progression, particularly in patients with risk factors such as older age, female sex, obesity, hypertension, obstructive sleep apnea, and heart failure. The multifactorial nature of Afib recurrence underscores the limitations of a "one-size-fits-all" ablation strategy. Instead, a patient-specific approach integrating advanced mapping techniques, multimodal imaging, and computational modeling is essential. Artificial intelligence (AI) and digital twin models hold promise for predicting recurrence by simulating individualized disease progression and optimizing ablation strategies. However, challenges remain regarding the standardization and validation of these novel approaches. A deeper understanding of the dynamic interconnections between the mechanisms driving recurrence is crucial for improving long-term CA outcomes. This review explores the evolving nature of Afib recurrence, emphasizing the need for a precision medicine approach that accounts for the continuous interaction of pathophysiological processes in order to refine patient selection, ablation strategies, and post-procedural management.

A new scoring system to predict the risk of late recurrence in extended follow-up after atrial fibrillation catheter ablation: APCEL score

Background

In studies where risk scores used to determine the risk of late recurrence after atrial fibrillation (AF) catheter ablation were defined, significant differences were observed in terms of parameters such as post-procedural follow-up time, pre-procedural AF time, energy sources used for ablation, and cut-off values of left atrium (LA) diameter. Considering all these factors, we aimed to develop a new recurrence risk score for prolonged follow-up after AF ablation.

Methods

The study included 206 patients who underwent index AF catheter ablation for paroxysmal or persistent AF. Independent predictors of late recurrence were identified at a median follow-up of 40 months (range: 21-57), and a risk score was created. The predictive ability of this score for late recurrence was compared with that of other risk scores.

Results

Independent predictors of late recurrence development included pre-ablation AF duration >19 months, persistent AF, early recurrence, chronic obstructive pulmonary disease, and LA volume index >31 mL/m2. The APCEL risk score, derived from these factors (Early recurrence: 3 points, AF duration >19 months: 2 points, others: 1 point), demonstrated good predictive performance for late recurrence at 6th [AUC: 0.940, 95% CI: 0.896-0.983], 12th [AUC: 0.865, 95% CI: 0.796-0.932], 24th [AUC: 0.814, 95% CI: 0.743-0.885], and 36th months [AUC: 0.798, 95% CI: 0.726-0.868].

Conclusions

The APCEL score, calculated at the end of the blanking period for patients who underwent AF ablation, can effectively identify those at high risk of late recurrence during extended follow-up.

Non-traditional risk factors for atrial fibrillation: epidemiology, mechanisms, and strategies

Atrial fibrillation (AF) has become the pre-dominant arrhythmia worldwide and is associated with high morbidity and mortality. Its pathogenesis is intricately linked to the deleterious impact of cardiovascular risk factors, emphasizing the pivotal imperative for early detection and mitigation strategies targeting these factors for the prevention of primary AF. While traditional risk factors are well recognized, an increasing number of novel risk factors have been identified in recent decades. This review explores the emerging non-traditional risk factors for the primary prevention of AF, including unhealthy lifestyle factors in current society (sleep, night shift work, and diet), biomarkers (gut microbiota, hyperuricaemia, and homocysteine), adverse conditions or diseases (depression, epilepsy, clonal haematopoiesis of indeterminate potential, infections, and asthma), and environmental factors (acoustic pollution and other environmental factors). Unlike traditional risk factors, individuals have limited control over many of these non-traditional risk factors, posing challenges to conventional prevention strategies. The purpose of this review is to outline the current evidence on the associations of non-traditional risk factors with new-onset AF and the potential mechanisms related to these risk factors. Furthermore, this review aims to explore potential interventions targeting these risk factors at both the individual and societal levels to mitigate the growing burden of AF, suggesting guideline updates for primary AF prevention.

Serum Homocysteine and Atrial Fibrillation Recurrence after Catheter Ablation: A Meta-Analysis of 11 Cohort Studies Involving 2147 Patients

The relationship between serum homocysteine (Hcy) levels and atrial fibrillation (AF) recurrence following catheter ablation remains unclear. This meta-analysis aims to investigate this association. Comprehensive searches in PubMed, Web of Science, Embase, Wanfang, and China National Knowledge Infrastructure (CNKI) databases identified relevant studies published up to May 25, 2024. Cohort studies that measured pre-ablation serum Hcy levels and reported AF recurrence post-ablation were included. Data were analyzed using random-effects models by incorporating the potential influence of heterogeneity, with odds ratios (ORs) and 95% confidence intervals (CIs) calculated for the association between serum Hcy levels and AF recurrence. Eleven retrospective cohort studies involving 2147 patients with AF who underwent catheter ablation were analyzed. Higher pre-ablation serum Hcy levels were associated with an increased risk of AF recurrence (OR for per 1 μmol/l increment of Hcy: 1.22, 95% CI: 1.17 to 1.28, p<0.001; I²=0%). Additionally, studies that categorized Hcy levels also found a higher risk of AF recurrence in patients with elevated Hcy (OR for patients with a high versus a low serum Hcy: 2.75, 95% CI: 2.02 to 3.75, p <0.001; I²=0%). Funnel plots and Egger's regression test indicated low risks of publication bias. In conclusions, elevated pre-ablation serum Hcy levels are significantly associated with an increased risk of AF recurrence post-catheter ablation. These findings suggest that Hcy could be a valuable biomarker for predicting AF recurrence and may inform pre-ablation risk stratification. Further prospective studies are warranted to confirm these results.

Cardiovascular outcomes of patients with atrial fibrillation and concomitant cardiac amyloidosis undergoing percutaneous catheter ablation

BACKGROUND

Atrial fibrillation has been linked with poor outcomes in patients with cardiac amyloidosis. We evaluate the in-hospital outcomes of patients with atrial fibrillation and concomitant cardiac amyloidosis with and without catheter ablation.

METHODS

The National Inpatient Sample databases (2016 to 2021) were queried to identify patients admitted with atrial fibrillation and concomitant cardiac amyloidosis using ICD 10 codes. The study population aged >18 years was divided into two cohorts; ablation (AB) vs. no ablation (NAB). Multivariate logistic regression model adjusting for baseline characteristics and comorbidities. The primary outcome was all-cause in-hospital mortality. Secondary outcomes were acute heart failure, cardiogenic shock, ventricular fibrillation, major bleeding, stroke, length of stay, and hospitalization cost.

RESULTS

73,160 patients were identified. 595(0.8 %) underwent ablation and 72,656 (99.2 %) did not. Both NAB and AB patients were predominantly white (69.6 % and 60.3 %) respectively. AB patients were younger with median age [74 years (IQR 66-80) vs. 78 years (IQR 71-84), p < 0.01], compared with NAB patients. AB patients were more likely to have heart failure (76.5 % vs. 65.3 %, p = 0.04), and have a family history of CAD (11.1 % vs. 4.8 %, p = 0.03). Contrarily, NAB patients were more likely to have dementia (11.5 % vs. 2.5 %, p = 0.01). After adjusting for baseline characteristics and comorbidity, there was no difference in all-cause mortality (OR 0.3, CI 0.08-1.35, p = 0.12), stroke (OR 1.1, CI 0.4-2.8, p = 0.87), or major bleeding (OR 1.4, CI 0.7-2.6, p = 0.37). Undergoing ablation was associated with higher odds of acute heart failure (OR 1.9, CI 1.1-3.3, p<0.01). After adjusting for inflation using the consumer price index, adjusted total cost of hospitalization was for higher AB patients was compared to NAB patients ($41,499.22 vs. $13,085.11) with a significantly longer length of stay among AB patients (7 days vs. 5days, p < 0.01).

CONCLUSION

Atrial fibrillation and concomitant cardiac amyloidosis in patients undergoing catheter ablation are associated with an increased risk of acute heart failure, higher cost, and a longer length of stay.

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.

Targeted Ganglionated Plexi Ablation With Nanoformulated Calcium Suppresses Postoperative AF Via Vagosympatholytic and Anti-Inflammatory Effects

BACKGROUND

The mechanisms underlying postoperative atrial fibrillation (POAF) remain unclear.

OBJECTIVES

The aim of this study was to test the hypothesis that targeted chemical ganglionated plexi (GP) modulation of all major left atrial-pulmonary vein GP using novel nanoformulated calcium chloride (nCaCl2) can reverse postoperative neuroelectrical remodeling by suppressing vagosympathetic nerve activity and the localized inflammatory process, both critical substrates of POAF.

METHODS

In a novel canine model of POAF with serial thoracopericardiotomies, sympathetic nerve activity (SNA), vagal nerve activity (VNA) and GP nerve activity (GPNA) were recorded; spontaneous and in vivo AF vulnerability were assessed; and atrial and circulating inflammatory markers and norepinephrine (NE) were measured to determine the neuroelectrical remodeling that promotes POAF and its subsequent modulation with nCaCl2 GP treatment (n = 6) vs saline sham controls (n = 6).

RESULTS

The first 3 postpericardiotomy weeks demonstrated increased plasma C-reactive protein (P = 0.034) and NE (P = 0.033), decreased atrial effective refractory period (P = 0.002), and increased AF vulnerability (P = 0.0008). Subsequent nCaCl2 GP treatment reversed atrial effective refractory period remodeling 6 weeks later (P < 0.001) and decreased AF vulnerability (P = 0.0002) and spontaneous AF burden (P = 0.03). nCaCl2 GP treatment acutely (3 days) and chronically (6 weeks) suppressed GPNA (P = 0.008 and P = 0.04), SNA (P = 0.048 and P = 0.041), and VNA (P = 0.041 and P = 0.046) and increased mean RR interval (P = 0.046 and P = 0.034). In sham controls, the opposite changes occurred (increased GPNA [P = 0.035 and P = 0.02], SNA [P = 0.048 and P = 0.042], and VNA [P = 0.041 and P = 0.042] and decreased mean RR interval [P = 0.041 and P = 0.046]). Plasma NE (P = 0.044), left atrial interleukin-6 (P = 0.008), nerve growth factor (P < 0.001), and sympathetic nerve levels (P < 0.001) were reduced, along with apoptosis of GP neurons in the nCaCl2 GP group.

CONCLUSIONS

Targeted GP modulation with nCaCl2 durably suppresses POAF by inducing apoptosis of GP neurons and inhibiting GP and vagosympathetic nerve activity. This exerts a localized anti-inflammatory effect to reverse the proarrhythmic neural-electrical remodeling following thoracopericardiotomy without myocardial damage or compensatory neural regrowth.

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.

Effects of colchicine on the prevention of AF recurrence after atrial ablation: a systematic review and meta-analysis

BACKGROUND

Catheter ablation has become a widely accepted treatment for atrial fibrillation, but early recurrences remain a challenge, often attributed to inflammatory responses triggered during the procedure. This systematic review and meta-analysis aimed to evaluate the effectiveness of colchicine in preventing short-term AF recurrence post-ablation.

METHOD

PubMed, Embase, and Cochrane Library were searched for studies comparing use of colchicine and placebo in patients after AF ablation. Outcomes included AF recurrence, GI side effects, and hospitalization. R program (version 4.3.2) was used for statistical analysis. Heterogeneity was assessed with I2 statistics.

RESULTS

Five studies, including 1592 patients, were analyzed. Pooled results revealed no statistically significant decrease in AF recurrence (OR 0.74; 95% CI 0.48-1.12; p = 0.153) and pericarditis rates (OR 0.67; 95% CI 0.26-1.72; p = 0.403) with colchicine use. No significant difference in hospitalization rates was observed between colchicine and placebo groups (OR 1.00; 95% CI 0.63-1.59; p = 0.996). In addition, gastrointestinal side effects were notably higher in the colchicine group (OR 4.84; 95% CI 2.58-9.05; p < 0.001).

CONCLUSION

Prophylactic use of colchicine after atrial ablation was not associated with a reduction in AF recurrence and pericarditis rates. In addition, there was no difference in the rate of all-cause hospitalization between the groups, and colchicine use was associated with gastrointestinal adverse events.

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.

Colchicine Prevents Post-Ablation Atrial Fibrillation Recurrence: A Systematic Review and Meta-Analysis

Catheter ablation for atrial fibrillation (AF) is a commonly performed procedure, however, post-ablation AF recurrence is often observed due to inflammation and oxidative stress. Colchicine is a potent anti-inflammatory agent with conflicting efficacy in preventing post-ablation AF recurrence. A comprehensive literature search of the major bibliographic databases was conducted to retrieve studies comparing colchicine use versus placebo in AF patients post-ablation. Odds ratios (ORs) with 95% confidence intervals (CIs) were pooled using the DerSimonian-Laird random-effects model. Statistical significance was set at P < 0.05. Six studies were included with 1791 patients (721 in the colchicine group and 1070 in the placebo group). Patients who received colchicine had significantly lower odds of AF recurrence on follow-up (OR, 0.62; 95% CI, 0.48-0.79; P = 0.0001) but had higher gastrointestinal side effects (OR, 2.67; 95% CI, 1.00-7.12; P = 0.05). There were no statistically significant differences in acute pericarditis (OR, 0.54; 95% CI, 0.27-1.05; P = 0.07) or hospitalization (OR, 1.03; 95% CI, 0.73-1.45; P = 0.87). Prophylactic use of colchicine after catheter ablation in patients with AF leads to a reduction in AF recurrence, albeit with increased gastrointestinal side effects. Colchicine use did not lead to a reduction in the rates of pericarditis and hospitalization after ablation. Large randomized controlled trials are necessary to evaluate the efficacy of colchicine in preventing AF recurrence, particularly focusing on the dose and duration of treatment to optimize the side effect profile.

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.

Factors predicting the recurrence of atrial fibrillation after catheter ablation: A review

Atrial fibrillation (AF) is the most common and clinically significant type of cardiac arrhythmia. Although catheter ablation (CA) can restore sinus rhythm in patients with AF, some patients experience recurrence after the procedure. This requires us to find a simple and effective way to identify patients at a high risk of recurrence and to intervene early in the high-risk population to improve patient prognosis. The mechanism of AF recurrence is unclear, but it involves several aspects including patient history, inflammation, myocardial fibrosis, and genes. This article summarizes the current predictors of AF recurrence after CA, including myocardial fibrosis markers, inflammatory markers, MicroRNAs, Circular RNAs, AF recurrence scores, and imaging indicators. Each predictor has its own scope of application, and the predictive capacity and joint application of multiple predictors may improve the predictive power. In addition, we summarize the mechanisms involved in AF recurrence. We hope that this review will assist researchers understand the current predictors of AF recurrence and help them conduct further related studies.

Bilirubin Elevation During Hospitalization Post Radiofrequency Catheter Ablation of Persistent Atrial Fibrillation: Variation Trend, Related Factors, and Relevance to 1-Year Recurrence

Background

The role of total bilirubin (TBIL) in cardiovascular disease has been increasingly recognized in recent decades. Studies have shown a correlation between total bilirubin levels and the prognosis of patients after heart surgery. This study aimed to investigate the clinical significance of bilirubin elevation in persistent atrial fibrillation (PAF) patients who received radiofrequency catheter ablation (RFCA).

Methods and Results

A total of 184 patients with PAF who received RFCA were retrospectively studied. Laboratory examinations and demographic data were analyzed to identify independent predictors of TBIL elevation. The relationship between TBIL and prognosis was further investigated. Our results indicated that TBIL increased significantly after RFCA. Multiple linear regression analysis showed that TBIL elevation owned a negative correlation with the percentile of low voltage areas (LVAs) in left atria (β=-0.490, P<0.001). In contrast, a positive correlation was observed with the white blood cell (WBC) ratio (β=0.153, P=0.042) and left atrial diameter (LAD) (β=0.232, P=0.025). It was found that postoperative TBIL levels increased and then gradually decreased to baseline within 5 days without intervention. The bilirubin ratio <1.211 indicated the possibility of 1-year AF recurrence after ablation with a predictive value of 0.743 (specificity = 75.00%, sensitivity = 66.67%).

Conclusion

Bilirubin elevation post PAF RFCA was a common phenomenon and was associated with 1-year recurrence of AF in PAF patients after RFCA.

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 Immune Cells Driving Electropathology and Atrial Fibrillation

Atrial fibrillation (AF) is the most common progressive cardiac arrhythmia worldwide and entails serious complications including stroke and heart failure. Despite decades of clinical research, the current treatment of AF is suboptimal. This is due to a lack of knowledge on the mechanistic root causes of AF. Prevailing theories indicate a key role for molecular and structural changes in driving electrical conduction abnormalities in the atria and as such triggering AF. Emerging evidence indicates the role of the altered atrial and systemic immune landscape in driving this so-called electropathology. Immune cells and immune markers play a central role in immune remodeling by exhibiting dual facets. While the activation and recruitment of immune cells contribute to maintaining atrial stability, the excessive activation and pronounced expression of immune markers can foster AF. This review delineates shifts in cardiac composition and the distribution of immune cells in the context of cardiac health and disease, especially AF. A comprehensive exploration of the functions of diverse immune cell types in AF and other cardiac diseases is essential to unravel the intricacies of immune remodeling. Usltimately, we delve into clinical evidence showcasing immune modifications in both the atrial and systemic domains among AF patients, aiming to elucidate immune markers for therapy and diagnostics.

Myocardial injury and inflammation following pulsed-field ablation and very high-power short-duration ablation for atrial fibrillation

INTRODUCTION

Pulmonary vein isolation (PVI) using radiofrequency ablation (RFA) is an established treatment strategy for atrial fibrillation (AF). To improve PVI efficacy and safety, high-power short-duration (HPSD) ablation and pulsed-field ablation (PFA) were recently introduced into clinical practice. This study aimed to determine the extent of myocardial injury and systemic inflammation following PFA, HPSD, and standard RFA using established biomarkers.

METHODS

We included 179 patients with paroxysmal AF receiving first-time PVI with different ablation technologies: standard RFA (30-40 W/20-30 s, n = 52), power-controlled HPSD (70 W/5-7 s, n = 60), temperature-controlled HPSD (90 W/4 s, n = 32), and PFA (biphasic, bipolar waveform, n = 35). High-sensitivity cardiac troponin T (hs-cTnT), creatine kinase (CK), CK MB isoform (CK-MB), and white blood cell (WBC) count were determined before and after ablation.

RESULTS

Baseline characteristics were well-balanced between groups (age 63.1 ± 10.3 years, 61.5% male). Postablation hs-cTnT release was significantly higher with PFA (1469.3 ± 495.0 ng/L), HPSD-70W (1322.3 ± 510.6 ng/L), and HPSD-90W (1441.2 ± 409.9 ng/L) than with standard RFA (1045.9 ± 369.7 ng/L; p < .001). CK and CK-MB release was increased with PFA by 3.4-fold and 5.8-fold, respectively, as compared to standard RFA (p < .001). PFA was associated with the lowest elevation in WBC (Δ1.5 ± 1.5 × 109 /L), as compared to standard RFA (Δ3.8 ± 2.5 × 109 /L, p < .001), HPSD-70W (Δ2.7 ± 1.7 × 109 /L, p = .037), and HPSD-90W (Δ3.6 ± 2.5 × 109 /L, p < .001).

CONCLUSION

Among the four investigated ablation technologies, PFA was associated with the highest myocardial injury and the lowest inflammatory reaction.

Reconsideration of the definition of blanking period and significance of early recurrences after catheter ablation of atrial fibrillation

PURPOSE OF REVIEW

Early recurrence of atrial tachyarrhythmia (ERAT) during blanking period (BP) is not uncommon after catheter ablation of AF. Current guidelines and consensus statements recommend conservative treatment of ERAT. This review summarized recent studies, underlying mechanism and clinical managements of ERAT, and proposed a reconsideration of the definition and clinical significance of BP.

RECENT FINDINGS

Recent studies have shown that the entity of ERAT in the very early phase of BP (i.e., first 4 weeks of the 3-month period) is different from those ERATs occurring late which is strongly associated with the late recurrence of atrial tachyarrhythmia. The optimal BP duration suggested by clinical observation ranges from 21 to 58 days. Using antiarrhythmic drugs and early electrical cardioversion are the effective management for ERAT, whereas re-ablation is a reasonable strategy although remains controversial.

SUMMARY

The definition of BP with a shorter duration, that is, 1 month instead of 3 months post AF ablation, is supported by the observations of latest clinical studies. Recurrent atrial tachyarrhythmia beyond the 1-month time frame is associated with higher risk of late recurrence and may warrant repeat ablation. A revisit to the guideline recommendation on management of ERAT is needed to change clinical practice.

Colchicine to Prevent Atrial Fibrillation Recurrence After Catheter Ablation: A Randomized, Placebo-Controlled Trial

BACKGROUND

Inflammation may promote atrial fibrillation (AF) recurrence after catheter ablation. This study aimed to evaluate a short-term anti-inflammatory treatment with colchicine following ablation of AF.

METHODS

Patients scheduled for ablation were randomized to receive colchicine 0.6 mg twice daily or placebo for 10 days. The first dose of the study drug was administered within 4 hours before ablation. Atrial arrhythmia recurrence was defined as AF, atrial flutter, or atrial tachycardia >30 s on two 14-day Holters performed immediately and at 3 months following ablation.

RESULTS

The modified intention-to-treat population included 199 patients (median age, 61 years; 22% female; 70% first procedure) who underwent radiofrequency (79%) or cryoballoon ablation (21%) of AF. Antiarrhythmic drugs were prescribed at discharge in 149 (75%) patients. Colchicine did not prevent atrial arrhythmia recurrence at 2 weeks (31% versus 32%; hazard ratio [HR], 0.98 [95% CI, 0.59-1.61]; P=0.92) or at 3 months following ablation (14% versus 15%; HR, 0.95 [95% CI, 0.45-2.02]; P=0.89). Postablation chest pain consistent with pericarditis was reduced with colchicine (4% versus 15%; HR, 0.26 [95% CI, 0.09-0.77]; P=0.02) and colchicine increased diarrhea (26% versus 7%; HR, 4.74 [95% CI, 1.95-11.53]; P<0.001). During a median follow-up of 1.3 years, colchicine did not reduce a composite of emergency department visit, cardiovascular hospitalization, cardioversion, or repeat ablation (29 versus 25 per 100 patient-years; HR, 1.18 [95% CI, 0.69-1.99]; P=0.55).

CONCLUSIONS

Colchicine administered for 10 days following catheter ablation did not reduce atrial arrhythmia recurrence or AF-associated clinical events, but did reduce postablation chest pain and increase diarrhea.

Effects of Inflammatory Cell Death Caused by Catheter Ablation on Atrial Fibrillation

Atrial fibrillation (AF) poses a serious healthcare burden on society due to its high morbidity and the resulting serious complications such as thrombosis and heart failure. The principle of catheter ablation is to achieve electrical isolation by linear destruction of cardiac tissue, which makes AF a curable disease. Currently, catheter ablation does not have a high long-term success rate. The current academic consensus is that inflammation and fibrosis are central mechanisms in the progression of AF. However, artificially caused inflammatory cell death by catheter ablation may have a significant impact on structural and electrical remodeling, which may affect the long-term prognosis. This review first focused on the inflammatory response induced by apoptosis, necrosis, necroptosis, pyroptosis, ferroptosis and their interaction with arrhythmia. Then, we compared the differences in cell death induced by radiofrequency ablation, cryoballoon ablation and pulsed-field ablation. Finally, we discussed the structural and electrical remodeling caused by inflammation and the association between inflammation and the recurrence of AF after catheter ablation. Collectively, pulsed-field ablation will be a revolutionary innovation with faster, safer, better tissue selectivity and less inflammatory response induced by apoptosis-dominated cell death.

Impact of catheter ablation and subsequent recurrence of atrial fibrillation on glucose status in patients undergoing continuous glucose monitoring

Although glucose metabolism and atrial fibrillation (AF) have complex interrelationships, the impact of catheter ablation of AF on glucose status has not been well evaluated. Continuous glucose monitoring (CGM) with a FreeStyle Libre Pro (Abbott) was performed for 48 h pre-procedure, during the procedure, and for 72 h post-procedure in 58 non-diabetes mellitus (DM) patients with symptomatic AF and 20 patients with supraventricular or ventricular arrhythmias as a control group. All ablation procedures including pulmonary vein isolation were performed successfully. Glucose levels during procedures consistently increased in the AF and control groups (83.1 ± 16.1 to 110.0 ± 20.5 mg/dL and 83.3 ± 14.7 to 98.6 ± 16.3 mg/dL, respectively, P < 0.001 for both), and Δ glucose levels (max minus min/procedure) were greater in the AF group than control group (P < 0.001). There was a trend toward higher mean glucose levels at 72 h after the procedures compared with those before the procedures in both the AF and control groups (from 103.4 ± 15.6 to 106.1 ± 13.0 mg/dL, P = 0.063 and from 100.2 ± 17.1 to 102.9 ± 16.9 mg/dL, P = 0.052). An acute increase in glucose level at the time of early AF recurrence (N = 9, 15.5%) could be detected by simultaneous CGM and ECG monitoring (89.7 ± 18.0 to 108.3 ± 30.5 mg/dL, P = 0.001). In conclusion, although AF ablation caused a statistically significant increase in the glucose levels during the procedures, it did not result in a pathologically significant change after ablation in non-DM patients. Simultaneous post-procedure CGM and ECG monitoring alerted us to possible acute increases in glucose levels at the onset of AF recurrence.

Elevated Levels of Neutrophil-to Monocyte Ratio Are Associated with the Initiation of Paroxysmal Documented Atrial Fibrillation in the First Two Months after Heart Transplantation: A Uni-Institutional Retrospective Study

BACKGROUND

Heart transplantation represents the treatment for patients with end-stage heart failure (HF) being symptomatic despite optimal medical therapy. We investigated the role of NMR (neutrophil-to-monocyte ratio), NLR (neutrophil-to-lymphocyte ratio), NPR (neutrophil-to-platelet ratio), NWR (neutrophil-to-white cells ratio), MLR (monocyte-to-lymphocyte ratio), PLR (platelet-to-lymphocyte ratio), MWR (neutrophil-to-white cells ratio), and LWR (lymphocyte-to-white cells ratio) at the same cut-off values previously studied, to predict complications after heart transplant within 2 months after surgery.

METHODS

From May 2014 to January 2021, was included 38 patients in our study from the Cardiovascular and Transplant Emergency Institute of Târgu Mureș.

RESULTS

Preoperative NMR > 8.9 (OR: 70.71, 95% CI: 3.39-1473.64; p = 0.006) was a risk factor for the apparition of post-operative paroxysmal atrial fibrillation (Afib). In contrast, preoperative MWR > 0.09 (OR: 0.04, 95% CI: 0.003-0.58; p = 0.0182) represented a protective factor against AFib, but being the risk of complications of any cause (OR: 14.74, 95% CI: 1.05-206.59, p = 0.0458).

CONCLUSION

Preoperative elevated levels of NMR were associated with the apparition of documented AFib, with high levels of MWR as a protective factor. High MWR was a risk factor in developing complications of any cause in the first 2 months after heart transplantation.

Concomitant surgical ablation for atrial fibrillation is associated with increased risk of acute kidney injury but improved late survival

BACKGROUND

Acute kidney injury (AKI) after cardiac surgery remains a common complication that has been associated with increased morbidity and mortality. This study implemented Kidney Disease Improving Global Outcomes criteria to evaluate renal outcomes after concomitant surgical ablation for atrial fibrillation.

METHODS

Patients with a history of atrial fibrillation who underwent elective cardiac surgery at our institution from 2008 to 2018 were retrospectively reviewed. Those with preoperative renal dysfunction were excluded. Patients were classified as those who underwent concomitant Cox-Maze IV (CMP-IV) (n = 376) or no surgical ablation (n = 498). Nearest neighbor 1:1 propensity matching was conducted on fourteen covariates. AKI was evaluated by mixed effects logistic regression analysis. Long-term survival was evaluated by proportional hazards regression.

RESULTS

Propensity matching yielded 308 patients in each group (n = 616). All preoperative variables were similar between groups. The concomitant CMP-IV group had a greater incidence of AKI: 32% (n = 99) versus 16% (n = 49), P < .001. After accounting for bypass time and nonablation operations on mixed effects analysis, concomitant CMP-IV was associated with increased risk of AKI (odds ratio, 1.89; confidence interval, 1.12-3.18; P = .017). While AKI was associated with decreased late survival (P < .001), patients who received a concomitant CMP-IV maintained superior 7-year survival to patients who received no ablation (P < .001). No patients required permanent dialysis.

CONCLUSIONS

Concomitant CMP-IV was independently associated with increased risk of AKI in the acute postoperative period. However, the long-term risks of AKI were offset by the significant survival benefit of CMP-IV. Concerns regarding new-onset renal dysfunction should not prohibit recommendation of this procedure in appropriate patients.

Colchicine for prevention of post-operative atrial fibrillation: Meta-analysis of randomized controlled trials

Objective

This study intended to assess the efficacy of colchicine for prevention of post-operative atrial fibrillation (AF).

Background

Post-operative AF is a common complication of surgery operations. Inflammation plays a crucial role in the pathogenesis of post-operative AF. Colchicine, a potent anti-inflammatory drug, may have a role in mitigating the incidence of post-operative AF.

Methods

We searched Cochrane Library, Web of Science, PubMed, China National Knowledge Infrastructure (CNKI), Database of Chinese sci-tech periodicals (COVIP), and Wanfang Database for randomized controlled trials (RCTs) comparing colchicine versus placebo, or usual care for prevention of post-operative AF. The main outcome was the occurrence of AF post operation, which includes cardiac surgery, lung surgery, or pulmonary vein isolation. The estimated risk ratio (RR) for the occurrence of post-operative AF was evaluated using a random-effects model. The safety end point was the development of any side effects.

Results

A total of 12 RCTs with 2274 patients were eventually included in this meta-analysis, where 1141 patients received colchicine and 1133 patients received placebo or usual care. Perioperative colchicine treatment was related to a decreased incidence of post-operative AF (RR: 0.65; 95% confidence interval [CI]: 0.56 to 0.75, p<0.001). Although the incidence of gastrointestinal side effects was increased with colchicine therapy when compared to placebo (RR = 2.49, 95% CI 1.85 to 3.34, p < 0.001), the incidence of major adverse events was not increased (RR = 0.86, 95% CI 0.46 to 1.60, p = 0.64).

Conclusion

In conclusion, the results of our meta-analysis suggest that colchicine treatment could lower the incidence of post-operative AF. Further studies are needed to determine the optimal colchicine treatment regime to minimize the incidence of adverse events.

Impact of the COVID-19 Pandemic and Public Restrictions on Outcomes After Catheter Ablation of Atrial Fibrillation

Background

Here we aimed to analyze changes in the outcomes of atrial fibrillation (AF) catheter ablation (AFCA) during the coronavirus disease 2019 (COVID-19) pandemic and examine the relationship between rhythm outcomes and the stringency of government social distancing measures.

Methods

We included 453 patients who underwent de novo AFCA between May 2018 and October 2019 (pre-COVID-19 era) and 601 between November 2019 and April 2021 (COVID-19 era). The primary outcome was late recurrence, defined as any episode of AF or atrial tachycardia documented after a 3-month blanking period. A multivariable Cox regression analysis was performed to estimate the relative hazards of AF recurrence in the two eras.

Results

In the study population (24.3% women; median age, 60 years), 660 (62.6%) patients had paroxysmal AF. Among those with paroxysmal AF, the late recurrence rate was significantly lower in the COVID-19 era than in the pre-COVID-19 era [9.4% vs. 17.0%, respectively, log-rank P = 0.004; adjusted hazard ratio (HR) 0.56, 95% confidence interval (CI) 0.35–0.90] during a median follow-up of 11 months. In patients with persistent AF, the late recurrence rate did not significantly differ between the pre-COVID-19 and COVID-19 era groups (18.9% vs. 21.5%, respectively; log-rank P = 0.523; adjusted HR 0.84, 95% CI 0.47–1.53) during the median follow-up of 11 months.

Conclusion

A decrease in AF recurrence after catheter ablation was observed in patients with paroxysmal AF during the COVID-19 outbreak, whereas no change was observed in those with persistent AF.

Serum n-6 polyunsaturated fatty acids and risk of atrial fibrillation: the Kuopio Ischaemic Heart Disease Risk Factor Study

Purpose

N-6 polyunsaturated fatty acids (PUFA), particularly linoleic acid (LA), have been associated with lower risk of coronary heart disease (CHD), but little is known about their antiarrhythmic properties. We investigated the association of the serum n-6 PUFAs with the risk of atrial fibrillation (AF), the most common type of cardiac arrhythmia.

Methods

The study included 2450 men from the Kuopio Ischaemic Heart Disease Risk Factor Study, aged 42–60 years at baseline. The total n-6 PUFA includes linoleic acid (LA), arachidonic acid (AA), γ-linolenic acid (GLA) and dihomo-γ-linolenic acid (DGLA). Cox proportional hazards regression was used to estimate hazard ratio (HR) of incident events.

Results

During the mean follow-up of 22.4 years, 486 AF cases occurred. The multivariable-adjusted HR in the highest versus the lowest quartile of total serum n-6 PUFA concentration was 0.79 (95% CI 0.58–1.08, P trend = 0.04). When evaluated individually, only serum LA concentration was inversely associated with AF risk (multivariable-adjusted extreme-quartile HR 0.69, 95% CI 0.51–0.94, P trend = 0.02). These associations were stronger among the men without history of CHD or congestive heart failure at baseline, compared to men with such disease history (P for interaction = 0.05 for total n-6 PUFA and LA). Similar associations were observed with dietary LA and AA intakes. No significant associations were observed with serum AA, GLA or DGLA concentrations.

Conclusions

Higher circulating concentration and dietary intake of n-6 PUFA, mainly LA, are associated with lower risk of AF, especially among men without history of CHD or congestive heart failure.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00394-021-02780-0.

The predictive role of early recurrences of atrial arrhythmias after pulmonary vein cryoballoon ablation. Is blanking period an outdated concept? Insights from 12-month continuous cardiac monitoring

Background

Early recurrences of atrial arrhythmias (ERAA) after atrial fibrillation (AF) catheter ablation do not predict procedural failure. A well-demarcated homogeneous lesion delivered by cryoballoon is less arrhythmogenic, and the recommended three-months blanking period may not refer to cryoballoon ablation (CBA).

Objective

We aimed to evaluate the predictive role of ERAA after second-generation CBA using an implantable loop recorder.

Methods

This prospective observational study enrolled 100 patients (58 males, median age 58) with paroxysmal/persistent AF undergoing pulmonary vein (PV) CBA using second-generation cryoballoon with simultaneous ECG loop recorder implantation. The duration of follow-up was 12 months, with scheduled visits at 3, 6 and 12 months.

Results

99 patients from 100 completed the 12-month follow-up period. ERAA occurred in 31.3 % of patients. 83.9 % of patients with ERAA also developed late recurrences. The 12-month freedom from AF in patients with ERAA was significantly lower than in those without ERAA (p < 0.0001). Non-paroxysmal AF and longer arrhythmia history were associated with increased risk of both early (HR 3.27; 95 % CI 1.32–8.08; p = 0.010 and HR 1.0147; 95 % CI 1.008–1.086; p = 0.015, respectively) and late recurrences (HR 3.89; 95 % CI 1.67–9.04; p = 0.002 and HR 1.0142; 95 % CI 1.007–1.078; p = 0.019, respectively) of AF. ERAA were another predictor for procedural failure (HR 15.2; 95 % CI (6.42–35.99; p = 0.019).

Conclusions

ERAA occurred in the third of the patients after PV second-generation CBA and are strongly associated with procedural failure. Longer duration of AF history and persistent AF are independent predictors of AF’s early and late recurrence.

Oxidative stress and radioiodine treatment of differentiated thyroid cancer

It is hypothesized that the oxidative stress level in thyroid cancer patients is additionally upregulated by radioactive iodine (RAI) treatment, that may exert an important impact on future health concerns. In our study, we evaluated the oxidative stress level changes using the measurement of malondialdehyde (MDA) concentration in patients with differentiated thyroid cancer (DTC) undergoing RAI treatment. Considering the results obtained in the study group, the serum levels of MDA in DTC patients were significantly higher compared to the healthy subjects (p < 0.05). The MDA concentration was significantly higher on the third day after RAI (p < 0.001) and significantly lower one year after RAI (p < 0.05) in DTC patients compared to the baseline concentration. Moreover, the redox stabilization after RAI treatment in patients with DTC during a year-long observation was demonstrated. Accordingly, an increased oxidative stress impact on the related biochemical parameters reflecting the health conditions of the DTC patients was determined. Our study showed that increased oxidative stress reflected by MDA measurements in DTC patients is further enhanced by RAI, but this effect is no longer observed one year after the therapy.

The Blinding Period Following Ablation Therapy for Atrial Fibrillation: Proarrhythmic and Antiarrhythmic Pathophysiological Mechanisms

Atrial fibrillation (AF) causes heart failure, ischemic strokes, and poor quality of life. The number of patients with AF is estimated to increase to 18 million in Europe in 2050. Pharmacological therapy does not cure AF in all patients. Ablative pulmonary vein isolation is recommended for patients with drug-resistant symptomatic paroxysmal AF but is successful in only about 60%. In patients in whom ablative therapy is successful on the long term, recurrence of AF may occur in the first weeks to months after pulmonary vein ablation. The early recurrence (or delayed cure) of AF is not understood but forms the basis for the generally accepted 3-month blinding (or blanking) period after ablation therapy, which is not included in the evaluation of the eventual success rate of the procedures. The underlying pathophysiological processes responsible for early recurrence and the delayed cure are unknown. The implicit assumption of the blinding period is that the AF mechanism in this period is different from the ablation-targeted AF mechanism (ectopy from the pulmonary veins). In this review, we evaluate the temporary and long-lasting pro- and antiarrhythmic effects of each of the pathophysiological processes and interventions (necrosis, ischemia, oxidative stress, edema, inflammation, autonomic nervous activity, tissue repair, mechanical remodeling, and use of antiarrhythmic drugs) occurring in the blinding period that can modulate AF mechanisms. We propose that stretch-reducing ablation scar is a permanent antiarrhythmic mechanism that develops during the blinding period and is the reason for delayed cure.

Impact of myocardial injury and inflammation due to ablation on the short-term and mid-term outcomes: Cryoballoon versus laser balloon ablation

BACKGROUND

Cryoballoon ablation (CBA) and laser balloon ablation (LBA) were developed as alternatives to conventional radiofrequency ablation for paroxysmal atrial fibrillation (PAF). Pathological findings after ablation such as myocardial injury and inflammation are thought to be different between CBA and LBA. However, the different impact of myocardial injury and inflammation after ablation on short- and mid-term outcomes remains unclear.

METHODS

Consecutive PAF patients who underwent CBA and LBA were enrolled from the Osaka Rosai Atrial Fibrillation ablation (ORAF) registry. The difference of the acute myocardial injury marker (hs-TnI), and changes of inflammation markers (C reactive protein; ΔCRP, and white blood cell; ΔWBC) after catheter ablation and the difference of the short-term (within 3 months after ablation) and mid-term (from 3 months to 6 months after ablation) outcomes were evaluated between the two groups.

RESULTS

The CBA and LBA groups consisted of 55 and 56 patients, respectively. After propensity score matching, CBA and LBA groups consisted of 37 patients, respectively. Hs-TnI value was significantly higher in CBA than LBA group, while ΔCRP and ΔWBC were significantly higher in LBA than CBA group. In the propensity score-matched pairs, the LBA group had a significantly greater risk of short-term arrhythmia recurrence than the CBA group, whereas no significant difference of mid-term arrhythmia recurrence were found between the two groups.

CONCLUSION

Myocardial injury and inflammation status differ between CBA and LBA groups. LBA group had stronger inflammation after ablation and had a significantly greater risk of short-term arrhythmia recurrence after PVI than CBA group.

Atrial fibrillation type modulates the clinical predictive value of neutrophil-to-lymphocyte ratio for atrial fibrillation recurrence after catheter ablation

BACKGROUND

The neutrophil-to-lymphocyte ratio (NLR) has been proposed as an indicator of a systemic inflammatory response. There are baseline differences in the inflammation status between paroxysmal atrial fibrillation (PAF) and persistent AF (PerAF). The NLR changes and late recurrences of AF (LRAF) after ablation depending on the AF type remain unknown.

METHODS

Consecutive AF patients undergoing pulmonary vein isolation (PVI) by radiofrequency catheter ablation were enrolled from September 2014 to June 2018. The peripheral blood leukocyte NLR 1 day before and 36-48 h after PVI were measured. First, the relationship between NLR changes after to before ablation (ΔNLR) and ERAFs/LRAFs in PAF and PerAF patients were investigated to exclude the baseline inflammation status and evaluate catheter ablation induced inflammation. Second, the clinical impact of the NLR for predicting LRAFs was evaluated.

RESULTS

There hundred sixty-nine PAF and 264 PerAF patients from Osaka Rosai AF registry were enrolled. The ratio of ERAFs/LRAFs in PAF and PerAF patients were 26.8%/22.5% and 39.4%/29.9%, respectively. In PAF and PerAF patients, the ΔNLR was significantly higher with ERAF than no-ERAF (p = 0.022 and p = 0.010, respectively). In PAF patients, the ΔNLR was significantly higher with LRAF than no-LRAF (p = 0.017), while with PerAF, the ΔNLR did not significantly differ between LRAFs and no-LRAFs. In PAF, the ΔNLR was independently and significantly associated with LRAFs after PVI (p = 0.029).

CONCLUSION

The ΔNLR was significantly higher only in PAF patients with LRAFs than no-LRAFs, but not in PerAF patients. The ΔNLR was useful for predicting LRAFs after PVI in PAF patients.

Association between body mass index and mortality in atrial fibrillation patients with and without diabetes mellitus: Insights from a multicenter registry study in China

BACKGROUND AND AIMS

The aim of this study was to evaluate the association between body mass index (BMI) and mortality in atrial fibrillation (AF) patients with and without diabetes mellitus (DM).

METHODS AND RESULTS

A total of 1991 AF patients were enrolled and divided into two groups according to whether they have DM at recruitment. Baseline information was collected and a mean follow-up of 1 year was carried out. The primary outcome was defined as all-cause mortality with the secondary outcomes including cardiovascular mortality, stroke and major adverse events (MAEs). Univariable and multivariable Cox regression were performed to estimate the association between BMI and 1-year outcomes in AF patients with and without DM. 309 patients with AF (15.5%) had comorbid DM at baseline. Patients with DM were more likely to have cardiovascular comorbidities, receive relevant medications but carry worse 1-year outcomes. Multivariable Cox regressions indicated that elevated BMI was related with reduced risk of all-cause mortality, cardiovascular mortality and major adverse events. Compared to normal weight, overweight [HR (95% CI): 0.548 (0.405-0.741), p < 0.001] and obesity [HR (95% CI): 0.541 (0.326-0.898), p = 0.018] were significantly related with decreased all-cause mortality for the entire cohort. Remarkably reduced all-cause mortality in the overweight [HR (95% CI): 0.497 (0.347-0.711), p < 0.001] and obesity groups [HR (95% CI): 0.405 (0.205-0.800), p = 0.009] could also be detected in AF patients without DM, but not in those with DM.

CONCLUSION

Elevated BMI was associated with reduced mortality in patients with AF. This association was modified by DM. The obesity paradox confined to AF patients without DM, but could not be generalized to those with DM.

Incidence and clinical impact of early recurrence of atrial tachyarrhythmia after surgical ablation for atrial fibrillation

BACKGROUND

Atrial tachyarrhythmias (ATAs) are common within the 3-month blanking period after catheter ablation of atrial fibrillation (AF). However, little evidence is available regarding the current guidelines on the blanking period after surgical AF ablation. We investigate the incidence and significance of early recurrence of atrial tachyarrhythmia (ERAT) and evaluate the optimal blanking period after surgical AF ablation.

METHODS

Data from 259 patients who underwent surgical AF ablation from 2009 to 2016 were collected. ERAT was defined as documented ATA episodes lasting for 30 s. A multivariate Cox proportional hazard model was constructed to evaluate the role of ERAT as a predictor of late recurrences (LR) for AF.

RESULTS

In total, 127 patients (49.0%) experienced their last episodes of ERAT during the first (n = 65), second (n = 14), or third (n = 48) month of the 3-month blanking period (p < .001). One year freedom from ATAs was 97.8% in patients without ERAT compared with 95.4%, 64.3%, and 8.3% in patients with ERAT in the first, second, and third months after the index procedure, respectively (p < .001). Hazard ratios of LR according to the timing of the last episode of ERAT first, second, and third months after the procedure were 2.84, 16.70, and 119.75, respectively.

CONCLUSIONS

The ERAT occurred in 49.0% of patients within the first 3 months after surgical ablation. The occurrence of ERAT within 3 months after surgical AF ablation was a significant independent predictor of LR. Hence, the currently accepted 3-month blanking period may be considered for redefining in patients with AF surgical ablation.

Highly Reactive Isolevuglandins Promote Atrial Fibrillation Caused by Hypertension

Oxidative damage is implicated in atrial fibrillation (AF), but antioxidants are ineffective therapeutically. The authors tested the hypothesis that highly reactive lipid dicarbonyl metabolites, or isolevuglandins (IsoLGs), are principal drivers of AF during hypertension. In a hypertensive murine model and stretched atriomyocytes, the dicarbonyl scavenger 2-hydroxybenzylamine (2-HOBA) prevented IsoLG adducts and preamyloid oligomers (PAOs), and AF susceptibility, whereas the ineffective analog 4-hydroxybenzylamine (4-HOBA) had minimal effect. Natriuretic peptides generated cytotoxic oligomers, a process accelerated by IsoLGs, contributing to atrial PAO formation. These findings support the concept of pre-emptively scavenging reactive downstream oxidative stress mediators as a potential therapeutic approach to prevent AF.

Evidence for Inflammation as a Driver of Atrial Fibrillation

Atrial fibrillation (AF) is one of the most common types of arrhythmias and increases cardiovascular morbidity and mortality. Current therapeutic approaches to AF that focus on rhythm control have high recurrence rates and no life prolongation value. While possible explanations include toxicity of current therapies, another likely explanation may be that current therapies do not address fundamental mechanisms of AF initiation and maintenance. Inflammation has been shown to affect signaling pathways that lead to the development of AF. This paper reviews the roles of inflammation in the occurrence, development, and mechanisms of AF and reviews the therapeutic implications of the correlation of inflammation and AF.

Myeloperoxidase - A bridge linking inflammation and oxidative stress with cardiovascular disease

Myeloperoxidase (MPO) is a member of the superfamily of heme peroxidases that is mainly expressed in neutrophils and monocytes. MPO-derived reactive species play a key role in neutrophil antimicrobial activity and human defense against various pathogens primarily by participating in phagocytosis. Elevated MPO levels in circulation are associated with inflammation and increased oxidative stress. Multiple lines of evidence suggest an association between MPO and cardiovascular disease (CVD) including coronary artery disease, congestive heart failure, arterial hypertension, pulmonary arterial hypertension, peripheral arterial disease, myocardial ischemia/reperfusion-related injury, stroke, cardiac arrhythmia and venous thrombosis. Elevated MPO levels are associated with a poor prognosis including increased risk for overall and CVD-related mortality. Elevated MPO may signify an increased risk for CVD for at least 2 reasons. First, low-grade inflammation and increased oxidative stress coexist with many metabolic abnormalities and comorbidities and consequently an elevated MPO level may represent an increased cardiometabolic risk in general. Second, MPO produces a large number of highly reactive species which can attack, destroy or modify the function of every known cellular component. The most common MPO actions relevant to CVD are generation of dysfunctional lipoproteins with an increased atherogenicity potential, reduced NO availability, endothelial dysfunction, impaired vasoreactivity and atherosclerotic plaque instability. These actions strongly suggest that MPO is directly involved in the pathophysiology of CVD. In this regard MPO may be seen as a mediator or an instrument through which inflammation promotes CVD at molecular and cellular level. Clinical value of MPO therapeutic inhibition remains to be tested.

Biomarkers Determining Prognosis of Atrial Fibrillation Ablation

Catheter ablation for rhythm control is recommended in specific patient populations with paroxysmal, persistent, or long-standing persistent atrial fibrillation. Pulmonary vein isolation is the cornerstone of the ablative therapy for atrial fibrillation. However, relapse is still common since the single procedure efficacy of atrial fibrillation ablation was estimated to be 60-80% in paroxysmal and 50-70% in persistent atrial fibrillation. It is important to identify predictors of successful atrial fibrillation patients ablation. In the present review, we will assess the role of available biomarkers to predict responders of an initial atrial fibrillation catheter ablation. Emphasis has been given on the role of myocardial injury biomarkers, natriuretic peptides and traditional inflammatory markers. Novel inflammatory markers, oxidative stress biomarkers and microRNAs have also been examined as predictors of a successful atrial fibrillation procedure. Notably, the impact of procedural and short-term administration of steroids, as well as the role of colchicine on preventing atrial fibrillation recurrence after ablation is thoroughly presented.

Effect of corticosteroids on atrial fibrillation after catheter ablation: a meta-analysis. J Zhejiang Univ Sci B 2018;19:57-64. [PMID: 29308608 DOI: 10.1631/jzus.b1600529]

OBJECTIVE

The purpose of this meta-analysis was to explore the effect of corticosteroids on atrial fibrillation (AF) following catheter ablation.

METHODS

We searched PubMed, Embase, and the Cochrane Central Register of Controlled Trials for published articles describing the effect of corticosteroids in preventing AF recurrence after catheter ablation. Data on study and patient were extracted. Risk ratios (RRs) and 95% confidence intervals (CIs) were calculated by use of a random-effect model, and P values of <0.05 were considered significant.

RESULTS

Two randomized controlled trials (RCTs) and three cohort studies involving 846 patients were included in this meta-analysis. Within one month of catheter ablation, corticosteroid use was associated with a declined risk of recurrence of AF in RCT (RR 0.57, 95% CI 0.39 to 0.85, P=0.005), but without significant effect in cohort studies (RR 1.01, 95% CI 0.79 to 1.30, P=0.94). After three months of catheter ablation, corticosteroids did not have a significant effect in the prevention of late recurrence of AF in either RCT (RR 0.78, 95% CI 0.38 to 1.59, P=0.49) or cohort studies (RR 0.96, 95% CI 0.70 to 1.31, P=0.78).

CONCLUSIONS

Our meta-analysis suggested that periprocedural administration of corticosteroids of catheter ablation was associated with reduction of early but not late recurrence of AF.

[Biomarkers and atrial fibrillation : Prediction of recurrences and thromboembolic events after rhythm control management]

Atrial fibrillation (AF) is the most common arrhythmia in clinical praxis and is associated with an increased risk for cardio- and cerebrovascular complications leading to an increased mortality. Catheter ablation represents one of the most important and efficient therapy strategies in AF patients. Nevertheless, the high incidence of arrhythmia recurrences after catheter ablation leads to repeated procedures and higher treatment costs. Recently, several scores had been developed to predict rhythm outcomes after catheter ablation. Biomarker research is also of enormous interest. There are many clinical and blood biomarkers pathophysiologically associated with AF occurrence, progression and recurrences. These biomarkers-including different markers in blood (e. g. von Willebrand factor, D‑dimer, natriuretic peptides) or urine (proteins, epidermal grown factor receptor) but also cardiac imaging (echocardiography, computed tomography, magnetic resonance imaging)-could help to improve clinical scores and be useful for individualized AF management and optimized patients' selection for different AF treatment strategies. In this review, the role of diverse biomarkers and their predictive value related to AF-associated complications are discussed.

Colchicine for prevention of post-cardiac procedure atrial fibrillation: Meta-analysis of randomized controlled trials

BACKGROUND

Development of atrial fibrillation after certain cardiac procedures is a common medical problem. The inflammatory process plays an important role in the pathogenesis of post-cardiac procedure atrial fibrillation (PCP-AF). Colchicine, a potent anti-inflammatory agent, has been used in several studies to reduce the risk of PCP-AF. This meta-analysis of randomized controlled trials (RCTs) was conducted to assess the efficacy of colchicine in prevention of PC-PAF.

METHODS

We searched PubMed, EMBASE, Web of Science, Cochrane Library database and Google Scholar for RCTs, using terms "Atrial fibrillation, atrial, or fibrillation and colchicine". The primary end-point was the occurrence of AF post cardiac procedure, which includes cardiac surgery or pulmonary vein isolation. The safety end point was the occurrence of any side effects. Estimated odds ratios (OR) and 95% confidence intervals (CI) were evaluated.

RESULTS

A total of six RCTs were included in this meta-analysis, enrolling a total of 1257 patients. Colchicine significantly reduced the odds of PCP-AF (OR 0.52; 95% CI, 0.40-0.68, P<0.001, I²=0%). However, occurrence of side effects was significantly higher with colchicine when compared to placebo (OR 2.10; 95% CI, 1.34-3.30, P<0.001, I²=0%). The number needed to treat is 7 and the number needed to harm is 11.2. The proportion of patients discontinuing treatment was 16%.

CONCLUSION

This meta-analysis shows that colchicine is an effective drug for prevention of PCP-AF. Colchicine could be considered as a prophylaxis to reduce PCP-AF, with some risk of treatment discontinuation due to the poor gastrointestinal tolerance (diarrhea).

Emerging pharmacotherapies for the treatment of atrial fibrillation

INTRODUCTION

The main aim of current research on the field of atrial fibrillation (AF) treatment is to find new antiarrhythmic drugs with less side effects. Areas covered: Dronedarone and vernakalant showed promising result in term of efficacy and safety in selected patients. Ranolazine and colchicine are obtaining a role as a potential antiarrhythmic drug. Ivabradine is used in experimental studies for the rate control of AF. Moreover, new compounds (vanoxerine, moxonidine, budiodarone) are still under investigation. Monoclonal antibodies or selective antagonist of potassium channel are under investigation for long term maintenance of sinus rhythm. Clinical evidence and new pharmacological investigation on new drugs will be accurately reviewed in this article. Expert opinion: Dronedarone use is not recommended in patients with symptomatic heart failure (HF), NYHA class III-IV, depressed ventricular function and permanent AF, especially in patients assuming a concomitant therapy with digoxin. Vernakalant had superior efficacy than amiodarone, flecainide and propafenone in single studies and similar efficacy to direct current cardioversion. Several of the developing drugs examined in this paper show an interesting potential, in particular the research on selective ionic channel inhibition and on compounds which reduce the inflammation state, especially after ablation or surgery.

What Does The Blanking Period Blank?

In the management of paroxysmal, drug-refractory atrial fibrillation, pulmonary vein isolation has become a widely accepted treatment option. Currently, the arrhythmias following any form of myocardial ablation are not considered within a period of three months, known as "the blanking period". Although this period is authority- rather than evidence-based, it has become universally recognized. Indeed, several mechanisms play a role to determine the transient increased risk of post-procedural atrial tachyarrhythmias, occurring early after the procedure. Acute inflammatory changes may be responsible for immediate recurrence, since application of ablative energy on atrial tissue has a pro-inflammatory- and potentially arrhythmogenic effect. Atrial arrhythmias within the first 3 months after ablation are very common (35% to 65% of cases) and their significance as predictor of late recurrences is more significant during the first month. Furthermore, the current biological evidences indicate that the edema of the surrounding and ablated tissue is no longer present after 1 month. In our letter we advocate the reasons why a blanking period of four weeks should appear more reasonable, fostering its clinical importance and utility.

Oxidized Low-density Lipoprotein (ox-LDL) Cholesterol Induces the Expression of miRNA-223 and L-type Calcium Channel Protein in Atrial Fibrillation

Atrial fibrillation (AF) is the most common sustained arrhythmia causing high morbidity and mortality. While changing of the cellular calcium homeostasis plays a critical role in AF, the L-type calcium channel α1c protein has suggested as an important regulator of reentrant spiral dynamics and is a major component of AF-related electrical remodeling. Our computational modeling predicted that miRNA-223 may regulate the CACNA1C gene which encodes the cardiac L-type calcium channel α1c subunit. We found that oxidized low-density lipoprotein (ox-LDL) cholesterol significantly up-regulates both the expression of miRNA-223 and L-type calcium channel protein. In contrast, knockdown of miRNA-223 reduced L-type calcium channel protein expression, while genetic knockdown of endogenous miRNA-223 dampened AF vulnerability. Transfection of miRNA-223 by adenovirus-mediated expression enhanced L-type calcium currents and promoted AF in mice while co-injection of a CACNA1C-specific miR-mimic counteracted the effect. Taken together, ox-LDL, as a known factor in AF-associated remodeling, positively regulates miRNA-223 transcription and L-type calcium channel protein expression. Our results implicate a new molecular mechanism for AF in which miRNA-223 can be used as an biomarker of AF rheumatic heart disease.

Effect of remote ischemic preconditioning on myocardial injury and inflammatory response induced by ablation for atrial fibrillation: A randomized controlled trial

BACKGROUND

Remote ischemic preconditioning (RIPC) has been suggested to reduce postoperative release of cardiac and inflammatory markers in patients undergoing cardiac surgery. This study aimed to evaluate the effect of RIPC on nonischemic myocardial damage and inflammatory response in patients undergoing radiofrequency catheter ablation for paroxysmal atrial fibrillation (AF).

METHODS

Seventy-two patients with drug-refractory paroxysmal AF undergoing radiofrequency catheter ablation were randomized into RIPC or control groups. RIPC (intermittent arm ischemia through four cycles of 5-min inflation and 5-min deflation of a blood-pressure cuff) was performed once daily on 2 consecutive days before the ablation and immediately before ablation. Cardiac troponin-I (cTnI), high-sensitive C-reactive protein (hs-CRP), and interleukin (IL)-6 levels were measured before RIPC/sham RIPC, after the ablation, and 24 and 72h later. The early recurrence of atrial fibrillation (ERAF) in the two groups was observed over the subsequent 3months.

RESULTS

Radiofrequency ablation resulted in a significant rise in cTnI, hs-CRP, and IL-6 in both groups, which persisted for 72h. The RIPC group showed a lower increase in cTnI (P<0.001), hs-CRP (P=0.003), and IL-6 (P=0.008) than the control and tended to have a lower risk of ERAF (hazard ratio [HR]=0.77, 95% confidence interval [CI]: 0.32-1.88).

CONCLUSIONS

These results show that RIPC before ablation for paroxysmal AF significantly reduces the increase in cTnI, hs-CRP, and IL-6 associated with the procedure and results in a lower risk of ERAF. These findings suggest that RIPC could provide cardioprotection against nonischemic myocardial damage.