Colchicine for prevention of atrial fibrillation recurrence after pulmonary vein isolation: mid-term efficacy and effect on quality of life

Acute-on-chronic inflammation in acute myocardial infarction

PURPOSE OF REVIEW

Acute myocardial infarction (AMI) is heralded by chronic inflammation and entails an excessive burst of acute-on-chronic inflammation (AoCI). This review describes the evolution from understanding atherosclerosis as a chronic inflammatory disease, to recent efforts in optimizing anti-inflammatory therapy to patients with AMI. It highlights the challenges and opportunities in selecting the optimal patient with AMI to derive maximal benefit from early anti-inflammatory therapy.

RECENT FINDINGS

The causal role of inflammation in atherosclerosis has been proven in large outcome trials. Since then, several smaller trials have sought to translate the concept of anti-inflammatory therapy targeting residual inflammatory risk to the dynamic early phase of AoCI after AMI. Current evidence highlights the importance of selecting patients with a high inflammatory burden. Surrogate criteria for large AMI (e.g., angiographic or electrocardiographic), as well as novel point-of-care biomarker testing may aid in selecting patients with particularly elevated AoCI. Additionally, patients presenting with AMI complicated by pro-inflammatory sequelae (e.g., atrial fibrillation, acute heart failure, left ventricular thrombosis) may dually profit from anti-inflammatory therapy.

SUMMARY

Improved understanding of the mechanisms and dynamics of acute and chronic inflammatory processes after AMI may aid the strive to optimize early anti-inflammatory therapy to patients with AMI.

Colchicine for the treatment of the spectrum of cardiovascular diseases: current evidence and ongoing perspectives

Colchicine is one of the oldest drugs in medicine. Traditionally used to treat and prevent gouty attacks, it has been introduced into cardiovascular medicine for the treatment and prevention of pericarditis, starting from the positive experience in the treatment and prevention of polyserositis in familial mediterranean fever. Colchicine is a lipophilic drug that enters the cells and is eliminated by glycoprotein P. As granulocytes are lacking in this protein, colchicine is able to concentrate in these cells, exerting a substantial anti-inflammatory action, even with low oral doses. As these cells may trigger acute cardiovascular events, colchicine has been shown to be efficacious and safe to prevent acute coronary syndromes and ischemic stroke with an efficacy comparable to more established treatments, such as antiplatelet agents and statins. On this basis, colchicine seems a promising, efficacious, well tolerated, and cheap option for the prevention of several cardiovascular events, and it may become an additional pillar in the pharmacologic treatment of cardiovascular diseases.

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.

Therapeutic Spp1 silencing in TREM2+ cardiac macrophages suppresses atrial fibrillation

Atrial fibrillation (AFib) and the risk of its lethal complications are propelled by fibrosis, which induces electrical heterogeneity and gives rise to reentry circuits. Atrial TREM2+ macrophages secrete osteopontin (encoded by Spp1), a matricellular signaling protein that engenders fibrosis and AFib. Here we show that silencing Spp1 in TREM2+ cardiac macrophages with an antibody-siRNA conjugate reduces atrial fibrosis and suppresses AFib in mice, thus offering a new immunotherapy for the most common arrhythmia.

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.

The efficacy of colchicine in preventing atrial fibrillation recurrence and pericarditis post-catheter ablation for atrial fibrillation - A systematic review and meta-analysis of prospective studies

Introduction

Catheter ablation (CA) initiates a proinflammatory process responsible for atrial fibrillation (AF) recurrence (25-40%) and pericarditis (0.8%). Due to its anti-inflammatory properties, colchicine, a microtubule inhibitor, is explored for the prevention of early AF recurrence and pericarditis after pulmonary vein isolation. We performed a pooled analysis to determine the rates of AF recurrence and pericarditis after CA in patients receiving colchicine.

Methods

A comprehensive literature review was conducted on PubMed and SCOPUS from inception to December 2023 using medical subject headings and keywords, followed by a citation and reference search. We identified prospective studies reporting recurrent AF and pericarditis outcomes after catheter ablation in patients taking colchicine versus placebo. A binary random effects model was used to estimate pooled odds ratios and 95% confidence intervals. Sensitivity analysis was conducted using the leave-one-out method, and heterogeneity was assessed using the I2 statistic.

Results

Of the 958 identified studies, 4 met our inclusion criteria. A total of 1,619 patients were analyzed; 743 received colchicine, and 875 were in the placebo group. Recurrent AF after CA occurred in 192 (29.0 %) of the colchicine group and 318 (39.5 %) of the placebo group. Post-ablation pericarditis occurred in 34 (5.3 %) of the colchicine group and 128 (16.5 %) of the placebo group. Pooled analysis of prospective studies showed that colchicine decreased the odds of recurrent AF [OR: 0.63 (95 % CI: 0.50-0.78), p < 0.01, I2  = 8 %] and post-ablation pericarditis [OR: 0.34 (95 % CI: 0.16-0.75), p < 0.01, I2  = 57 %]. Odds of GI disturbance were increased with colchicine use in our analysis [OR: 2.77 (95 % CI: 1.17-6.56), p = 0.02, I2  = 84 %].

Conclusion

Colchicine use is associated with decreased odds of recurrent AF and pericarditis post-CA from the analysis of prospective studies. These results underscore the potential for colchicine therapy for future exploration with randomized and controlled research with different dosages.

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.

Deciphering mechanisms of cardiomyocytes and non-cardiomyocyte transformation in myocardial remodeling of permanent atrial fibrillation

INTRODUCTION

Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia, and it significantly increases the risk of cardiovascular complications and morbidity, even with appropriate treatment. Tissue remodeling has been a significant topic, while its systematic transcriptional signature remains unclear in AF.

OBJECTIVES

Our study aims to systematically investigate the molecular characteristics of AF at the cellular-level.

METHODS

We conducted single-nuclei RNA-sequencig (snRNA-seq) analysis using nuclei isolated from the left atrial appendage (LAA) of AF patients and sinus rhythm. Pathological staining was performed to validate the key findings of snRNA-seq.

RESULTS

A total of 30 cell subtypes were identified among 80, 592 nuclei. Within the LAA of AF, we observed a specific subtype of dedifferentiated cardiomyocytes (CMs) characterized by reduced expression of cardiac contractile proteins (TTN and TRDN) and heightened expression of extracellular-matrix related genes (COL1A2 and FBN1). Transcription factor prediction analysis revealed that gene expression patterns in dedifferentiated CMs were primarily regulated by CEBPG and GISLI. Additionally, we identified a distinct subtype of endothelial progenitor cells (EPCs) demonstrating elevated expression of PROM1 and KDR, a population decreased within the LAA of AF. Epicardial adipocytes disclosed a reduced release of the anti-inflammatory and anti-fibrotic factor PRG4, and an augmented secretion of VEGF signals targeting CMs. Additionally, we noted accumulation of M2-like macrophages and CD8+ T cells with high pro-inflammatory score in LAA of AF. Furthermore, the analysis of intercellular communication revealed specific pathways related to AF, such as inflammation, extracellular matrix, and vascular remodeling signals.

CONCLUSIONS

This study has discovered the presence of dedifferentiated CMs, a decrease in endothelial progenitor cells, a shift in the secretion profile of adipocytes, and an amplified inflammatory response in AF. These findings could offer crucial insights for future research on AF and serve as valuable references for investigating novel therapeutic approaches for AF.

A systematic literature review of randomised controlled trials evaluating colchicine for cardiovascular prevention: There is an elephant in the room

OBJECTIVES

To review randomised controlled trials (RCT) investigating colchicine (COL) for cardiovascular (CV) prevention in patients at high to very high CV risk aiming to extract data that could be useful in rheumatology practice.

METHODS

A systematic search of multiple databases according to the PICO framework was performed from inception to April 3, 2023. Three researchers independently screened abstracts/titles and reviewed full texts reviewed. Data extraction was performed using a pilot-tested data extraction form.

RESULTS

A total of 14,096 references were retrieved by the search and 30 articles, describing 28 RCTs, were included in the review (Total number of patients 16,795, of which 8,463 randomised to COL; dose 0.5-2 mg/day, treatment duration 1day-29 months). Only one of the 28 RCTs provided clear information on whether patients with rheumatic diseases (more specifically gout) were enrolled in the study cohorts and previous use of COL was an exclusion criterion only in 14 (50 %) RCTs. Previous therapy with glucocorticoids and/or non-steroidal anti-inflammatory drugs and/or immune suppressive therapies was an exclusion criterion only in 9 (32 %) RCTs.

CONCLUSION

Our results highlight the need to redefine the eligibility criteria as well as the reporting of results in future RCTs in order to minimise bias or previous exposure to COL and also obtain data that could be useful in rheumatology practice.

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.

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.

Detection and modification of biomarkers of inflammation determining successful rhythm control in patients with atrial fibrillation

INTRODUCTION

Multiple pathophysiological mechanisms are involved in the pathogenesis of atrial fibrillation (AF). Growing evidence suggests that both local and systemic inflammation plays a key role even in early stages and its progression towards persisting and permanent AF. Rhythm control therapy via pulmonary vein isolation or cardioversion is the cornerstone of AF therapy for most symptomatic patients, yet arrhythmia recurrence after treatment is still common, especially in patients with persistent AF.

MATERIAL AND METHODS

In this review, we summarize the current state of knowledge of biomarkers of inflammation with prognostic value in patients with atrial fibrillation as well as anti-inflammatory medication with potential benefits after rhythm control therapy.

RESULTS AND DISCUSSION

Both onset of AF, progression and arrhythmia recurrence after rhythm control therapy can be caused by local and systemic inflammation. Various inflammatory biomarkers have been established to predict treatment success. Furthermore, additional anti-inflammatory therapy may significantly improve success rates.

Comparison of myocardial injury and inflammation between ablation index-guided and conventional contact force-guided ablation in atrial fibrillation patients

PURPOSE

Ablation index (AI)-guided ablation improves the incidence of arrhythmia recurrence as compared to conventional contact force (CF)-guided ablation. The aim of this study was to elucidate the differences in the biomarkers associated with myocardial injury and inflammation between conventional CF-guided and AI-guided ablation.

METHODS

Atrial fibrillation (AF) patients who underwent pulmonary vein isolation (PVI) from the Osaka Rosai Atrial Fibrillation ablation (ORAF) registry were enrolled. We divided the patients into two groups: conventional CF-guided PVI (CF group) and AI-guided PVI (AI group). The differences in biomarkers associated with myocardial injury and inflammation, and long-term durability of PVI between the two groups were evaluated.

RESULTS

This study population included a total of 794 patients (CF-guided, 241 patients; AI-guided, 553 patients). Total application time was significantly shorter, and total application number was significantly smaller in AI than CF group. High-sensitive troponin I (hs-TnI) post-ablation was significantly higher in AI than CF group (p < 0.001), even after taking the total application number and total application time into consideration. No significant differences in inflammatory markers changes from pre- to post-ablation were observed between the two groups. AI-guided ablation was significantly associated with the hs-TnI post-ablation by multiple regression analysis. The PV reconnection ratio was significantly smaller in AI than CF group (p = 0.037).

CONCLUSIONS

AI-guided ablation had the ability to create larger lesions than CF-guided ablation despite no increase in inflammation and achieved the better PVI durability than that of CF-guided.

Early recurrence of atrial tachyarrhythmia indicates pulmonary vein reconduction independent of blanking period duration in the RACE-AF trial

INTRODUCTION

Atrial tachyarrhythmia recurrence during the blanking period (early ATA) after pulmonary vein isolation (PVI) is associated with an increased risk of later recurrence, but its relationship with pulmonary vein reconduction (PVR) is poorly understood. The objective of the present study was to evaluate the relationship between early ATA and PVR. Second, to provide data on the optimal blanking period by (a) evaluating how the predictive values of ATA for PVR are affected by blanking period duration, and (b) assessing the temporal development in atrial fibrillation (AF) burden.

METHODS

In this RACE-AF substudy, 91 patients with paroxysmal AF undergoing PVI randomized to radiofrequency or cryoballoon ablation were included. All patients received an implantable cardiac monitor and underwent a protocol-mandated repeat procedure after 4-6 months for assessment of PVR. ATA ≥ 30 s. ≤ 90 days after PVI constituted early ATA.

RESULTS

PVR was found in 37/54 (69%) patients with early ATA and in 11/37 (30%) patients without (p < .001). The positive predictive value of ATA for PVR was independent of blanking period duration (range 0-90 days). In both patients with and without PVR, AF burden was higher in the first month after PVI, but AF burden from the second month was similar to AF burden after the conventional blanking period.

CONCLUSION

Early ATA indicates PVR, and the positive predictive value is independent of the blanking period duration. Altogether, the results of this study support substantially shortening the blanking period after PVI for paroxysmal AF.

The relationship between atrial fibrillation and NLRP3 inflammasome: a gut microbiota perspective

Atrial fibrillation (AF) is a common clinical arrhythmia whose pathogenesis has not been fully elucidated, and the inflammatory response plays an important role in the development of AF. The inflammasome is an important component of innate immunity and is involved in a variety of pathophysiologic processes. The NLRP3 inflammasome is by far the best studied and validated inflammasome that recognizes multiple pathogens through pattern recognition receptors of innate immunity and mediates inflammatory responses through activation of Caspase-1. Several studies have shown that NLRP3 inflammasome activation contributes to the onset and development of AF. Ecological dysregulation of the gut microbiota has been associated with the development of AF, and some evidence suggests that gut microbiota components, functional byproducts, or metabolites may induce or exacerbate the development of AF by directly or indirectly modulating the NLRP3 inflammasome. In this review, we report on the interconnection of NLRP3 inflammasomes and gut microbiota and whether this association is related to the onset and persistence of AF. We discuss the potential value of pharmacological and dietary induction in the management of AF in the context of the association between the NLRP3 inflammasome and gut microbiota. It is hoped that this review will lead to new therapeutic targets for the future management of AF.

Colchicine for the Prevention of Recurrent Arrhythmia After Catheter Ablation of Atrial Fibrillation: Results of a Single-Center, Retrospective Study

BACKGROUND

There is evidence to suggest that colchicine reduces the risk of recurrent atrial fibrillation (AF) after catheter ablation; however, the tolerability and safety of colchicine in routine practice is unknown.

METHODS

Patients undergoing catheter ablation for AF who received colchicine after ablation were matched 1:1 to patients who did not by age, sex, and renal function. Recurrent AF was compared between groups categorically at 12 months and via propensity weighted Cox proportional hazards models with and without a 3-month blanking period.

RESULTS

Overall, 180 patients (n = 90 colchicine and n = 90 matched controls) were followed for a median (Q1, Q3) of 10.3 (7.0, 12.0) months. Mean age was 65.3 ± 9.1 years, 33.9% were women, mean CHA2DS2-VASc score was 2.9 ± 1.5, and 51.1% had persistent AF. Most patients (70%) received colchicine 0.6 mg daily for a median of 30 days. In the colchicine group, 55 patients (61.1%) were receiving at least one known interacting medication with colchicine. After ablation, one patient required colchicine dose reduction and four patients required discontinuation. After adjusting for covariate imbalance using propensity weighting, no significant association between colchicine use and AF recurrence was identified (adjusted hazard ratio 0.94, 95% confidence interval [CI] 0.48-1.85; p = 0.853). No significant association was found between colchicine use and all-cause hospitalizations (adjusted odds ratio 0.74, 95% CI 0.28-1.96; p = 0.548).

CONCLUSION

Despite the frequent presence of drug-drug interactions, a 30-day course of colchicine is well-tolerated after AF ablation; however, we did not observe any association between colchicine and lower rates of AF recurrence or hospitalization.

Colchicine in atrial fibrillation: are old trees in bloom?

Colchicine is a widely used drug that was originally used to treat gout and rheumatic diseases. In recent years, colchicine has shown high potential in the cardiovascular field. Atrial fibrillation (AF) is a cardiovascular disease with a high incidence. One of the most frequent complications following cardiovascular surgery is postoperative atrial fibrillation (POAF), which affects patient health and disease burden. This article reviews the research status of colchicine in AF and summarizes the relevant progress.

Blanking period antiarrhythmic drugs after catheter ablation for atrial fibrillation: a meta-analysis of randomized controlled trials

Background

Antiarrhythmic drugs (AADs) are frequently prescribed following catheter ablation (CA) for atrial fibrillation (AF). However, to date, there is a lack of large-scale, multicenter controlled studies that have confirmed the efficacy of AADs in reducing the incidence of late recurrence of AF after CA. Furthermore, the optimal duration of short-term use of AADs after CA remains a controversial topic.

Methods

PubMed, Embase, Cochrane Library, CNKI, and ClinicalTrials.gov were searched until April 25, 2022. We conducted a meta-analysis of randomized controlled trials (RCTs) to assess the efficacy of blanking period AADs in predicting both early and late recurrence of AF. In addition, Grading of Recommendations Assessment, Development and Evaluation (GRADE) was used to assess the quality of evidence in this meta-analysis.

Results

12 RCTs with 3,625 patients were included in this meta-analysis. Short-term use of AADs after AF ablation reduced the risk of early recurrence of AF compared with the no-AADs group. In the subgroup analysis of AADs use time, it was found that only using AADs for more than 2 months can reduce the early recurrence of AF after CA. However, when compared with the no-AADs group, short-term use of AADs after CA did not reduce the incidence of late recurrence of AF.

Conclusions

Short-term use of AADs (more than 2 months) can reduce the early recurrence but not the late recurrence of AF after CA.

Colchicine usage for prevention of post atrial fibrillation ablation pericarditis in patients undergoing high-power short-duration ablation

INTRODUCTION

Radiofrequency ablation (RFA) for atrial fibrillation (AF) has been associated with variable incidence (0.88%-10%) of pericarditis manifested as chest pain, possibly more prevalent with the advent of high-power short-duration (HPSD) ablation. This has led to the widespread use of colchicine in preventative protocols for postablation pericarditis. However, the efficacy of preventative colchicine has not been validated yet.

OBJECTIVE

To evaluate the efficacy of a routine postoperative colchicine regimen (0.6 mg twice a day for 14 days post-AF ablation) for prevention of postablation pericarditis in patients undergoing HPSD ablation.

METHOD

We retrospectively evaluated consecutive single-operator HPSD AF ablation procedures at our institution from June 2019 to July 2022. A colchicine protocol was introduced in June 2021 for the prevention of postablation pericarditis. All ablations were performed with 50 watts. Patients were divided into colchicine and noncolchicine groups. We recorded incidence of postablation chest pain, emergency room (ER) visit for chest pain, pericardial effusion, pericardiocentesis, any ER visit, hospitalization, AF recurrence, and cardioversion for AF within the first 30 days following ablation. We also recorded colchicine-related side effects and medication compliance.

RESULTS

Two hundred and ninety-four consecutive HPSD AF ablation patients were screened for the study. After implementing the prespecified exclusion criteria, a total of 205 patients were included in the final analysis, yielding 101 patients in the colchicine group and 104 patients in the noncolchicine group. Both groups were well-matched for demographic and procedural parameters. There was no significant difference in postablation chest pain (9.9% vs. 8.6%, p = .7), pericardial effusion (2.9% vs. 0.9%, p = .1), ER visits (11.9% vs. 12.5%, p = .2), 30-day hospitalization for AF recurrence (0.9% vs. 0.96%, p = .3), and 30-day need for cardioversion for AF (3.9% vs. 5.7%, p = .2). Fifteen (15) patients had severe colchicine-related diarrhea, out of which 12 discontinued it prematurely. There were no major procedural complications in either group.

CONCLUSION

In this single-operator retrospective analysis, prophylactic colchicine was not associated with significant reduction in the incidence of postablation chest pain, pericarditis, 30 day hospitalization, ER visits, or AF recurrence or need of cardioversion within first 30 days after HPSD ablation for AF. However, its usage was associated with significant diarrhea. This study concludes no additional advantage of prophylactic use of colchicine after HPSD AF ablation.

Impact of Colchicine Monotherapy on the Risk of Acute Pericarditis Following Atrial Fibrillation Ablation

BACKGROUND

Acute pericarditis is a known complication of ablation procedures for atrial fibrillation (AF).

OBJECTIVES

This study aimed to evaluate the benefits of colchicine monotherapy in terms of reducing the risk of pericarditis and related hospitalization rate in AF patients undergoing catheter ablation.

METHODS

Consecutive AF patients undergoing first catheter ablation were classified into 3 groups based on their colchicine use: Group 1: no colchicine; group 2: colchicine from 7 days before to 1 month after ablation; and group 3: colchicine from the day of the procedure to 1 month after. Standard institutional protocol was used to follow all patients for 1 year.

RESULTS

A total of 1,075 patients were classified into groups 1 (n = 607), 2 (n = 213), and 3 (n = 255). Symptoms of acute pericarditis were reported in 129 patients (12%): group 1: n = 106 (17.5%); group 2: n = 4 (1.9%); and group 3: n = 19 (7.5%); P < 0.001. Rate of mild-moderate as well as severe pericarditis were significantly lower in group 2. In the multivariable regression analysis, pre- and post-ablation colchicine use was seen to be associated with significantly lower risk of acute pericarditis and related hospitalization compared with the other 2 groups. In addition, at 1-year follow-up, arrhythmia-free survival rate was significantly higher in paroxysmal AF patients receiving colchicine compared with the no-colchicine population.

CONCLUSIONS

Colchicine therapy starting 7 days before to 1 month after the ablation procedure was associated with significantly lower risk of acute pericarditis and related hospitalization. In addition, paroxysmal AF patients receiving colchicine had a higher arrhythmia-free survival rate compared with those not receiving colchicine.

Prophylactic Colchicine After Radiofrequency Ablation of Atrial Fibrillation: Post Ablation Pericarditis Reduction Study (PAPERS)

BACKGROUND

Pericarditis is common after radiofrequency ablation for atrial fibrillation (AF).

OBJECTIVES

Study investigators hypothesized an empirical post-AF ablation treatment protocol with colchicine may reduce the incidence and severity of pericarditis. PAPERS (Post-Ablation PEricarditis Reduction Study) aimed to quantify the risks and benefits associated with prophylactic use of colchicine to prevent pericarditis following AF ablation.

METHODS

PAPERS is a multicenter, prospective, randomized controlled study. Patients were randomized on the day of the procedure to receive no postprocedure prophylaxis (group A; standard of care arm) or colchicine 0.6 mg orally twice daily for 7 days starting immediately post-procedure (group B; study arm). All participants underwent a follow-up survey at 14 days postoperatively. The primary endpoint was the development of clinical pericarditis within 2 weeks following ablation. Secondary outcomes included the incidence of pericarditis by ablation type and medical therapy.

RESULTS

Among 139 patients enrolled, 66 were randomized to standard of care (group A), and 73 patients were randomized to the colchicine arm (group B). The primary outcome of clinical pericarditis was reached in 7 of 66 (10.6%) patients in group A and in 7 of 73 (9.6%) patients in group B (P = 0.84). The rate of gastrointestinal discomfort was 10 of 66 (15%) in group A and 34 of 73 (47%) in group B (P < 0.001). There was an increased incidence of pericarditis in patients who underwent cavotricuspid isthmus ablation (17 of 50; 34%) in addition to pulmonary vein isolation (6 of 69; 8.7%; P = 0.001).

CONCLUSIONS

Prophylactic colchicine therapy initiated after the ablation procedure in patients with AF did not affect the incidence of post-ablation pericarditis and was associated with an increased incidence of gastrointestinal side effects.

Single-Dose Intraprocedural Steroid Administration Does Not Impact Early Atrial Fibrillation Recurrence

PURPOSE

To evaluate the effect of single-dose intravenous dexamethasone on atrial fibrillation (AF) recurrence following radiofrequency catheter ablation.

METHODS

A cohort of 84 adult patients (> 18 years) underwent catheter ablation at Mayo Clinic Rochester from January to March 2019. Only first-time ablation patients were included, with all re-do ablations excluded to minimize heterogeneity. Administration of intraoperative dexamethasone 4 mg or 8 mg was determined by chart review from the procedure. At our institution, intraoperative intravenous steroids are administered for postoperative nausea and vomiting (PONV) prophylaxis at the discretion of the anesthesiologist. AF recurrence was determined by ECG or cardiac monitoring within 3 months or between 3 and 12 months post-ablation with an in-person follow-up visit.

RESULTS

A total of 31 (36.9%) patients received intravenous dexamethasone compared to 54 (63.1%) who did not (approximating a 2:1 comparison group). The incidence of documented AF or atrial flutter, lasting greater than 30 s, within the first 3 months post-ablation was 29.0% in the dexamethasone group versus 24.5% in the non-dexamethasone group (p value 0.80). AF or atrial flutter recurrence at 3-12 months post-ablation was 3.2% in the dexamethasone group compared to 9.4% in the non-dexamethasone group (p value 0.41).

CONCLUSION

These data suggest that intraoperative intravenous dexamethasone administered during AF ablation for postoperative nausea and vomiting prophylaxis may not have a significant effect on AF recurrence rates.

The Effect of Colchicine on Atrial Fibrillation: A Systematic Review and Meta-Analysis

Colchicine is a potent anti-inflammatory agent whose benefits have been explored for various conditions, including atrial fibrillation (AF). In this article, we tried to understand why colchicine might be beneficial in AF and reviewed various studies that looked at the effect of colchicine against AF. We followed the PRISMA algorithm and undertook a literature search to identify studies with control groups that looked at the effect of colchicine against AF and conducted a meta-analysis. We identified six studies on post-cardiac surgical patients, three on post-pulmonary vein isolation (PVI)/ablation patients, and two on coronary artery disease. In patients who underwent cardiac surgery, we found that colchicine is beneficial against postoperative atrial fibrillation (POAF) with a relative risk (RR) of 0.70 (95% CI of 0.58 to 0.84) and a p-value of 0.0001. We also found that in patients who underwent PVI/ablation, colchicine is beneficial in decreasing AF recurrence over three months with an RR of 0.57 (95% CI of 0.39 to 0.83) and a p-value of 0.0032 and over 12 months follow-up with an RR of 0.58 (95% CI of 0.42 - 0.80) and a p-value of 0.0008. Our meta-analysis showed that in patients with coronary artery disease, colchicine had no significant benefit in decreasing the incidence of AF with a hazard ratio (HR) of 0.86 (95% CI of 0.69 - 1.06) and a p-value of 0.16. From this study, we conclude that colchicine may be beneficial for decreasing the incidence of AF in post-cardiac surgery patients and post-PVI/ablation patients. It may not decrease the incidence of AF in patients with coronary artery disease.

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.

Select drug-drug interactions with colchicine and cardiovascular medications: A review

Several randomized clinical trials have demonstrated the clinical utility of colchicine in the prevention and management of various cardiovascular conditions, including secondary prevention of atherosclerotic cardiovascular disease, acute and chronic pericarditis, and atrial fibrillation. As a result, it is reasonable to anticipate increased use of colchicine within the cardiovascular specialty. However, colchicine is metabolized by cytochrome P450 3A4 (CYP3A4) and a substrate of the efflux transporter, P-glycoprotein (P-gp), creating the potential for clinically significant drug-drug interactions (DDIs). Therefore, when colchicine is administered concomitantly with other cardiovascular agents that inhibit CYP3A4 or P-gp, there is an increased risk of significant DDIs, potentially leading to negative sequelae. This article summarizes the evidence supporting the use of colchicine for cardiovascular disease, describes the mechanisms behind DDIs with select cardiovascular medications, and provides suggestions regarding colchicine dosing and management of DDIs to minimize the risk of poor tolerability and colchicine toxicity.

A meta-analysis of colchicine in prevention of atrial fibrillation following cardiothoracic surgery or cardiac intervention

BACKGROUND

Postoperative atrial fibrillation (POAF) is the most common complication after cardiothoracic surgery or cardiac intervention. Colchicine is an anti-inflammatory agent that was associated with improved cardiovascular outcomes. However, its effect on POAF prevention was inconsistent across studies. Therefore, the aim of this meta-analysis was to evaluate the efficacy of colchicine in prevention of POAF.

METHODS

We searched PubMed, Embase, ClinicalTrials.gov, Cochrane Library database and Google Scholar for randomized controlled trials (RCTs), using terms "atrial fibrillation" and "colchicine". The primary end point was the occurrence of clinically diagnosed atrial fibrillation. The relative risk (RR) and 95% confidence interval (CI) were evaluated. Estimates were pooled using DerSimonian-Laird random-effects model. We also performed subgroup analyses based on the duration and dose of colchicine treatment.

RESULTS

A total of 9 RCTs were included in this meta-analysis, enrolling a total of 2031 patients. Colchicine significantly reduces the incidence of POAF (RR 0.62; 95% CI, 0.52-0.74, P < 0.001, I2 = 0%). Subgroup analyses indicated that the protective effect of colchicine on POAF was slightly stronger in the long-duration group (RR 0.60; 95% CI, 0.48-0.75, P < 0.001, I2 = 0%) than in the short-duration group (RR 0.65; 95% CI, 0.49-0.86, P < 0.001, I2 = 0%).

CONCLUSION

Colchicine is effective in preventing the occurrence of POAF. The efficacy of colchicine can be slightly increased over treatment duration, with no obvious adverse reactions.

Immune remodeling and atrial fibrillation

Atrial fibrillation (AF) is a highly prevalent arrhythmia that causes high morbidity and mortality. However, the underlying mechanism of AF has not been fully elucidated. Recent research has suggested that, during AF, the immune system changes considerably and interacts with the environment and cells involved in the initiation and maintenance of AF. This may provide a new direction for research and therapeutic strategies for AF. In this review, we elaborate the concept of immune remodeling based on available data in AF. Then, we highlight the complex relationships between immune remodeling and atrial electrical, structural and neural remodeling while also pointing out some research gaps in these field. Finally, we discuss several potential immunomodulatory treatments for AF. Although the heterogeneity of existing evidence makes it ambiguous to extrapolate immunomodulatory treatments for AF into the clinical practice, immune remodeling is still an evolving concept in AF pathophysiology and further studies within this field are likely to provide effective therapies for AF.

Colchicine for cardiovascular medicine: a systematic review and meta-analysis

Aim: Colchicine, a microtubule-disassembling (antitubulin) agent used for centuries for the treatment of gout and autoimmune diseases, is a drug of growing interest in the cardiovascular field. While in the last decades it has become cornerstone of pericarditis treatment, it has also emerged in the last few years as a promising drug in the management of coronary artery disease, atrial fibrillation and heart failure. This systematic review and meta-analysis aimed to assess the efficacy of colchicine in patients with cardiovascular diseases. Methods: Systematic search in electronic databases (MEDLINE/PubMed, Scopus, BioMed Central, the Cochrane Collaboration Database of Randomized Trials, ClinicalTrials.gov, EMBASE, Google Scholar) was performed to identify randomized controlled trials (RCTs) up to February 2021. Random-effects meta-analysis was performed to assess the risk of cardiovascular events, defined according to clinical setting. Results: Among 15,569 pooled patients from 21 RCTs, colchicine was superior to placebo in the reduction of cardiovascular events. In the setting of pericardial diseases, it was associated with a lower risk of recurrent pericarditis (17 vs 34%, RR = 0.50, 95% CI: 0.42-0.60, I² = 10%). In other studies assessing coronary artery disease patients, colchicine was associated with a reduced risk of major adverse cardiovascular events (MACE) such as myocardial infarction, stroke, cardiovascular death, coronary revascularisation and hospitalization (6.3 vs 9%, RR = 0.67, 95% CI: 0.54-0.84, I² = 55). Among patients with atrial fibrillation, it was associated with lower rates of recurrence (20 vs 30%, RR = 0.68, 95% CI: 0.58-0.81, I² = 0). In the single RCT on heart failure, colchicine was not associated with improved NYHA class. Conclusion: Colchicine is a valuable anti-inflammatory agent for the prevention of cardiovascular events in patients with inflammatory cardiac conditions such as pericardial diseases, coronary artery disease and atrial fibrillation.

Colchicine - new horizons for an ancient drug. Review based on the highest hierarchy of evidence

Colchicine is an old, inexpensive, and relatively safe anti-inflammatory drug traditionally used in gout and over the last 50 years in familial Mediterranean fever. A search of all high-hierarchy studies (randomized controlled trials [RCTs], systematic reviews and meta-analysis of RCTs) over the last 20 years revealed myriad other evidence-based applications. Colchicine seems efficacious in the treatment of acute pericarditis and prevention of recurrences and in the prevention of postcardiac injury syndrome and atrial fibrillation following cardiac surgery or percutaneous interventions. In patients already fully treated with statins and antiplatelet agents following acute coronary syndromes or stable coronary disease, adding low-dose colchicine achieved secondary prevention of major cardiovascular events (myocardial infarction, stroke, or cardiovascular death) with pooled risk reduction 0.75. Colchicine may also be useful in Behcet's syndrome and most recently, in improving outcomes of COVID-19 infection. Colchicine in the low doses used in most trials (≤ 1 mg/d) was generally safe and well-tolerated, excepting diarrhea (approximately 10%) which sometimes led to drug discontinuation. Further RCTs are required to confirm these results, and will likely lead to expanding indications for low-dose colchicine. Increasing numbers of patients will be treated with colchicine in the near future, with improved health outcomes, as long as basic caveats are heeded.

Early arrhythmia recurrence after cryoballoon ablation in atrial fibrillation: a systematic review and meta-analysis

BACKGROUND

Early arrhythmia recurrence within the three-month blanking period is a common event that historically has been attributed to reversible phenomena. While its' mechanistic links remain obscure, accumulating evidence support the argument of shortening the blanking period. We aimed to elucidate the association between early and late arrhythmia recurrence after atrial fibrillation cryoablation.

METHODS

The MEDLINE database, ClinicalTrials.gov, medRxiv and Cochrane Library were searched for studies evaluating early and late arrhythmia recurrence rates in patients undergoing cryoablation for AF. Data were pooled by meta-analysis using a random-effects model. The primary endpoint was late arrhythmia recurrence.

RESULTS

Early arrhythmia recurrence was found predictive of decreased arrhythmia-free survival after evaluating 3975 patients with paroxysmal or persistent atrial fibrillation who underwent cryoablation (OR: 5.31; 95% CI: 3.75-7.51). This pattern remained unchanged after sub-analyzing atrial fibrillation type (paroxysmal; OR: 7.16; 95% CI: 4.40-11.65 and persistent; OR: 7.63; 95% CI: 3.62-16.07) as well as cryoablation catheter generation (first generation; OR: 5.15, 95% CI: 2.39-11.11 and advanced generation; OR: 5.83, 95% CI: 3.68-9.23). Studies permitting anti-arrhythmic drug utilization during blanking period or examining early recurrence as a secondary outcome were found to be a significant source of statistical heterogeneity.

CONCLUSION

Our findings suggest that early arrhythmia recurrence is predictive of late outcomes after cryoablation for atrial fibrillation. Identifying which patients deserve earlier re-intervention is an open research avenue. This article is protected by copyright. All rights reserved.

Repurposing Colchicine for Heart Disease

Colchicine is one of the most ancient medications still prescribed. It is extracted from the Colchicum autumnale plant and is routinely used because of its broad anti-inflammatory properties to treat gout and familial Mediterranean fever. Colchicine has shown efficacy in various clinical settings in which inflammation is a key component, and it has become first-line therapy for acute and recurrent pericarditis. Two landmark clinical trials have recently shown that colchicine significantly improves cardiovascular outcomes on background statin and antiplatelet therapy in patients with coronary artery disease, supporting its role for the prevention of atherothrombotic events. Favorable results have also emerged in atrial fibrillation. We herein briefly review the most recent data related to the multiple cardiovascular conditions for which colchicine has been successfully repurposed. Expected final online publication date for the Annual Review of Pharmacology and Toxicology, Volume 62 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Molecular Insights in Atrial Fibrillation Pathogenesis and Therapeutics: A Narrative Review

The prevalence of atrial fibrillation (AF) is bound to increase globally in the following years, affecting the quality of life of millions of people, increasing mortality and morbidity, and beleaguering health care systems. Increasingly effective therapeutic options against AF are the constantly evolving electroanatomic substrate mapping systems of the left atrium (LA) and ablation catheter technologies. Yet, a prerequisite for better long-term success rates is the understanding of AF pathogenesis and maintenance. LA electrical and anatomical remodeling remains in the epicenter of current research for novel diagnostic and treatment modalities. On a molecular level, electrical remodeling lies on impaired calcium handling, enhanced inwardly rectifying potassium currents, and gap junction perturbations. In addition, a wide array of profibrotic stimuli activates fibroblast to an increased extracellular matrix turnover via various intermediaries. Concomitant dysregulation of the autonomic nervous system and the humoral function of increased epicardial adipose tissue (EAT) are established mediators in the pathophysiology of AF. Local atrial lymphomononuclear cells infiltrate and increased inflammasome activity accelerate and perpetuate arrhythmia substrate. Finally, impaired intracellular protein metabolism, excessive oxidative stress, and mitochondrial dysfunction deplete atrial cardiomyocyte ATP and promote arrhythmogenesis. These overlapping cellular and molecular alterations hinder us from distinguishing the cause from the effect in AF pathogenesis. Yet, a plethora of therapeutic modalities target these molecular perturbations and hold promise in combating the AF burden. Namely, atrial selective ion channel inhibitors, AF gene therapy, anti-fibrotic agents, AF drug repurposing, immunomodulators, and indirect cardiac neuromodulation are discussed here.

2-Hydroxybenzylamine (2-HOBA) to prevent early recurrence of atrial fibrillation after catheter ablation: protocol for a randomized controlled trial including detection of AF using a wearable device

Background

Although catheter ablation is an effective therapy for atrial fibrillation (AF), the most common cardiac arrhythmia encountered in clinical practice, AF ablation generates inflammation and oxidative stress in the early postoperative period predisposing to recurrence of AF. Isolevuglandins (IsoLGs) are reactive lipid mediators of oxidative stress injury that rapidly react with endogenous biomolecules to compromise their function. 2-Hydroxybenzylamine (2-HOBA), a potent small molecule scavenger of IsoLGs, sequesters the reactive species as inert adducts. This mechanism, coupled with reported safety in humans, supports the investigation of 2-HOBA as a novel therapeutic to reduce AF caused by oxidative stress, such as that which occurs after catheter ablation. Accordingly, we seek to test the hypothesis that treatment with 2-HOBA will decrease early recurrence of AF and other atrial arrhythmias following AF ablation by decreasing IsoLG adducts with native biomolecules.

Methods

The proposed trial will randomly assign 162 participants undergoing cryo- or radiofrequency catheter ablation for AF to 2-HOBA (N = 81) or placebo (N = 81). Individuals will begin the study drug 3 days prior to ablation and continue for 28 days. Participants will be given a wearable smartwatch capable of detecting and recording atrial arrhythmias. They will be instructed to record ECGs daily with additional ECGs if they experience symptoms of AF or when alerted by the smartwatch AF detection alarm. The primary clinical endpoint will be an episode of AF, atrial tachycardia, or atrial flutter lasting 30 s or more within 28 days post-AF ablation. Secondary measures will be the change in IsoLG adduct levels from blood samples collected immediately pre-ablation and post-ablation and reduction in AF burden as calculated from the smartwatch.

Discussion

The proposed trial will test the hypothesis that 2-HOBA reduces post-ablation atrial arrhythmias through sequestration of reactive IsoLG species. The results of this study may improve the understanding of the role of IsoLGs and oxidative stress in AF pathogenesis and provide evidence to advance 2-HOBA and related compounds as a new therapeutic strategy to treat AF.

Trial registration

ClinicalTrials.gov NCT04433091. Registered on June 3, 2020.

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.

Colchicine and the heart

Colchicine is a unique, sophisticated anti-inflammatory agent that has been used for decades for the prevention of acute inflammatory flares in gout and familial Mediterranean fever. In recent years, clinical trials have demonstrated its potential in a range of cardiovascular (CV) conditions. Colchicine is avidly taken up by leucocytes, and its ability to bind to tubulin and interfere with microtubular function affects the expression of cytokines and interleukins, and the ability of neutrophils to marginate, ingress, aggregate, express superoxide, release neutrophil extracellular traps, and interact with platelets. In patients with acute and recurrent pericarditis, clinical trials in >1600 patients have consistently shown that colchicine halves the risk of recurrence [relative risk (RR) 0.50, 95% confidence interval (CI) 0.42–0.60]. In patients with acute and chronic coronary syndromes, multicentre randomized controlled trials in >11 000 patients followed for up to 5 years demonstrated that colchicine may reduce the risk of CV death, myocardial infarction, ischaemic stroke and ischaemia-driven revascularization by >30% (RR 0.63, 95% CI 0.49–0.81). The use of colchicine at doses of 0.5–1.0 mg daily in CV trials has proved safe. Early gastrointestinal intolerance limits its use in ∼10% of patients; however, ∼90% of patients tolerate it well over the long term. Despite isolated case reports, clinically relevant drug interactions with moderate to strong CYP3A4 inhibitors/competitors or P-glycoprotein inhibitors/competitors are rare if this dosage of colchicine is used in the absence of advanced renal or liver disease. The aim of this review is to summarize the contemporary data supporting the efficacy and safety of colchicine in patients with CV disease.

Inflammation, atrial fibrillation, and the potential role for colchicine therapy

Increasing evidence suggests that the "NACHT-LRR and PYD domain-containing protein 3" (NLRP3) inflammasome plays an important role in atherosclerotic cardiovascular disease (ASCVD). Recent preclinical evidence has suggested that the NLRP3 inflammasome may play a prominent role in the pathogenesis of atrial fibrillation (AF). As such, the therapies that have shown efficacy in reducing ASCVD events may also prove beneficial in AF. In this article, we review the findings that implicate the NLRP3 inflammasome in the pathogenesis of AF, discuss existing evidence behind the use of anti-inflammatory agents for AF, and discuss the future role that colchicine and other anti-inflammatory agents may play in the prevention and treatment of AF.

Repurposing colchicine's journey in view of drug-to-drug interactions. A review

Colchicine's medical evolution is historically bound to the Mediterranean basin, since remarkable researchers from this region underscored its valuable properties. With the passing of years colchicine became an essential pharmaceutical substance for the treatment of rheumatologic and cardiovascular diseases. In light of recent findings, the therapeutic value of colchicine has grown. In clinical practice, colchicine remains underutilized in view of its proven efficacy and safety. Its complex pharmacokinetics and multifaceted anti-inflammatory role remain under investigation. The current review addresses the safe administration of colchicine in view of key drug to drug interactions. Finally, we are briefly presenting colchicine's future potential applications.

Decreased anxiety after catheter ablation for paroxysmal atrial fibrillation is associated with augmented parasympathetic reactivity to stress

Background

Psychological improvement after catheter ablation for atrial fibrillation (AF) has been reported, but its mechanism is unclear.

Objective

This study aimed to clarify the relationship between cardiac autonomic modification and psychological changes after catheter ablation for paroxysmal AF (PAF).

Methods

Thirty-five consecutive patients (60.5 ± 11.9 years; male, n = 24) with PAF treated by catheter ablation were enrolled. Autonomic activity and reactivity to stress and psychological status were measured before (baseline) and at 1 and 3 months after ablation. We assessed autonomic activity and reactivity to stress by measuring heart rate variability (HRV) at rest (Rest), and during (Task) and after (After) the execution of a task and assessed relationships between HRV parameters and psychological changes using the State-Trait Anxiety Inventory (STAI) and Self-Rating Depression Scale (SDS).

Results

The STAI state and trait scores significantly decreased at 3 months compared with baseline, whereas SDS scores essentially remained unchanged. The high-frequency (HF) response index (Task/Rest) and HF recovery index (After/Rest) were significantly higher than baseline at 3 months (0.40 [0.29–0.90] vs 1.30 [0.64–2.18], P = .007 for HF response index; 1.13 [0.92–2.19] vs 1.87 [1.19–2.97], P = .049 for HF recovery index). Reductions in STAI scores positively correlated with increments in the HF recovery index in the entire cohort as well as in 5 patients with recurrent AF.

Conclusions

Some augmentation of parasympathetic reactivity to stress correlated with reduced anxiety, implying that cardiac autonomic modification plays roles in psychological improvement after catheter ablation for AF.

The Efficacy of Anti-inflammatory Agents in the Prevention of Atrial Fibrillation Recurrences

Several studies have indicated an association between inflammation and the recurrence of Atrial Fibrillation (AF), especially after ablation, which is a therapeutic option leading to local inflammation. On the other hand, each AF can lead to another AF, as a general rule. Thus, preventing recurrences of AF is extremely important for patient outcomes. In this paper, we attempted to review the effect of medicinal agents with anti-inflammatory properties on the prevention of AF recurrence. There are several randomized controlled trials (RCTs) and meta-analyses on the prevention of AF recurrence using agents with anti-inflammatory properties, which include steroids, colchicine, statins, and n-3 fatty acids (n-3 FA). Clinical trials evaluating the efficacy of anti-inflammatory drugs in preventing the recurrence of AF led to inconsistent results for corticosteroids, statins and n-3 FAs. These results may be related to the fact that inflammation is not the only factor responsible for triggering recurrences of AF. For example, the presence of structural, mechanical and electrical remodeling could potentially be the most important factors that trigger recurrences of AF but these factors have not been addressed in most of the reported studies. Therefore, future clinical trials are needed to compare the efficacy of anti-inflammatory drugs in AF patients with, or without other factors. For colchicine, a potent anti-inflammatory drug, there are limited studies. However, all the studies investigating colchicine in the context of AF were consistent and promising, especially when colchicine was used on a short-term basis following ablation in patients with paroxysmal AF. Therefore, colchicine could be a promising candidate for further clinical studies involving recurrent AF.

Colchicine for the treatment of cardiovascular diseases: old drug, new targets

: Well known in past centuries as a herbal remedy for osteoarticular pain and commonly used in the treatment of gout and familial Mediterranean fever, colchicine has an emerging role in the setting of cardiovascular diseases. Its unique properties not only target the key mechanisms of recurrent inflammation underlying pericardial syndromes but also inflammation within atherosclerotic plaques, atrial fibrillation recurrence and adverse ventricular remodelling leading to heart failure.The effect of colchicine in the treatment of cardiovascular diseases along with essential pharmacology will be discussed, reviewing the most important and recent clinical studies. Colchicine is a valuable, well tolerated and inexpensive drug in the setting of cardiovascular diseases.

Association of pericardial effusion after pulmonary vein isolation and outcomes in patients with paroxysmal atrial fibrillation

BACKGROUND

The clinical implications of pericardial effusion (PE) after catheter ablation for atrial fibrillation (AF) are not well understood. We evaluated the association between newly developed PE after pulmonary vein isolation (PVI) for paroxysmal AF and arrhythmic recurrence.

METHODS

From a prospective AF ablation registry, 184 patients (mean age 59 ± 10 years, 65% male) who underwent first-time PV isolation using a smart touch surround flow catheter (Biosense Webster, Diamond Bar, CA) were analyzed. Postablation transthoracic echocardiography (TTE) was performed within 1-3 days after ablation, and the occurrence of PE was assessed.

RESULTS

PE developed in 91 patients (49.5%), and most were of minimal severity (minimal, 93.4%; mild, 6.6%). Patients with PE had significantly lower body mass index and underwent cavotricuspid isthmus ablation more frequently. Early arrhythmic recurrence (EAR) (within 3 months) was observed in 28.8% of patients and was not different according to the PE development (PE [+]: 29.7% vs PE [-]: 28.0%; P = .80). During a median follow-up of 696 days, the cumulative rate of the late arrhythmic recurrence (LAR) (after 3 months) was 36.4%, and there was no difference between groups (PE [+]: 36.7% vs PE [-]: 35.1%; P = .988). The only predictor of LAR was EAR, and no echocardiographic parameters showed a significant correlation with LAR.

CONCLUSIONS

Minimal or mild PE after PVI for paroxysmal AF is a frequent echocardiographic finding, and it had no significant association with AF recurrence. Routine TTE after AF ablation has no clinical implication.

Colchicine as a Potential Therapeutic Agent Against Cardiovascular Complications of COVID-19: an Exploratory Review

Coronavirus disease-19 (COVID-19) may result in serious complications involving several organ systems, including myocardial tissue. An exaggerated host inflammatory response, described as a cytokine storm, has been linked to play a major role in these complications. Colchicine and other pharmaceutical agents have been proposed to counter the cytokine storm and improve outcomes. In this exploratory review, we utilized a PubMed and Cochrane Database search aiming to identify the biochemical characteristics of the cytokine storm as well as to identify the potential effect of colchicine on these inflammatory biomarkers. The research yielded 30 reports describing the characteristics of the cytokine storm and 44 reports describing the effect of colchicine on various inflammatory biomarkers. According to our research, colchicine may be an agent of interest in the treatment of COVID-19 via its anti-inflammatory properties. However, there are potential drug interactions with cytochrome P450 3A4 inhibitors resulting in acute colchicine toxicities. Additionally, there is scarce evidence regarding the efficacy of colchicine in the acute phase of disease, since most trials evaluated its effect in chronic conditions. In this direction, our team proposes three different hypotheses for evaluating the place of colchicine in the treatment of COVID-19.

Colchicine prevents atrial fibrillation promotion by inhibiting IL-1β-induced IL-6 release and atrial fibrosis in the rat sterile pericarditis model

A few clinical trials have recently reported the potential effect of colchicine in preventing post-operative atrial fibrillation (POAF) and early atrial fibrillation (AF) recurrence after catheter pulmonary vein isolation. However, the molecular mechanisms through which colchicine inhibits AF remain unclear. We aim to assess the anti-AF effect of colchicine in the rat sterile pericarditis (SP) model and to investigate its molecular mechanisms. SP was induced in Sprague-Dawley rats by the epicardial application of sterile talc. Treatment with colchicine or vehicle began 1 d before pericardiotomy. AF was induced by transesophageal burst pacing on day 3 after surgery. Treatment with colchicine reduced the duration of AF and the probability of induction of AF in SP rats. The dose of 0.5 mg kg^-1·day^-1 had the best effect. Such treatment also reduced neutrophil infiltration, the mRNA expression of IL-6, TGF-β, and TNF-α, atrial fibrosis, fibrosis related genes, and signal molecules (STAT3, P38, and AKT). Meanwhile, the release of IL-1β (4-24 h) and IL-6 (4-72 h) in atria after surgery was significantly inhibited by colchicine. In cultured rat cardiac fibroblasts, colchicine treatment inhibited IL-1β-induced expression of IL-6, which was accompanied by significantly decreased phosphorylation of P38, AKT, JNK, and NFκB. Interestingly, the supplementation of IL-6 abolished the anti-AF effect of colchicine in SP rats. Colchicine prevents AF in SP rats through the inhibition of IL-1β-induced IL-6 release and subsequent atrial fibrosis. However, further studies are required to investigate whether colchicine inhibits POAF through other mechanisms.

Recurrent Atrial Fibrillation After Radiofrequency Ablation: What to Expect

Recurrent atrial fibrillation after radiofrequency ablation is observed in up to 50% of patients within 3 months. Early and multiple recurrences predict late recurrences within 1 year, which occurs in 20% to 50% of patients. Although no consensus exists regarding patient selection and timing of redo ablation, we refer symptomatic patients with multiple recurrences and persistent atrial fibrillation for ablation. Reisolation of reconnected pulmonary veins and ablation of nonpulmonary vein triggers is the primary ablation strategy. In addition to repeat ablation, we recommend weight loss, treatment of sleep-disordered breathing, and management of comorbid conditions for durable maintenance of sinus rhythm.

Genetic Susceptibility for Atrial Fibrillation in Patients Undergoing Atrial Fibrillation Ablation

BACKGROUND

Ablation is a widely used therapy for atrial fibrillation (AF); however, arrhythmia recurrence and repeat procedures are common. Studies examining surrogate markers of genetic susceptibility to AF, such as family history and individual AF susceptibility alleles, suggest these may be associated with recurrence outcomes. Accordingly, the aim of this study was to test the association between AF genetic susceptibility and recurrence after ablation using a comprehensive polygenic risk score for AF.

METHODS

Ten centers from the AF Genetics Consortium identified patients who had undergone de novo AF ablation. AF genetic susceptibility was measured using a previously described polygenic risk score (N=929 single-nucleotide polymorphisms) and tested for an association with clinical characteristics and time-to-recurrence with a 3 month blanking period. Recurrence was defined as >30 seconds of AF, atrial flutter, or atrial tachycardia. Multivariable analysis adjusted for age, sex, height, body mass index, persistent AF, hypertension, coronary disease, left atrial size, left ventricular ejection fraction, and year of ablation.

RESULTS

Four thousand two hundred seventy-six patients were eligible for analysis of baseline characteristics and 3259 for recurrence outcomes. The overall arrhythmia recurrence rate between 3 and 12 months was 44% (1443/3259). Patients with higher AF genetic susceptibility were younger (P<0.001) and had fewer clinical risk factors for AF (P=0.001). Persistent AF (hazard ratio [HR], 1.39 [95% CI, 1.22-1.58]; P<0.001), left atrial size (per cm: HR, 1.32 [95% CI, 1.19-1.46]; P<0.001), and left ventricular ejection fraction (per 10%: HR, 0.88 [95% CI, 0.80-0.97]; P=0.008) were associated with increased risk of recurrence. In univariate analysis, higher AF genetic susceptibility trended towards a higher risk of recurrence (HR, 1.08 [95% CI, 0.99-1.18]; P=0.07), which became less significant in multivariable analysis (HR, 1.06 [95% CI, 0.98-1.15]; P=0.13).

CONCLUSIONS

Higher AF genetic susceptibility was associated with younger age and fewer clinical risk factors but not recurrence. Arrhythmia recurrence after AF ablation may represent a genetically different phenotype compared to AF susceptibility.