Biomarkers as predictors of recurrence of atrial fibrillation post ablation: an updated and expanded systematic review and meta-analysis

Background A high proportion of patients undergoing catheter ablation (CA) for atrial fibrillation (AF) experience recurrence of arrhythmia. This meta-analysis aims to identify pre-ablation serum biomarker(s) associated with arrhythmia recurrence to improve patient selection before CA. Methods A systematic approach following PRISMA reporting guidelines was utilised in libraries (Pubmed/Medline, Embase, Web of Science, Scopus) and supplemented by scanning through bibliographies of articles. Biomarker levels were compared using a random-effects model and presented as odds ratio (OR). Heterogeneity was examined by meta-regression and subgroup analysis. Results In total, 73 studies were identified after inclusion and exclusion criteria were applied. Nine out of 22 biomarkers showed association with recurrence of AF after CA. High levels of N-Terminal-pro-B-type-Natriuretic Peptide [OR (95% CI), 3.11 (1.80–5.36)], B-type Natriuretic Peptide [BNP, 2.91 (1.74–4.88)], high-sensitivity C-Reactive Protein [2.04 (1.28–3.23)], Carboxy-terminal telopeptide of collagen type I [1.89 (1.16–3.08)] and Interleukin-6 [1.83 (1.18–2.84)] were strongly associated with identifying patients with AF recurrence. Meta-regression highlighted that AF type had a significant impact on BNP levels (heterogeneity R2 = 55%). Subgroup analysis showed that high BNP levels were more strongly associated with AF recurrence in paroxysmal AF (PAF) cohorts compared to the addition of non-PAF patients. Egger’s test ruled out the presence of publication bias from small-study effects. Conclusion Ranking biomarkers based on the strength of association with outcome provides each biomarker relative capacity to predict AF recurrence. This will provide randomised controlled trials, a guide to choosing a priori tool for identifying patients likely to revert to AF, which are required to substantiate these findings. Graphical abstract

Association of ZFHX3 Genetic Polymorphisms and Extra-Pulmonary Vein Triggers in Patients With Atrial Fibrillation Who Underwent Catheter Ablation

Background: The ZFHX3 gene (16q22) is the second most highly associated gene with atrial fibrillation (AF) and is related to inflammation and fibrosis. We hypothesized that ZFHX3 is associated with extra-pulmonary vein (PV) triggers, left atrial (LA) structural remodeling, and poor rhythm outcomes of AF catheter ablation (AFCA).Methods: We included 1,782 patients who underwent a de novo AFCA (73.5% male, 59.4 ± 10.8 years old, 65.9% paroxysmal AF) and genome-wide association study and divided them into discovery (n = 891) and replication cohorts (n = 891). All included patients underwent isoproterenol provocation tests and LA voltage mapping. We analyzed the ZFHX3, extra-PV trigger-related factors, and rhythm outcomes.Result: Among 14 single-nucleotide polymorphisms (SNPs) of ZFHX3, rs13336412, rs61208973, rs2106259, rs12927436, and rs1858801 were associated with extra-PV triggers. In the overall patient group, extra-PV triggers were independently associated with the ZFHX3 polygenic risk score (PRS) (OR 1.65 [1.22–2.22], p = 0.001, model 1) and a low LA voltage (OR 0.74 [0.56–0.97], p = 0.029, model 2). During 49.9 ± 40.3 months of follow-up, clinical recurrence of AF was significantly higher in patients with extra-PV triggers (Log-rank p < 0.001, HR 1.89 [1.49–2.39], p < 0.001, model 1), large LA dimensions (Log-rank p < 0.001, HR 1.03 [1.01–1.05], p = 0.002, model 2), and low LA voltages (Log-rank p < 0.001, HR 0.73 [0.61–0.86], p < 0.001, model 2) but not the ZFHX3 PRS (Log-rank p = 0.819).Conclusion: The extra-PV triggers had significant associations with both ZFHX3 genetic polymorphisms and acquired LA remodeling. Although extra-PV triggers were an independent predictor of AF recurrence after AFCA, the studied AF risk SNPs intronic in ZFHX3 were not associated with AF recurrence.

Association of left atrial strain by cardiovascular magnetic resonance with recurrence of atrial fibrillation following catheter ablation

Background Atrial fibrillation (AF) is a progressive condition, which is characterized by inflammation/fibrosis of left atrial (LA) wall, an increase in the LA size/volumes, and decrease in LA function. We sought to investigate the relationship of anatomical and functional parameters obtained by cardiovascular magnetic resonance (CMR), with AF recurrence in paroxysmal AF (pAF) patients after catheter ablation. Methods We studied 80 consecutive pAF patients referred for ablation, between January 2014 and December 2019, who underwent pre- and post-ablation CMR while in sinus rhythm. LA volumes were measured using the area–length method and included maximum, minimum, and pre-atrial-contraction volumes. CMR-derived LA reservoir strain (ℇR), conduit strain (ℇCD), and contractile strain (ℇCT) were measured by computer assisted manual planimetry. We used a multivariate logistical regression to estimate the independent predictors of AF recurrence after ablation. Results Mean age was 58.6 ± 9.4 years, 75% men, mean CHA2DS2-VASc score was 1.7, 36% had prior cardioversion and 51% were taking antiarrhythmic drugs. Patients were followed for a median of 4 years (Q1–Q3 = 2.5–6.2 years). Of the 80 patients, 21 (26.3%) patients had AF recurrence after ablation. There were no significant differences between AF recurrence vs. no recurrence groups in age, gender, CHA2DS2-VASc score, or baseline comorbidities. At baseline, patients with AF recurrence compared to without recurrence had lower LV end systolic volume index (32 ± 7 vs 37 ± 11 mL/m2; p = 0.045) and lower ℇCT (7.1 ± 4.6 vs 9.1 ± 3.7; p = 0.05). Post-ablation, patients with AF recurrence had higher LA minimum volume (68 ± 32 vs 55 ± 23; p = 0.05), right atrial volume index (62 ± 20 vs 52 ± 19 mL/m2; p = 0.04) and lower LA active ejection fraction (24 ± 8 vs 29 ± 11; p = 0.05), LA total ejection fraction (39 ± 14 vs 46 ± 12; p = 0.02), LA expansion index (73.6 ± 37.5 vs 94.7 ± 37.1; p = 0.03) and ℇCT (6.2 ± 2.9 vs 7.3 ± 1.7; p = 0.04). Adjusting for clinical variables in the multivariate logistic regression model, post-ablation minimum LA volume (OR 1.09; CI 1.02–1.16), LA expansion index (OR 0.98; CI 0.96–0.99), and baseline ℇR (OR 0.92; CI 0.85–0.99) were independently associated with AF recurrence. Conclusion Significant changes in LA volumes and strain parameters occur after AF ablation. CMR derived baseline ℇR, post-ablation minimum LAV, and expansion index are independently associated with AF recurrence.

Characteristics of anatomical difficulty for cryoballoon ablation: insights from CT

BackgroundThe limited availability of balloon sizes for cryoballoon leads to anatomical limitations for pulmonary vein (PV) isolation. We conducted a comprehensive systematic analysis on procedural success rate, atrial fibrillation (AF) recurrence rate and complications of cryoballoon ablation in association with the anatomy of the left atrium and PV based on preprocedural CT to gain insights into proper treatments of patients with AF using cryoballoon.MethodA systematic search of literature databases, including PubMed, Web of Science and Cochrane Library, from the inception of each database through February 2021 was conducted. Search keywords included ‘atrial fibrillation’, ‘cryoballoon ablation’ and ‘anatomy’.ResultsOverall, 243 articles were identified. After screening, 16 articles comprising 1396 patients were included (3, 5 and 8 for acute success, AF recurrence and complications, respectively). Regarding acute success and AF recurrences, thinner width of the left lateral ridge, higher PV ovality, PV ostium-bifurcation distance, shorter distance from the non-coronary cusp to inferior PVs, shallower angle of right PVs against the atrial septum and larger right superior PV (RSPV) were associated with poor outcomes. Regarding complications, shorter distance between the RSPV ostium and the right phrenic nerve, larger RSPV-left atrium angle, larger RSPV area and smaller right carina width were associated with incidences of phrenic nerve injury.ConclusionThis study elucidated several key anatomical features of PVs possibly affecting acute success, AF recurrence and complications in patients with AF using cryoballoon ablation. CT analysis has helped to describe benefits and anatomical limitations for cryoballoon ablation.

Safety and Efficacy of Cryoballoon Ablation of Atrial Fibrillation in relation to the Patients’ Age: Results from a Large Real-World Multicenter Observational Project

Background. The real-world efficacy and safety of atrial fibrillation (AF) ablation in particularly young and elderly patients are still under debate. The aim of the analysis was to investigate the effect of age on the efficacy and safety of cryoballoon ablation (CBA). Methods. 2,534 patients underwent pulmonary vein isolation (PVI) by way of CBA for paroxysmal or persistent drug-resistant and symptomatic AF. The population was divided into age quartiles for evaluation, including (1) <53 years, (2) ≥53 and <61 years, (3) ≥61 and <67 years, and (4) ≥67 years. Furthermore, outcomes were analyzed in patients <41 years, ≥41 and ≤74, and >74 years old. Procedural data and complications were collected, and atrial fibrillation recurrences were evaluated during follow-up. Results. Procedural-related complications (4.1%) were similar in the four subgroups according to age. At the 12-month follow-up, freedom from AF recurrence was 79.2%, 77.4%, 76.8%, and 75.2% ( p = 0.21 ), respectively (with increasing age). At 24-month follow-up, similar incidences of AF recurrence were observed in the four subgroups. When the sample was arbitrarily divided into the three age groups, a higher rate of recurrence was observed in older patients with regard to long-term follow-up (freedom from AF recurrence was 71.8% and 40.9%, respectively, at 12 and 24-month follow-up). In the univariate and multivariate analysis, age did not result in a significant predictor of AF recurrence during follow-up; however, a trend toward higher AF recurrences rates in patients ≥67 years was observed. Conclusion. The data demonstrated a high degree of safety during CBA across all patient ages. Procedural performance and complications were similar between different ages; AF recurrences seem to be more frequent in patients over 74 years.

Effects of Acupuncture on Cardiac Remodeling in Patients with Persistent Atrial Fibrillation: Results of a Randomized, Placebo-Controlled, Patient- and Assessor-Blinded Pilot Trial and Its Implications for Future Research

Background and Objectives: In this study, we attempted to determine the effects of acupuncture on cardiac remodeling and atrial fibrillation (AF) recurrence rates in patients with AF after electrical cardioversion (EC). Materials and Methods: We randomly assigned 44 patients with persistent AF to an acupuncture group or a sham acupuncture group. An electroacupuncture treatment session was administered once weekly for 12 weeks at four acupuncture points (left PC5, PC6, ST36, and ST37). Results: Among the 44 recruited participants, 16 (treatment group) and 15 (control group) completed the trial. The three-month AF recurrence rate (primary outcome) was not significantly different between the two groups. Following the completion of treatment, patients who had been treated with acupuncture had a significant reduction in left atrial volume index (42.2 ± 13.9 to 36.1 ± 9.7 mL/m2; p = 0.028), whereas no change in atrial size was observed in the sham acupuncture group. No serious adverse events were observed. The AF recurrence rate and cardiac function did not differ significantly between the two groups. At three months, the acupuncture treatment group showed more favorable atrial structural remodeling compared to the sham acupuncture group. Conclusion: In future research on acupuncture in AF management, it is recommended that the inclusion criteria be amended to include only symptomatic AF, that an appropriate control group is designed, and that the acupuncture treatment frequency is increased to several times per week.

A Novel Alternately Energy Source Strategy for Re-Ablation of Patients with Recurrent Atrial Fibrillation—Cryoballoon or Radiofrequency Current Energy Ablation. A Case-Control Study

Background: Atrial fibrillation recurrence after circumferential pulmonary vein (PV) isolation was common. Which ablation technique is better for repeat ablation in patients with recurrent atrial fibrillation (AF) remains unclear. We aimed to investigate long-term efficacy of repeat ablation using a novel alternately energy source sequence for re-ablation of patients with recurrent atrial fibrillation: cryoballoon (CB) re-ablation for patients with a failed radiofrequency (RFC) ablation (RFC-CB redo group); radiofrequency energy re- ablation for patients with a failed cryoballoon ablation (CB-RFC redo group).Method: Recurrent AF patients received a repeat ablation procedure in our hospital were enrolled into the study. Demographic and re-ablation procedural characteristics and outcomes were compared among groups.Results: A total of 156 patients were enrolled into the study, 60 patients (38.5%) were in the CB-RFC-redo group and 96 patients (61.5%) were in the RFC-CB-redo group. Longer duration of AF (69.31±64.69 vs 50.78 ±51.48 months; P=0.039) and longer time from first ablation to re-ablation (54.02 ±38.10 vs 14.2 ±10.5 months; P=0.001) were observed in the RFC-CB-redo group as compared with the CB-RFC redo group. Early recurrence rates of atrial fibrillation following initial ablation were equal among groups (RFC-CB-redo group: 42.7% vs CB-RFC-redo group:48.3% , p=0.515).The number of reconnected PVs was significantly higher in the RFC-CB redo group than the CB-RFC redo group (3.36 ± 0.96 vs 1.50 ± 0.81, p=0.01). During the average follow-up of 10.7 ±2.41 months, significantly less AF recurrence was observed in the CB-RFC redo group (16.7% vs 31.3%, p=0.045). In the multivariate analysis, different energy ablation sequence, AF type and early recurrence after the initial ablation were independent predictors of AF recurrence after re-ablation.Conclusions: Alternate energy source sequence strategy for re-ablation of patients with recurrent atrial fibrillation was safe and moderately effective. However, Large multi-center studies must be warranted to provide conclusive evidence.

Left Atrial Appendage Circular RNAs Are New Predictors of Atrial Fibrillation Recurrence After Surgical Ablation in Valvular Atrial Fibrillation Patients

Background: Atrial fibrillation (AF) recurrence after ablation will increase mortality and morbidity during follow up. We attempted to evaluate the relationship between circular RNAs (circRNA) and AF recurrence to establish a predictive model for early intervention. Methods: Patients who received surgical ablation retrospectively were analyzed. The expression of circRNAs were detected in the left atrial appendage. The independent risk factors of late recurrence were analyzed by multivariate analysis. The predictive model was visualized by Nomogram and tested by receiver operating characteristic curve and calibration plot. Kaplan-Meier plot was used to compare the rate of freedom from AF recurrence after surgery. The relationships between circRNAs and clinical characteristics were detected by Spearman’s correlation analysis. Results: A total of 136 patients were enrolled from September 2018 to June 2019, 55 patients experienced late recurrence during one-year follow up. Increased age, longer AF duration and increased circ 81906-RYR2, circ 44782-LAMA2, circ 418-KCNN2 and circ 35880-ANO5 were detected in recurrent patients. Multivariate analysis revealed that increased age (odds ratio (OR)=1.072, P = 0.006), longer AF duration (OR=1.007, P = 0.036) and increased circ 81906-RYR2 (OR=2.210, P < 0.001) were independent risk factors for late recurrence. Area under the curve was 0.77, and the cut-off value was 70 points of the predictive model. Kaplan-Meier plots showed that patients over 70 points tended to experience AF recurrence. Conclusion: Circ 81906-RYR2 could be a new predictor of late recurrence after surgical ablation. A predictive model consists of age, atrial fibrillation duration, and circ 81906-RYR2 was alternative for early intervention of AF recurrence.

Influence of characteristics of epicardial adipose tissue and myocardial sympathetic innervation on the development of late recurrence of atrial fibrillation after radiofrequency ablation

Aim. To investigate the relationship between radiological characteristics of epicardial adipose tissue (EAT) and myocardial sympathetic activity, as well as to study their association with late recurrence of atrial fibrillation (AF) after radiofrequency ablation (RFA).Material and methods. This prospective study included 26 people with persistent and long-standing persistent AF scheduled for interventional AF treatment. Before the RFA procedure, all patients underwent cardiac 123I-metaiodobenzylguanidine (123I-MIBG) scintigraphy to assess the myocardial sympathetic innervation and contrast-enhanced cardiac multislice computed tomography to assess pulmonary vein anatomy, left atrial volume, and EAT volume. Clinical follow-up, including 12-lead electrocardiography (ECG) and 24-hour ECG monitoring, was carried out 3, 6 and 12 months after RFA.Results. After the end of follow-up, the patients were divided into two groups: with AF recurrence (group 1, n=8) and without AF recurrence (group 2, n=18). Multivariate logistic analysis found that only the 123I-MIBG washout rate (odds ratio, 1,0943; 95% confidence interval, 1,0138-1,1812) proved to be an independent predictor of late AF recurrence after RFA. ROC analysis revealed that a 123I-MIBG washout rate >21% with a sensitivity of 75% and a specificity of 83,3% (AUC=0,844; p<0,001) predicts late AF recurrence after RFA.Conclusion. Parameters of myocardial sympathetic activity, assessed by 123I-MIBG myocardial scintigraphy, are associated with late AF recurrence after RFA in patients with persistent and long-standing persistent AF. There were no reliable data confirming associations between myocardial sympathetic innervation and radiological EAT indicators, as well as the effect of the latter on the risk of AF recurrence after RFA.

Recurrence of atrial fibrillation after pulmonary vein isolation in dependence of arterial stiffness

Background Arterial stiffness (AS) has emerged as a strong predictor of cardiovascular (CV) diseases. Although increased AS has been described as a predictor of atrial fibrillation (AF), its role as a risk marker for AF recurrence has not yet been elucidated. Methods Patients with AF who underwent pulmonary vein isolation (PVI) were included in this study. Presence of AS was evaluated by measuring aortic distensibility (AD) of the descending aorta by transoesophageal echocardiography. Results In total, 151 patients (mean ± standard deviation (SD) age 71.9 ± 9.8 years) were enrolled and followed for a median duration of 21 months (interquartile range 15.0–31.0). During follow-up, AF recurred in 94 (62.3%) patients. AF recurrence was seen more frequently in patients with permanent AF (27% vs 46%, p = 0.03) and in those who had undergone prior PVI (9% vs 23%, p = 0.02). AD was significantly reduced in patients with AF recurrence (mean ± SD 2.6 ± 2.3 vs 1.5 ± 0.7 × 10−3 mm Hg−1, p < 0.0001), as well as left atrial volume index (LAVI) (mean ± SD 29 ± 12 vs 44 ± 15 ml/m2, p < 0.0001). Multivariable analysis revealed LAVI (odds ratio (OR) 2.9, 95% confidence interval (CI) 1.2–3.4) and AS (OR 3.6, 95% CI 2.8–4.1) as independent risk factors of AF recurrence. Conclusion Increased AS and left atrial size were independent predictors of AF recurrence after PVI. AD as surrogate marker of AS seemed to reflect the overall CV risk. In addition, AD was significantly correlated with left atrial size, which suggests that increased AS leads to atrial remodelling and thus to AF recurrence. Trial registration German registry for clinical studies (DRKS), DRKS00019007.