Analysis of oxidative stress expressed by urinary level of 8-hydroxy-2′-deoxyguanosine and biopyrrin in atrial fibrillation: Effect of sinus rhythm restoration

Background

Oxidative stress is considered to contribute to the pathological consequences of atrial fibrillation (AF). We examined the level of oxidative stress in AF patients and changes in its level following sinus rhythm restoration.

Methods

Oxidative stress level was evaluated by urinary 8-hydroxy-2′-deoxyguanosine (8-OHdG), a biomarker of oxidative DNA damage, and urinary biopyrrin, an oxidative metabolite of bilirubin. In Study 1, we compared 8-OHdG/creatinine levels between patients with permanent AF (AF-group, n = 40) and sinus rhythm (SR-group, n = 133). In Study 2, we examined the changes in 8-OHdG and biopyrrin levels in 36 patients with persistent AF following sinus rhythm restoration by electrical or pharmacological cardioversion (n = 15) and radiofrequency catheter ablation (n = 21).

Results

In Study 1, 8-OHdG/creatinine levels were significantly higher in AF-group than in SR-group (19.1 ± 8.6 vs. 12.3 ± 5.5 ng/mg, p < 0.001). Multivariate analysis showed that the presence of AF was an independent factor that significantly correlated with 8-OHdG/creatinine level after adjustment for other covariates to oxidative stress (β = 0.36, p < 0.001). Sinus rhythm was maintained at the chronic phase in patients of all Study 2 (7.2 ± 5.8 months after cardioversion or catheter ablation). 8-OHdG/creatinine and biopyrrin/creatinine levels at the chronic phase were significantly lower than those before cardioversion or catheter ablation (8.7 ± 3.2 vs. 21.7 ± 15.1 ng/mg, p < 0.0001 and 1.7 ± 1.1 vs. 3.0 ± 1.9 mU/mg, p < 0.0001).

Conclusions

Oxidative stress level is significantly increased in AF patients, but can be improved by restoration of sinus rhythm. The results suggest that the pathogenic process of AF is promoted by AF itself through the production of oxidative stress.     

Calreticulin overexpression correlates with integrin-α5 and transforming growth factor-β1 expression in the atria of patients with rheumatic valvular disease and atrial fibrillation

Objectives

The aim of this study was to determine whether altered calreticulin expression and distribution contribute to the pathogenesis of atrial fibrillation (AF) associated with valvular heart disease (VHD).

Background

AF affects electrophysiological and structural changes that exacerbate AF. Atrial remodeling reportedly underlies AF generation, but the precise mechanism of atrial remodeling in AF remains unclear.

Methods

Right and left atrial specimens were obtained from 68 patients undergoing valve replacement surgery. The patients were divided into sinus rhythm (SR; n = 25), paroxysmal AF (PaAF; n = 11), and persistent AF (PeAF; AF lasting > 6 months; n = 32) groups. Calreticulin, integrin-α5, and transforming growth factor-β1 (TGF-β1) mRNA and protein expression were measured. We also performed immunoprecipitation for calreticulin with either calcineurin B or integrin-α5.

Results

Calreticulin, integrin-α5, and TGF-β1 mRNA and protein expression were increased in the AF groups, especially in the left atrium in patients with mitral valve disease. Calreticulin interacted with both calcineurin B and integrin-α5. Integrin-α5 expression correlated with TGF-β1 expression, while calreticulin expression correlated with integrin-α5 and TGF-β1 expression. Despite similar cardiac function classifications, calreticulin expression was greater in the PeAF group than in the SR group.

Conclusions

Calreticulin, integrin-α5, and TGF-β1 expression was increased in atrial tissue in patients with AF and was related to AF type, suggesting that calreticulin is involved in the pathogenesis of AF in VHD patients.     

Post-shock sinus node recovery time is an independent predictor of recurrence after catheter ablation of longstanding persistent atrial fibrillation

Background

Electro-anatomical remodeling of the atria has been reported to be associated with sinus node dysfunction in patients with atrial fibrillation (AF). We hypothesized that post-shock sinus node recovery time (PS-SNRT: the time from cardioversion to the earliest sinus node activation) is related to the degree of left atrial (LA) remodeling and the clinical outcome of radiofrequency catheter ablation (RFCA) in patients with longstanding persistent AF (L-PeAF).

Methods and results

We included 117 patients with L-PeAF (82.0% males, 55.4 ± 10.7 years old) who underwent RFCA. PS-SNRTs were measured after internal cardioversion (serial shocks 2, 3, 5, 7, 10, and 15 J) before RFCA. All patients underwent the same ablation design, and we compared regional LA volume (3D-CT imaging) and LA voltage (NavX). Results: 1. During the 13.5 ± 5.8-month follow-up period, it was noted that the patients with recurrent AF 3 months after RFCA (n = 31) had longer PS-SNRTs (1622.90 ± 1196.92 ms vs. 1112.53 ± 690.68 ms, p = 0.005) and greater anterior LA volume (p = 0.032) than those who remained in sinus rhythm. 2. The patients with PS-SNRT ≥ 1100 ms showed lower AF-free rates (58.3%) compared to those with PS-SNRT < 1100 ms (89.5%, p < 0.001). However, shock energy, number of cardioversion, and LA volume were not different between two groups. 3. Multivariate Cox regression analysis demonstrated PS-SNRT ≥ 1100 ms was a significant predictor of clinical recurrence of AF (HR 5.426, 95% CI 2.099–14.028, p < 0.001).

Conclusion

In patients with L-PeAF, prolonged PS-SNRT is an independent predictor of clinical recurrence of AF after RFCA, but not closely associated with electro-anatomical remodeling of LA.     

Efficiency of radiofrequency ablation for surgical treatment of chronic atrial fibrillation in rheumatic valvular disease

Background

It remains unclear whether concomitant radiofrequency ablation procedure in valvular surgery could offer additional benefits to patients with rheumatic valvular disease. We designed a prospective and randomized control study to evaluate the efficacy of surgical radiofrequency ablation in patients with rheumatic heart disease.

Methods

From June 2008 to July 2011, 210 patients with chronic atrial fibrillation and rheumatic heart disease were randomized: (1) control group, patients underwent only valve replacement followed by amiodarone for rhythm control, (2) left atrial group (LA group), patients underwent valve replacement and left atrial mono-polar radiofrequency ablation, (3) bi-atrial group (BA group), patients underwent valve replacement and bi-atrial mono-polar radiofrequency ablation. The primary endpoints included: cardiac death, stroke, and recurrent AF after discharge.

Results

There was no perioperative death. One patient died 4 months after MVR in BA group. In univariate Cox analysis, the two ablation groups were associated with less AF (BA group vs control group: P < 0.001; LA group vs control group: P < 0.001) as well as atrial tachycardia arrhythmia (AF/AT/AFL) recurrent (BA group vs control group: P < 0.001; LA group vs control group: P = 0.02). The comparison between BA and LA groups revealed no differences in terms of AF (P = 0.06) or AF/AT/AFL (P = 0.09). Atrial transport function restoration rate 12 months after operation was 31.4% in LA group, 32.9% in BA group, and 8.6% in control group respectively (P < 0.01).

Conclusions

Radiofrequency ablation concurring with valvular surgery can bring a higher sinus rhythm restoration rate when compared with medical anti-arrhythmic drug therapy in low-medium risk rheumatic heart disease.The trial was registered on Clinicaltrials.gov (registry number NCT01013688).     

Don't move during ablation of atrial fibrillation!

Background

Restless patient is recalcitrant during ablation of atrial fibrillation (AF). We aimed to assess the association between patient movements during AF ablation and its outcome.

Methods

We examined the body movement during AF ablation in 78 patients with the use of a novel portable respiratory monitor, the SD-101, which also has the ability to quantify the frequency of body movements.

Results

The body movement index, defined as the number of the units of time with body movement events divided by the recording time (11.4 ± 6.5 events/h), was significantly correlated with the ablation time defined as the time from the first point of the ablation to the end of the procedure (1.2 ± 0.3 h) (r = 0.35; p = 0.0014) and a total radiofrequency energy applied (56.6 ± 17.7 kW) (r = 0.36; p = 0.0015). A multiple linear regression analysis showed that non-paroxysmal AF (β = 0.25; p = 0.036) and the body movement index (β = 0.36; p = 0.0019) were independent determinants of the ablation time. The body movement index was similar in patients with and without recurrence of AF.

Conclusions

Keeping patients motionless may be important to reduce the procedural duration of AF ablation.     

Variations in the human soluble epoxide hydrolase gene and recurrence of atrial fibrillation after catheter ablation

Background

Single nucleotide polymorphisms (SNPs) of EPHX2 alter sEH activity and are associated with increased [rs41507953 (K55R)] or reduced [rs751141 (R287Q)] cardiovascular risk via modulation of fibrosis, inflammation or cardiac ion channels. This indicates an effect on development and therapy response of AF. This study tested the hypothesis that variations in the EPHX2 gene encoding human soluble epoxide hydrolase (sEH) are associated with atrial fibrillation (AF) and recurrence of atrial fibrillation after catheter ablation.

Methods and results

A total of 218 consecutive patients who underwent catheter ablation for drug refractory AF and 268 controls were included. Two SNPs, rs41507953 and rs751141, were genotyped by direct sequencing. In the ablation group, holter recordings 3, 12 and 24 months after ablation were used to detect AF recurrence. No significant association of the SNPs and AF at baseline was detected. In the ablation group, recurrence of AF occurred in 20% of the patients 12 months after ablation and in 35% 24 months after ablation. The presence of the rs751141 polymorphism significantly increased the risk of AF recurrence 12 months (odds ratio [OR]: 3.2, 95% confidence interval [CI]: 1.237 to 8.276, p = 0.016) and 24 months (OR: 6.076, 95% CI: 2.244 to 16.451, p < 0.0001) after catheter ablation.

Conclusions

The presence of rs751141 polymorphism is associated with a significantly increased risk of AF recurrence after catheter ablation. These results point to stratification of catheter ablation by genotype and differential use of sEH-inhibitory drugs in the future.     

Benefits and risks of additional ablation of complex fractionated atrial electrograms for patients with atrial fibrillation: A systematic review and meta-analysis

Background

The benefits and risks of additional complex fractionated atrial electrograms (CFAE) ablation in patients with atrial fibrillation (AF) remain unclear.

Methods

Trials were identified in PubMed, Embase, Web of Science, and Cochrane Database, reviews, and reference lists of relevant papers. The primary end point was the recurrence of atrial arrhythmias after a single ablation.

Results

We meta-analyzed 11 studies (total, n = 983) using random-effects model to compare PVI (n = 478) with PVI plus CFAE ablation (PVI + CFAE) (n = 505). Additional CFAE ablation reduced recurrence of atrial tachyarrhythmia after a single procedure (pooled RR 0.73; 95% CI 0.61, 0.88; P = 0.0007) at ≥ 3-month follow-up. There was no evidence of heterogeneity among studies (I² = 33%). Subgroup analysis demonstrated that additional CFAE ablation reduced rates of recurrence in nonparoxysmal AF (RR 0.68; 95% CI 0.47, 0.99; P = 0.05), whereas had no effect on patients with paroxysmal AF (RR 0.79; 95% CI 0.59, 1.06; P = 0.12). Eight studies reported results of post-procedure ATs. The addition of CFAE ablation increased the rate of post-procedure ATs (RR 1.77; 95% CI 1.02, 3.07; P = 0.04). Additional CFAE ablation significantly increased mean procedural times (245.4 + 75.7 vs. 189.5 + 62.3 min, P < 0.001), mean fluoroscopy (72.1 + 25.6 vs. 59.5 + 19.3 min, P < 0.001), and mean RF energy application times (75.3 + 38.6 vs. 53.2 + 27.5 min, P < 0.001).

Conclusions

The adjunctive CFAE ablation could provide additional benefit in terms of reducing recurrence of atrial tachyarrhythmia for patients with nonparoxysmal AF but not for patients with paroxysmal AF after a single procedure with or without antiarrhythmic drugs (AADs). The main risk of adjunctive CFAE ablation is the increasing rate of untraceable postablation ATs.     

Prevalence and predictors of worsened left ventricular diastolic dysfunction after catheter ablation of atrial fibrillation

Background

The interactions between atrial fibrillation (AF) and left ventricular diastolic dysfunction (LVDD) are complex and not well defined. Despite the high prevalence of LVDD in the AF population, therapies for LVDD remain limited. Previous studies have suggested that restoration of sinus rhythm with catheter ablation has a positive effect on LVDD, but the prevalence and predictors for worsened LVDD are unknown.

Methods

70 consecutive patients included in prospective AF catheter ablation registry (61 ± 10 years, 66% male) with paroxysmal (n = 40) or persistent AF (n = 30) were examined by transthoracic echocardiography, before and 12 months after ablation. LVDD was classified according to current guidelines. Rhythm outcome of the ablation was verified by serial 7-day Holter ECG.

Results

LVDD was present in 27 patients (38%) at baseline and in 33 patients (47%) at 12 months follow-up (p = .327). An improvement of LVDD was observed in 13 patients (19%), an aggravation was found in 19 (27%), while it was unchanged in the remaining 38 patients (54%). In uni- and multivariable regression analysis, total ablation time (OR 1.611 per 10 min ablation time, 95% CI 1.088 – 2.386, p = .017) was associated with LVDD progression, while neither baseline characteristics nor rhythm during follow-up influenced LVDD alterations. There was no association between echocardiographic deterioration and symptoms.

Conclusions

Catheter ablation of AF can worsen LVDD in a substantial proportion of patients with more aggressive ablation leading to aggravation of LVDD. While there are no apparent negative short-term effects, long-term consequences need to be determined.     

Does the amount of atrial mass reduction improve clinical outcomes after radiofrequency catheter ablation for long-standing persistent atrial fibrillation? Comparison between linear ablation and defragmentation

Background

Although a large isolated surface area of the left atrium (LA) may improve the success rate of catheter ablation (CA) for paroxysmal atrial fibrillation (AF), little is known about the relation between clinical outcomes and the amount of atrial mass reduction (AMR: ratio of total isolated and ablated areas to LA surface area) in different ablation strategies for patients with long-standing persistent AF (L-PeAF).

Methods

We randomly assigned 119 consecutive L-PeAF patients to adjunctive linear ablation (n = 60) or complex fractionated atrial electrogram (CFAE)-guided ablation (n = 59) after circumferential antral pulmonary vein isolation (PVI). Linear lesions included roof and anterior lines with conduction block. LA defragmentation was performed with an automated CFAE-detection algorithm. Cavotricuspid isthmus block was performed in all patients. Creatine kinase-MB (CK-MB) and troponin-T levels were measured 1 day post-CA.

Results

CK-MB and troponin-T levels were higher, ablation time was longer, and AMR was greater in the CFAE-guided ablation group than in the linear ablation group. AF termination during CA was more frequently observed in the linear ablation group than in the CFAE-guided ablation group (P = 0.031). Twelve months after a single procedure, recurrence occurred in 16 (26.7%) patients with linear ablation and 27 (45.8%) patients with CFAE-guided ablation (P = 0.023). On multivariate analysis, LA volume and ablation method were the only independent risk factors for arrhythmia recurrence.

Conclusion

Conduction block through linear lines + PVI was an efficient ablation strategy for L-PeAF, whereas the AMR amount did not influence clinical outcomes.     

Failure of hybrid therapy for the prevention of long-term recurrence of atrial fibrillation

Objectives

To determine the long-term effectiveness of hybrid therapy in the control of atrial fibrillation (AF) as well as the differences in clinical outcomes between patients with antiarrhythmic drug atrial flutter (AAD-AFl), those with coexistent AFl and AF, and isolated AFl.

Methods

Four hundred eight patients who consecutively underwent cavotricuspid isthmus (CTI) ablation between 1998 and 2010 were followed for 5.9 years. Twenty-seven patients had AAD-AF1 (Group 1): they had AF but not AFl at baseline but on AAD therapy they showed typical AFl. They underwent CTI ablation and continued with AAD therapy, 96 patients had coexistent AF1 and AF at baseline (Group 2) and continued with AAD therapy at the discretion of their cardiologists and 284 patients had isolated AFl (Group 3).

Results

AF recurred in the majority of the AAD-AF1 patients (74%, incident density rate (IDR): 19.1/100 person-years). This incidence rate was similar to the recurrence rate of AF in patients with coexistent AFl and AF (59%, IDR: 19.2/100 person-years). The patients in Group 1 had a similar IDR of stroke as Group 2 and a slightly higher rate than Group 3. There were no significant differences in the IDR for death among Groups 1, 2 and 3.

Conclusions

Hybrid therapy was not effective for long-term control of AF. The clinical outcomes (AF, stroke and death) were similar for AAD-AF1 patients and patients with coexistent AF and AFl.     

Does linear ablation and defragmentation really improve the success rate of persistent AF? Follow-up results and electrophysiological findings from 169 consecutive patients

Background

Catheter ablation of persistent atrial fibrillation (AF) has been performed with varying results using a combination of different techniques. We sought to evaluate the efficacy of additional linear lesion and defragmentation of left atrium (LA).

Methods

A cohort of 169 patients with persistent AF was studied. Ablation was performed following a sequential strategy consisted of circumferential pulmonary vein isolation (CPVI), LA roof linear ablation, posterior mitral area, coronary sinus and cavotricuspid isthmus, and complex fractionated electrograms ablation.

Results

During a mean follow-up of 15 ± 8 months after a single procedure, 84 (50%) patients were in sinus rhythm, 34 (20%) had an AF recurrence and 51(30%) developed atrial tachycardias (ATs). Repeat procedures were performed in 24 recurrent AF and 46 AT patients. A total of 81 different ATs were mapped and ablated in 46 AT patients, characterized as focal for 45 and macroreentry for 36 ATs. Most of the ATs were likely to be attributed to the previous lesions by an analysis of substrate and activation mapping in the redo procedure and a review of the lesions placed in the initial procedure. Overall, 75 (93%) ATs were ablated successfully. Procedural complications occurred in 11 of the 239 procedures. After a mean follow-up of 20 ± 9 months, 128 (76%) patients were free of arrhythmias after the final procedure.

Conclusions

CPVI supplemented by linear ablation and defragmentation does not seem to improve the overall success rate of persistent AF. The efficacy of linear ablation and defragmentation might be diluted by their proarrhythmic effects.     

Comparison of catheter ablation and surgical ablation in patients with long-standing persistent atrial fibrillation and rheumatic heart disease: A four-year follow-up study

Background

In our previous prospective and randomized study, we have demonstrated that the concomitant surgical ablation using saline-irrigated cooled tip radiofrequency ablation (SICTRA) system is more effective than subsequent circumferential pulmonary vein isolation (CPVI) combined with substrate modification in treating patients with long-standing persistent atrial fibrillation (LS-AF) and rheumatic heart disease (RHD) undergoing cardiac surgery during middle-term follow-up. Whether this strategy also decreases longer-term arrhythmia recurrence is unknown. This study describes the 4-year efficacy of SICTRA for these patients. Furthermore, we seek to compare the electrophysiological characteristics for recurrent atrial tachyarrhythmia (ATa) at the session of catheter ablation between two groups.

Methods

Long-term follow-up was performed in 95 patients who underwent the catheter ablation strategy (n = 47, Group A) or SICTRA (n = 48, Group B) combined with valvular surgery for symptomatic LS-AF patients with RHD.

Results

After one procedure, Group B had a significantly higher freedom from ATa compared with Group A (29/48 vs 15/47, P = 0.005) after a mean follow-up of 54 months (range 48 to 63 months). Catheter-based mapping and ablation of recurrent ATa showed larger amounts of macro-reentrant atrial tachycardias (ATs) in Group B and higher incidence of pulmonary vein (PV) recovery in Group A. After multiple catheter ablations for recurrent ATa, sinus rhythm (SR) could be maintained equally between two groups.

Conclusions

Single procedure success seems to be higher with SICTRA but repeated catheter ablation potentially results in comparable outcomes in treating patients with LS-AF and RHD during long-term follow-up. More macro-reentrant ATs and more PV recoveries are identified to be responsible for ATa in SICTRA and catheter ablation group, respectively.     

Serum sRANKL/OPG predict recurrence after radiofrequency catheter ablation of lone atrial fibrillation

Background

Radiofrequency catheter ablation (RFCA) is a widely accepted strategy for eliminating atrial fibrillation (AF). A considerable recurrence rate has partly been ascribed to atrial remodeling. Osteoprotegerin (OPG)/receptor activator of nuclear factor-κB (RANK)/RANK ligand (RANKL) axis may contribute to the development and progression of AF by regulating atrial structural remodeling. This study aimed to determine the relationship between serum soluble RANKL (sRANKL)/OPG and the risk of recurrent arrhythmia after ablation of lone AF.

Methods

We enrolled 527 lone AF patients undergoing first-time RFCA with complete follow-up data. Pre-ablation venous blood samples were obtained for measurement of serum sRANKL and OPG.

Results

During the follow-up period of 15 (3–64) months, AF recurred in 187 patients (35.5%). Recurrence was associated with an elevation of serum sRANKL level and sRANKL/OPG ratio. In multivariate survival regression, persistent AF, AF duration, left atrial diameter, amiodarone after ablation, particularly serum sRANKL level and sRANKL/OPG ratio independently predicted AF recurrence. According to ROC curve analysis, the best diagnostic values of serum sRANKL level and sRANKL/OPG ratio for predicting recurrence were 4.89 pmol/l and 0.76, respectively.

Conclusions

Baseline serum high sRANKL level and sRANKL/OPG ratio are associated with AF recurrence after primary ablation procedure in lone AF patients, and may be used in the prediction of AF recurrence in these patients.     

A proposal for a new scoring system in the prediction of catheter ablation outcomes: Promising results from the Turkish Cryoablation Registry

Background

Although cryoballoon based catheter ablation is an effective therapeutic option in atrial fibrillation (AF), a significant amount of patients failed to remain in sinus rhythm at long term follow-up. Appropriate selection of patients for catheter ablation reduces unnecessary interventions and prevents complications related with catheter ablation. The purpose of our study is to propose a new scoring system in the prediction of recurrence after AF ablation with cryoballoon.

Method

A total of 236 patients (54% male, age 54.6 ± 10.45 years and 79.6% paroxysmal) with symptomatic AF underwent an index cryoablation. The first 3 months after AF ablation is defined as blanking period. Predictors of AF recurrence after cryoablation were analyzed with multivariate Cox regression analysis. BASE-AF₂ score [acronym stands for Body mass index > 28 kg/m² (1); Atrial dilatation > 40 mm (1); current Smoking (1); Early recurrence (1); duration of AF history > 6 years (1) and non-paroxysmal type (1) of AF] is identified by the total number of significant predictors of recurrence in each patient (range = 0–6).

Results

At median 20 (range: 12–30) months follow-up, 74.5% of the patients were free from AF recurrence. Of these patients, 64 (27.1%) patients had a BASE-AF₂ score of ≥ 3. Patients with AF recurrence had a higher mean BASE-AF₂ score (3.27 ± 0.82 vs. 1.1 ± 0.95, p < 0.001) compared to patients without AF recurrence. ROC analysis showed that a BASE-AF₂ score of ≥ 3 well predicted AF recurrence with a sensitivity of 80.8% and a specificity of 91.6% (AUC = 0.94; 95% CI: 0.89–0.97, p < 0.001). A BASE-AF₂ score of ≥ 3 was found to be an independent predictor of AF recurrence (HR: 3.34, 95% CI: 2.34–4.76, p = 0.001).

Conclusion

BASE-AF₂, which was identified as a new scoring system, has well predicted AF recurrence and could be helpful in selecting appropriate patients for interventional strategy.     

Importance of pericardial fat in the formation of complex fractionated atrial electrogram region in atrial fibrillation

Background/Objectives

Pericardial fat (PF) and complex fractionated atrial electrogram (CFAE) are both associated with atrial fibrillation (AF). Therefore, we examined the relation between PF and CFAE area in AF.

Methods

The study population included 120 control patients without AF and 120 patients with AF (80 paroxysmal AF and 40 persistent AF) who underwent catheter ablation. Total cardiac PF volume, representing all adipose tissue within the pericardial sac, was measured by contrast-enhanced computed tomography. The location and distribution of CFAE region were identified by left atrial endocardial mapping using a three-dimensional mapping system. We analyzed the significance of total cardiac PF volume and total area of CFAE region on AF, persistence of AF from paroxysmal to persistent form, and the relation between total cardiac PF volume and total CFAE area. We also evaluated the regional distribution of PF volume and CFAE area in five areas of the left atrium (LA).

Results

Total cardiac PF volume correlated with AF (odds ratio [OR]: 1.024, p < 0.001). Total cardiac PF volume and total CFAE area were both independently associated with persistence of AF (OR: 1.018, p = 0.018, OR: 1.144, p = 0.002, respectively). Multivariate linear regression analysis identified total cardiac PF volume as a significant and independent determinant of total CFAE area (r = 0.488, p < 0.001). Furthermore, regional PF volume correlated with local CFAE area in an each LA area.

Conclusions

PF volume correlated significantly with CFAE area in patients with AF. This finding suggests that PF is directly related to the progression of CFAE area and promotes the pathogenic process of AF.     

Midterm results of left atrial bipolar radiofrequency ablation combined with a mitral valve procedure in persistent atrial fibrillation

Introduction

The aim of the study was to assess the midterm results of left atrial bipolar radiofrequency ablation combined with a mitral valve procedure in patients with mitral valve disease and persistent atrial fibrillation.

Methods

Between October 2006 and July 2009, 95 patients with mitral valve disease and persistent atrial fibrillation underwent a mitral valve procedure and left atrial bipolar radiofrequency ablation. The postoperative data of the combined procedure were collected at the time of discharge and at one, three, six and 12 months after the operation.

Results

Hospital mortality rate was 6.3% (six patients). Normal sinus rhythm was achieved in 77.2% of patients during the early postoperative period in hospital, and in 73.3, 72.0 and 75% of patients at three, six and 12 months postoperatively, respectively. Patients were followed up for a mean duration of 14.02 ± 5.71 months (range: 6–19 months). During this midterm follow-up period, nine patients had late recurrence of atrial fibrillation. No risk factor was identified for late recurrence of atrial fibrillation.

Conclusion

Our midterm follow-up results suggest that the addition of left atrial bipolar radiofrequency ablation to mitral valve surgery is an effective and safe procedure to restore sinus rhythm in patients with chronic atrial fibrillation.     

Differences in catheter ablation of paroxysmal atrial fibrillation between males and females

Background

Catheter ablation (CA) has become a standard treatment for patients with atrial fibrillation (AF). However, gender-related differences associated with CA of paroxysmal AF (PAF) remain unclear.

Methods

We compared 1124 consecutive patients (mean age, 61 ± 10 years; male, n = 864) with PAF scheduled for CA between the genders.

Results

Females were significantly older (p < 0.0001), and had a lower body-mass-index (p = 0.02), smaller left atrial dimension (LAD; p = 0.04), larger LAD indexed by the body-surface-area (LADI; p < 0.0001) and better left ventricular ejection fraction (p < 0.0001) at baseline. Ischemic heart disease (p = 0.007) was more frequent in males, whereas hypertrophic cardiomyopathy (p = 0.007) and mitral stenosis (p = 0.001) were more frequent in females. More additional procedures were performed to eliminate non-pulmonary vein foci in females than males (p < 0.05), but those locations were similar between the genders. The incidence of procedure-related complications was similar between genders (p = 0.73). Sinus rhythm was similarly maintained between females and males after the first CA (56.4% vs. 59.3% at 5 years, p = 0.24), but was significantly lower in females after the last CA (76.5% vs. 81.3% at 5 years, p = 0.007). More females did refuse multiple CA procedures (especially a second one) than males (37.8% in females vs. 27.4% in males, p = 0.02). The age (HR, 0.98/y, p = 0.01), duration of AF (HR, 1.04/y, p = 0.0001), number of failed anti-arrhythmic-drugs (HR, 1.10, p = 0.03) and LADI (HR, 1.89 per 10 mm/m², p = 0.001) were significantly associated with AF-recurrence in males, but not in females.

Conclusions

Specific differences and similarities between the genders were observed in PAF patients undergoing CA.     

Adherence to guidelines and mortality in atrial fibrillation

Objective

Determining the adherence to ACC/AHA/ESC 2006 guidelines and its influence on the survival of patients with atrial fibrillation.

Methods

Prospective observational study of patients discharged during 2007 from an Internal Medicine department with a main or secondary diagnose of atrial fibrillation. The stroke risk was estimated with the CHADS₂ score. The follow-up was carried out in outpatient medical office or via telephone.

Results

We included 259 patients (mean age 80.9 years); 73% of them had a high risk of stroke. Oral anticoagulants were administered to 134 (51.7%), and antiplatelet drugs to 71 (27%) patients. A rate control strategy was chosen for 155 (59.8%) patients and a rhythm control one for 28 (10.8%). In 100 (38.6%) patients, treatment was adherent to the guidelines. Adherence to the guidelines was associated with age (0.95 95%CI 0.92–0.99; p = 0.03), contraindication to the use of oral anticoagulants (0.38 95%CI 0.18–0.81; p = 0.01) and mitral valve heart disease/valvular prosthesis (2.10 95%CI 1.04–4.25; p = 0.04). The median follow-up was 727 days, and 191 patients died. Patients treated according to the guidelines had a higher rate of survival during the first three years (0.47 vs. 0.36; p = 0.049). The use of oral anticoagulants was associated with a higher probability of survival over a 5 year period (0.34 vs 0.21; p = 0.001) and the rate control strategy during the first year (0.69 vs 0.57; p = 0.04).

Conclusions

In the real world, the treatment of atrial fibrillation according to the guidelines is associated with improved survival for up to three years during follow-up.     

A novel individualized substrate modification approach for the treatment of long-standing persistent atrial fibrillation: Preliminary results

Background

The most effective approach for long-standing persistent atrial fibrillation (LPAF) ablation remained undetermined. Our goal was to explore the heterogeneous left atrial substrate in patients with LPAF and to evaluate the effectiveness of a novel individualized substrate modification (ISM) approach in LPAF ablation.

Methods

One hundred and twenty-four patients with LPAF were randomized to ISM group (n = 64) or stepwise ablation (SA) group (n = 60). After pulmonary vein isolation, ISM was performed in the ISM group and SA was applied in the SA group. The clinical effectiveness after a single and a repeated procedure was compared.

Results

The total procedural time was significantly shorter in ISM than that in SA. In the ISM group, mild left atrial substrate was observed in 17 (27.4%), moderate in 26 (41.9%) and severe in 19 (30.6%) patients after successful cardioversion of the 62 patients. The intention-to-treat analysis showed that sinus rhythm was maintained in 65.5% of patients in the ISM group and in 45.0% of patients in the SA group after a single procedure, P = 0.04. Atrial tachycardia (AT) recurred in 5 of 22 in the ISM group and in 20 of 33 in the SA group, P = 0.01. After a repeated procedure, 75% of patients in the ISM group and 63.3% of patients in the SA group were free of further recurrence, P = 0.16.

Conclusions

Left atrial substrate varied noticeably in patients with LPAF. The ISM approach was superior to SA approach in terms of procedural time, recurrence rate of AT and clinical effectiveness after a single procedure. However, they yielded comparable outcomes after a repeated procedure.     

Short stature and ischemic stroke in nonvalvular atrial fibrillation: New insight into the old observation

Background

For decades, repeated epidemiologic observations have been made regarding the inverse relationship between stature and cardiovascular disease, including stroke. However, the concept has not been fully evaluated in patients with atrial fibrillation (AF). We investigated whether patient’s height is associated with ischemic stroke in patients with nonvalvular AF and attempted to ascertain a potential mechanism.

Methods

All 558 AF patients were enrolled: 211 patients with ischemic stroke (144 men, 68 ± 10 years) and 347 no-stroke patients (275 men, 56 ± 11 years) as a control group. Clinical characteristics and echocardiographic parameters were compared between the two groups.

Results

(1) Stroke patients were shorter than those in the control group (164 ± 8, vs. 169 ± 8 cm, p < 0.001). However, body mass index failed to predict ischemic stroke; (2) Short stature (OR 0.93, 95% CI 0.91– 0.95, p < 0.001) along with left atrial (LA) anterior-posterior diameter and diastolic mitral inflow velocity (E) to diastolic mitral annuls velocity (E’) (E/E’) were independent predictor of stroke; (3) Height showed inverse correlation with E/E’ independently, even after adjusting for other variables, including age, sex, and body weight, and comorbidities β − 0.20, p = 0.003); (4) LA size showed no correlation with stature (R = − 0.06, p = 0.18), whereas left ventricular size increases according to height of patients.

Conclusions

Short stature is associated with occurrence of ischemic stroke and diastolic dysfunction in patients with AF and preserved systolic function. Height is a non-modifiable risk factor of stroke and might be more important than obesity in Asian AF patients, who are relatively thinner than western populations.