Shaohui Wu

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 (I(2)=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.

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.

The impact of age on the efficacy and safety of catheter ablation for long-standing persistent atrial fibrillation

BACKGROUND Catheter ablation (CA) has been the most effective treatment for both paroxysmal and persistent atrial fibrillation (AF). However, the impact of age on CA for persistent AF is not well defined. METHODS Between January 2010 and August 2011, 258 consecutive patients (85 females, 32.9%), with long-standing persistent AF who underwent CA were prospectively recruited. Age-related differences in clinical presentation, peri-procedural complications, and outcomes were compared. RESULTS The study population included 258 patients (85 females, 32.9%): 71 patients in Group I (≤ 55 years), 89 patients in Group II (56-65 years), and 98 patients in Group III (≥ 66 years). Younger patients were more likely to have lone AF (49.3% in Group I, 32.6% in Group II, and 30.6% in Group III; P = 0.029). There was a significant difference in the success rate with advancing age after a single CA (69.0% in Group I, 50.6% in Group II, 40.8% in Group III; P = 0.001). A Cox regression analysis demonstrated age (for each 10 years increase, HR 1.307, CI 1.081-1.580; P = 0.006), sex (HR 1.460, CI 1.017-2.097; P = 0.040) and total AF duration (per year, HR 1.033, CI 1.006-1.060; P = 0.015) as the independent predictors for recurrence after the first CA. However, there was no significant difference in the incidence of peri-procedural complications among the three groups. CONCLUSIONS In this consecutive series of patients with long-standing persistent AF, female gender, total AF duration and advanced age were associated with the success of a single CA. The overall rate of complications was similar among all age groups.

The role of valvular regurgitation in catheter ablation outcomes of patients with long-standing persistent atrial fibrillation

AIMS The role of valvular regurgitation (VR) in outcomes of patients obtaining current ablation endpoints with long-standing persistent atrial fibrillation (LS-AF) was evaluated. METHODS AND RESULTS In all, 216 consecutive patients obtaining current ablation endpoints with LS-AF were studied. A standard two-dimensional and Doppler transthoracic echocardiography (TTE) was performed in every patient before the procedure. The presentation and the grade of mitral regurgitation (MR), tricuspid regurgitation, and aortic regurgitation were evaluated. The clinical characteristics, TTE, and procedural characteristics were compared between the sinus rhythm group and the recurrent atrial tachyarrhythmia (ATa) group. After a follow-up of 18.9 ± 2.7 months, there were 48 patients in the ATa group. The patients in the ATa group had greater MR, longer AF duration, and larger left atrium (LA). In multivariate analyses, MR, LA size, and AF duration were independent predictors of recurrent ATa. The grades of MR severity were correlated with the rate of recurrent ATa, and more severe grade of MR indicated more recurrent ATa. Compared with the patients with organic MR, the patients with functional MR had a lower rate of recurrent ATa and lesser degrees of MR. CONCLUSION In the three types of VR, MR was associated with recurrent ATa after AF ablation. Patients with ATa recurrence had more severe MR and greater organic MR.

Atrial Substrate Modification in Atrial Fibrillation: Targeting GP or CFAE? Evidence from Meta-Analysis of Clinical Trials.

Several clinically relevant outcomes post atrial substrate modification in patients with atrial fibrillation (AF) have not been systematically analyzed among published studies on adjunctive cardiac ganglionated plexi (GP) or complex fractionated atrial electograms (CFAE) ablation vs. pulmonary vein isolation (PVI) alone. Out of 176 reports identified, the present meta-analysis included 14 randomized and non-randomized controlled trials (1613 patients) meeting inclusion criteria. Addition of GP ablation to PVI significantly increased freedom from atrial tachyarrhythmia in short- (OR: 1.72; P = 0.003) and long-term (OR: 2.0, P = 0.0006) follow-up, while adjunctive CFAE ablation did not after one or repeat procedure (P<0.05). The percentage of atrial tachycardia or atrial flutter (AT/AFL) after one procedure was higher for CFAE than GP ablation. In sub-analysis of non-paroxysmal AF, relative to PVI alone, adjunctive GP but not CFAE ablation significantly increased sinus rhythm maintenance (OR: 1.88, P = 0.01; and OR:1.24, P = 0.18, respectively). Meta regression analysis of the 14 studies indicated that sample size was significant source of heterogeneity either in outcomes after one or repeat procedure. In conclusion, in patients with AF, adjunctive GP but not CFAE ablation appeared to significantly add to the beneficial effects on sinus rhythm maintenance of PVI ablation alone; and CFAE ablation was associated with higher incidence of subsequent AT/AFL.

The role of superior vena cava in catheter ablation of long-standing persistent atrial fibrillation

Aims The superior vena cava (SVC) has been established as an important source of atrial fibrillation (AF). The role of SVC in long-standing persistent AF and the efficacy of empiric electrical isolation of the SVC are still unclear. The purpose of this study was to judge the role of SVC in catheter ablation of long-standing persistent AF. Methods and results A total of 102 consecutive patients with long-standing persistent AF were enrolled. All patients underwent circumferential pulmonary vein isolation, complex fractionated atrial electrograms ablation, and linear ablation during the index procedure. Superior vena cava-triggered AF and an SVC associated with the maintenance of AF were evaluated by mapping catheters during the procedure. The arrhythmogenicity of the SVC was confirmed in only 1 of the patients (0.98%). At the end of 12 months follow-up, the arrhythmia-free survival rate after a single procedure was 43.1%. After the last procedure (mean 1.47 ± 0.58 procedures), sinus rhythm was maintained in 71 (69.6%) patients, 63 of whom without antiarrhythmic drugs. The patients in AF recurrence group had higher rates of right atrium enlargement (71 vs. 34%, P = 0.03), ≥2 procedures (65 vs. 34%, P < 0.05), longer AF duration (84 ± 46 vs. 45 ± 34 months, P < 0.05), and larger left atrium diameter (50 ± 5 vs. 45 ± 6 mm, P < 0.05). In the multivariate analysis, left atrium diameter and AF duration were independent predictors of AF recurrence. Conclusion The arrhythmogenic SVC is rarely detected in patients with long-standing persistent AF. Empiric SVC electrical isolation in the stepwise approach of long-standing persistent AF seems unnecessary.

Vagal response during pulmonary vein isolation: Re-recognized its characteristics and implications in lone paroxysmal atrial fibrillation

BACKGROUND The role of autonomic innervation around the pulmonary vein (PV) antrum in the genesis of atrial fibrillation (AF) has been demonstrated but the characteristics of radiofrequency induced vagal response (VR) in the PV antrum and its clinical impact on pulmonary vein isolation (PVI) for paroxysmal AF need to be further elucidated. METHOD Of 995 consecutive patients with symptomatic paroxysmal AF undergoing PVI at a single center over a 2-year period, 516 met exclusion criteria and the remaining 479 patients, 156 positive VR (PVR) and 323 negative VR (NVR), underwent 12-month follow-up. The primary endpoint was freedom from AF or other sustained atrial tachycardia (AT), verified by monthly visits and electrocardiographic monitoring. The frequency-domain analysis was performed to evaluate the autonomic activity before and after the procedure. RESULTS VR was most commonly elicited during PVI at the LSPV roof (65.4%) and anterior RSPV (44.9%, with a >5s sinus pause in 37/70 [52.8%] cases). Compared with the NVR group, ablation was associated with reduced AF recurrence at 12 months in the PVR (hazard ratio: 0.53, 95% confidence interval: 0.22-0.89). Furthermore, the PVR group showed a significantly abbreviated AF cycle length at the left PV, and significantly lower HF and LF parameters with stable LF/HF ratio during follow-up. CONCLUSION Complete elimination of vagal response, most commonly elicited by radiofrequency application around the roof of LSPV and anterior RSPV, appeared associated with reduced 12-month recurrence of AF and with marked heart rate variability changes consistent with autonomic nervous withdrawal.

Role of the MAPKs/TGF-β1/TRAF6 signaling pathway in postoperative atrial fibrillation

Objectives To explore the relationship between the MAPKs/TGF-β1/TRAF6 signaling pathway and atrial fibrosis in patients with rheumatic heart disease (RHD) and its role in atrial fibrillation (AF) after cardiac surgery on the basis of our previous animal study of the MAPKs/TGF-β1/TRAF6 signaling pathway in atrial fibrosis. Methods A total of 57 patients with RHD without a history of AF consented to left atrial biopsy. Histopathology quantified the percentage of fibrosis, and real-time PCR and western blot assessed the mRNA and protein expression of TGF-β1, TRAF6, and connective tissue growth factor (CTGF), respectively. Western blot was also used to measure the protein expression of phosphorylated MAPKs and TGF-β-activated kinase 1 (TAK1). Serum angiotensin II (Ang II) levels were assayed using enzyme-linked immunosorbent assay (ELISA). Results Eighteen patients developed AF, whereas 39 remained in sinus rhythm (SR). The severity of atrial fibrosis was significantly higher in patients who developed AF versus those who remained in SR; the mRNA and protein expression of TGF-β1, TRAF6 and CTGF were significantly higher in patients with AF. The protein expression of phosphorylated MAPKs and TAK1 was significantly increased in patients who developed AF compared with the patients who remained in SR. Serum Ang II levels were significantly higher in patients who developed AF versus those who remained in SR. Conclusion The MAPKs/TGF-β1/TRAF6 signaling pathway is involved in atrial fibrosis in patients with RHD, which results in the occurrence of AF after cardiac surgery.

Long-term outcomes of catheter ablation of atrial fibrillation in dilated cardiomyopathy

OBJECTIVE The long-term outcomes, efficacy and safety of catheter ablation in atrial fibrillation (AF) patients with dilated cardiomyopathy (DCM) have not been reported previously. METHODS AND RESULTS Forty nine patients with AF (59% longstanding persistent AF, LSP-AF) and DCM were enrolled. Circumferential pulmonary vein ablation (CPVA, paroxysmal AF), bidirectional block of lines and disappearance of complex fractionated atrial electrograms (CFAEs, persistent and LSP-AF) were the endpoints of the index and repeat procedures. Cumulative success rate reached 49% (mean, 1.4 procedures) during the first year, and dropped to 38% at median follow-up of 45 months (range, 36-64 months) for multiple procedures (mean, 1.9 ± 0.8 [1-4]). Incidence of procedural complications was similar to that of conventional procedures. In multivariate analysis, LSP-AF (OR, 7.40 [95% CI, 1.42-38.34]; P = 0.017) and larger left ventricular end-diastolic diameter (OR, 1.24 [95% CI, 1.01-1.52]; P = 0.034) were significant independent predictors of recurrent atrial tachyarrhythmia (ATa). Compared with patients with ATa recurrence, those free from ATa had better New York Heart Association functional class, 6-minute walk distance and left ventricular ejection fraction during long-term follow-up compared with pre-ablation, but this improvement was not sustained beyond 3 years. CONCLUSION In patients with DCM, current commonly used ablation strategies including CPVA, linear ablation and CFAE ablation are not associated with long-term AF treatment success up to five years. Freedom from ATa is associated with improved heart failure during but not beyond 3 years post ablation.

Optimal endpoint for catheter ablation of longstanding persistent atrial fibrillation: A randomized clinical trial: WANG et al.

In longstanding persistent atrial fibrillation (LPeAF), the ideal endpoint of ablation remains to be determined. This study was to explore the value of pursuing AF termination or no with the same strategy during ablation on the long‐term outcomes in patients with LPeAF.