Jia-ning Gu

Beneficial effect of pioglitazone on the outcome of catheter ablation in patients with paroxysmal atrial fibrillation and type 2 diabetes mellitus

AIMS Pioglitazone, one of the peroxisome proliferator-activated receptor-gamma activators, possesses anti-inflammatory and antioxidant properties. In the present study, we sought to identify the impact of pioglitazone on the outcome of catheter ablation for paroxysmal atrial fibrillation (PAF). METHODS AND RESULTS We conducted a prospective observational cohort study of 150 consecutive patients undergoing catheter ablation of drug-refractory PAF. All patients had a history of type 2 diabetes mellitus (T2DM) and were divided based on whether they received pioglitazone before ablation or not. After grouping, 51 patients treated with pioglitazone and 99 control subjects were followed up at least 15 months after ablation. After a single ablation, sinus rhythm was maintained in 44 patients (86.3%) of the pioglitazone group vs. 70 patients (70.7%) of the control group (P = 0.034) without antiarrhythmic drug during a mean follow-up of 22.9 ± 5.1 months. The second ablation was performed in 5 patients (9.8%) from the pioglitazone group and in 24 patients (24.2%) from the control group (P = 0.034). Multivariate logistic analysis showed left atrium diameter was associated with a high risk of atrial tachyarrhythmias recurrence, and treatment with renin-angiotensin system inhibitor as well as pioglitazone was associated with a reduced atrial tachyarrhythmias recurrence rate. CONCLUSION Pioglitazone improved the preservation of sinus rhythm and reduced the reablation rate in patients with PAF and T2DM after catheter ablation.

Pulmonary vein isolation combined with superior vena cava isolation for atrial fibrillation ablation: a prospective randomized study

AIMS Circumferential pulmonary vein isolation (CPVI) is an established strategy for atrial fibrillation (AF) ablation. Superior vena cava (SVC), by harbouring the majority of non-pulmonary vein (PV) foci, is the most common non-PV origin for AF. However, it is unknown whether CPVI combined with SVC isolation (SVCI) could improve clinical results and whether SVCI is technically safe and feasible. METHODS AND RESULTS A total of 106 cases (58 males, average age 66.0 +/- 8.8 years) with paroxysmal AF were included for ablation. They were allocated randomly to two groups: CPVI group (n = 54) and CPVI + SVCI group (n = 52). All cases underwent the procedure successfully. Pulmonary vein isolation was achieved in all cases. The procedural time and fluoroscopic time were comparable between the two groups. The mean ablation time for SVC was 7.8 +/- 2.7 min. Superior vena cava isolation was obtained in 50/52 cases. In the remaining two cases, SVCI was not achieved because of obviating diaphragmatic nerve injury. During a mean follow-up of 4 +/- 2 months, 12 (22.2%) cases in the CPVI group and 10 (19.2%) cases in the CPVI + SVCI group had atrial tachyarrhythmias (ATa) recurrence (P = 0.70). Nine of 12 cases in the CPVI group and 8/10 cases in the CPVI + SVCI group underwent reablation (P = 0.86), and PV reconnection occurred in 7/9 cases in the CPVI group and in 8/8 cases in the CPVI + SVCI group. All PV reconnection was reisolated by gaps ablation. There was no SVC reconnection in the CPVI + SVCI group. In two cases without PV reconnection from the CPVI group, SVC-originated short run of atrial tachycardia was identified and eliminated by the SVCI. At the end of 12 months of follow-up, 50 cases (92.6%) in the CPVI group and 49 (94.2%) in the CPVI + SVC group were free of ATa recurrence (P = 0.73). CONCLUSION In our series of paroxysmal AF patients, empirically adding SVCI to CPVI did not significantly reduce the AF recurrence after ablation. Superior vena cava isolation may be useful, however, in selected patients in whom the SVC is identified as a trigger for AF. However, because of the preliminary property of the study and its relatively small sample size, the impact of SVCI on clinical results should be evaluated in a large series of patients.

Efficacy of catheter ablation and surgical CryoMaze procedure in patients with long-lasting persistent atrial fibrillation and rheumatic heart disease: a randomized trial

AIMS Catheter ablation and surgical Maze procedure are effective in treating atrial fibrillation (AF) patients. However, there is no study that compares the effect of circumferential pulmonary vein isolation (CPVI) combined with substrate ablation after valvular surgery and the concomitant Maze procedure for the treatment of AF in patients with rheumatic heart disease (RHD). The aim of this study was to compare the effectiveness of CPVI combined with substrate modification and surgical Maze procedure using Saline-Irrigated Cooled-tip Radiofrequency Ablation (SICTRA) system for the treatment of long-lasting persistent AF in patients with RHD. METHODS AND RESULTS Between January 2006 and June 2008, 99 patients with long-lasting persistent AF and RHD were randomly assigned to undergo valvular operation and CPVI combined with substrate modification 6 months after the surgery (Group A, 49 patients) or valvualr operation and concomitant Maze procedure (Group B, 50 patients). The mean follow-up periods were 15 ± 5 and 20 ± 8 months in Groups A and B, respectively. After one procedure, Group B had a significantly higher freedom from artial arrhythmias compared with Group A (82% in Group B vs. 55.2% in Group A, P < 0.001). Fifteen patients in Group A underwent a redo procedure. Six patients in Group B underwent catheter ablation and four were treated successfully. The cumulative rates of sinus rhythm were 71% in Group A and 88% in Group B (P < 0.001). CONCLUSION The concomitant Cox Maze procedure using SICTRA is more effective than subsequent CPVI combined with substrate modification in treating patients with long-lasting persistent AF and RHD.

Decreased Connexin 43 and Increased Fibrosis in Atrial Regions Susceptible to Complex Fractionated Atrial Electrograms

Background and Objectives: Complex fractionated atrial electrograms (CFAE) is distributed at preferential sites of atrium, and the mechanism underlying CFAE is not fully understood. We hypothesized that preexisting atrial abnormalities may be involved in the formation of CFAE. Methods: Twelve pigs were subjected to acetylcholine infusion and right atrial pacing to induce sustained atrial fibrillation. The shortest complex interval map was used to visualize CFAE on three-dimensional anatomic structure of left atrium, and the CFAE sites were labeled by ablation. The expression of connexin 43 (Cx43) and myocardial fibrosis were examined. Results: The expression of Cx43 at CFAE sites was significantly decreased when compared with non-CFAE sites, while myocardial fibrosis was enhanced in CFAE sites compared with non-CFAE sites. Conclusions: These results suggested that the decreased expression of Cx43 and enhanced myocardial fibrosis at CFAE sites of the left atrium may be the structure abnormalities underlying CFAE.

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.

Efficacy, safety and outcome of catheter ablation for atrial fibrillation in octogenarians

BACKGROUND AND OBJECTIVES Catheter ablation is effective in treating patients with atrial fibrillation (AF). The aim of the study was to evaluate the safety, efficacy and outcome of catheter ablation for AF in octogenarians. METHODS AND RESULTS 377 consecutive patients were divided into three groups based on age: ≥80 years (group 1; n=49), 70-79 years (group 2; n=151), 60-69 years (group 3; n=177). The efficacy and safety for those three groups were determined. The success rate after one procedure was similar in three groups (70% in group 1, 72% in group2 and 74% in group 3, P=NS) during a mean follow-up of 18 months. Major complication rates were comparable between the three groups. However, the octogenarians were less likely to undergo a repeated procedure than other groups (8% in group 1, 15% in group 2 and 18% in group 3, P<0.05), and were more likely to remain on antiarrhythmic drugs. CONCLUSION Catheter ablation for AF attempted in octogenarians appears to be effective and with low risk. Ablation results are comparable with those noted in younger patients.

Efficacy and Safety of Catheter Ablation for Long‐Standing Persistent Atrial Fibrillation in Women

It is uncertain whether gender affects the outcomes of catheter ablation (CA) for atrial fibrillation (AF). The objective of the study is to evaluate the efficacy and safety of CA for long‐standing persistent AF in women.

Impact of Chronic Obstructive Pulmonary Disease on Procedural Outcomes and Quality of Life in Patients with Atrial Fibrillation Undergoing Catheter Ablation

Impact of COPD on Atrial Fibrillation Ablation. Background: Chronic obstructive pulmonary disease (COPD) is a risk factor for atrial fibrillation (AF). The aim of this study was to investigate the impact of COPD on outcomes of catheter ablation in patients with AF in terms of recurrence and quality of life (QoL).

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.