Effects Of Radiofrequency Catheter Ablation On The Left Atrial Structure And Function In Patients With Atrial Fibrillation:a Meta-Analysis

BACKGROUND:Current evidence suggests that radiofrequency catheter ablation (RFCA) has played an important part in treating atrial fibrillation (AF). However, there is still controversy about the effects of RFCA on left atrial (LA) structure and function in patients with AF.OBJECTIVE:This meta-analysis was designed to systematically assess the effects of RFCA on LA structure and function in patients with AF.METHODS:A systemic literature search was performed by retrieving all literature before October1st2013in Medline, Embase, and The CoChrane Library databases. Studies involving the changes in LA size or volumes and/or function before and after RFCA in patients with AF were collected. Primary outcome measures were appointed to be changes in LA diameter (LAD), LA maximum volume (LAVmax), LA minimum volume(LAVmin), LA ejection fraction(LAEF), and the LA active emptying fraction (LAAEF). Review manager5.2was used to conduct the calculation and analysis of the data collected from the included studies, and weighted mean differences(WMD) with95%confidence interval (CI) for these indicators were estimated using the random-effects model of meta-analysis. Subgroup analysis and meta-regression was performed to explore the reason for heterogeneity.RESULTS:A total of1739patients from26trials were included in this study. Heterogeneity between selected trials was tested using the Chi-squared test and I2test. There was obvious heterogeneity among these enrolled trials in LAD (Q(df=26=140.33,P<0.00001,I2=81%), LAVmax (Q(df=25)=57.06, P=0.0003,I2=56%), LAEF (Q(df=21)=83.40, P<0.00001,I2=75%), LAAEF (Q(df=7)=67.38, P<0.00001, I2=90%). Compared to the values before ablation, there were significant decreases in LAD(WMD-2.04mm,95%CI-3.21to-0.87), LAVmax (WMD-6.31ml,95%CI-8.58to-4.04) and LAVmin(WMD-3.63ml,95%CI-5.50to-1.75) at follow-up≥lmonths after ablation. However, there were no significant differences in LAEF(WMD0.36%,95%CI-1.98to2.70) and LAAEF(WMD1.66%,95%CI-4.56to7.87) after ablation during follow-up. In terms of effects on LAEF, subgroup analysis showed that there were no significant differences between single pulmonary vein isolation(PVI) strategy and complicated ablation strategy, but it seems that the former(WMD2.43%,95%CI-0.05to4.90) was superior to the latter(WMD-2.51%,95%CI-6.28to1.27) on LA function. In patients with AF recurrence after ablation, there were no significant decreases in LA size and volumes, while decreases existed in LAEF and LAAEF. However, when analyzed on the basis of the effect of preoperative LA size on postoperative LA function, no obviously beneficial effect was observed in the subgroup with lager LA size(Z=0.06, P=0.95).CONCLUSIONS:This study suggests that RFCA improves left atrial remodeling in patients with AF and does not seem to adversely affect LA function. No significant difference was discovered between different ablation strategies in effects on LA structure and function. Compared to those without AF recurrence, no obvious changes in LA structure remodeling and adverse influence on LA function can be observed in patients with AF recurrence. Basic LA size seems not obviously related to post-ablation LA function.