3.2.1 Procedural success rate
All eligible two-arms studies reported the acute procedural success data and there was no significant difference in procedural success rate (RR=1.01; 95% CI: 1.00,1.02; P =0.171; I²=0.00%) between two groups (Figure 2 )[6-15]. Our result was similar to those of several other meta-analyses[26-28]. Subgroup analysis was performed with a total of eight subgroup factors for the acute procedural success of LAAO, and the results are displayed inFigure 3 . There was no significant difference between TEE group and ICE group in the study design subgroup, follow-up subgroup, ICE sample size subgroup, male proportion subgroup, age cutoff subgroup, hypertension proportion subgroup, paroxysmal AF proportion subgroup, and device types subgroup, suggesting that all subgroup results were consistent with the pooled result.
We also performed a sensitivity analysis and the results showed no significant change, ranging from 1.00 (95% CI: 0.99,1.02) to 1.01 (95% CI:1.00,1.03), in the overall combined proportion, suggesting that there was no single study in the domination of the combined proportion and heterogeneity. Moreover, no publication bias was presented in Egger’s test (P =0.208).