Background: Cooled-tip RFA (cRFA) and conventional 8-mm-tip catheters were found to be more effective and as safe as conventional 4-mm-tip catheters for atrial flutter (AFL) radiofrequency ablation (RFA), facilitating the rapid achievement of bi-directional isthmus block (BIB), but studies comparing cRFA and 8-mm-tip catheters are not randomized or results are discussed. Thus, we performed a meta-analysis of available randomized trials to evaluate the effectiveness in terms of primary success and procedure parameters.
Methods: Reports of trials were identified through a Medline, Embase, Current Contents, Cardline, and an extensive bibliography search. Trials that met the following criteria were included: (1) prospective, randomized, controlled, and open trials; (2) patients assigned to an 8-mm-tip or a cRFA catheter for AFL RFA; (3) endpoints events related to primary success rate (BIB achievement), and procedure parameters (number of RF applications, x-ray exposure and ablation duration).
Results: Seven trials met the inclusion criteria. They included 603 patients with established AFL randomized to an 8-mm-tip or cRFA catheter group. Comparing 8-mm groups with cRFA groups, the meta-analysis showed similar BIB achievement relative risk (RR) 0.96, 95% confidence interval (CI): 0.92 to 1.01, (P = 0.13); total RF application time weighted mean difference (WMD) 0.88, 95% CI: -0.36 to 2.12, (P = 0.16); duration of x-ray exposure (min) (WMD = 1.07, 95% CI: -0.81 to 0.295, (P = 0.26); ablation procedure duration (min) (WMD = 0.68, 95% CI: -3.37 to 4.73; P = 0.74).
Conclusion: The present meta-analysis confirms that cooled-tip and large-tip catheters are equally efficient for cavotricuspid isthmus ablation with both similar primary success rates and procedure parameters.