5. Limitations
We acknowledge certain limitations within our study. First,
extracted/calculated HRs were not adjusted for confounders. Secondly,
there were differences in follow-up times with 3 and 2 studies that
followed patients up to 12 and 24 months, respectively. Also, there was
a difference in the definition of arrhythmia recurrences used for the
clinical endpoint as discussed above. Nevertheless, we did not observe
major differences in the HR, and the random-effect model did not reveal
significant heterogeneity from our analysis (I2=0.0%). Thirdly, data
regarding the adverse event were limited due to the overall low event
rates which subsequently limited the power of the analysis.