Application of the preoperative ECG to predict Cox-Maze surgery mid-term outcome

The Cox-Maze surgery is today the procedure with the highest long-term cure rate for patients in atrial fibrillation (AF). Nonetheless, its mid-term outcome prediction could avoid the application of aggressive pharmacologic treatments in some patients. Previous works have revealed that parameters computed from the preoperative ECG, such as the fibrillatory waves amplitude (fWP), the dominant atrial frequency (DAF) and the sample entropy (SampEn), can identify successfully the Cox-Maze immediate outcome at discharge. This work focuses on analyzing the ability of these parameters to predict the patient´s rhythm six months post-surgery. Results showed sensitivity, specificity and accuracy values of 71.43%, 52.94% and 58.33% for fWP, 85.71%, 52.94% and 62.5% for DAF and 85.71%, 58.82% and 66.66% for SampEn, respectively, reporting no statistically significant differences between patients in AF or normal rhythm. Therefore, in contrast to previous results, these metrics did not show to be significant predictors of the Cox-Maze surgery at mid-term. The atrial substrate alteration due to pharmacological and electrical cardioversion in patients relapsing to AF during the follow-up could be the main reason for this result. Further analyses are required to clarify this question.