Can we change the operative criteria for the MAZE procedure combined with valve surgery in the era of radiofrequency devices?

PURPOSE

After radiofrequency (RF) ablation became available, the indication of MAZE procedure conducted with bipolar RF was expanded. We examined the efficacy and feasibility of the RF MAZE procedure in valve surgery and identified the predictors of atrial fibrillation (AF) recurrence.

METHODS

Forty-four patients had permanent AF at the time of operation and underwent a biatrial RF MAZE procedure. Univariate and multivariate analysis for the predictor of permanent AF recurrence and follow-up studies were performed.

RESULTS

Of the patients, 37 (84.1%) were in non-AF rhythm at discharge and 25 (80.6%) were at the latest follow-up (mean, 2.1 ± 1.2 years). In stepwise multivariate analysis, left atrial dimension (LAD) > 61.5 mm was an independent predictor of early-term recurrence of AF (P = 0.006) and late-term recurrence (P = 0.038) as well. F-wave voltage <0.1 mV was significant in univariate analysis but was not significant in multivariate analysis for predictor of late-term AF recurrence. Avoidance of AF in the late term was 56% for LAD > 60 mm whereas it was 91% for LAD ≤ 60 mm (P = 0.043), 67% for F-wave < 0.1 mV compared to 100% for F-wave ≥ 0.1 mV (P = 0.031), and 43% for LAD > 60 mm and F-wave < 0.1 mV compared to 91% for LAD ≤ 60 mm and/or F-wave ≥ 0.1 mV (P = 0.016), respectively. Although avoidance of AF in the late term was lower in patients with LAD > 60 mm or F-wave < 0.1 mV, more than half of these patients were free from AF in the late term.

CONCLUSION

LA size was assumed to be a simple and strong predictor of recurrent AF in this procedure. Predictive criteria that had been widely employed for the "cut-and-sew" MAZE procedure accompanied with valve surgery can be expanded in the MAZE procedure with RF devices.