Novel risk score for predicting recurrence of atrial fibrillation after the Cryo-Maze procedure

OBJECTIVES This study aimed to develop a novel risk score model for quantitative prediction of the rate of atrial fibrillation (AF) recurrence after the Cryo-Maze procedure in patients with persistent AF. METHODS We enrolled 450 consecutive patients who underwent the Cryo-Maze procedure for persistent AF concomitant with other cardiac procedures in our institute between 2001 and 2019. We randomly divided the cohort into two groups. We derived a model in a ‘development cohort’ (270 patients; 60%) and validated it in a ‘test cohort’ (180 patients; 40%) by receiver operating characteristic curve analysis. RESULTS The median follow-up was 5.2 (interquartile range: 2.0–9.9) years. The 1-, 5-, 10- and 15-year rates of freedom from AF recurrence in the entire cohort were 91.4%, 83.5%, 76.2% and 57.1%, respectively. Risk factors for AF recurrence examined by logistic regression analysis included F-wave voltage in V1 < 0.2 mV, preoperative AF duration >5 years and left atrial volume index >100 ml/m2. Points were assigned to each risk factor according to its odds ratio. A novel risk score model was developed using these three variables and age, with a range up to 10 points. High score (>7) predicted high rates of AF recurrence after the Cryo-Maze procedure. The area under the receiver operating characteristic curve of the novel risk model score was 0.78 (95% confidence interval: 0.65–0.91) in the test cohort. CONCLUSIONS Use of the Cryo-Maze procedure should be carefully considered in patients with a higher model score because of a higher risk of AF recurrence.