Effectiveness of the Cox-maze III procedure in the long term and its relationship with the postoperative size of the left atrium

Introduction: The cox-maze III procedure is designed to eliminate atrial fibrillation (AF). Objective: To determine the relationship of left atrial (LA) postoperative size after undergoing the Cox-maze III procedure. Method: From July 2012 to April 2016, 50 patients with primary mitral valve disease and concomitant AF were operated on. A "cut-and-sew" cox-maze III procedure with a full biatrial lesion pattern was used. AF preoperative duration was 3.5 +/- 2.1 years. Results: There was no operative mortality. Freedom from AF was 92%, 88% and 73.7% at three months and at one and 3 years, respectively. A direct relationship was found between LA postoperative size and the probability of cox-maze failure when LA is > 6.5 cm at one year (relative risk [RR] = 10.5; 95% confidence interval [CI]: 4.30-26.67, p < 0.0001) and at 3 years (RR = 27.1; 95% CI: 3.87-189.86, p = 0.0009). LA size decreased from 7.1 +/- 0.5 cm to 6.2 +/- 0.5 cm (p < 0.0001). Conclusions: The cox-maze III procedure is efficacious for eliminating mitral valve disease-associated AF when LA postoperative size is = 6.5 cm.