Concomitant Surgical Atrial Fibrillation Ablation (Modified Cox Maze IV) in Patients With Long-Standing Persistent Atrial Fibrillation Undergoing Mitral Valve Surgery: Experience From a UK Tertiary Center

Background:In patients with persistent atrial fibrillation (AF) and chronic severe mitral valve (MV) regurgitation, the success rate of cardioversion and long-term maintenance of sinus rhythm is poor. Concomitant AF ablation during MV surgery may improve outcomes. We report short- and medium-term results in patients undergoing concomitant AF ablation during MV surgery.Methods:This was a retrospective study of all consecutive patients with long-standing persistent AF who underwent MV surgery for severe MV regurgitation with concomitant biatrial surgical ablation (biatrial modified Cox-maze IV with completion of the full lesion set) between June 2015 and June 2018. Patients were followed at 3, 6, and 12 months postoperatively. Data from 24-hour Holter monitoring, baseline clinical parameters, complications, and AF recurrence were collected.Results:A total of 62 patients with severe mitral regurgitation and long-standing persistent AF underwent MV surgery with concomitant AF ablation. A standardized energy source (bipolar radiofrequency plus cryoablation) was used in all cases. The mean age was 70 ± 11 years; 32 (51.6%) were female, and the mean CHA2DS2-VASc score was 2.7 ± 1. At 12 months, sinus rhythm was documented in 43 (69.4%) patients on 24-hour Holter monitoring; 88.4% of those in sinus rhythm at follow-up demonstrated atrial contractility on echocardiography. Pacemaker implantation was required in 5 (8.1%) patients, and cerebrovascular events occurred in 3 (4.8%). Meanwhile, two patients (3.2%) required re-exploration for bleeding, but none needed re-intervention on the MV.Conclusions:Biatrial surgical AF ablation is a safe and effective adjunct in patients with long-standing persistent AF undergoing concomitant MV surgery and may be beneficial in the long term for maintaining a normal rhythm.