Comparison of radiofrequency and cryoablation procedures for mitral valve surgery patients with atrial fibrillation

Objectives: This study aims to compare the success of two different energy sources, radiofrequency versus cryoablation, in patients with atrial fibrillation. Patients and methods: Between August 2012 and August 2017, a total of 55 patients (27 males, 28 females; mean age 51.6±11.2 years; range, 44 to 71 years) with atrial fibrillation who underwent isolated left atrial ablation during mitral valve surgery in our clinic were included. Radiofrequency was applied to 41 patients and cryoablation to 14 patients. In both procedure, ablation was performed to isolate all pulmonary veins. Radiofrequency ablation utilized a RF current that was applied in a point-by-point mode, heating the tissue and leading to cellular necrosis. Cryogenic ablation induced necrosis by pumping refrigerant (nitrous oxide) through a balloon in a single-step mode, thereby freezing the tissue. The success of both techniques was evaluated through control echocardiography and electrocardiography. Results: There was no statistically significant difference in the success rates of both techniques in terms of returning to the sinus rhythm. Two patients in the radiofrequency ablation group developed third-degree atrioventricular block with the need of permanent pacemaker implantation. In contrast no patient in the cryoablation group developed the same block. In patients who underwent radiofrequency ablation, the need for inotropic support in the postoperative period was higher with prolonged length of stay in the intensive care unit. Conclusion: Our study results show that the success rate of both techniques is similar in patients with atrial fibrillation undergoing mitral valve surgery.