Ultrasonic Cardiac Ablation for Atrial Fibrillation During Concomitant Cardiac Surgery: Long-Term Clinical Outcomes

Background Therapeutic ultrasound as an alternative to the maze procedure was evaluated in this large US experience. Safety and efficacy were assessed at 6-, 12-, and 18-month visits with systematic 24-hour Holter monitoring. Methods From February 2005 to February 2007, 220 patients were prospectively enrolled in a single center study, and among them 129 patients with concomitant cardiac surgery and at least 6-month follow-up were reviewed. Primary procedures were mitral surgery in 50% of the cases, coronary bypass in 32%, and aortic surgery in 16%. Atrial fibrillation was permanent in 66 (51.1%), paroxysmal in 43 (33.3%), and persistent in 20 (15.5%) patients. An epicardial and circumferential left atrial encircling line was created on the beating heart. Routinely a mitral isthmus line was also created from the left atrium epicardium using an ultrasonic handheld device. Results No morbidity or mortality was device-related. There were four (2.33%) early deaths and six late extra-cardiac deaths. Follow-up ranged from 6 to 670 days with a mean follow-up of 358.5 days, median 340 days with two patients lost to follow-up. Freedom from atrial fibrillation or left-sided flutter was 83.2%, 84.4%, and 86.2% at 6, 12, and 18 months, respectively. A pacemaker was implanted in seven patients (5.4%). Male gender and left atrial dimension were significant risk factors for failure. Conclusions The study confirms the excellent safety record of the technology, and the efficacy at the level reported in a previous European multicenter study. Efficacy is also maintained at longer (12 and 18 months) follow-up.