Epicardial microwave ablation: effective treatment option for patients with permanent atrial fibrillation

Atrial fibrillation, one of the most common arrhythmias, is responsible for a high percentage of strokes. Efficacy of epicardial microwave (MW) ablation was investigated by a research group at the Heart Center Dresden (Dr. Knaut, Dr. Brose, Dr. Forker and Dr. Matschke) and Prof. Dr. Jung (Center for Biomaterial Development and Berlin Brandenburg Center for Regnerative Therapies, Teltow, Germany) and they recently presented their first clinical results of epicardial MW ablation as a concomitant procedure during cardiac surgery where opening of the left atrium was not required.

One year survival rate was 92,5% in the ablation group (40 patients treated with epicardial MW in combination with aortic valve replacement and/or coronary artery bypass grafting) and 86,9% in the control group (145 patients with equivalent operations without ablation therapy). In the ablation group, mortality during follow-up was 7,5% compared to 13,1% in the control group. No device-related complications were observed.

Success rates defined as maintenance of sinus rhythm at all follow-up dates, were at least more than 5 times higher in patients in the ablation group than in the non-ablated group. After one year, 65,7% of the ablated patients were in sinus rhythm compared to 9,6% in the control group (p = 0.000001).

The advantage of the epicardial approach was that ablation could be performed on the heart’s surface, leaving the endocardium intact and minimizing the risk of postoperative thromboembolic or bleeding complications. Concomitant heart surgery was only minimally prolonged without lengthening ischemic time (15 to 20 minutes required for epicardial ablation). As their pilot study has excellently shown efficacy of the procedure, the research group at the Heart Centre Dresden will carry out a prospective, randomised, controlled trial to confirm these results.