Author + information
- Silke D. Braun, MD∗ ()
- ↵∗University Hospital Carl Gustav Carus, Department of Pneumology, Fetscherstrasse 74, 01304 Dresden, Germany
To alleviate palpitations and secondary detrimental effects in patients with atrial fibrillation (AF), the interventional AF therapies have become a kind of gold-standard in the treatment of patients with symptomatic AF, which is why about 50,000 procedures are performed each year in the United States alone. Because pulmonary vein isolation is less effective in patients with enlarged left atria with permanent AF, there is a trend to treat younger patients with paroxysmal AF with only moderate atrial structural changes. Nonetheless, it is well known that patients with lone AF have low annual rates of thromboembolism and low annual rates of heart failure during conservative follow-up. According to the CHA2DS2-VASc score (score to predict stroke in patients with atrial fibrillation), patients with low CHADS2 score do not require oral anticoagulants because of the more benign prognosis in lone AF (1). In the prospective, multicenter, randomized, controlled STOP AF cryoballoon trial (A Clinical Study of the Arctic Front Cryoablation Balloon for the Treatment of Paroxysmal Atrial Fibrillation), Packer et al. (2) assessed the safety and the efficacy of a novel cryoballoon ablation technology compared with AF drug therapy in 245 patients with paroxysmal AF and a mean CHADS2 score of 0.6. Mean age of all patients was 56 years, 77% were male, with 93% New York Heart Association (NYHA) none/I; 163 of the patients were assigned to cryoablation and 82 to antiarrhythmic drugs. In this study the long-term effectiveness in the cryoablation group was reported as 69.9% after 12 months, with a mean fluoroscopy exposure time of 63 min. Regarding the adverse events during follow-up, only 1 adverse event (1.2%) occurred in the drug therapy arm (transfusion because of hemorrhage) compared with 32 adverse events (14.2%) in the cryoablation group, not regarding the 24 patients who suffered temporary phrenic nerve palsy. Five strokes, 4 transient ischemic attacks, 2 cases of tamponades, 2 myocardial infarctions, 3 transfusions, 2 atriovenous fistulas, 2 pseudoaneurysms, 4 cases of persistent phrenic nerve palsy, 7 cases of pulmonary vein stenosis > 75%, and even 1 death occurred in the cryoablation arm. Therefore, there is reasonable doubt regarding the safety of the interventional AF procedures. Especially in patients with lone AF it is questionable if the benefit of the AF ablation procedures in fact outweighs their risk. Further studies are needed to assess the net-benefit of these interventional procedures. From the pulmonological point of view, serial quantitative lung perfusion scans (3) and serial body plethysmography are required in further prospective AF ablation trials to assess the long-term effect of mild to moderate pulmonary vein stenosis and to assess the loss of vital capacity because of phrenic nerve palsy.
- 2013 American College of Cardiology Foundation