Circulation Journal Official Journal of the Japanese Circulation Society http://www. j-circ.or.jp
Perspectives on Catheter Ablation of Atrial Fibrillation Yoshihide Takahashi, MD
trial fibrillation (AF) is the most common tachyarrhythmia in clinical practice, and the number of patients is now estimated at nearly 1 million in Japan. The development of novel oral anticoagulants has facilitated anticoagulation therapy in a considerable number of patients without increasing the risk of intracranial bleeding.1 The management of AF is, however, still complex because of the wide variety of comorbidities in AF patients. It is well known that comorbidities are associated with an increased risk of stroke in AF patients. Not only the risk of stroke, but also the risk of heart failure increases according to the comorbidities. In AF patients, the presence of structural heart disease is associated with a 3.5-fold increased risk of heart failure.2 As for patients with hypertrophic cardiomyopathy (HCM), AF is associated with a 3.7-, 17.7-, and 2.8-fold increased risk of mortality, stroke and NYHA class of III or IV, respectively.3 One may argue that the occurrence of AF is not a cause of poor clinical outcome, but a marker of the severity of the heart disease. This is perhaps partly true, but previous studies demonstrated that catheter ablation of AF improves quality of life, exercise capacity, and left ventricular (LV) systolic and diastolic function in patients with heart failure.4–6 These findings indicate that AF worsens heart failure even with appropriate rate control and the elimination of AF without use of antiarrhythmic drugs is able to improve clinical outcomes in heart failure patients.
Article p 419 The efficacy of AF ablation in patients with HCM has been reported, and an improvement in quality of life after ablation was shown.7 However, freedom from atrial tachyarrhythmias in HCM patients after a single procedure was 48–62%,7–10 which is lower than in lone AF patients. It was demonstrated that the risk factors associated with recurrence after AF ablation in HCM patients were persistent AF and enlarged left atrium.7,8 In this issue of the Journal, Okamatsu et al10 report that LV diastolic function (E/e’) was also a predictor of the arrhythmia-free rate after AF ablation in HCM patients. In their study, E/e’