Department of Cardiology and Intensive Care, General Hospital Wels, Wels, Austria
* Correspondence to: Dr J. Auer, Department of Cardiology and Intensive Care, Grieskirchnerstraße 42, A-4600 Wels, Austria. Tel: +43 72424152215; Fax: +43 72424153992
E-mail address: johann.auer{at}khwels.at
Received 26 August 2003; accepted 10 September 2003
To the Editor
We read with great interest the paper by de Simone and colleagues1showing that the addition of verapamil to class IC or III antiarrhythmic drugs significantly reduced the atrial fibrillation (AF) recurrences.
Recurrences of AF were assessed mainly on the basis of patients symptoms. Such a strategy may result in a failure to detect brief, symptom-free episodes of AF. Moreover, verpamil, that decreases ventricular rate during AF, could have reduced the symptoms associated with AF recurrences and the capability of patients to recognize AF. Thus, the reduction of AF recurrences with the addition of verapamil to other antiarrhythmic drugs may be strictly confined to symptomatic AF episodes. Frequent asymptomatic (and therefore unrecognized) AF recurrences may be of paramount importance as a risk factor for the occurrence of thromboembolic events.
Anticoagulant therapy is frequently stopped after sinus rhythm has been maintained for at least one month. However, effective preservation of sinus rhythm does not preclude the occurrence of cardiovascular events.2Moreover, among the patients treated with rhythm control, morbidity and mortality may be similar whether sinus rhythm is maintained or atrial fibrillation recurred. This finding suggests that the cardiovascular risk is not reduced with rhythm control even when sinus rhythm is maintained.2In particular, although maintaining sinus rhythm is generally believed to reduce the risk of stroke, patients with risk factors may have a stroke after the cessation of anticoagulant therapy, despite the maintenance of sinus rhythm.3
We agree with de Simone and colleagues that prevention of symptomatic AF recurrences by pharmacological strategies is a desirable goal. But this strategy does not preclude the occurrence of cardiovascular events in the future. The high risk for thromboembolic eventsassociated with both, the frequent asymptomatic and unrecognized AF recurrences and persistent comorbid conditions (e.g. heart failure) may require long term anticoagulation in at least some patients with obviously effective pharmacological therapy for prevention of symptomatic AF recurrences.
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