PubMed · 9988665
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T O Cheng. 1999. OPALS study.. https://doi.org/10.1016/s0196-0644(99)70403-8
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The clinical categorization of patients who present with atrial fibrillation is a major determinant of the most appropriate strategy for rhythm management. For those patients with recurrent atrial fibrillation that has not become permanent the two available strategies are rhythm control and anticoagulation or rate control and anticoagulation. There is no clear evidence that one of these strategies is superior to the other. In the AFFIRM trial these two strategies are being compared to one another in a randomized trial. Patients are randomly assigned to one of the two strategies and the treating physician then uses therapies from an approved menu as clinically indicated. Both pharmacologic and nonpharmacologic therapies are used. An overview of the main study protocol is presented. The primary endpoint is total mortality but there are a number of clinically important secondary endpoints. Several substudies will explore important ancillary questions and some of these are also described. At this time over 3000 patients have been enrolled and the planned enrollment is 4300. Enrollment will end late in 1999 and the last patient enrolled will be followed for two years. The AFFIRM Trial will provide important information concerning the management of atrial fibrillation in a large portion of the patients who have this arrhythmia.
External cardioversion of AF is an established and accepted method for termination of individual episodes of AF. Recent advances have taken place in the area of non-pharmacologic management of AF, and despite its long history and well established technique, defibrillation has not been spared from these advances. The success of low-energy internal atrial defibrillation for the termination of both chronic and acute onset atrial fibrillation has resulted in the development of implantable defibrillators that treat this arrhythmia. Many of the advances have come about as a result of the use of defibrillation in implanted devices for recurrent AF due to the substantial efforts in an attempt to make this form of restoration of sinus rhythm more efficacious and tolerable to the patient. Additionally, the use of other non-pharmacologic control of atrial fibrillation has also been recently explored, namely the use of ablation and atrial pacing. The use of these other non-pharmacologic therapies are likely to both reduce the recurrence rate, as well as enhance the efficacy of defibrillation. However, defibrillation is likely to still be needed to terminate atrial fibrillation for persistent episodes, and its combination with these other therapies is likely synergistic. Electrical therapy to restore sinus rhythm for persistent episodes of atrial fibrillation is likely to be perceived by the patient. Therefore, the concept of patient controlled therapy from implanted devices to treat atrial fibrillation has shown promising results and will likely be a requirement of such devices in the future. Major advances in defibrillation therapy for atrial fibrillation have been made and have resulted in the development of implantable atrial defibrillators. Despite these advances in defibrillation and other therapies for atrial fibrillation, it is likely that combined pharmacologic and non-pharmacologic therapies for atrial fibrillation will prevail over the individual entities themselves. Future study is needed to determine the best therapy or combination of therapies for individual patients with atrial fibrillation.
At least 50% of patients who received an ICD have been treated with antiarrhythmic drugs (AAD). The potential indications for combining antiarrhythmic drugs and ICD are generally the following: reduction of the number of episodes of ventricular tachycardia or ventricular fibrillation and therefore of the number of shocks, improving patient's quality of life and extending the battery life of the ICD, prevention of supraventricular arrhythmias and/or control of their rate, lengthening of the tachycardia cycle length to allow ventricular tachycardia conversion by antitachycardia pacing and reduction of the number of episodes of syncope. Although previous papers reported conflicting results about pharmacologic therapy in reducing the frequency of iCD shocks, some recent randomized prospective studies showed the efficacy of pharmacologic therapy in reducing the frequency of ICD shocks. The use of antiarrhythmic drugs can have also adverse effect: an increase in the defibrillation threshold, an increase in the pacing threshold and an increase in the VT cycle length leading to detection failure. We have also to consider that some advantages derived from antiarrhythmic drugs can be reached by the new devices with atrial sensing and pacing and/or the possibility of atrial defibrillation or by using catheter ablation as adjunctive therapy to ICD. For these reasons, the concomitant use of antiarrhythmic drugs and ICD should be evaluated in each patient in relation to specific clinical and electrophysiologic features including: the frequency, the rate and the clinical presentation of the ventricular arrhythmia, the effect of the selected drug on the defibrillation threshold, the defibrillation threshold at the implant, the effect of the selected drug on the ventricular function and the likelihood of proarrhythmic events.