Differences in the treatment of patients with ventricular arrhythmias in some European countries and U.S.A. after the CAST study.

Under the auspices of the GIA, a National and International Survey on Antiarrhythmic Agents (AA) Use ('NISA') has been set up. Data from all the Italian Arrhythmias and Cardiology centers (IC) of the Italian Group of Arrhythmology (GIA), and from a comparable number of centers, with and without advanced experience in arrhythmia patients management, in the U.S. (USC), in France, Spain and Germany, as well as European countries (EC), have been compared. Preliminary data on the treatment of different ventricular arrhythmias (VA), after the CAST study, have been collected from the various countries considered. The treatment of VA, such as complex and frequent EVBs and NSVT, sustained VT and VF or cardiac arrest patients has been documented. Furthermore, a comparative evaluation of the treatment strategies used in patients suffering from VA, with and without heart failure, has been undertaken. A specific analysis of the methods used in the evaluation of antiarrhythmic drugs efficacy has been performed. A simultaneous assessment of the clinical indications of programmed electrical stimulation (PES), for the clinical diagnosis of VA and for the choice of the most appropriate antiarrhythmic agent or non pharmacological procedures, has been conducted in the survey. The most important results of the survey are: 1. a reduction in the use of Class I A antiarrhythmic agents; 2. a differential use of class 1 C antiarrhythmic agents, due to the results observed with these drugs, in the CAST; these drugs are mainly used in the treatment and long term prophylaxis of supraventricular arrhythmias and rarely in ventricular arrhythmias; 3. a different and more widespread use of Amiodarone and other class III drugs, not only for ventricular arrhythmias, but even for common supraventricular arrhythmias, regardless of the absence or presence of congestive heart failure; 4. a more diffuse and increasing use of electrical treatment of ventricular and supraventricular arrhythmias, where radiofrequency ablation is preferred to drug treatment; 5. a more cautious approach to patients with complex and frequent EVBs and NSVT who rarely receive antiarrhythmic agents, versus patients with VT and cardiac arrest, where PES evaluation of antiarrhythmic agents and electrical procedures are largely preferred to other non-invasive approaches. In conclusion, different prescribing habits have been documented in the different monitored countries, due to 1. commercially available drugs, 2. old and new prescribing attitudes, 3. different medical expertise and therapeutical options availability in the treatment of the arrhythmia patient, more than widely accepted guidelines. New, more adequate standards in the diagnosis and treatment of VA, should be proposed.