Long-Term Treatment After Acute Myocardial Infarction: Antiarrhythmic Therapy and Prophylaxis. Which Drug for Which Patient?

Even if the prognostic significance of ventricular arrhythmias (VA) has been documented in post-AMI CAD, which post-AMI patient showing VA should be treated is still controversial, because no beneficial effects of antiarrhythmic treatment has ever been proved in clinical trials using phenytoin, aprindine, tocainide, mexiletine, and the drugs recently utilized in the CAPS for EVBs. Probably, the rationale for antiarrhythmic therapy is more conclusive in patients with ventricular arrhythmias other than EVBs, and the need for antiarrhythmic drugs should be evaluated in each case, considering other clinical variables of prognostic importance (EF%, extent of coronary lesions, etc.). The type of antiarrhythmic drugs to be used is discussed, considering that, while many traditional antiarrhythmic agents are undoubtedly effective in the treatment of an acute arrhythymia, in the chronic setting, most of the time, a significant reduction in ventricular arrhythmias on Holter monitoring can be proved, without a significant reduction in total mortality. Conversely, we comment on the positive results of some empirical studies showing beneficial effects of antiarrhythmic therapy in high-risk patients reported by Lownʼs group. Furthermore, it can be stated that patients showing efficacy of antiarrhythmic therapy by both non-invasive and invasive evaluation of antiarrhytmic therapy efficacy had better long-term outcomes. To confirm these data, we report the results of a clinical study of the treatment of complex and frequent EVBs in cardiac patients. A different mortality on follow-up was observed in responders and nonresponders vs. patients not receiving drugs (2.2, 28, and 24%, respectively). In 98 post-AMI patients with sustained recurrent VT or life-treathening arrhythmias, we report the data of a clinical protocol, including first empirical use of amiodarone and propafenone as first choice and, in the case of recurrences, therapy guided by EPS. In this group, global mortality was 21% at 5 years mean follow-up and 26% at 6 years mean follow-up. Propafenone showed a recurrence rate of VT of 19% while amiodarone showed a recurrence rate of 20% in the same follow-up period.