The many NOs to the use of Class IC antiarrhythmics: weren’t the guidelines too strict?

Class IC antiarrhythmic drugs (AADs) currently represent a cornerstone in the therapy of atrial fibrillation, both for the restoration of sinus rhythm and for the prophylaxis of long-term relapses. They also play an important role in the treatment of idiopathic ventricular arrhythmias. Following the results of the Cardiac Arrhythmia Suppression Trial study, flecainide and by extension the other Class IC AADs were contraindicated in patients with ischaemic and structural heart disease, due to their pro-arrhythmic effect and the consequent increase in mortality observed in the study. Recent studies carried out on patients with chronic coronary heart disease without previous heart attacks and/or residual ischaemia have shown a good safety profile for this class of drugs. In addition, other studies have shown excellent efficacy in the absence of pro-arrhythmic effects of Class IC AADs in patients with structural heart disease such as arrhythmogenic right ventricular cardiomyopathy (ARVC) and tachy-cardiomyopathy. The purpose of this review is to evaluate the appropriate use of Class IC AADs in the different patient subgroups, in the light of the evidence and new diagnostic and therapeutic tools available.