Ivabradine for chronic heart rate control in persistent atrial fibrillation. Design of the BRAKE-AF project

Ivabradine is an inhibitor of the If channel, the main determinant of the pacemaker function of the sinus node. The drug has been approved for the treatment of angina and heart failure. There is some evidence of its role as an inhibitor of atrial-ventricular node (AVN) conduction. The aim of the BRAKE-AF project is to assess ivabradine use for rate control in atrial fibrillation (AF). A multicenter, randomized, parallel, open-label, noninferiority phase III clinical trial will be conducted to compare ivabradine vs digoxin in 232 patients with uncontrolled permanent AF despite beta-blockers or calcium channel blockers. The primary efficacy endpoint is the reduction in daytime heart rate measured by 24-hour Holter monitoring at 3 months. This clinical trial will be supported by an electrophysiological study of the effect of ivabradine on the action potential of the human AVN. To do this, an experimental model will be used with Chinese hamster ovarium cells transfected with the DNA encoding the expression of the t channels involved in this action potential and recording of the ionic currents with patch clamp techniques. New data will be obtained on the effect of ivabradine on the human AVN and its safety and efficacy in patients with permanent AF. The results of the BRAKE-AF project might allow inclusion of ivabradine within the limited arsenal of drugs currently available for rate control in AF. Clinical trial registration: http://www.clinicaltrials.gov. Identifier: NCT03718273. La ivabradina es un inhibidor de la corriente If, principal determinante de la función marcapasos del nódulo sinusal, aprobado como antianginoso y para tratar la insuficiencia cardiaca. Existen indicios sobre su capacidad para inhibir la conducción a través del nódulo auriculoventricular (NAV). Sobre esta base, el proyecto BRAKE-AF plantea el uso de ivabradina como agente cronotrópico negativo en fibrilación auricular (FA). Se realizará un ensayo clínico multicéntrico de fase III, aleatorizado, abierto, en paralelo, con diseño de no inferioridad, para comparar la ivabradina frente a la digoxina en 232 pacientes con FA permanente no controlada con bloqueadores beta o antagonistas del calcio; el objetivo primario es la reducción de la frecuencia cardiaca media diurna en un Holter de 24h a los 3 meses. El ensayo se apoyará en un estudio electrofisiológico que analizará el efecto de la ivabradina en el potencial de acción del NAV humano, utilizando un modelo experimental en células de ov