Sacubitril Does Not Exert Proarrhythmic Effects in Combination with Different Antiarrhythmic Drugs

Background: Previous studies suggest a direct effect of sacubitril on cardiac electrophysiology and indicate potential arrhythmic interactions between sacubitril and antiarrhythmic drugs. Therefore, the aim of this study was to explore the electrophysiologic effects of combining sacubitril with the antiarrhythmic drugs d,l-sotalol and mexiletine in isolated hearts. Methods and results: A total of 25 rabbit hearts were perfused using a Langendorff setup. Following baseline data collection, hearts were treated with mexiletine (25 µM, 13 hearts) or d,l-sotalol (100 µM, 12 hearts). Monophasic action potential demonstrated an abbreviation of action potential duration (APD₉₀) after administration of mexiletine. Spatial dispersion of repolarization remained unchanged after mexiletine treatment, whereas effective refractory periods (ERP) were significantly prolonged. D,l-sotalol prolonged cardiac repolarization and amplified spatial dispersion. Further infusion of sacubitril (5 µM) led to a significant reduction in APD₉₀ and ERP in the mexiletine group. In the d,l-sotalol group, additional administration of sacubitril shortened cardiac repolarization duration without affecting spatial dispersion. No proarrhythmic effect was observed after mexiletine treatment as assessed by a predefined pacing protocol. Additional sacubitril treatment did not increase ventricular vulnerability. When potassium concentration was reduced, 30 episodes of torsade de pointes tachycardia occurred after d,l-sotalol treatment. Additional sacubitril treatment significantly suppressed torsade de pointes tachycardia (eight episodes) in the d,l-sotalol-group. Conclusions: In class IB- and class III-pretreated hearts, sacubitril shortened refractory periods and cardiac repolarization duration. The combination of sacubitril with the antiarrhythmic drugs d,l-sotalol and mexiletine demonstrates a safe electrophysiologic profile and sacubitril reduces the occurrence of class III-related proarrhythmia, i.e., torsade de pointes tachycardia.