Abstract 9629: Combination Therapy of Cilostazol and Bepridil Suppresses Recurrent Ventricular Fibrillation Related to J-Wave Syndromes

Abstract

Introduction: Brugada syndrome (BrS) and idiopathic ventricular fibrillation (VF) associated with infero-lateral early repolarization patterns (early repolarization syndrome (ERS)) are termed “J-wave syndromes”. In such patients, an implantable cardioverter-defibrillator (ICD) is first-line therapy for prevention of sudden cardiac death. However, frequent ICD shocks due to recurrent VF remain serious problems. We investigated if combination therapy using cilostazol and bepridil could suppress recurrent VF. Methods: Our cohort comprised 22 consecutive patients (BrS, 16; ERS, 3; unknown, 3) with J-wave syndromes in whom ICDs were implanted for spontaneous episodes of VF. We enrolled 7 patients with J-wave syndromes who experienced ICD shocks due to recurrent VF after ICD implantation. At first, cilostazol was instituted. In all subjects, palpitations due to sinus tachycardia caused by cilostazol were symptomatic. Addition of bepridil attenuated cilostazol-induced palpitations (87±12 to 66±7 bpm, P<0.01) and maintained the suppressive effect of cilostazol against VF. Results: Prior to the onset of the cilostazol/bepridil combination therapy, all 7 patients had a total of 20 shocks over an accumulated period of 79 months. In contrast, after the onset of therapy, they accumulated a combined follow-up period of 375 months, and during that significantly longer period only one of them received 2 shocks. Three patients underwent replacement of the ICD generator 4-5 years after ICD implantation. Cilostazol was discontinued 2 days before replacement because of its anti-platelet effects. In all 3 patients, temporary discontinuation of cilostazol led to the reappearance of J waves, culminating in VF and an appropriate ICD shock in one of them. J waves disappeared upon re-institution of cilostazol. Conclusions: These data suggest that combination therapy of cilostazol and bepridil may be effective and safe in suppressing VF recurrence in some cases of J-wave syndromes.