Outcomes in Patients With High-Degree Atrioventricular Block as the Initial Manifestation of Cardiac Sarcoidosis

Although high-degree atrioventricular block (AVB) is a common initial manifestation of cardiac sarcoidosis, little is known about the outcomes. The aim of this study was to assess outcomes in patients with AVB as an initial manifestation of cardiac sarcoidosis compared with those in patients with ventricular tachyarrhythmia (VT) and/or heart failure (HF). Fifty-three consecutive patients with cardiac sarcoidosis, who had high-degree AVB (n = 22) or VT and/or HF (n = 31), were enrolled. The end point was defined as major adverse cardiac events, including cardiac death, ventricular fibrillation, sustained VT, and hospitalization for HF. Over a median follow-up period of 34 months, the outcomes of major adverse cardiac events were better in patients with high-degree AVB than in those with VT and/or HF (log-rank test, p = 0.046). However, this difference was due mainly to HF hospitalization. The outcomes of fatal cardiac events, including cardiac death, ventricular fibrillation, and sustained VT, were comparable between the 2 groups (log-rank test, p = 0.877). The fatal cardiac events in patients with high-degree AVB were not associated with the initiation of steroid treatment or left ventricular dysfunction. In conclusion, the outcomes of major adverse cardiac events are better in patients with high-degree AVB than in those with VT and/or HF. However, patients with high-degree AVB have a high rate of fatal cardiac events, similar to those with VT and/or HF. An indication for an implantable cardioverter-defibrillator, but not a pacemaker system, can be considered in patients with cardiac sarcoidosis manifested by high-degree AVB.