Incidence and predictors of new-onset sustained ventricular tachycardia in patients with cardiac sarcoidosis and high-grade AV block as first cardiac symptom

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Background Cardiac sarcoidosis (CS) is infrequently affecting the heart and may cause heart failure and dangerous arrhythmias. If left untreated, it usually progresses to end-stage heart failure or can cause sudden cardiac death. A frequent initial presentation is AV block, but malignant ventricular arrhythmias can occur in the course of the disease, as well. Ventricular tachycardia or fibrillation (VT/VF) can occur even in patients with normal or nearly normal ejection fraction. Therefore, the current guidelines recommend implantation of ICD devices whenever a pacemaker implantation is needed, such as in case of AV block, although there are little data supporting this opinion. Purpose The purpose of this study was to establish the risk for occurrence of VT/VF in patients with CS, initially presenting with AV block. Furthermore, we sought to establish possible predictors for occurrence of VT/VF. Methods We analyzed 128 patients diagnosed with CS according to the latest JCS criteria. Patients with AV block as initial cardiac presentation were selected and were followed for occurrence of VT/VF or death. We analyzed the differences between the baseline characteristics and the cardiac imaging between those with and without VT/VF. Results Out of 128 patients with CS, 30 (23%) patients (13 female, age 50 ± 10 y; EF 48 ± 12%) with high-grade AV Block as initial cardiac symptom were identified. In 7 of them, a permanent pacemaker had already been implanted. In 15 (50%) patients the diagnosis was confirmed histologically. Cardiac MRI showed presence of LGE in 10 patients with mean LGE volume of 14±8%, and RV involvement in 5 cases. 18FDG-PET showed abnormal tracer enhancement in 12 (40%) patients with SUVmax 9 ± 5. A new sustained VT/VF occurred during the follow up in 10 (30%) patients; and non-sustained VT in other 4. Death occurred suddenly in 2 patients, both without an ICD device. In the univariate analysis, the following baseline characteristics were not associated with occurrence of VT: age, LVEF, amount of LGE, SUVmax, ACE and sIL2-R. Patients with new VT/VF during FU had more frequently RV involvement ( 50% vs. 0 %); LGE in CMR (100% vs 50%) and positive PET ( 100% vs. 57%). Conclusions Patients with cardiac sarcoidosis and AV block as initial presentation have a very high risk of developing sustained VT/VF. Death occurred only in patients without an ICD. ICD implantation, instead of pacemaker, should be considered in all patients with AV block, especially in presence of LGE in CMR, abnormal 18FDG PET and RV involvement.