Impact of the inflammation on the outcomes of catheter ablation of drug-refractory ventricular tachycardia in cardiac sarcoidosis

Introduction: Catheter ablation (CA) of ventricular tachycardia (VT) in cardiac sarcoidosis (CS) has been reported with varying success. However, there is a scarcity of data on the outcomes of CA based on ongoing inflammation. Objective: We hypothesized that the response to VT ablation depends upon the stage of the disease. Methods: Between July 2004 and December 2018, 24 patients of CS presented with drug-refractory VT at CARE Hospital (Hyderabad) and the University of Minnesota (Minneapolis, MN). Patients were classified into two groups based on cardiac magnetic resonance imaging and positron emission tomography: (a) inflammatory phase, (b) scar phase. All patients underwent 3D electro-anatomic mapping guided CA. Results: The clinical VT was ablated in all but one patient. In 16 patients (66.6%), both the clinical and nonclinical VTs were ablated (complete success), while in seven patients (29.1%) nonclinical VTs was still inducible. In patients with inflammation (group A), complete success for VT ablation was achieved in 10 out of 17 (58.8%). In patients without inflammation (group B), complete success was achieved in six out of seven patients (85.7%). Eleven patients (45.8%) had a recurrence of VT. Among patients in the inflammatory phase (group A): 10 out of 17 patients had a recurrence of VT, while only one out of seven patients in the scar phase (group B) had VT recurrence over a mean follow-up of 5.7 ± 3.9 years. Epicardial ablation was performed in 10 (41.6%) patients. Conclusion: CA of drug-refractory VT in CS is effective, often requiring the epicardial approach. Incomplete success and recurrence of VT were higher in the inflammatory phase of the disease.