Outcome‐Guided Immunosuppressive Therapy and Clinical Events in Patients With Cardiac Sarcoidosis: An Observational Registry

Background Immunosuppressive therapy (IST) is commonly used in cardiac sarcoidosis, but the strategy to guide it is unclear and its effectiveness uncertain. We assessed the association between IST, guided by clinical course and positron emission tomography, and clinical outcomes in cardiac sarcoidosis. Methods We compared 83 patients with cardiac sarcoidosis who received IST with 20 who declined therapy. IST was escalated for persistent symptoms and inflammation. Ventricular arrhythmia recurrence, ventricular pacing, New York Heart Association class, and left ventricular (LV) ejection fraction were assessed after 12 months. Death, LV assist device, and heart transplantation were assessed during a median follow‐up of 24.9 months. Results Sustained ventricular tachycardia recurred in 12% of patients with IST versus 20% of those without IST ( P =0.264). Within the IST group, New York Heart Association class and LV ejection fraction improved during 12 months ( P =0.011 and P =0.002), but the between‐group difference in New York Heart Association change was not significant ( P =0.490). Major adverse cardiovascular events occurred less frequently with IST (10.8% versus 40.0%, P =0.004). After adjustment for baseline LV ejection fraction, IST had a lower hazard of major adverse cardiovascular events (hazard ratio, 0.30 [95% CI, 0.11–0.80]; P =0.017), consistent among sensitivity analyses. Given only 17 events and baseline imbalance, residual confounding cannot be excluded and this is hypothesis‐generating. Conclusions In this observational registry, glucocorticoid‐based IST was associated with lower rates of death, heart transplantation, and LV assist device implantation. No significant between‐group difference was detected in sustained ventricular tachycardia recurrence, although the study was underpowered to exclude smaller differences. Because treatment was not randomized, these associations cannot establish causality.