Assessing the Effect of Repeat PET Imaging on Treatment Response and Cardiovascular Outcomes among a Homogenously Treated Cohort of Patients with Suspected Cardiac Sarcoidosis.

Abstract

Introduction: Serial PET imaging is routinely employed to monitor treatment response in patients with suspected cardiac sarcoidosis (CS). Corticosteroids remain the mainstay of therapy in CS. However, there are no data available on the cardiovascular outcomes and optimal timing interval to obtain repeat PET while factoring in the influence of corticosteroid taper in relation to surveillance imaging.

Methods: We identified 81 patients with suspected CS (Age: 56.3 ± 1.9, 67% male, LVEF 46.5 ± 3) who were treatment naïve and demonstrated inflammation on baseline PET, subsequently started on moderate-dose prednisone monotherapy (i.e., 30-40 mg/day), and had a diagnostic follow-up PET. Treatment response was graded as complete (CTR) or partial (PTR), and no-response (NTR). Patients were divided into tertiles based on follow-up time between PET scans; tertile-1 (<3.2 months; median 3.1 months), tertile-2 (3.2 - 6.8 months; median 5.9 months), and tertile-3 (>6.8 months; median 9.8 months). Corticosteroid taper was captured by measuring weekly changes in prednisone from start of treatment to up to one-year follow-up. Major adverse cardiovascular events (MACE), defined as sustained ventricular arrhythmias were documented during the first year post-baseline PET.

Results: Treatment response CTR/PTR/NTR rates were similar across tertiles: (tertile-1 (92%) vs tertile-2 (86.2%) vs tertile-3 (85.2%); p=0.76). Taper rates and one-year cumulative prednisone dose were similar between the three groups (P=0.9). No significant difference was found in short-term MACE between the tertile groups (p=0.89). Similarly, MACE did not differ significantly according to treatment response status (p=0.39).

Conclusion: Surveillance time and taper rates do not seem to influence treatment response on PET scans among patients initiated on moderate-dose prednisone only. Similar MACE rates were observed despite variations in follow-up time and treatment response status.