An oxidative stress biomarker, urinary 8-hydroxy-2′-deoxyguanosine, predicts cardiovascular-related death after steroid therapy for patients with active cardiac sarcoidosis

Background We investigated whether urinary 8-hydroxy-2′-deoxyguanosine (U-8-OHdG), a marker of oxidative DNA damage, is a prognosticator of cardiovascular-related death in patients with cardiac sarcoidosis (CS). Methods and results In this prospective study, 30 consecutive patients were divided into the active CS (n=20) and non-active CS (n=10) groups, based on abnormal isotope accumulation in the heart on 18F-fluorodeoxyglucose positron-emission tomography/computed tomography (18F-FDG PET/CT) imaging. Nineteen patients in the active CS group underwent corticosteroid therapy. Before corticosteroid therapy initiation, U-8-OHdG, brain natriuretic peptide (BNP), other biomarkers, and indices of cardiac function were measured. Patients were followed-up for a median of 48months. The primary endpoint was the incidence of cardiovascular-related death.During the follow-up period, in the corticosteroid-treated active CS group, 7 of 19 patients experienced cardiovascular-related death. By contrast, in the non-active CS group, 1 of 10 patients died from cardiovascular-related causes. Univariate and multivariate analyses showed that U-8-OHdG and BNP were independent predictors for cardiovascular-related death. The cut-off values for predicting cardiovascular death in corticosteroid-treated patients with active CS were 19.1ng/mg·Cr and 209pg/mL for U-8-OHdG and BNP, respectively. Patients with a U-8-OHdG concentration ≥19.1ng/mg·Cr or a BNP concentration ≥209pg/mL had a significantly higher cardiovascular-related death risk, but U-8-OHdG had better predictive value compared with BNP. Conclusion These findings suggested that U-8-OHdG was a powerful predictor of cardiovascular-related death in patients with CS, suggesting that active CS patients with elevated U-8-OHdG levels might be resistant to corticosteroid therapy.