CardiomyopathyUsefulness of Cardiac Troponins as Markers of Early Treatment Response in Cardiac Sarcoidosis

Evaluation and treatment of cardiac sarcoidosis (CS) suffer from lack of sensitive and easily repeatable markers of disease activity. We studied measurements of high-sensitivity cardiac troponin T or troponin I (hs-cTnT/I) taken at presentation and during treatment in 62 patients with new-onset CS (48 women, mean age 49 years). Hs-cTnT was measured in 50 patients and was elevated (>13 ng/L) at presentation in 26 of them (52%). Hs-cTnI was measured in the remaining 12 patients and was elevated (>0.04 ng/mL) in 7 of them (58%). Left ventricular ejection fraction averaged 43 ± 14% in association with elevated hs-cTnT/I (n = 33) versus 53 ± 10% with normal hs-cTnT/I (n = 29; p = 0.001). Hs-cTnT/I was remeasured after 4 weeks of steroid therapy in 38 patients and was normalized in 16 of the 24 (67%) with an elevated pretreatment concentration and remained normal in the rest of the 14 patients (p <0.001). During follow-up (median, 17 months), cardiac death (n = 2), aborted sudden death (n = 5), sustained ventricular tachycardia (n = 8), or new complete atrioventricular block (n = 1) was recorded in 11 of 33 patients with elevated hs-cTnT/I versus in 5 of 29 with normal hs-cTnT/I (log-rank p = 0.068). Two-year event-free Kaplan-Meier cardiac survival estimate (95% confidence interval) was 67% (48% to 81%) with elevated hs-cTnT/I versus 93% (76% to 99%) with normal hs-cTnT/I. In CS, circulating hs-cTnT/I may help clinicians evaluate disease activity and treatment response. Their prognostic value remains tentative pending more follow-up data.