Although conventional cardiac troponin T (cTnT) and I (cTnI) markers have been reported to predict adverse outcome in dilated cardiomyopathy (DCM), the usefulness of a new-generation high-sensitivity assay of cardiac troponin T (hs-cTnT) compared with these conventional biomarkers is unclear.
We performed clinical evaluation including measurements of troponin markers in 54 patients with DCM under a clinically stable condition. At baseline, the serum concentration of hs-cTnT was 0.014 ± 0.016 ng/mL and 17 (31%) of the patients showed abnormal hs-cTnT values (> 0.014 ng/mL). During a mean follow-up period of 5.1 ± 1.6 years, there were 16 cardiac events: heart failure death in 6 patients, sudden cardiac death in 2 patients, and hospitalization for heart failure in 8 patients. Patients with abnormal hs-cTnT or abnormal cTnT (> 0.01 ng/mL) values had significantly more frequent cardiac events than did those with normal hs-cTnT or cTnT values. On the other hand, abnormal cTnI (> 0.03 ng/mL) value did not reach statistical significance for these adverse events. Multivariate analysis showed that only an abnormal hs-cTnT value was an independent predictor of all cardiac events (HR: 5.68, P = 0.003). When the patients were divided into 4 groups according to the degree of hs-cTnT levels, the clinical course was significantly worse in patients with higher hs-cTnT values.
These results suggest that the serum concentration of hs-cTnT provides better risk stratification in DCM patients.