Prognostic value of changes in high-sensitivity cardiac troponin T beyond biological variation in stable outpatients with cardiovascular disease: a validation study.

OBJECTIVE To evaluate the prognostic implications of longitudinal long-term changes beyond the biological variation of high-sensitivity cardiac troponin T (hs-cTnT) in outpatients with stable or asymptomatic cardiovascular disease (CV) and to assess possible differences in the prognostic value while using reference change value (RCV) and minimal important differences (MID) as metric for biological variation. METHODS Hs-cTnT was measured at index visit and after 12 months in outpatients presenting for routine follow-up. The prognostic relevance of a concentration change of hs-cTnT values exceeding the biological variation defined by RCV and MID of a healthy population within the next 12 months following the stable initial period was determined regarding three endpoints: all-cause mortality (EP1), a composite of all-cause mortality, non-fatal myocardial infarction and stroke (EP2), and a composite of all-cause mortality, non-fatal myocardial infarction, stroke, hospitalization for acute coronary syndrome (ACS) or decompensated heart failure, and planned and unplanned percutaneous coronary interventions (PCI, EP3). RESULTS Change in hs-cTnT values exceeding the biovariability defined by MID but not by RCV discriminated a group with a higher cardiovascular risk profile. Changes within MID were associated with uneventful course (NPV 91.6-99.7%) while changes exceeding MID were associated with a higher occurrence of all endpoints within the next 365 days indicating a 5.5-fold increased risk for EP 1 (p = 0.041) a 2.4-fold increased risk for EP 2 (p = 0.049) and a 1.9-fold increased risk for EP 3 (p < 0.0001). CONCLUSIONS In stable outpatients MID calculated from hs-cTnT changes measured 365 ± 120 days apart are helpful to predict an uneventful clinical course. CLINICAL TRIALS IDENTIFIER NCT01954303.