Association of Longitudinal High-Sensitivity Troponin T With Mortality in Patients With Chronic Kidney Disease

Cardiac troponin T (cTnT) is associated with mortality in chronic kidney disease (CKD). However, the association between longitudinal cTnT measurements and survival has not previously been assessed.This study determined whether various parameterizations of longitudinal cTnT measurements were associated with patient survival in the older population with advanced CKD.The EQUAL (European QUALity) study is an observational prospective cohort study that includes subjects with stage 4-5 CKD aged ≥65 years and not on dialysis. The study includes 176 participants in Sweden, where longitudinal information of cTnT was collected. The study uses joint models for longitudinal and time-to-event data to assess the longitudinal association between cTnT and survival.There were 927 cTnT measurements (median 6 per patient) collected over a median follow-up of 2.4 years. The overall 5-year survival was 57% (95% CI: 46%-69%). Longitudinally measured cTnT was associated with mortality risk, with every SD increase in cTnT, at any time point, associated with a 3.3-fold increase in mortality risk (HR: 3.3; 95% CI: 2.5-4.6). The slope of the cTnT trajectory was also associated with increased mortality risk (HR: 3.2; 95% CI: 2.0-6.0), as was the area under the cTnT trajectory (HR: 4.2; 95% CI: 2.6-7.2), which reflected the cumulative cTnT exposure.Longitudinally measured cTnT is independently associated with mortality risk in older patients with stage 4 and 5 CKD, which suggests that monitoring patients with cTnT could be a valuable tool for the identification of subjects with a high mortality risk.