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

Background: 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. Objectives: This study determined whether various parameterizations of longitudinal cTnT measurements were associated with patient survival in the older population with advanced CKD. Methods: 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. Results: 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. Conclusions: 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.