Cardiac troponin T is elevated in asymptomatic patients with chronic renal failure

Abstract

Patients with chronic renal failure (CRF) are at increased risk for myocardial events that are difficult to evaluate due to atypical symptoms and chronically elevated protein markers of cardiac damage. This study evaluated cardiac troponin T (cTnT), a sensitive marker of cardiac injury, in patients with CRF without myocardial infarction symptoms, and assessed potential causes for elevated cTnT. Blood was obtained from 38 patients with CRF immediately before hemodialysis and from 16 of them post-dialysis, from 21 peritoneal dialysis patients, 10 patients with CRF not on dialysis, 11 patients with cardiomyopathy, and 10 adolescent patients with CRF undergoing hemodialysis. Samples were analyzed for myoglobin, creatine kinase, creatine kinase isoenzyme-MB (CK-MB), lactate dehydrogenase, lactate dehydrogenase isoenzyme-1 (LD-1), and cTnT. Cardiac TnT was elevated in: 71% of patient with CRF undergoing hemodialysis with no significant differences between pre- and post-dialysis values, 57% of patients with CRF on peritoneal dialysis, 30% of patients with CRF without dialysis, 18% of patients with cardiomyopathy, and 20% of adolescent patients with CRF undergoing hemodialysis. Myoglobin was elevated in almost all patients with CRF undergoing hemodialysis and without dialysis, whereas CK-MB and LD-1 were rarely elevated. Cross-reacting dialyzable substances and myocardial stretch were not major causes for elevated cTnT. Until future studies clarify the etiology of elevated cTnT in patients with CRF, results should be interpreted cautiously.