Baseline cardiac troponin I in patients on maintenance dialysis

There have been conflicting reports in the medical literature regarding baseline levels of cardiac troponins and their usefulness as specific markers of acute myocardial injury in patients on maintenance dialysis. Hence we undertook a study of the normal range of baseline cardiac troponin I (cTnI) in patients on maintenance dialysis in our center.

Seventy-five patients aged 45 years or more on maintenance dialysis for at least 1 month were included in the study. None had had an acute cardiac event requiring admission to the hospital during the preceding month. Samples of blood were collected and cTnI levels were estimated using an immunoenzymatic assay (Access Immunoassay system, Beckmann). Correlation of cTnI with gender, age, body mass index (BMI), and adequacy of dialysis (Kt/v) were also done.

Forty-six (61.3%) patients were on maintenance hemodialysis and 29 (38.6%) were on peritoneal dialysis. Twenty-four (32%) were over the age of 65 years and 37 (49.3%) were men. Levels of cTnI ranged from 0.000 to 0.568 ng/mL, with mean of 0.040 +/- 0.080. Only six (8%) had levels above 0.1 ng/mL, which was the cut off level for significance in our laboratory. There was no statistically significant correlation of cTnI levels with gender, age, BMI, or Kt/v.

Baseline cTnI levels were below significant levels in the majority of maintenance dialysis patients aged at least 45 years or more. Hence cTnI can be used as a valid marker of acute myocardial injury in this group of patients.