Cardiac troponin I in patients with chronic kidney disease stage 3 to 5 in conditions other than acute coronary syndrome.

BACKGROUND

Elevations of cardiac troponin I (cTnI) not associated with acute coronary syndrome (ACS) have been reported in patients with chronic kidney disease (CKD) stage 5 or end-stage renal disease (ESRD). The aim of this study was to determine the prevalence of elevated cTnI in patients with CKD stage 3 to 5 in conditions other than ACS.

METHODS

The study population consisted of 426 patients with CKD stage 3 to 5 (estimated glomerular filtration rate < 60 mL/minute/1.73m2 calculated with the MDRD-4 equation) admitted with symptoms of ACS but finally this diagnosis was ruled out with determinations of cTnI and medical history, physical examination, and electrocardiography. Levels of cTnI in serum were measured at admission, at 6 - 12 hours and at 6 months with two different analytical methods (Access and Vidas analyzers). Patients were assigned into the following two groups according to the clinical diagnosis: 1) patients with Other Cardiac Diseases (OCD) and 2) patients with Other Noncardiac Diseases (ONCD).

RESULTS

The OCD group included 140 patients (33%) and the ONCD group included 286 patients (67%). We found elevated cTnI (higher than 99th percentile) with the Access and Vidas analyzers in 32% of patients. The prevalence of elevated cTnI was higher in patients with CKD stage 5 or ESRD. In the OCD group, the most common diagnoses were congestive heart failure (52.1%) and atrial fibrillation (20%), whereas in the ONCD group they were arterial hypertension (8.4%) and cerebrovascular accident (8.1%). The rate of mortality in patients with CKD stage 3 to 5 was 17% but was higher in patients with CKD stage 5 (40%).

CONCLUSIONS

Elevations of cTnI not associated with ACS were common in patients with CKD stage 3 to 5, and there was an increase in mortality with higher concentrations of cTnI.