Cardiac troponins in children with chronic renal failure

ABSTRACT

Cardiac troponins T and I [cTnT, cTnI] are highly sensitive biomarkers for the detection of myocardial damage. Patients with chronic renal failure [CRF]on regular hcmodialysis [HD] often have increased serum concentrations of cardiac troponins and left ventricular hypertrophy [LVH] with or without evidence of acute myocardial injury. Thirty eight pediatric patients [23 males and 15 females], aged 4-18 years, suffering from CRF and on regular HD for more than one year were prospectively included in this study as well as 15 apparently healthy children matched for age and sex as controls. All patients and controls had detailed history and full clinical examination. Serum levels of Na, K, cTnT, cTnI, creatinin kinase [CK] and creatinin kinase MB [CK-MB] and hematocrit were estimated. Echocardiographic estimation of left ventricular [LV] dimensions, FS, EF, LV mass index [LVMI] and relative wall thickness [RWT] was done. Patients were classified into three subgroups according to presence or absence of LVH, congestive heart failure [CHF] and anurea. Serum levels of cTnT, cTnI and CK-MB were significantly higher in the patient group [0.086 +/- 0.054, 0.357+0.17, 5.65 +/- 3.94ng/ml] compared to controls [0.052 +/- 0.036, 0.26 +/- 0.12, 4.2 +/- 2.88ng/ml] respectively [p<0.05 for all]. In the patient group, cTnT was elevated in 58% [22/38], cTnI was elevated in 15.7% [6/38], while CK-MB was elevated in only 8% [3/38]. Significantly higher cTnT was detected in patients with LVH, CHF and anurea [0.126 +/- 0.11, 0.132 +/- 0.123, 0.134 +/- 0.13ng/ml] than those-without [0.054 +/- 0.034, 0.062 +/- 0.048, 0.071 +/- 0.049ng/ml], [p<0.01, 0.025, 0.05] respectively. Also, cTnI was significantly higher in patients with LVH, CHF and anurea [0.381 +/- 0.05, 0.391 +/- 0.12, 0.389 +/- 0.13ng/ml] than those without [0.337 +/- 0.07, 0.339 +/- 0.014, 0.323 +/- 0.019ng/ml] p<0.05 for all. LVH was found in 58% of patients who had significantly higher LVMI than controls [39.9 +/- 14.2 Vs. 24.3 +/- 6.3g/m[2.7], p<0.001]. Concentric LVH was found in 8 [36%] of them. LVMI correlated significantly, with systolic BP [r=0.72, p=0.011], diastolic BP [r=0.83, p=0.002], indexed end diastolic LV dimension [r=0.68, p=0.010]. In addition, a highly significant positive correlation was detected between LVMI and cTnT serum level [r=0.591, p<0,001]. Serum levels of cardiac troponins [cTnT and cTnI] and LVMI are increased in pediatric patients with chronic renal failure on regular hemodialysis particularly those with cardiac complications. Cardiac troponins and LVH appear to predict cardiac complications in this group of patients