Changes and clinical values in serum levels of cardiac troponin I, cystatin C and N-terminal B-type natriuretic propeptide in patients with type 4 cardiorenal syndrome

Objective  To explore the clinical values of serum levels of cardiac troponin I (cTnI), cystatin C (CysC) and N-terminal B-type natriuretic propeptide (NT-proBNP) in patients with type IV cardiorenal syndrome (CRS) and examine their correlations with cardiac function.

Methods  From April 2020 to April 2022, thr relevant clinical data were retrospectively reviewed for 92 hospitalized patients of type IV CRS due to chronic renal insufficiency (CKD). Another 88 patients were selected as CKD group. The levels of cardiac troponin-I (cTnI), N-terminal B-type natriuretic propeptide (NT-proBNP), cystatin C (CysC) and echocardiographic results were collected and compared between two groups and those with different concentric functions.

Results  In CRS group, the levels of cTnI 0.026(0.013, 0.062)μg/L vs 0.010(0.005, 0.021)μg/L, NT-proBNP 15 292.0(2971.0, 35 000.0)μg/L vs 498.7(335.4, 1318.8)μg/L and CysC (4.48±1.73)mg/L vs (3.33±1.58)mg/L, left ventricular end diastolic dimension (48.26±9.42)mm vs (45.65±5.28)mm, interventricular septal thickness at end-diastole (11.52±1.76)mm vs (10.38±1.37)mm, left ventricular posterior wall thickness at end-diastole (11.27±1.61)mm vs (10.21±1.29)mm were significantly higher than those in nephrotic group. Meanwhile left ventricular ejection fraction in CRS group were lower than those in nephrotic group (45.56±9.33)% vs (55.46±5.93%), P<0.05. With worsening cardiac function, serum levels of cTnI, NT-proBNP and CysC spiked markedly and correlated positively (r=0.543, 0.766, 0.421, P<0.001) while LVEF declined significantly and correlated negatively (r=−0.469, P<0.001). The area under curve (AUC) of serum levels of cTnI, NT-proBNP and CysC for type 4 CRS was 0.778 (95%CI:0.710-0.846), 0.920(95%CI:0.880-0.961) and 0.707(95%CI:0.630-0.784) respectively while AUC of combining the above three was 0.924(95%CI:0.885-0.962).

Conclusions  Serum levels of cTnI, NT-proBNP and CysC in patients with type IV CRS are correlated positively with cardiac function. And cTnI and CysC may aid the diagnosis of type IV CRS and NT-proBNP is a sensitive and accurate biomarker.