Kidney Function Specific Reference Limits for N-terminal Pro Brain Natriuretic Peptide and High Sensitivity Troponin T: The Systolic Blood Pressure Intervention Trial

Association of cardiac biomarkers, kidney function, and mortality among adults with chronic kidney disease

Background and Aims

The performance of high sensitivity troponin T (hs-cTnT), hs-cTnI, and N-terminal pro-hormone brain natriuretic peptide (NT-proBNP) in patients with chronic kidney disease (CKD) is poorly understood.

Methods

We included adults with CKD (eGFR<60 ml/min/1.73m2) in the 1999-2004 NHANES. We calculated the 99th percentile of hs-cTnT, hs-cTnI (Abbott, Ortho, and Siemens assays), and NT-proBNP, measured the association between eGFR and cardiac biomarker concentration, and used Cox regression models to assess the relationship between cardiac biomarkers and CVD mortality.

Results

Across 1,068 adults with CKD, the mean [SD] age was 71.9[12.7] years and 61.2% were female; 78.8% had elevated NT-proBNP and 42.6% had elevated hs-cTnT based on traditional clinical reference limits. The 99th percentile of hs-cTnT was 122 ng/L (95% confidence interval (CI) 101-143), hs-cTnIAbbott was 69 ng/L (95% CI 38-99), and NT-proBNP was 8952 pg/mL (95% CI 7506-10,399). A 10 ml/min decrease in eGFR was associated with greater increases in hs-cTnT and NT-proBNP than hs-cTnI (hs-cTnT: 27.5% increase (β=27.5, 95% CI 28.2-43.3)), NT-proBNP 46.0% increase (β=46.0, 95% CI 36.0-56.8), hs-cTnISiemens 17.9% (β=17.9, 95% CI 9.7-26.7). Each doubling of hs-cTnT, hs-cTnI, and NT-proBNP were associated with CVD mortality (hs-cTnT HR 1.62 [95% CI 1.32-1.98], p<0.0001; hs-cTnISiemens HR 1.40 [95% CI 1.26-1.55], p<0.0001; NT-proBNP HR 1.29 [95% CI 1.19-1.41], p<0.0001).

Conclusions and Relevance

Community dwelling adults with CKD have elevated concentrations of cardiac biomarkers, above established reference ranges. Of the troponin assays, hs-cTnI concentration appears to be most stable across eGFR categories and is associated with CVD mortality.

Natriuretic peptide testing strategies in heart failure: A 2023 update

Natriuretic peptides (NPs), including B-type natriuretic peptide (BNP) and N-terminal pro-BNP (NT-proBNP), have been recommended as standard biomarkers for diagnosing heart failure (HF), and one of the strongest risk predictors for mortality and HF hospitalization regardless of ejection fraction (EF) and etiology of HF. BNP is an active neurohormone opposing renin-angiotensin-aldosterone and sympathetic nervous system overactivated in HF, whereas NT-proBNP is an inactive prohormone released from cardiomyocytes in response to wall stress. Despite substantial advances in the development of guideline-directed medical therapy (GDMT) for HF with reduced EF, studies demonstrating direct benefits of NP-guided chronic HF therapy on mortality, HF hospitalization, and GDMT optimization have yielded conflicting results. However, accumulating evidence shows that achieving prespecified BNP or NT-proBNP target over time is significantly associated with favorable outcomes, suggesting that benefits of serially measured NPs may be limited to particular groups of HF patients, such as those with extreme levels of baseline BNP or NT-proBNP, which could represent severe phenotypes of HF associated with natriuretic peptide resistance or cardiorenal syndrome. Over the past decade, clinical utilization of BNP and NT-proBNP has been expanded, especially using serial NP measurements for guiding HF therapy, optimizing GDMT and identifying at-risk patients with HF phenotypes who may be minimally symptomatic or asymptomatic.