Am J Kidney Dis. 2021 Jul 19:S0272-6386(21)00760-5. doi: 10.1053/j.ajkd.2021.06.017. Online ahead of print.
RATIONALE & OBJECTIVE: The utility of conventional upper reference limits (URL) for N-terminal pro brain natriuretic peptide (NT-proBNP) and high-sensitivity cardiac troponin T (hsTnT) in chronic kidney disease (CKD) remains debated. We analyzed the distribution of hsTnT and NT-proBNP in people with CKD in ambulatory settings to examine the diagnostic value of conventional URL in this population.
STUDY DESIGN: Observational study.
SETTING & PARTICIPANTS: We studied participants of the Chronic Renal Insufficiency Cohort with CKD and no self-reported history of cardiovascular disease (CVD).
EXPOSURE: Estimated glomerular filtration rate (eGFR).
OUTCOMES: NT-proBNP and hsTnT at baseline.
ANALYTICAL APPROACH: We described the proportion of participants above the conventional URL for NT-proBNP (125 pg/ml) and hsTnT (14 ng/L) overall, and by eGFR. We then estimated 99th percentile URL for NT-proBNP and hsTnT. Using quantile regression of the 99th percentile, we modeled the association of eGFR with NT-proBNP and hsTnT.
RESULTS: Among 2,312 CKD participants, 40% and 43% had levels of NT-proBNP and hsTnT above conventional URL, respectively. In those with eGFR<30 ml/min/1.73 m2, 71% and 68% of participants had concentrations of NT-proBNP and hsTnT above conventional URL, respectively. Amongst all CKD participants, the 99th percentile for NT-proBNP was 3,592(95% CI: 2,470, 4,849) pg/mL and for hsTnT was 126(95% CI: 100, 144) ng/L. Each 15 ml/min/1.73 m2 decrement in eGFR was associated with a ∼40% higher threshold for the 99th percentile of NT-proBNP [1.43 (1.21, 1.69)] and hsTnT [1.45 (1.31, 1.60)].
LIMITATIONS: Study included ambulatory patients; we could not test the accuracy of upper reference limits of NT-proBNP and hsTnT in the acute care setting.
CONCLUSIONS: In this ambulatory CKD population with no self-reported history of CVD, a range of 40-88% of participants had concentrations of NT-proBNP and hsTnT above conventional URL, depending on eGFR strata. Developing eGFR-specific thresholds for these commonly-used cardiac biomarkers in the setting of CKD may improve their utility for evaluation of suspected heart failure and myocardial infarction.