NT-proBNP in CKD Interpretation — EECC MCQ

Correct answer: D — NT-proBNP is partly cleared by the kidneys — levels are disproportionately elevated in CKD relative to the degree of cardiac dysfunction; adjusted thresholds or serial measurements (relative change from individual baseline) should be used rather than absolute values in CKD

NT-proBNP is cleared through multiple pathways including renal excretion. In CKD: (1) NT-proBNP levels are disproportionately elevated relative to cardiac dysfunction (accumulation from reduced clearance); (2) the diagnostic and prognostic thresholds established in patients with normal renal function may overestimate HF severity in CKD; (3) eGFR-adjusted thresholds have been proposed but are not universally adopted. The ESC HF Guidelines acknowledge the confounding effect of CKD and recommend: (1) using serial measurements (relative change from individual baseline is more meaningful than absolute values); (2) considering eGFR when interpreting NT-proBNP; (3) BNP is similarly affected by renal function (and additionally by neprilysin inhibition from ARNI). In clinical practice, markedly elevated NT-proBNP in CKD should not be automatically attributed to renal dysfunction — concurrent HF is common and should be actively assessed.

Reference: ESC (2023): HF Guidelines