Multiple biomarker strategy for improved diagnosis of acute heart failure in older patients presenting to the emergency department.

Abstract

Biomarkers can help to identity acute heart failure (AHF) as the cause of symptoms in patients presenting to the emergency department (ED). Older patients may prove a diagnostic challenge due to co-morbidities. Therefore we prospectively investigated the diagnostic performance of N-terminal pro-B-type natriuretic peptide (NT-proBNP) alone or in combination with other biomarkers for AHF upon admission at the ED. 302 non-surgical patients aged ≥ 70 years were consecutively enrolled upon admission to the ED. In addition to NT-proBNP, mid-regional pro-adrenomedullin (MR-proADM), mid-regional pro-atrial natriuretic peptide (MR-proANP), C-terminal pro-endothelin-1 (CT-proET-1) and ultra-sensitive C-terminal pro-vasopressin (Copeptin-us) were measured at admission. Two cardiologists independently adjudicated the final diagnosis of AHF after reviewing all available baseline data excluding the biomarkers. We assessed changes in C-index, integrated discrimination improvement (IDI), and net reclassification improvement (NRI) for the multimarker approach. AHF was diagnosed in 120 (40%) patients (age 81±6 years, 64 men, 56 women). Adding MR-ADM to NT-proBNP levels improved C-index (0.84 versus 0.81; p=0.045), and yielded IDI (3.3%; p=0.002), NRI (17%, p<0.001) and continuous NRI (33.3%; p=0.002). Adding CT-proET-1 to NT-proBNP levels improved C index (0.86 versus 0.81, p=0.031), and yielded robust IDI (12.4%; p<0.001), NRI (31.3%, p<0.001) and continuous NRI (69.9%; p<0.001). No other dual or triple biomarker combination showed a significant improvement of both C-index and IDI. In older patients presenting to the ED, the addition of CT-proET-1 or MR-proADM to NT-proBNP improves diagnostic accuracy of AHF. Both dual biomarker approaches offer significant risk reclassification improvement over NT-proBNP.