Ischemic biomarker heart-type fatty acid binding protein (hFABP) in acute heart failure - diagnostic and prognostic insights compared to NT-proBNP and troponin I

BACKGROUND To evaluate diagnostic and long-term prognostic values of hFABP compared to NT-proBNP and troponin I (TnI) in patients presenting to the emergency department (ED) suspected of acute heart failure (AHF). METHODS 401 patients with acute dyspnea or peripheral edema, 122 suffering from AHF, were prospectively enrolled and followed up to 5 years. hFABP combined with NT-proBNP versus NT-proBNP alone was tested for AHF diagnosis. Prognostic value of hFABP versus TnI was evaluated in models predicting all-cause mortality (ACM) and AHF related rehospitalization (AHF-RH) at 1 and 5 years, including 11 conventional risk factors plus NT-proBNP. RESULTS Additional hFABP measurements improved diagnostic specificity and positive predictive value (PPV) of sole NT-proBNP testing at the cutoff <300 ng/l to "rule out" AHF. Highest hFABP levels (4th quartile) were associated with increased ACM (hazard ratios (HR): 2.1-2.5; p = 0.04) and AHF-RH risk at 5 years (HR 2.8-8.3, p = 0.001). ACM was better characterized in prognostic models including TnI, whereas AHF-RH was better characterized in prognostic models including hFABP. Cox analyses revealed a 2 % increase of ACM risk and 3-7 % increase of AHF-RH risk at 5 years by each unit increase of hFABP of 10 ng/ml. CONCLUSIONS Combining hFABP plus NT-proBNP (<300 ng/l) only improves diagnostic specificity and PPV to rule out AHF. hFABP may improve prognosis for long-term AHF-RH, whereas TnI may improve prognosis for ACM. TRIAL REGISTRATION ClinicalTrials.gov identifier: NCT00143793 .