Endocrine Abstracts

Introduction: The study aimed to analyze the efficiency of a concomitant N-terminal pro-brain natriuretic peptide (NT-proBNP) and cardiac high-sensitivity troponin T (hs-cTnT) testing in diagnosing non-ST-segment-elevation myocardial infarction (NSTEMI) in patients initially negative for the standard fourth-generation assay of cardiac troponin T (cTnT), but with high clinical probability of non-ST-segment-elevation acute coronary syndrome (NSTE-ACS).

Methods: One hundred and eight patients, 57 (52.8%) men, mean age 61.3±15.4, admitted for high-risk symptoms of NSTE-ACS in a time-interval <4 h after the symptoms onset, but with initial cTnT levels <0.01 ng/ml, were prospectively investigated. Plasma cTnT, NT-proBNP, and hs-cTnT were measured by electrochemiluminescence on admission, then 3 and 6 h afterwards. NSTEMI was considered at plasma hs-cTnT levels ≥ the 99th percentile cut-off (0.014 ng/ml), and a ≥20% dynamic variation within 6 h. Aortic dissection, pulmonary embolism, left ventricular hypertrophy, myocarditis, renal dysfunction and obesity were excluded by clinical, echocardiographic and biological data. Local Ethics Committee approved the study protocol and informed consent was signed by each patient. Statistics: MedCalc 12.2.1.0.

Results: Using a combination of hs-cTnT plasma levels ≥0.014 ng/ml and a ≥20% 6-h hs-cTnT dynamic plasmatic variation testing, NSTEMI was diagnosed within the cTnT ‘blind interval’ in 37 (34.26%) additional patients with high-risk symptoms of NSTE-ACS The aria under the receiver operating characteristic (AUC) for NT-proBNP in diagnosing NSTEMI was 0.68 (95% CI=0.56–0.74), P=0.0345. The optimal cut-off NT-proBNP plasma level for the diagnosis of NSTEMI on the ROC curve was 205 pg/ml, with a sensitivity of 72.28 (95% CI: 51.72–84.41) and a specificity of 65.42 (95% CI: 48.78–77.68), a positive predictive value of 58.84 (95% CI: 42.44–68.82) and a negative predictive value of 74.82 (95% CI: 62.82–82.42).

Conclusion: A multimarker strategy using NT-proBNP concomitant with hs-cTnT testing on admission in the early diagnosis of NSTEMI in patients with high clinical probability of acute coronary syndrome showed only an additional value of NT-proBNP testing.