Takotsubo cardiomyopathy has a unique cardiac biomarker profile: NT-proBNP/myoglobin and NT-proBNP/troponin T ratios for the differential diagnosis of acute coronary syndromes and stress induced cardiomyopathy

Abstract

BACKGROUND: Takotsubo cardiomyopathy (TC) usually is not recognized until heart catheterization reveals typical wall motion abnormalities in the absence of significant coronary artery disease. It was our aim to identify TC by its unique cardiac biomarker profile at an early stage and, preferably, with non-invasive procedures only. METHODS: Ratios of N-terminal prohormone of brain natriuretic peptide (NT-proBNP) and myoglobin, NT-proBNP and troponin T (TnT), NT-proBNP and creatinekinase-MB (CK-MB) were compared in patients with TC (n=39), patients with ST-elevation myocardial infarction (STEMI, n=48) and patients with non-ST-elevation myocardial infarction (NSTEMI, n=34). Biomarkers were recorded serially at admission and at the three consecutive days. Optimal cut-off values to distinguish TC from STEMI and NSTEMI were calculated with receiver operator characteristic (ROC) curves. RESULTS: At admission a NT-proBNP (ng/l)/myoglobin ( g/l) ratio of 3.8, distinguished TC from STEMI (sensitivity: 89%, specificity: 90%), while a NT-proBNP (ng/l)/myoglobin ( g/l) ratio of 14 separated well between TC and NSTEMI (sensitivity: 65%, specificity: 90%). Best differentiation of TC and ACS was possible with the ratio of peak levels of NT-proBNP (ng/l)/TnT ( g/l). A cut-off value of NT-proBNP (ng/l)/TnT ( g/l) ratio of 2889, distinguished TC from STEMI (sensitivity: 91%, specificity: 95%), while a NT-proBNP (ng/l)/TnT ( g/l) ratio of 5000 separated well between TC and NSTEMI (sensitivity: 83%, specificity: 95%). CONCLUSIONS: TC goes along with a singular cardiac biomarker profile, which might be useful to identify patients with TC among patients presenting with acute coronary syndromes (ACS).

Ratio of high-sensitivity troponin to creatine kinase-MB in takotsubo syndrome

“…differences in CKMB values were observed on admission and at the corresponding peak troponin sample times. As previously reported with conventional troponin [9,10,13,15], the ratio of NT-proBNP to hs-TnT proved to be significantly different (Table 2) between TT and MI patients (NT-proBNP available in 23 and 26 patients respectively). ROC curves (Fig.…”

“…Of these, the ratio of BNP or NT-proBNP to troponin has been extensively studied [9,10,13,15]. Of note, two of these studies only compared TT with STEMI patients in whom management would not be altered on the basis of biomarkers which are often available only after coronary angiography.…”

“…Thus, clinicians are frequently confronted with challenging cases where diagnosis is equivocal especially when imaging of the left ventricle is performed late in the clinical course. Moreover, many authors now suggest that invasive imaging may not be necessary in patients presenting without ST segment elevation [9,10]. In this setting, much research has been conducted to find discriminatory markers between acute coronary syndromes, especially ST-segment elevation myocardial infarction (STEMI), and TT as appropriate diagnosis has important implications with regards to management and prognosis.…”

“…Exclusion criteria included significant kidney disease (defined arbitrarily in accordance with other similar studies [10] by a glomerular filtration rate (GFR) inferior to 35 mL/min/1.73 m 2 according to the MDRD formula) and cardiac/muscle biomarker elevation due to other causes.…”

'GET QT': Clinical Criteria to Differentiate Takotsubo Cardiomyopathy from STEMI

“…As in our study, this study also carried the same inherent problem of using TnTp instead of the TnTi. 17,18 On the other hand, Randhawa et al 10 proposed the ratios of simultaneously ordered initial BNP/troponin T and BNP/CKMB as specific markers for the distinction. Using the TnTi has the inherent risk of giving a false positive result for TCM as most of the AMI patients present with a low troponin but usually show an uptrend depending on the stage of the presentation, so its utility is low.…”