Value of Cardiac Biomarkers in the Early Diagnosis of Takotsubo Syndrome.

Background: Bedside diagnosis between Takotsubo syndrome (TTS) and ST elevation (STEMI) and non-ST elevation (NSTEMI) myocardial infarction remains challenging. We sought to determine a cardiac biomarker profile to enable their early distinction. Methods: 1100 patients (TTS n = 314, STEMI n = 452, NSTEMI n = 334) were enrolled in two centers. Baseline clinical and biological characteristics were compared between groups. Results: At admission, cut-off values of BNP (B-type natriuretic peptide)/TnI (Troponin I) ratio of 54 and 329 distinguished respectively STEMI from NSTEMI, and NSTEMI from TTS. Best differentiation was obtained by the use of BNP/TnI ratio at peak (cut-of values of 6 and 115 discriminated respectively STEMI from NSTEMI, and NSTEMI from TTS). We developed a score including five parameters (age, gender, history of psychiatric disorders, LVEF, and BNP/TnI ratio at admission) enabling good distinction between TTS and STEMI (77% specificity and 92% sensitivity, AUC 0.93). For the distinction between TTS and NSTEMI, a four variables score (gender, history of psychiatric disorders, LVEF, and BNP at admission) achieved a good diagnostic performance (89% sensitivity, 85% specificity, AUC 0.94). Conclusion: A distinctive cardiac biomarker profile enables at an early stage a differentiation between TTS and ACS. A four (NSTEMI) or five variables score (STEMI) permitted a better discrimination.