External Validation of a Clinical Score to Differentiate Takotsubo Syndrome From Non-ST-Elevation Myocardial Infarction in Women.

ABSTRACT

BACKGROUND AND AIMS: Clinical presentation of Takotsubo Syndrome (TS) mimics acute coronary syndrome (ACS). A score to differentiate TS from ACS would be helpful to facilitate appropriate investigation and management. We have previously developed a clinical score (NSTE-Takotsubo Score) to distinguish women with non-ST-segment elevation myocardial infarction (NSTEMI) from TS with non-ST-segment elevation (NSTE-TS). This study sought to assess the diagnostic validity of this score in an external validation cohort. METHODS: The external cohort consisted of women with NSTE-TS (n=110) and NSTEMI (n=113) from two major tertiary hospitals in New Zealand. The five variables in the arithmetic score (range -6 to +5) and their relative weights are T-wave inversion (TWI) in ≥6 leads (3 points), recent stress (2 points), diabetes mellitus (DM) (-1 point), prior cardiovascular disease (CVD) (-2 points) and presence of ST depression (-3 points). Two clinicians blinded to the diagnoses calculated the score using clinical and electrocardiogram (ECG) data on day 1 post-admission. RESULTS: The NSTE-Takotsubo Score discriminated well between NSTE-TS and NSTEMI. The sensitivity and specificity of a score ≥1 to distinguish NSTE-TS from NSTEMI were 78% and 85%, respectively. The area under the receiver operator curve was 0.78 (95% CI 0.72 to 0.84). CONCLUSION: In an external validation cohort, the NSTE-Takotsubo Score was easy to apply and useful to identify women likely to have NSTE-TS on day 1 post-admission.