Value of plasma D-dimer level for prediction of in-hospital mortality in patients presenting with Takotsubo syndrome

AIMS: D-dimer, degradation product of cross-linked fibrin, has been described as the prognostic marker in some cardiovascular diseases. However, the association between D-dimer levels and prognosis has not been fully evaluated in patients with Takotsubo syndrome (TTS). METHODS AND RESULTS: We retrospectively analysed data of 580 patients with TTS from the Tokyo Cardiovascular Care Unit Network registry. The primary endpoint was in-hospital all-cause death. Logistic regression analysis was used to investigate the relationship between D-dimer level and mortality. The additive effect of D-dimer level on the conventional prognostic risk score (InterTAK) was assessed using C-statistic, net reclassification improvement (NRI), and integrated discrimination improvement (IDI). In the entire sample (median age, 77 years; 79.5% women), 174 (30.0%) patients had an emotional trigger, while 177 (30.5%) patients had a physical trigger, causing 28 (4.8%) deaths (cardiac death n = 13, 46.4%, non-cardiac death n = 15, 53.6%). D-dimer levels on admission were significantly higher in those who died than in those who survived (6.4 3.9-18.3 vs. 1.1 0.7-2.9 µg/mL, P < 0.001). On multivariable logistic regression analysis, the odds ratio (OR) for in-hospital mortality significantly increased with D-dimer levels ≥3.5 µg/mL (OR: 7.06 95% confidence interval: 2.90-17.16, P < 0.001). The InterTAK Prognostic Score was 17 (11-24), and NRI and IDI were improved by incorporating D-dimer levels (NRI: 1.08, P < 0.001; IDI: 0.05, P < 0.001). CONCLUSION: Elevated D-dimer levels may serve as an additional predictor of increased in-hospital mortality in patients with TTS. Patients with higher D-dimer levels may warrant intensified monitoring and management.