Troponin I in predicting cardiac or pulmonary complications and outcome in subarachnoid haemorrhage

Background: Patients with aneurysmal subarachnoid haemorrhage ( SAH) are at risk of cardiac and pulmonary complications. Troponin I (cTnI), a reliable marker of myocardial injury, is frequently raised after SAH. Aims: To investigate the additional value of (cTnI) in predicting cardiac or pulmonary complications and outcome in patients with SAH. Methods: Admission cTnI was measured in a prospective series of patients admitted within 24 hours of SAH. By means of univariate and multivariate logistic regression models the additional prognostic value of raised cTnI (> 0.3 mg/ litre) was investigated compared with established prognosticators (clinical condition on admission, age, and amount of blood on admission computed tomography) for predicting the occurrence of pulmonary oedema, pulmonary gas exchange abnormalities, rhythm disturbances, inadequate cardiac performance, a combination of these complications, and poor outcome. Area under the operator characteristic curve (AUC- ROC) was used to assess additional prognostic value. Results: Abnormal cTnI concentrations were found on admission in 35 of 68 patients. Abnormal cTnI concentrations and poor clinical condition independently predicted cardiac or pulmonary complications. After extending the model with World Federation of Neurological Surgeons scale and age in addition to abnormal cTnI, the AUC- ROC improved from 0.70 (95% confidence interval (CI), 0.57 to 0.83) to 0.83 (95% CI, 0.72 to 0.93). Abnormal cTnI also independently predicted poor outcome. The additional prognostic value of cTnI for poor outcome is limited. Conclusions: cTnI measurement is a powerful predictor for the occurrence of pulmonary and cardiac complications, but does not carry additional prognostic value for clinical outcome in patients with aneurysmal SAH.