Objective To investigate the predicting value of electrocardiography (ECG) deviation, plasma levels of troponin I (cTnI) and Combination of conventional biomarkers in the risk stratification and prognosis for patients with non-ST elevation acute coronary syndromes (ACS).
Methods 264 patients with acute chest pain were admitted to Zhu Jiang hospital consecutively with the diagnosis of non-ST elevation acute coronary syndromes from June 2001 to January 2010.18 leads of ECG and cTnI all biomarkers comprising cTnI test were performed as soon as admission. All patients were assigned to ST depression group and non ST depression group according to ECG, while cardiac troponin I (cTnI) was determined at bedside and the patients were re-divided into cTnI positive group (TnI ≥0.1 μg/l) and TnI-negative group (TnI <0.1 μg/l) according to TnI level. Observing composite cardiac events during hospitalisation to determine the cut-off point of each biochemical marker depending on whether cardiac events occured, When there was an abnormal value, we scored it for one point to calculate multimarker score. Patients were categorised into 3 strata : low stratum (0–3 scores), Intermediate stratum (4–6 scores) and high stratum (7–9 scores). The cardiac events were analysed in each group in-hospital. The logistic regression analysis was used to analysis the relation among multivariate factor to cardiac events, and the predictive power of admission ECG, cTnI and multimarker score to cardiac events were analyed with ROC curves.
Result Compared with non-ST segment depression, composite cardiac events were increased significantly in ST segment depression group. Compared with troponin I-negative group, composite cardiac events were significantly increased in Troponin I positive group. And patients in high stratum had a higher cardiac event rate than in low. Multivariate logistic regression analysis showed that multimarker score, troponin I and ST segment had independent predictive ability to cardiac events repectivly. The predictive power of multimarker score for cardiac events was significantly higher than cTnI and ECG (area under the ROC: 0.832, 0.717 and 0.636, respectively). Jointing the above together, the predictive power was significantly improved (area under ROC: 0.893).
Conclusion The changes of ST segment, plasma cTnI level and multimarker score play an important role on risk stratification and prediction of cardiac events in patients with non-ST elevation ACS, but multimarker score may demonstrate a more strong prognostic discriminatory capacity, and Jointing the above together, may increase the prognostic accuracy obviously.
- Non-ST-segment elevation acute coronary syndrome
- troponin I
- ST segment depression
- biochemical markers