[Cardiac troponin I testing for the prognosis of non-cardiogenic critically ill patients].

OBJECTIVE

To investigate the role of cardiac troponin I (CTN I) for predicting 28-day mortality of non-cardiogenic critically ill patients at emergency department (ED).

METHODS

A total of 431 non-cardiogenic critically ill patients at ED were prospectively enrolled and blood samples obtained for CTN I measurements. A variety of laboratory variables and the Acute Physiology and Chronic Health Evaluation (APACHE) II scores were recorded. At Day 28, the survival status of each patient was ascertained and the association between CTN I at presentation and mortality assessed.

RESULTS

Two hundred patients had elevated CTN I levels and 231 had normal levels. Compared with those with normal levels, the patients with elevated CTN I levels had a higher 28-day mortality. The CTN I concentration alone had an area under the receiver operating characteristic curve (AUC) of 0.733 for mortality prediction. The optimal CTN I cut-off point for predicting the 28-day mortality was 0.05 ng/L. By multivariate analysis, an elevated CTN I level (> 0.05 ng/L, HR 1.979, 95% CI 1.398 - 2.802, P < 0.001), a high APACHE II score (> 16, HR 4.428, 95% CI 3.019 - 6.494, P < 0.001) and hypoalbuminemia (< 25 g/L, HR 1.812, 95% CI 1.276 - 2.573, P = 0.001) were the three most important independent predictors for a shorter survival. Combination analysis showed a shorter survival in patients with a high APACHE II score plus elevated CTN I levels than those with a high APACHE II score or an elevated CTN I level alone.

CONCLUSION

An elevated serum CTN I level is a independent predictor of 28-day mortality in non-cardiogenic critically ill patients. And CTN I level and APACHE II score have an additive effect in outcome prediction.