The relative utility of cardiac troponin I, creatine kinase MBmass, and myosin light chain-1 in the long term risk stratification of patients with chest pain.

Background: Sensitive and specific cardiac markers convey important short-term prognostic information about patients with an acute coronary syndrome. There are, however, few data assessing their value as long-term predictors.

Hypothesis: The aim of the current study was to assess the relative value of three such markers and clinical characteristics in determining the long-term prognosis of patients with chest pain.

Methods: Cardiac troponin I (cTnI), myosin light chain-1 (MLC-1), and creatine kinase-MBmass levels were obtained on admission (0 h) and at 4, 8, 16, and 24 h in 208 patients with chest pain. Eligible subjects were determined, at the time of hospital admission, to be at >7% risk of acute myocardial infarction (MI), but without new ST-segment elevation on their presenting electrocardiogram. Follow-up was performed a median of 28 (range 1-46) months later. The primary study endpoint was death or nonfatal MI, subsequent to the index admission.

Results: Cardiac TnI levels greater than or equal to0.2 ng/ml (odds ratio [OR] 1.93, 95% confidence interval [CI] 1.09-3.40) and MLC-1 levels greater than or equal to1 ng/ml (OR 3.24, 95% CI 1.83-5.73) were both significant predictors of death or MI during long-term follow-up; MLC-1 was, however, the only independent biochemical predictor (OR 2.11, 95% CI 1.14-3.93).

Conclusions: Both cTnI and MLC-1 predict the long-term outcome of patients with chest pain, but, in this cohort, MLC-1 proved to be a better predictor of mortality and nonfatal acute MI.