Ultimately, the true value of a cardiac marker lies in its ability to predict adverse outcome or, even better, to predict treatment benefit.
Prognostic cohort studies are increasingly used to demonstrate the value of new markers. However, it is unlikely that prognostic studies will be designed to evaluate cardiac markers specifically in low risk patients.
These patients generally have an excellent prognosis, with a 6 month mortality of less than 1%, so a cohort study would need to be unfeasibly large to identify useful prognostic value from a cardiac marker. Hence we are likely to need to extrapolate prognostic data from studies of high risk patients.