NPPB and myocardial infarction: It is also possible that the association between the biomarkers we tested might have been stronger at a time of clinical stability or, conversely, at the time of acute presentation, since our samples for both 25(OH)D and NT-proBNP were taken prior to discharge; however the prognostic importance of NT-proBNP at the time of MI has consistently been shown to be strong [18,19], and we performed the 1-month analysis to increase confidence in our findings.