Potential Mechanisms
Emerging evidence suggests that functional abnormalities in the microvasculature can lead to ischemia (20,21), which would be consistent with possible rises in troponin and NT-proBNP and compensatory changes in cardiac structure and function. Indeed, several studies have recently investigated an association between troponin elevation and microvascular complications after myocardial infarction and percutaneous coronary intervention (22,23). It is important to note that the additional predictive information added by cardiac biomarkers noted herein occurred despite the addition of previous history of CVD, which is a well-known risk factor (6). Renal function is likely to be an important determinant of circulating levels of biomarkers (24), and as such there may be some reverse causality, although this study is prospective and we have adjusted for baseline eGFR and ACR. Therefore, although cardiac biomarkers undoubtedly increase with progressive renal dysfunction, that cardiac biomarkers predict future decline in renal function independently of baseline renal function suggests potential clinical utility. The findings also hint at a potential for cardiac dysfunction to contribute to renal dysfunction.