**8. Summary and future perspectives**

There is a complex association between ventricular dysfunction, cardiac biomarkers, malnutrition, inflammation and overhydration among patients with CKD, which could partly explain the high CV morbidity and mortality among these patients, comparing with the general population.

Probably, these alterations begin in the very early stages of CKD and volume overload could be an important underlying factor. The inability of the insufficient kidney for excreting water and salt induces an increase in extracellular volume, which may be underestimated in the early phases of CKD. Persistently volume overload can induce an increment in blood pressure, myocardial hypertrophy and myocardial fibrosis. Over time, diastolic dysfunction develops. In this setting, further small increments in end-diastolic volume produce an exaggerated increment in end-diastolic pressure favoring the release of BNP and also, myocardial damage and cardiac remodeling. During cardiac remodeling, death of cardiomyocites is produced inducing a serum increment in troponins, and normal myocardium is progressively substituted by a fibrotic matrix, worsening so diastolic dysfunction. In this situation, systemic inflammation is produced by a yet non clear mechanism.

Thus, in this chapter, it is tried to highlight the importance of early intervention for controlling volume excess in the very early stages of CKD in order to prevent future cardiac dysfunction and inflammation, reducing so the bad CV prognosis of these patients.

It is noteworthy that at this early stage of CKD some patients can show normal plasma creatinine, especially older patients or patients with low muscle mass, but they may be subclinically overhydrated. A prescription of low sodium diet and the carefully use of diuretics at this phase of CKD could be the main tool for preventing volume overload and future CV damage.
