Inclusion Criteria: 1)Hemodialysis 2)high risk for heart failure (DM, age&gt;50, and/or systolic dysfunction) 3) first arteriovenous fistula/graft 4) informed consent 5) technically adequate echocardiogram 6) stable hgb(&gt;100) 7) stable mineral metabolism (normal calcium, phosphate &lt;2.1mmol/L, PTH&gt;50pmol/L)