Patients at moderate and high risk for contrast induced nephropathy (CIN) should receive sufficient hydration before application of contrast to prevent CIN, but hydration could obviously increase the preload for congestive heart failure (CHF) patients. It is important to make an individual hydration protocol for patients with dysfunction of heart and renal to reduce the incidence rate of CIN. This prospective, randomized, double-blind, comparative clinical trial randomly selected 264 patients with estimated glomerular filtration rate, (eGFR) <60 ml/min per 1.73 m2 and CHF undergoing coronary angiography to receive either the convention hydration (n=132) or the central venous pressure (CVP) guided hydration (n=132).

Investigators enrolled 264 patients from February 2014 to February 2015, the principal inclusion criterion included CHF: left ventricular eject fraction (LVEF) <= 50%; moderate to severe CKD was diagnosed as an eGFR 15 to 59 mL/min per 1.73 m2, calculated via the abbreviated Modification of Diet in Renal Disease (MDRD) study equation from SCr obtained within 72 hours of enrollment, patients were scheduled to undergo diagnostic cardiac angiography or percutaneous coronary interventions. We randomly assigned eligible patients in a 1:1 ratio to either CVP guided therapy or a standard hydration administration protocol. Investigators used the same fluid type commercially available 0.9% sodium chloride in all patients. Investigators monitored the CVP by placing an 5-French catheter in the jugular vein. Investigators recorded the CVP with commercially available haemodynamic monitoring software. In the CVP guided group the fluid rate was adjusted according to the CVP as follows: 3 mL/kg/h for CVP lower than 6 mmHg, 1.5 mL/kg/h for pressure of 6-12 mmHg, and 1mL/kg/h for pressure higher than 12 mmHg. The control group was hydrated at 1 mL/kg per h. The fluid rate was set at the start of the procedure (before contrast exposure). Thus, both study groups received intravenous fluids for the same duration but at different rates. All study participants received intra-arterial Visipaque(320 mg I/ml; GE Healthcare) iso-osmolar contrast medium.

Primary end point of the study was the incidence of CIN: The median peak increase in serum creatinine concentration between day 0 (when contrast was administered) and day 7. Definition of CIN was an absolute increase in serum creatinine (SCr) >0.5 mg/dl or a relative increase >25% compared to baseline SCr. Definition of non-Q-wave myocardial infarction was a creatine kinase-myocardial band enzyme elevation 3 times the upper normal value without new Q waves on the electrocardiogram. Definition of Q-wave myocardial infarction was presence of new pathologic Q waves on an electrocardiogram in conjunction with an elevation in creatine kinase greater than 3 times the normal value. All adverse clinical events as well as study end points were monitored and adjudicated by the independent event committee. Each patient was contacted in every week after administration of the contrast, investigated if dialysis or main cardiovascular events (myocardial infarction,acute heart failure and death), and record any adverse events.

Inclusion Criteria:

1. congestive heart failure: objective evidences for decreased left ventricular eject fraction (LVEF) <= 50%;
2. moderate to severe chronic kidney disease was defined as an eGFR 15 to 59 mL/min per 1.73 m2, calculated via the abbreviated Modification of Diet in Renal Disease (MDRD) study equation from SCr obtained within 72 hours of enrollment;
3. patients were scheduled to undergo diagnostic cardiac angiography or percutaneous coronary interventions.

Exclusion Criteria:

1. hemodialysis-dependent patients;
2. complicated with severe short-term progressive disease;
3. Patients < 18 years;
4. pregnancy;
5. emergency cardiac catheterisation (eg, primary percutaneous coronary intervention for ST-segment elevation myocardial infarction);
6. exposure to radiographic contrast media within the previous 7 days;
7. acute decompensated heart failure.