Recommendation 119: We recommend that patients with cardiorenal syndrome (CRS) should be managed by a multispecialty team that has expertise in this area (Strong Recommendation, Low Quality Evidence).

Recommendation 120: We suggest that for patients with persistent volume overload despite optimal medical therapy and increases in loop diuretics, cautious addition of a second diuretic (a thiazide/low dose metolazone) may be considered as long as it is possible to closely monitor morning weight, renal function, and serum potassium (Weak Recommendation, Moderate Quality Evidence).

Recommendation 121: We suggest that patients with the cardiorenal syndrome who develop diuretic resistance should be tried on stepped pharmacologic therapy [Figure 10] (Weak Recommendation, Low Quality Evidence).

Values and preferences: These recommendations place a high value on the understanding that diuretics have not been shown to improve survival but are frequently required to relieve congestion.

Serum potassium should be maintained at 4 to 5.5 mmol/l. Serum magnesium levels should be checked if there is persistent or resistant hypokalemia or the patient develops muscle cramps or ventricular arrhythmia, but has no additional proven benefit to test or replace magnesium in routine HF care.

Recommendation 122: We recommend that heart failure patients with stable, chronic mild-to-moderate renal insufficiency (GFR > 30) should receive standard therapy with an ACEi or ARB and a MRA (Strong Recommendation, Moderate Quality Evidence).

• As the isolated measurement of serum creatinine might not accurately reflect the degree of renal function we recommend using the eGFR when evaluating renal function. The standard definition of chronic renal insufficiency should be used when evaluating renal function.
• No large, randomized, outcome trials on the use of diuretics have been conducted in patients with renal insufficiency.
• Monitoring of electrolytes and creatinine in patients with CRS should be more frequent especially with acute illness, dehydration and when increasing the doses of cardiac drugs, including diuretics.
• Changes in GFR after commencing therapy are not necessarily associated with worsening outcome.
• As a general rule, the serum creatinine can rise or eGFR can fall by as much as 30% from baseline before it becomes necessary to stop or reduce the dose of the ACEis, ARB’s or MRA’s.

Recommendation 123: We recommend that in all cases, potential reversible causes for declining renal function must be excluded and referral to a nephrologist should be considered (Strong Recommendation, Moderate Quality Evidence).

Recommendation 124: We recommend that digoxin should be avoided in patients with acute renal injury and in patients with chronic, severe renal insufficiency (GFR < 30). In mild to moderate, stable renal insufficiency, digoxin should be used judiciously, at a low dose. As renal function declines, digoxin usage should be re-assessed to avoid development of digoxin toxicity (Strong Recommendation, Low Quality Evidence).