What is the optimal management of heart failure with reduced ejection fraction in a patient with chronic kidney disease and an estimated glomerular filtration rate of about 18 mL/min/1.73 m²?

Management of HFrEF in a Patient with CKD Stage 4 (eGFR 18)

Start SGLT2 inhibitors immediately as first-line therapy, followed by beta-blockers, then ACE inhibitors or ARBs (not ARNI at this eGFR), while deferring MRAs until renal function and potassium are optimized. 1

Immediate Initiation: SGLT2 Inhibitors

• SGLT2 inhibitors are the safest and most effective option in severe renal impairment and should be started immediately without dose adjustment or uptitration required. 1
• Dapagliflozin can be initiated down to eGFR ≥25 mL/min/1.73 m², while empagliflozin can be used down to eGFR ≥20 mL/min/1.73 m². 2
• At eGFR 18, empagliflozin is the appropriate choice. 2
• These agents reduce cardiovascular death and HF hospitalization even in advanced CKD, and enhance diuretic efficacy. 1, 3
• Expect a modest initial eGFR decline (3-10%), which is hemodynamic and does not indicate harm—do not discontinue therapy. 2

Second Priority: Beta-Blockers

• Use one of three evidence-based beta-blockers: bisoprolol, carvedilol, or sustained-release metoprolol succinate. 1
• Titrate to target dose or maximally tolerated dose regardless of renal function. 1
• Bisoprolol may accumulate in renal impairment but should still be titrated to 10 mg daily based on clinical response. 4
• Beta-blockers are safe and effective for mortality reduction even in CKD stage 4. 3

Third Priority: ACE Inhibitors or ARBs (NOT ARNI)

• Use ACE inhibitors or ARBs instead of ARNI when eGFR <30 mL/min/1.73 m². 1
• Sacubitril/valsartan (ARNI) is not recommended at eGFR <30 mL/min/1.73 m² per FDA labeling and guidelines. 2, 4
• Limited data suggest ARNI may be associated with higher HF hospitalization rates in dialysis patients. 5
• Start ACE inhibitor or ARB at low dose with frequent monitoring of renal function and potassium. 1, 4
• Tolerate acute eGFR decreases ≤30% after initiation—this is hemodynamic and expected. 2

Mineralocorticoid Receptor Antagonists: Defer Initially

• Traditional guidelines recommend MRAs only if eGFR >30 mL/min/1.73 m² and potassium <5.0 mEq/L. 1
• However, recent evidence shows MRAs remain effective even when eGFR declines to <30. 1
• At eGFR 18, defer MRA initiation until other GDMT is established and potassium/renal function are stable. 2
• If potassium remains <5.0 mEq/L after optimizing other therapies, consider starting spironolactone at very low dose (6.25-12.5 mg daily or 12.5 mg every other day). 4
• Consider potassium binders (patiromer or sodium zirconium cyclosilicate) to facilitate MRA use if hyperkalemia develops. 2

Diuretic Management

• Use loop diuretics as needed to control congestion—aggressive decongestion improves outcomes even with transient eGFR decline. 2
• SGLT2 inhibitors enhance diuretic efficacy and may reduce the need for loop diuretic intensification. 1
• Higher loop diuretic doses will be required at eGFR 18 due to reduced tubular secretion. 4

Implementation Strategy

• Start SGLT2 inhibitor and beta-blocker simultaneously at low doses rather than sequential uptitration. 1
• Add ACE inhibitor or ARB once beta-blocker is at stable dose. 2
• Space out medication administration times to reduce synergistic hypotensive effects. 2

Monitoring Protocol

• Check potassium and renal function weekly for the first 2-4 weeks after initiating or uptitrating GDMT, then every 2 weeks until stable. 1
• Monitor for signs of congestion (weight, symptoms, jugular venous pressure) at each visit. 2
• Measure natriuretic peptides (BNP or NT-proBNP) and albuminuria (UACR) to track disease progression. 2

Critical Pitfalls to Avoid

• Do not withhold SGLT2 inhibitors due to low eGFR—they are safe and effective down to eGFR 20. 1
• Do not discontinue ACE inhibitor/ARB or SGLT2 inhibitor for eGFR decline <30% unless acute kidney injury is suspected. 2, 3
• Do not use metformin if eGFR <30 due to lactic acidosis risk. 1
• Do not prematurely discontinue life-saving therapies for asymptomatic laboratory changes. 3

Management of Complications

If Hyperkalemia (K+ >5.0 mEq/L) Develops:

• Recheck elevated potassium before making therapeutic changes. 2
• Reduce or stop MRA first if already initiated. 2
• Consider potassium binder to maintain RAAS inhibition. 2
• Implement low-potassium diet. 2

If Symptomatic Hypotension Develops:

• Reduce or stop ACE inhibitor/ARB first (least mortality benefit at this eGFR). 2
• Space out medication administration times. 2
• Consider switching carvedilol to metoprolol or bisoprolol if beta-blocker contributing. 2

If eGFR Declines >30%:

• Ensure euvolemia by adjusting diuretic dosage. 2
• Discontinue nonessential nephrotoxic agents (NSAIDs, aminoglycosides). 2
• Evaluate alternative etiologies (contrast, infection, obstruction). 2
• Do not automatically discontinue GDMT unless acute kidney injury confirmed. 3