From the Guidelines
ACE inhibitors (ACE-Is) should not be routinely discontinued in people with GFR < 30 ml/min/1.73 m2 as they remain nephroprotective. This recommendation is based on the most recent and highest quality study available, which emphasizes the importance of continuing ACE-Is in patients with chronic kidney disease (CKD) unless there are specific contraindications or significant adverse effects 1. The concern with continuing ACE-Is at very low GFR levels stems from their mechanism of action, which reduces efferent arteriolar tone in the kidney, potentially further decreasing glomerular filtration pressure in already compromised kidneys. However, the benefits of ACE-Is in reducing proteinuria and slowing the progression of CKD often outweigh the risks, even at lower GFR levels.
Some key points to consider when using ACE-Is in patients with low GFR include:
- Assessing GFR and measuring serum potassium within 1 week of starting or following any dose escalation 1
- Temporarily suspending ACE-Is during intercurrent illness, planned IV radiocontrast administration, bowel preparation prior to colonoscopy, or prior to major surgery 1
- Avoiding the use of ACE-Is in people with suspected functional renal artery stenosis 1
- Monitoring blood chemistry frequently and serially until potassium and creatinine have plateaued, especially if there are significant changes in renal function or hyperkalemia develops 1
It's also important to note that the decision to discontinue ACE-Is should be made on a case-by-case basis, taking into account individual patient factors and the presence of any contraindications or adverse effects. In general, ACE-Is should not be discontinued unless there is a significant increase in creatinine or potassium, or if the patient develops hyperkalemia or other adverse effects that cannot be managed with dose adjustments or concomitant medication changes 1.
From the Research
Discontinuation of Angiotensin-Converting Enzyme Inhibitors (ACE-I) based on Glomerular Filtration Rate (GFR)
- The decision to discontinue ACE-I due to low GFR is complex and depends on various factors, including the presence of underlying kidney disease, renovascular hypertension, and the risk of hyperkalemia 2, 3, 4, 5.
- Studies suggest that ACE-I can be safely used in patients with GFR higher than 40 mL/min/1.73 m^2, but the risk of hyperkalemia increases significantly when GFR falls below 30 mL/min/1.73 m^2 2.
- In patients with advanced CKD (GFR < 30 mL/min/1.73 m^2), the use of ACE-I may need to be carefully weighed against the potential benefits and risks, including the risk of worsening renal function and hyperkalemia 6, 5.
- The presence of diuretic-induced sodium depletion and underlying chronic renal insufficiency are major predisposing factors for renal insufficiency in patients treated with ACE-I 5.
- In general, ACE-I should be used cautiously in patients with renal insufficiency, and the dosage should be reduced in renal failure, with close monitoring of blood pressure, renal function, and plasma potassium 3, 4, 5.
Specific GFR Thresholds for Discontinuation
- There is no specific GFR threshold below which ACE-I should be discontinued, but the risk of hyperkalemia and worsening renal function increases significantly when GFR falls below 30 mL/min/1.73 m^2 2, 6, 5.
- In patients with GFR between 31 and 40 mL/min/1.73 m^2, the risk of hyperkalemia is increased, but the use of ACE-I may still be beneficial in some cases 2.
- In patients with GFR lower than 30 mL/min/1.73 m^2, the use of ACE-I should be carefully considered, and alternative antihypertensive agents may be preferred 6, 5.