How often do you monitor Albumin-to-Creatinine Ratio (ACR) in Chronic Kidney Disease (CKD) patients?

From the Guidelines

Monitoring albumin-to-creatinine ratio (ACR) in chronic kidney disease (CKD) patients should be performed at least once annually for stable patients, with more frequent monitoring for those with higher risk or changing clinical status, as recommended by the most recent guideline 1. For newly diagnosed CKD patients, I recommend checking ACR at baseline and then 3-6 months later to establish a trend. Patients with albuminuria (ACR ≥30 mg/g) should have more frequent monitoring, typically every 3-6 months, while those with severe albuminuria (ACR ≥300 mg/g) may need assessment every 3 months, especially if management changes are being implemented, as suggested by the Kidney Disease: Improving Global Outcomes (KDIGO) guideline 1. The ACR test requires a spot urine sample, preferably first morning void, and should be interpreted alongside estimated glomerular filtration rate (eGFR) and other clinical parameters. Regular ACR monitoring is crucial because albuminuria is both a marker of kidney damage and an independent risk factor for CKD progression and cardiovascular events, as highlighted in the Mayo Clinic Proceedings study 1. Changes in ACR can indicate treatment effectiveness or disease progression, allowing for timely adjustments in management strategies such as blood pressure control, diabetes management, or medication adjustments. Some key considerations for ACR monitoring include:

• The frequency of monitoring should be individualized based on the patient's risk factors and clinical status.
• More frequent monitoring is recommended for patients with higher levels of albuminuria or those with rapidly changing clinical status.
• The use of ACR in conjunction with eGFR can improve risk stratification and diagnostic accuracy, as noted in the study 1. Overall, regular ACR monitoring is essential for the effective management of CKD patients, and the frequency of monitoring should be tailored to the individual patient's needs, as recommended by the most recent and highest quality study 1.

From the FDA Drug Label

The Trial to Evaluate the Effect of Dapagliflozin on Renal Outcomes and Cardiovascular Mortality in Patients with Chronic Kidney Disease (DAPA-CKD, NCT03036150) was an international, multicenter, randomized, double-blind, placebo-controlled trial in adult patients with chronic kidney disease (CKD) (eGFR between 25 and 75 mL/min/1. 73 m2) and albuminuria [urine albumin creatinine ratio (UACR) between 200 and 5000 mg/g] Table 16: Treatment Effect for the Primary Composite Endpoint, its Components, and Secondary Composite Endpoints, in the DAPA-CKD Trial The primary objective was to determine whether dapagliflozin reduces the incidence of the composite endpoint of ≥50% sustained decline in eGFR, progression to end-stage kidney disease (ESKD) (defined as sustained eGFR <15 mL/min/1. 73 m2, initiation of chronic dialysis treatment or renal transplant), CV or renal death.

The frequency of monitoring ACR (Albumin to Creatinine Ratio) in CKD (Chronic Kidney Disease) patients is not explicitly stated in the provided drug label. However, the label does mention that patients in the DAPA-CKD trial had a median UACR (Urine Albumin Creatinine Ratio) of 950 mg/g at baseline, and the trial included patients with UACR between 200 and 5000 mg/g.

• Key points:
  • eGFR was measured and used as an inclusion criterion and to assess the primary composite endpoint.
  • UACR was measured and used as an inclusion criterion.
  • The label does not provide a specific monitoring schedule for ACR in CKD patients. Based on the information provided, it appears that ACR or UACR should be monitored in CKD patients, but the exact frequency is not specified in the drug label 2.

From the Research

Monitoring ACR in CKD Patients

• The frequency of monitoring albumin-to-creatinine ratio (ACR) in chronic kidney disease (CKD) patients is not explicitly stated in the provided studies.
• However, study 3 suggests that a single random abnormal urine ACR has a good positive predictive value (PPV) for the diagnosis of CKD in patients with type 2 diabetes, implying that repeated testing may not be necessary for diagnosis.
• Study 4 compares the performance of calculated versus measured ACR in predicting kidney failure and death in people with CKD, but does not provide information on the frequency of monitoring.
• Studies 5, 6, and 7 focus on the use of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin II receptor blockers (ARBs) in CKD patients, but do not address the frequency of ACR monitoring.

ACR Monitoring in Clinical Practice

• Study 3 found that the PPV of an abnormal urine ACR to diagnose CKD was 96.80% (95% CI 95.37% to 98.21%), suggesting that a single test may be sufficient for diagnosis.
• However, the study does not provide guidance on how often ACR should be monitored in CKD patients.
• Study 4 suggests that calculated ACR can be used for risk predictions when measured ACR is not available, but does not address the frequency of monitoring.

Gaps in Current Research

• There is a lack of research on the optimal frequency of ACR monitoring in CKD patients.
• Further studies are needed to determine the best approach to monitoring ACR in CKD patients and to inform clinical practice guidelines.