Renal Vein Renin Sampling with IV Contrast
A catheter-based test that compares renin levels in blood from a renal vein with a peripheral sample. IV contrast may be used to guide vein catheterization.
["This test can help determine whether one kidney is producing unusually high renin activity, which may occur with renal artery narrowing."]
Key facts at a glance
- LOINC
- 43783-0
- Short code
- RFA Renal v Vs renin samp W contr IV
- Synonyms
- RFA Renal v Vs renin samp W contr IV
- Category
- liver
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- rf-angio
- CPT
- 86430
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
What is this test?
Renal vein renin sampling measures renin, an enzyme involved in regulating blood pressure and fluid balance, in blood drawn directly from a kidney vein. The result may be compared with a sample from a peripheral vein. Intravenous contrast may be given to help guide the catheter procedure.
Why might I need this test?
This test may be used in selected people with suspected renal artery narrowing to determine whether one kidney is releasing more renin than the other. It is usually considered only after less invasive kidney-vessel imaging has raised concern or failed to provide a clear answer.
How is the test performed?
A clinician inserts a catheter through a blood vessel, usually in the groin, and obtains blood from a renal vein. Renin activity or concentration is measured in the laboratory and may be compared with a peripheral venous sample. IV contrast may be administered under imaging guidance.
How do I prepare for the test?
Follow the clinic's instructions about eating, drinking, and medicines. Blood-pressure medicines such as ACE inhibitors, ARBs, beta blockers, and diuretics can affect renin results, but they should not be stopped unless the prescribing clinician directs you. Tell the team about kidney disease, prior contrast reactions, iodine allergy, pregnancy, and blood-thinning medicines.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
A marked difference in renin activity between the sampled renal vein and the comparison sample may indicate that one kidney is overproducing renin. In the appropriate clinical setting, this can support the presence of renal artery narrowing affecting that kidney. The result must be interpreted with blood pressure findings, kidney function, medication use, and vascular imaging because renin levels can also change with other conditions.
Short name
Renal vein renin sampling
Frequently asked questions
Is this the same as a routine blood test?
Does the test use IV contrast?
Can I take my blood-pressure medicines before the test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy