Patient selection: primary aldosteronism
Parameters:
(1) serum potassium in mmol/L
(2) aldosterone-renin ratio after captopril challenge test
(3) adrenal nodules on CT imaging
aldosterone to renin activity ratio =
= (aldosterone in pg/mL) / (renin activity in ng/mL per hour)
|
Parameter
|
Finding
|
Points
|
|
serum potassium
|
>= 3.5 mmol/L
|
2
|
|
|
< 3.5 mmol/L
|
0
|
|
aldosterone-renin ratio
|
< 490
|
2
|
|
|
>= 490
|
0
|
|
adrenal nodules on CT
|
none
|
3
|
|
|
one or more
|
0
|
total score =
= SUM(points for all 3 parameters)
Interpretation:
• minimum score: 0
• maximum score: 7
• Possible scores:0, 2, 3, 4, 5, 7.
• A score of 7 had a sensitivity of 50% and specificity of 100% for bilateral disease.
• A score of 5 had a sensitivity of 67% and specificity of 94%.
• A patient with a score of 7 was treated with medications.
• Other patients had adrenal venous sampling to help establish the diagnosis.
Performance:
• The area under the ROC curve is 0.92.
