Renal artery stenosis: a clinical diagnosis rule could help diagnose it

Clinical bottom line (level 2b)

  1. A fifth of patients with suspected renal artery stenosis had it - most had atheroscelerotic disease.
  2. The presence of an abdominal bruit made renal artery stenosis more likely (LR + 6.7) .
  3. A clinical diagnosis rule could rank patients at low and high risk for renal artery stenosis.
Krijnen et al: Ann Intern Med 1998; 129 : 705-711
Expires May 2004

The study

Setting: 26 hypertension clinics, the Netherlands

477 patients (aged mean 52, 56% male) with drug-resistant hypertension (mean diastolic bp > 95 mmHg over 3 visits on standard antihypertensive medication) or an increase in serum creatinine concentration > 20 mmol/l during therapy with ACE inhibitors

Excluded if
  • serum creatinine > 200 micromol/l

Derivation of a clinical diagnosis rule.
Independent ?blinded reference standard, applied in all patients from a consecutive appropriate spectrum.
Reference standard:
  • intraarterial digital subtraction renal angiography: renal artery stenosis diagnosed if > 50% stenosis of one or more renal arteries
Diagnostic test: Clinical diagnosis rule derived from logisitic regression analysis of associated clinical features
  • Sum the score for the following components if present (for intermediate values, the score can be linearly interpolated)
  • Age
    • 20 - never smoked: 0 - ever smoked: 3
    • 30 - never smoked: 1 - ever smoked: 4
    • 40 - never smoked: 2 - ever smoked: 4
    • 50 - never smoked: 3 - ever smoked: 5
    • 60 - never smoked: 4 - ever smoked: 5
    • 70 - never smoked: 5 - ever smoked: 6
  • Female sex: 2
  • Signs and symptoms of atherosceloritic disease (femoral or carotid bruit, angina pectoris, claudication, myocardial infarction, ischaemic stroke or vascular surgery): 1
  • Onset of hypertension within 2 years: 1
  • Body mass index < 25 kg/m^2: 2
  • Presence of abdominal bruit: 3
  • Serum creatinine concentration
    • 40 micromol/l: 0
    • 60 micromol/l: 1
    • 80 micromol/l: 2
    • 100 micromol/l: 3
    • 150 micromol/l: 6
    • 200 micromol/l: 9
  • Serum cholesterol > 6.5 mmol/l or on cholesterol-lowering therapy: 1

The evidence

pre-test probability of renal artery stenosis: 22%, (95% CI: 19% to 26%)

differential diagnosis number of patients prevalence
(95% CI)
atherosclerotic stenosis 90 84%
(77% to 91%)
fibromuscular dysplasia 17 16%
(9% to 23%)


diagnostic test renal artery stenosis no renal artery stenosis LR
(95% CI)		 post-test probability
score > 15 28 5 18
(7.3 to 47) 		85%
13 to 15 24 15 5.3
(2.9 to 9.7) 		62%
12 to 13 21 27 2.6
(1.5 to 4.3) 		44%
9 to 11 21 115 0.60
(0.40 to 0.91) 		15%
< 9 13 191 0.22
(0.13 to 0.38) 		6%
total 107 353


diagnostic test renal artery stenosis no renal artery stenosis LR+
(95% CI)		 post-test probability LR-
(95% CI)		 post-test probability
atheroscelerotic vascular disease 67 104 2.2
(1.8 to 2.8) 		39% 0.52
(0.40 to 0.67) 		13%
ever smoked 85 241 1.2
(1.1 to 1.4) 		26% 0.59
(0.40 to 0.88) 		15%
abdominal bruit 29 15 6.7
(3.7 to 12) 		66% 0.76
(0.68 to 0.85) 		18%
total 107 370

Comments

  1. This clinical diagnosis rule needs to be validated in another set of patients.

Citation

  1. Krijnen P, van Jaarsveld BC, Steyerberg EW, et al: a clinical prediction rule for renal artery stenosis. Ann Intern Med 1998; 129 : 705-711
Search Terms: from ACP Journal Club other articles noted
Contributor: Chris Ball, May 2002
Reviewer:

Clinical Question.
Patient drug-resistant hypertension or rising creatinine on ACE inhibitor
Intervention or Exposure clinical diagnosis rule
Comparison digital subtraction angiography
Outcome renal artery stenosis