Objective: To investigate methods to diagnose renal artery stenosis (RAS) among the general hypertensive population.
Methods: We studied the value of clinical and biochemical characteristics at the outpatient clinic to identify subjects with a renal artery narrowing of more than 50% of the luminal surface among 1047 hypertensive patients. Included in the analysis were: blood pressure, age, sex, body mass index, endogeneous creatinine clearance, smoking and plasma renin activity.
Results: Among the 1047 patients, 355 were selected for angiography. In this subgroup 104 patients (29%) had RAS. The subjects with RAS had significantly higher diastolic and systolic blood pressures than did those without stenosis. Forward stepwise logistical regression analysis showed that systolic blood pressure, stimulated plasma renin activity and smoking were the most predictive independent screening variables for the presence of RAS. Yet, none of these characteristics or their combinations were sufficiently sensitive to distinguish reliably between patients with essential hypertension and those with RAS. Sytolic blood pressure > 160 mmHg or diastolic blood pressure > 100 mmHg on automatic (Dinamap) recording as criteria selected a subgroup of patients with a RAS prevalence of 30%.
Conclusions: By using blood pressure screening criteria a subgroup of hypertensive patients with a high prevalence of RAS can be formed in whom further invasive tests for RAS are indicated and efficient.