Prognosis

• increasing age ^a  
• essential hypertension ^a  
• increasing creatinine levels ^a  
• serum urea 10 mmol/l or more ^b  
• increasing duration of known hypertension ^b  
• grade II-IV hypertensive retinopathy ^c  

Renal artery stenosis

Renal failure and death is common. ^a
The risk of worsening renal function is increased with ^a

• a resistance index of 80 or more
• creatinine clearance < 40 ml/min

and reduced with smoking.