New guidelines for drive-by renal arteriography may lead to an unjustifiable increase in percutaneous intervention

[...]even where clinically significant RAS is the initial cause of hypertension, reversal of the stenosis may not result in a normal blood pressure or renal function if longstanding hypertension has produced irreversible contralateral renal injury. 2 RAS is most commonly due to atherosclerotic renal artery stenosis (ARAS) and has been reported to be present in around 30% of patients having routine coronary angiography and up to 50% of patients undergoing peripheral angiography. 2 The presence and anatomical location of RAS can be confirmed by non-invasive imaging with duplex ultrasound, computed tomographic or magnetic resonance angiography or by invasive imaging with catheter-based angiography. 2 Isotope renography combined with administration of the ACE inhibitor captopril can be used to assess the functional severity of the stenosis, and comparison of the renin activity in the two renal veins is sometimes useful to confirm the diagnosis. 2 However, none of these investigations can reliably indicate which patients will respond to percutaneous or surgical intervention and which are best managed with antihypertensive drugs. The medical management of ARAS centres on effective blood pressure control, lipid-lowering treatment, smoking cessation and antiplatelet treatment. 1 2 Restoration of near-normal blood flow to the kidney by angioplasty or surgery (revascularisation) holds an intuitive appeal, but a recent systematic review found no clear evidence to suggest that revascularisation was better than medical treatment. 3 There may be modest improvements in hypertension control but cure of hypertension is unlikely, and no firm conclusions can be drawn about the impact of renal artery revascularisation on the development of ischaemic heart disease, stroke and death. 3 4 In contrast, medical management of hypertension is well established and has a large evidence base. 5 Also, there is no good evidence to support an improvement in kidney function after renal artery revascularisation. 3 On the other hand, angioplasty can produce serious complications such as renal artery occlusion and cholesterol embolisation 2 and, with a lack of robust evidence demonstrating benefit, its role is still unclear.