Aim: To evaluate whether measurement of mean pressure gradient (MPG) over a renal artery stenosis (RAS) before and after percutaneous transluminal renal angioplasty (PTRA) predicts initial and long-term outcome.

Materials and methods: In our institution, PTRA has generally been performed in RAS patients with MPG > 10 mmHg. We related MPG before and after PTRA in 287 consecutive RAS patients (age 65 +- 14 years, 152 (53%) men) undergoing PTRA on 332 kidneys to blood pressures (BP), renal function and treatment during 4.1 +- 3.3 years of retrospective follow-up. The patients were divided into four groups according to MPG before PTRA: group A, MPG 0--29 mmHg, n = 60 patients, 79 kidneys; group B, MPG 30--59 mmHg, n = 48 patients, 57 kidneys; group C, MPG 60--199 mmHg, n = 40 patients, 43 kidneys; group D, occlusive pressure without numerical value obtainable, n = 139 patients, 153 kidneys.

Results: In groups A, B, and C, MPG before PTRA correlated with systolic BP (SBP) before PTRA, (r = 0.242; p = 0.0032) and with the reduction in SBP during follow-up (r = 0.243; p = 0.0034). MPG decreased from 38.7 +- 26.8 mmHg before PTRA to 1.3 +- 3.2 mmHg after PTRA (p < 0.0001). SBP and diastolic BP and the number of antihypertensive drugs decreased in all groups. Residual MPG after PTRA predicted the need for later endovascular re-do (52% vs. 14%; p < 0.0001).

Conclusion: PTRA has positive effects on BP and treatment in RAS patients with MPG > 10 mmHg. Whether PTRA is also indicated with MPG < 10 mmHg requires further evaluation. Residual MPG post PTRA predicts re-do but not the outcome of the intervention.