Hemodynamic index of atheromatous renal artery stenosis for angioplasty.

BACKGROUND AND OBJECTIVES Trans-stenotic pressure gradient across the constriction (PG), a hemodynamic variable of atheromatous renal artery stenosis (ARAS), is a widely used indicator for angioplasty, but its association with the outcome of angioplasty has not been fully investigated. DESIGN, SETTING, PARTICIPANTS & MEASUREMENTS In 34 hypertensive cases with unilateral ARAS, we evaluated hemodymanic variables of ARAS with reference to the systemic BP reduction after angioplasty as the outcome. RESULTS In each phase, PG divided by its corresponding prestenotic arterial BP (PG/preBP) had better association with the outcome than PG. The mean phase PG/preBP had the largest area under the curve in the receiver operating characteristic analysis (0.794) with the sensitivity/specificity of 0.957/0.545 for its cut-off >0.15. Although the plasma renin activity, which reflects the perfusion to renal parenchyma, was higher in the angioplasty-efficacious cases than in the angioplasty-inefficacious cases before angioplasty (7.8 +/- 6.6 versus 3.4 +/- 3.8 ng/ml/h, P = 0.049), it was not generally reduced by angioplasty independent of the outcome. CONCLUSIONS As the index to select ARAS for angioplasty, PG/preBP was better than PG and the mean phase PG/preBP could be the best. However, other factors such as the microvascular kidney disease, which affect the perfusion to renal parenchyma, would influence the outcome.