Hemodynamic index of atheromatous renal artery stenosis for angioplasty
Masayuki Tanemoto1, Takehiro Suzuki, Michiaki Abe
1Department of Medicine, Division of Nephrology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan. mtanemoto-tky@umin.ac.jp
Insights
The pressure gradient divided by prestenotic blood pressure (PG/preBP) better predicts angioplasty outcomes in atheromatous renal artery stenosis (ARAS) than the pressure gradient (PG) alone. Mean phase PG/preBP is the most effective predictor.
Area of Science:
- Cardiovascular Medicine
- Nephrology
- Interventional Cardiology
Background:
- Atheromatous renal artery stenosis (ARAS) is a common condition often treated with angioplasty.
- The trans-stenotic pressure gradient (PG) is a key hemodynamic indicator for ARAS, guiding angioplasty decisions.
- The predictive value of PG for angioplasty outcomes requires further investigation.
Purpose of the Study:
- To evaluate hemodynamic variables, specifically the pressure gradient (PG) and its ratio with prestenotic blood pressure (PG/preBP), for predicting angioplasty outcomes in ARAS.
- To compare the efficacy of PG/preBP versus PG in identifying patients who will benefit from angioplasty.
Main Methods:
- A study involving 34 hypertensive patients with unilateral ARAS.
- Evaluation of hemodynamic variables, including PG and PG/preBP, in relation to systemic blood pressure reduction post-angioplasty.
- Receiver operating characteristic (ROC) analysis to determine the optimal cut-off value for PG/preBP.
Main Results:
- The ratio PG/preBP demonstrated a stronger association with angioplasty outcomes than PG alone.
- The mean phase PG/preBP showed the highest area under the curve (0.794) in ROC analysis, with a cut-off >0.15 yielding high sensitivity (0.957).
- Plasma renin activity was higher in patients with successful angioplasty outcomes but was not consistently reduced by the procedure.
Conclusions:
- PG/preBP is a superior index for selecting ARAS patients for angioplasty compared to PG.
- The mean phase PG/preBP may serve as the optimal predictor of successful angioplasty.
- Microvascular kidney disease can influence angioplasty outcomes and should be considered alongside hemodynamic factors.
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.
