7 - Predicting Response to Renal Artery Stenting for Atherosclerotic Stenosis: Regression Analysis of a 20-year Single Center Cohort

Purpose: Recent data indicates renal artery stenting (RASt) could benefit patients with severe stenosis, high systolic blood pressure (SBP), and/or poor kidney function. However, limited data is available on what variables are predictive of a beneficial response to RASt. This study identified pre-stenting variables which predict benefit following RASt.

Materials and Methods: An IRB approved, retrospective search for patients that underwent RASt at a single institution from January 2004 to December 2023 was performed. Multiple linear regressions (MLR) were constructed for SBP and creatinine (Cr) change at 3 months post-stenting. Significant predictors were visualized with simple linear regression (SLR) against either SBP or Cr change at 3 months and 1-year post-stenting. Predictors included age, sex, bilateral stent, stenosis > 90%, any prior smoking, single functional kidney, and diabetes. Baseline antihypertensive burden and diastolic blood pressure (DBP) were included to predict SBP change. Cr change prior to stenting and baseline SBP were included as predictors of Cr change at 3 months. Variance inflation factors assessed multicollinearity in MLR’s. Interactions were not included. Residual plots identified outliers in SLR’s. Model validity was assessed by removing outliers and checking for changes in significance.

Results: 99 patients (69.2±11.8 years; 41 men) were stented for atherosclerotic renal artery stenosis. MLR showed higher baseline DBP correlated with a larger decrease in SBP 3 months after stenting (β=-1.10, p< 0.001). Further, larger increases in Cr within a year prior to stenting were associated with greater reduction in Cr 3 months after stenting (β=-0.37, p=0.013). All other predictors did not significantly correlate with change in SBP or Cr. SLR showed that higher baseline DBP correlated with a larger decline in SBP at 3 months (β=-0.69, p< 0.001, r²=0.16) and 1 year (β=-0.58, p=0.009, r²=0.09) after stenting. Change in Cr pre-stenting was inversely related to change in Cr after stenting at 3 months (β=-0.71, p< 0.001, r²=0.53) and 1 year (β=-0.69, p< 0.001, r²=0.47). The subgroup of patients with stenosis >90% showed similar correlations at 3 months (β=-0.82, p=0.003, r²=0.18 for SBP; β=-0.70, p< 0.001, r²=0.53 for Cr). Finally, 73% (16/22) of patients with stenosis >90% and DBP >80mmHg had a SBP drop ≥20mmHg and 61% (14/23) of patients with stenosis >90% and rising Cr ≥0.3mg/dL pre-stenting had Cr decrease by ≥0.3mg/dL at 3 months post stenting.

Conclusion: High DBP and increasing Cr within a year prior to stenting are significant predictors of lower SBP and Cr following RASt.