Renal Salvage with Renal Artery Stenting Improves Long-term Survival

Abstract

Background: The Cardiovascular Outcomes in Renal Atherosclerotic Lesions (CORAL) Trial cast doubt on the benefits of renal artery stenting (RAS). However, the outcomes for patients with chronic kidney disease (CKD) were not analyzed separately in the CORAL Trial. We hypothesized that patients who experienced a significant improvement in renal function after RAS would have improved long-term survival, compared with patients whose renal function was not improved by stenting.

Methods: This single-center retrospective study included 60 patients with stage 3 or worse CKD and renal artery occlusive disease who were treated with RAS for renal salvage. Patients were categorized as "responders" or "nonresponders" based on postoperative changes in estimated glomerular filtration rate (eGFR) after RAS. "Responders" were those patients with an improvement of at least 20% in eGFR over baseline; all others were categorized as "nonresponders." Survival was analyzed using the Kaplan-Meier method. Cox proportional hazards regression was used to identify predictors of long-term survival.

Results: The median age of the cohort was 66 years (interquartile range [IQR], 60-73). Median preoperative eGFR was 34 mL/min/1.73 m² (IQR, 24-45). At late follow-up (median 35 months, IQR, 22-97 months), 16 of 60 patients (26.7%) were categorized as "responders" with a median increase in postoperative eGFR of 40% (IQR, 21-67). Long-term survival was superior for responders, compared with nonresponders (P = 0.046 by log-rank test). Cox proportional hazards regression identified improved renal function after RAS as the only significant predictor of increased long-term survival (hazard ratio = 0.235, 95% confidence interval = 0.075-0.733; P = 0.0126 for improved versus worsened renal function after RAS).

Conclusions: Successful salvage of renal function by RAS is associated with improved long-term survival. These data provide an important counter argument to the prior negative clinical trials that found no benefit to RAS.