The impact of renal artery stenosis on outcomes after open-heart surgery

Abstract

Objectives: The aim of this study was to assess the impact of atherosclerotic renal artery stenosis (ARAS) on outcomes after open-heart surgery (OHS).

Background: Acute kidney injury after OHS portends significant morbidity and mortality.

Methods: Data from all adult patients undergoing OHS from January 2000 to April 2010 who underwent renal duplex ultrasound were prospectively collected. ARAS was severe (60% to 99% stenosis) if peak systolic velocity was >200 cm/s. The associations between ARAS and post-operative reduction in glomerular filtration rate (GFR), need for renal replacement therapy, length of stay, and overall short-term and long-term mortality (up to 8 years) were tested using multivariate time-to-event adjusted analysis.

Results: A total of 714 patients were evaluated, with a mean age of 67 ± 12 years (63% men) and a mean GFR of 52 ± 25.9 ml/min/1.73 m(2). A total of 206 (29%) had ARAS; of these, 79% (n = 163) had unilateral and 21% (n = 43) had bilateral ARAS. ARAS was associated with peripheral artery disease (p = 0.004) and lower high-density lipoprotein levels (p = 0.04). Patients with advanced age (p = 0.01) and descending aorta grafting (p = 0.004) had significant post-operative reductions in GFR. Adjusted models showed a nonsignificant trend between ARAS and reduction in GFR (p = 0.09). ARAS was not associated with need for renal replacement therapy (p = 0.4), longer length of stay (p = 0.7), or mortality (p = 0.7), but low pre-operative GFR was a strong predictor of long-term mortality.

Conclusions: ARAS does not appear to be associated with post-operative change in GFR, need for hemodialysis, longer length of stay, or mortality in patients undergoing OHS.

Keywords: AKI; ARAS; GFR; OHS; PSV; RAR; RFA; RRT; acute kidney injury; atherosclerotic renal artery disease; atherosclerotic renal artery stenosis; glomerular filtration rate; hemodialysis; mortality; open-heart surgery; peak systolic velocity; random forest analysis; renal dysfunction; renal replacement therapy; renal/aortic resistive index.