The Impact of Renal Artery Stenosis on Outcomes After Open-Heart Surgery

Abstract

The aim of this study was to assess the impact of atherosclerotic renal artery stenosis (ARAS) on outcomes after open-heart surgery (OHS). Acute kidney injury after OHS portends significant morbidity and mortality. 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 >200cm/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. A total of 714 patients were evaluated, with a mean age of 67 ± 12 years (63% men) and a mean GFR of 52±25.9ml/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 inGFR (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. 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.