Abstract 5562: Renal Resistive Index is Strongly Associated With Poor Outcome After Coronary Bypass Surgery: A Prospective Study
Backgound: The presence of peripheral artery disease and renal failure are known as poor prognostic markers in patients undergoing coronary revascularization. While the presence of renal artery stenosis (RAS) is frequent in patients with coronary artery disease, the prognostic value of this lesion has never been assessed in the setting of coronary revascularization.
Hypothesis: We hypothesized that renal vascular disease is associated with poorer postoperative outcome after coronary bypass surgery (CABG), independent of renal function.
Methods: We prospectively assessed by Duplex the renal arteries of 401 consecutive patients prior to CABG. We defined RAS by the presence of at least 2 out of the 3 following criteria: maximal velocity >1.8 m/s, reno-aortic velocity ratio >3.5, reno-renal velocity ratio >2.7. Additionally we defined high renal arterial resistance (HRAR) in case of resistive index >0.80. The 30-days post-operative outcome was composite, combining death, stroke or myocardial infarction. Logistic regression models were used to assess associations.
Results: Among the 68 women and 333 men enrolled (age 67.6±10.7 years), RAS and HRAR were found in 33 (8.2%) and 45 (11.2%) cases, respectively. Adjusted for age, sex, glomerular filtration rate, CVD risk factors, treatments, the presence of peripheral artery disease, and the presence of chronic pulmonary disease, we did not find any significant association between RAS and the composite outcome (OR=0.90, 95%CI:0.28 –2.95, p=ns). Conversely, in the same model, HRAR was strongly associated with the primary composite outcome (OR=3.97, 95%CI:1.36 –11.02, p=0.01).
Conclusion: Beyond the glomerular filtration rate and other usual prognostic markers, renal artery ultrasound provides additional prognostic information. While the presence of renal artery stenosis is not found of any post-operative prognostic value, a high renal arterial resistance is strongly and independently associated with short-term cardiovascular outcomes.