SAT-185 FEATURES OF ATHEROSCLEROTIC RENAL ARTERY STENOSIS: AN AUTOPSY BASED STUDY

Abstract

Atherosclerotic renal artery stenosis (ARAS) is a common condition, affecting up to 7% of individuals over 65 years of age. The diagnosis, management (medical vs. surgical), and outcome of ARAS represent issues of considerable controversy. In particular, the risks and benefits of angiotensin enzyme inhibitors (ACEI) in unilateral and bilateral ARAS has been a topic of much discussion. We identified 51 patients with an autopsy diagnosis of ARAS between 1994 and 2013. We classified patients with a stenotic kidney/contralateral kidney weight ratio of <0.8 to have unilateral ARAS and patients with a ratio >0.8 to have bilateral ARAS. 40 patients received medical therapy for hypertension, 11 patients received a stent. Results are summarized below:Tabled 1Received ACE InhibitorsDid not receive ACE InhibitorsDiagnosed with ARAS prior to deathMedical Therapy: bilateral ARAS7114Medical Therapy: unilateral ARAS1394Stent: bilateral ARAS325Stent: unilateral ARAS426 Open table in a new tab For both patients with unilateral and bilateral ARAS, there were no differences in pre-mortem systolic blood pressure or glomerular filtration rate in patients who received ACEI versus those that did not. For patients with unilateral ARAS, the contralateral kidney weight normalized to body weight was higher in those who did not receive ACEI (6.8 vs 5.2, p=0.04). For patients with bilateral ARAS, the weights of both the smaller and larger kidneys (normalized to body mass index) were higher in those receiving ACEI than those that did not. There were no significant differences in normalized stenotic (ST) or contralateral (CTL) kidney weights between those medically treated or those surgically treated (stent placement). Pre-mortem GFR was lower in patients who underwent surgery compared to those receiving medical therapy (26.8 +/- 5.1 vs. 41.9 +/- 3.4, p=0.0352), perhaps reflecting more severe renovascular disease in those who had surgery. For all patients, there were no significant differences in normalized ST or CTL kidney weights, percent cortical atrophy of the ST kidney, systolic blood pressure, or GFR between those who received ACEI and those that did not. As expected, the normalized ST kidney weight was significantly lower (2.7 +/- 0.3 vs 4.9 +/- 0.4, P<0.0001) and percent cortical atrophy was higher (54+/- 7% vs 25 +/- 5, p=0.0014) in those with unilateral versus bilateral ARAS. The most common cause of death in this group of patients was myocardial infarction. A pre-mortem diagnosis of ARAS was made in only 20% (8 of 40) patients who received medical treatment for hypertension. Half of patients with unilateral or bilateral ARAS received ACEI therapy prior to death. However, there were no differences in pre-mortem systolic blood pressure or glomerular filtration rate between those treated or not treated with ACEI. Based on this autopsy study, ACEI may limit potentially maladaptive compensatory hypertrophy of the CTL kidney in patients with unilateral ARAS and does not appear to decrease kidney size in those with bilateral ARAS. Although ACEI may affect short-term renal function, this autopsy based study indicates that ACEI do not adversely affect long-term renal structure in patients with ARAS.