Effect Of Losartan On Contrast-induced Acute Kidney Injury And Serum Uric Acid

Objective:To observe the effect of different doses of losartan on CIAKI and serum uric acid’s level in patients undergoing coronary artery interventional therapy with contrast administration.Methods:In a randomized controlled trial,221patients admitted for coronary artery interventional therapy were studied. The patients were randomly divided into three groups:control group; low dose group:losartan50mg per day; high dose group: losartan100mg per day. Furthermore, we divided into four subgroups according to different risk factors, such as elderly people, diabetes, hypertension, renal insufficiency. We measured blood urea nitrogen(BUN), serum creatinine(Scr), serum uric acid(SUA), all items of renin, Cystatin C(CysC) and Neutrophil Gelatinase Associated Lipocalin(NGAL) at24hours before and after the angioplasty procedure and estimated effective glomerular filtration rate(eGFR) with MDRD abbreviated. Patients were followed up for90days and clinical terminal events were recorded.Results:①BUN and SUA significantly decreased in the patients treated with either low dose of losartan or high dose after operation(P<0.05), comparing with control group, and this uricosuric effect of losartan is dose-dependent. Control group significantly increased Scr and reduced eGFR(P<0.05), which was associated with a concomitant rise(P<0.05) in the serum CysC and NGAL, whereas losartan group did not or slightly alter these parameters. There was a negative correlation between the decline of SUA and the increase of eGFR in low(r=－0.383, P=0.001) and high dose group(r=－0.342,P=0.003). On the other hand, losartan group blockaded the rennin-angiotensin system induced by interventional therapy.②For hypertensive patients, BUN and SUA significantly decreased in the patients treated with either low dose of losartan or high dose after operation(P<0.05), comparing with control group, and this uricosuric effect of losartan is dose-dependent. Control group significantly reduced eGFR(P<0.05), which was associated with a concomitant rise(P<0.05) in the serum CysC and NGAL, whereas losartan group did not or slightly alter these parameters. There was a negative correlation between the changes of SUA and eGFR in low(r=－0.411, P=0.003) and high dose group(r=-0.432, P<0.001). On the other hand, losartan group also blockaded the rennin-angiotensin system.③For renal insufficiency patients, BUN and SUA significantly decreased in three groups after operation(P<0.05). Control group significantly increased serum CysC and NGAL(P<0.05), whereas losartan group did not or slightly alter these parameters. There was a negative correlation between the changes of SUA and eGFR in control group(r=－0.362, P=0.028). Losartan group also blockaded the rennin-angiotensin system.④For elderly patients, BUN and SUA significantly decreased in three groups after operation (P<0.05). There was a negative correlation between the changes of SUA and eGFR in low dose group(r=－0.427, P=0.004). Losartan group also blockaded the rennin-angiotensin system. All groups significantly increased serum CysC after operation(P<0.05), and low dose group had a concomitant rise in the serum NGAL(P<0.05).⑤For diabetes patients, BUN and SUA significantly decreased in three groups after operation(P<0.05). There was no correlation between SUA and eGFR in all groups(P>0.05). Serum CysC significantly increased in control and low dose groups after operation(P<0.05). Losartan group also blockaded the rennin-angiotensin system.⑥There were8patients occurring CIAKI, the incidence of it was3.6%, two cases occurred in both control and high dose group, and four in low dose group.⑦There were no statistical difference in no-mace-survival for90days among three groups(Log-Rank,P>0.05), so did each subgroup.Conclusions:This study demonstrates that losartan significantly improved renal function and serum uric acid’s level in patients undergoing coronary artery interventional therapy with contrast administration, especially for patients with hypertension, diabetes or renal insufficiency. This is not only probably caused by blockading the rennin-angiotensin system induced by interventional therapy, but also the uricosuric effect of losartan.