Role of carvedilol treatment versus metoprolol treatment in prophylaxis of contrast agent mediated nephropathy

Contrast agent related nephropathy is a serious complication occurring after application of contrast agent. Pathogenesis is not well understood but the possible mechanisms are impairment in renal blood flow, oxidative stres related with contrast agent, renal tubular damage and decrease in medullary blood flow due to vasoconstriction. Carvedilol is a third generation beta-blocker commonly used in clinical practice. It has vasodilatory and antioxidant effects. We aimed to search the role of a third generation betablocker carvedilol versus a second generation beta blocker metoprolol in prophylaxis of contrast related acute renal injury in patients undergoing coronary angiography. In this study was designed as a prospectively. First group consisted of 100 patients taking carvedilol and in the second group 100 patients taking metoprolol were included. The primary end-point was the incidance of contrast media related nephropathy in both groups. Secondary end-points were changes in BUN, creatinin, glomerular filtration rate, cystatin C levels, serum oxidant and antioxidant media levels, and factors related with the development of contrast media related nephropathy. Also the incidance of contrast media related nephropathy, levels of serum oxidant and antioxidant media in patients with high risk for developing contrast nephropaty were evaluated (diabetics, advanced age [>75 y], and low glomerular filtration rate [<60 ml/min/1,73 m²]). Serum samples were drawn before coronary angiography and 48 hours after coronary angiography. Serum creatinin, malone dialdehyde, total antioxidan capacity and cystatin-C levels were evaluated before and after angiography. We calculated glomerular filtration rate with Cockcrof-Gault formula. More than 0,5 mg/dl increase or more than %25 increase in creatinin levels compared to basal levels was accepted as contrast media related nephropathy. The primary end-point was significantly lower in carvedilol group than metoprolol group. (%7 vs. %22, p=0.003). When secondary end-points were considered post-procedural serum BUN and creatinin levels were higher in metoprolol group (p values were 0.001 and vii 0.01 consecutively) but there were no statistical differences in glomerular filtration rate and cystatin-c levels (p values were 0.08 and 0.2, consecutively). Delta cystatin-C value was found statistically lower in carvedilol group (p=0.01). Post-procedural TAOK level was higher in carvedilol group however nevertheless post-procedural MDA level was higher in metoprolol group (p values 0.001 and 0.004 consecutively). Contrast agent amount used in procedure, hidration, basal GFR, basal creatinin value and diabetes mellitus were accepted as confounding factors related with contrast media nephropathy (p values were <0.001, 0.017, 0.018, 0.023, 0.048 consecutively). Contrast related nephropathy was seen lower in diabetic patients taking carvedilol than those taking metoprolol (%6,9 vs %38, p=0.001). In this subgroup of diabetic patients, ∆cystatin-c and ∆MDA values were lower in carvedilol group (p values were 0.017 and 0.003). There were no differences in ∆TAOK levels between two groups (p=0.15). In patients who have low basal glomerular filtration rate and advanced age patients, no differences in contrast related nephropathy were detected. In conclusion; carvedilol seems to be more effective than metoprolol for protecting renal functions in exposed to taking contrast agent.