Objective: To evaluate the urine microglobulin change after interventional therapy in patients with renal artery stenosis.
Methods: According to the results of renal artery angiography, 69 consecutive patients with coronary heart disease were divided into 2 groups, including 44 patients with severe renal artery stenosis RAS (luminal narrowing > 70%, group I) and 25 patients with atherosclerotic lesion in renal artery (luminal narrowing > 50% but < 70%, group II). The urine alpha(1), beta(2)-microglobulin (alpha(1), beta(2)-MG) were measured respectively. The successful procedural rates, rates of complication, serum creatitine and the urine alpha(1), beta(2)-MG 3 months after procedure were also recorded. The acute results and long-term follow-up outcomes were compared between the 2 groups.
Results: Urine alpha(1)-MG [(5.2 +/- 2.5) microg/L vs (3.0 +/- 2.7) microg/L, P > 0.001] and beta(2)-MG [(377 +/- 173) microg/L vs (202 +/- 184) microg/L, P > 0.001] were significantly higher in group I than in group II. However, the urine alpha(1)-MG of the 2 groups did not exceed the normal range (<6 microg/L). The urine beta(2)-MG [(237 +/- 187) microg/L vs (377 +/- 173) microg/L, P > 0.01] 3 months after stenting procedure in group I were significantly decreased. There were no significance change in urine alpha(1)-MG in group I and both the microglobulins in group II during follow-up. There was significant difference in improvement of blood pressure between the 2 groups (62.5% vs 9.1%, P > 0.01). As compared with group II, group I patients had more re-admission (22.5% vs 9.1%), renal failure (5% vs 0) and higher mortality (5% vs 0). However, these measurements did not differ significantly. Multivariate analysis revealed that persistent elevation of urine beta(2)-MG was an independent predictor of severe events (including re-admission and renal failure) after renal artery stenting (OR = 3.01, 95% CI 1.01 - 8.95, P = 0.036).
Conclusions: Severe RAS causes damage of tubular reabsorption. Renal artery stenting improves tubular function, but in patients with persistent elevation of beta(2)-MG, the rates of re-admission and renal failure remain high.