Abstract 385: Endothelial Vasomotor Dysfunction in Brachial Artery Predicts Early Renal Dysfunction in Patients with Coronary Artery Disease

Abstract

There is an intimate relation between coronary artery disease (CAD) and chronic kidney disease. Endothelial function in renal vasculature plays an important role in regulation of renal hemodynamics in normal and pathological states. Endothelial dysfunction is a systemic disorder, and there may be possible relation of endothelial function between brachial artery and renal vasculature. We examined whether endothelial vasomotor dysfunction in brachial artery may predict early renal dysfunction in patients with CAD. Methods and Results: Flow-mediated endothelium-dependent dilation (FMD, % increase in diameter from baseline) in brachial artery was measured by ultrasound in 558 consecutive patients with CAD. Patients with advanced renal failure (glomerular filtration rate [GFR] < 50 mL/min/1.73 m 2 ) were not included. A subgroup of 402 patients with normal renal function at the enrollment (normo-albuminuria [< 30 mg/day] and normal serum creatinine levels [< 1.0 mg/dL]) were prospectively followed up for 1 year. The end point was the occurrence of either microalbuminuria (≥ 30 mg/day) or serum creatinine levels > 1.5 mg/dL. At the enrollment, patients with impaired FMD (≤ 4.4%, 50 th percentile of the distribution in all study patients) had higher levels of urine albumin excretion (24 ± 2 vs. 17 ± 1 mg/day, p < 0.05) and serum creatinine (0.8 ± 0.1 vs. 0.5 ± 0.1 mg/dL, p <0.05), and lower GFR (72 ± 3 vs. 80 ± 2 mL/min/1.73 m 2 , p < 0.05) than patients with preserved FMD (> 4.4%). Over 1 year follow up, 30 (17%) patients with impaired FMD had an end point (12 patients, increase in serum creatinine levels; 18, microalbuminuria), while 15 (6.7%) patients with preserved FMD had an end point (6, increase in serum creatinine levels; 9, microalbuminuria) (p < 0.01). Using multivariate logistic analysis, impaired FMD was the most strongest predictor of occurrence of either increase in serum creatinine levels or microalbuminuria during 1 year follow up (OR; 2.8, 95% CI; 1.5 – 5.5, p < 0.01) among covariates including hypertension, diabetes, age. Conclusion: Endothelial vasomotor dysfunction in brachial artery is an independent predictor of development of early renal dysfunction in patients with CAD. Measurement of FMD is useful for stratification of risk for future renal dysfunction.