Abstract 5121: Sustained Impairment of Endothelial Vasomotor Function Predicts Development of Renal Dysfunction in Patients With Chronic Ischemic Heart Disease
Endothelial dysfunction in systemic arteries is associated with renal dysfunction. It is unclear whether reversibility of endothelial dysfunction in systemic arteries in response to risk factors reduction has prognostic value for future renal dysfunction. This study examined whether changes in endothelial vasomotor function in the brachial artery after optimized therapy for coronary artery disease (CAD) predict the development of renal dysfunction.
Methods: This study included 214 patients with newly diagnosed chronic CAD who had an impaired flow-mediated dilation (FMD) of the brachial artery and chronic kidney disease (CKD) stage 1 or 2 at enrollment. After enrollment, all patients had individualized, optimized therapies including medications and life style changes based on AHA guidelines to reduce risk factors for CAD. Measurement of FMD was repeated at enrollment (1st test) and 6 months after therapies were initiated (2nd test). Thereafter, all patients continued their same medications and were prospectively followed for ≤ 36 months or until the progression to CKD stage 3. Impairment of FMD was defined as < 5.5% (mean minus 1 SD of FMD in 100 age- and sex-matched normal subjects).
Results: FMD was persistently impaired (< 5.5%) in 114 (53.2%) patients at the 2nd test, whereas it was improved (FMD ≥ 5.5%) in the remaining 100 (46.7%) patients. During the follow-up period, the progression to CKD stage 3 occurred in 46 (40%) patients with persistently impaired FMD and in 21 (21%) patients with improved FMD (p < 0.01). Multivariate Cox proportional hazards analysis showed that persistent impairment of FMD was a significant predictor of the progression to CKD stage 3 (HR 2.04, 95% CI 1.1 - 3.9, p < 0.01) that was independent of 1st FMD, hypertension, diabetes, and age. Using a c-statistic, the predictive value of persistently impaired FMD was incremental over that of 1st FMD, hypertension, diabetes and age (area under the ROC curve; 0.80 and 0.71, respectively, p = 0.01).
Conclusions: Persistent impairment of endothelial vasomotor function despite optimized therapy to reduce CAD risk factors is an independent predictor of the development of renal dysfunction. The periodic measurement of FMD is useful for risk stratification for future renal dysfunction.