The Effect of Renal Failure on the Clinical Outcome of Patients Undergoing Coronary Artery Bypass

Background: Renal Failure is associated with acute myocardial infarction, unstable angina, and death in a higher rate compared with subjects without renal failure. There is no enough data about the effect of renal failure on the clinical outcome following CABG surgery.

Methods: A retrospective study that followed 239 patients that underwent CABG surgery in the Baruch Padeh Medical Center in the last 4 years. There were 34 women and 205 men, aged 61.85±9.57 years. Glomerular filtration rate (GFR) was the independent variable, and the dependent variables included the post-operative atrial fibrillation, mortality, re-admission rate, hospitalization time and the time that patients were connected to the cardio-pulmonary bypass machine (CPBM). We used logistic regression analysis to study the effect of GFR on all the dependent variables.

Results: Patients with impaired renal function had a worse prognosis compared with patients who had a normal GFR. Patients with renal failure had more re-admissions (OR=0.988, p=0.04). Impaired renal function did not affect the development of post-operative ventricular or atrial fibrillation.

Discussion: Renal failure affect the clinical outcome post CABG. It leads to higher mortality and re-admission rates. Impaired renal failure leads to higher levels of asymmetric Dimethyl Arginine (ADMA)’ a competitive inhibitor of L-Arginine, with impaired ability to produce nitric oxide (NO), because of blockage of the endothelial nitric oxide synthase within the endothelial cells. Lack of NO is the pathway to develop accelerated atherosclerosis and unstable angina pectoris, higher inflammatory burden, higher level of free oxygen radicals and vascular instability.