IMPACT OF GLOMERULAR FILTRATION RATE ON LONG-TERM SURVIVAL AFTER OFF-PUMP CORONARY ARTERY BYPASS SURGERY

Abstract

Chronic renal failure (CRF) is a marker of poor long-term survival after coronary surgery. Off-pump coronary artery bypass (OPCAB) surgery has been thought to decrease prevalence of post-operative renal failure. The objective of this study is to assess the influence of preoperative CRF stage on survival rates and major adverse cardiac event (MACE) after OPCAB surgery. Data on 1400 consecutive patients who underwent off-pump isolated OPCAB between September 1996 and April 2007 were prospectively collected. Preoperative creatinine clearance (CrCl) was estimated according to Cockcroft and Gault equation. Patients were divided in 4 groups according to preoperative CrCl (ml/min): Gr 1: >90; Gr 2: >60 and ≤90; Gr 3: >30 and ≤60; and Gr 4: ≤30. Kaplan-Meier and Cox regression analysis were performed to assess long term and MACE-free survival rates and to identify their risk factors. Severity of CRF correlated with age (p < 0.001), female sex (p < 0.001), diabetes (p < 0.001), cerebrovascular disease (p < 0.001), lower ventricular ejection fraction (p < 0.001), hypertension (p < 0.001), chronic heart failure (p < 0.001), preoperative atrial fibrillation (p=0.04), peripheral and cerebral vascular disease (p < 0.001), and previous myocardial infarction (p=0.02). Hypercholesterolemia, smoking habit, and obesity negatively correlated with CRF. Kaplan-Meier overall survival decreased with severity of CRF but after correcting for demographics and risk factors only Gr 4 had a lower overall and MACE-free 10-year survival (Cox regression analysis; p=0.01 and p=0.03 respectively). Among the MACE, cardiac death, rehospitalization for congestive heart failure (CHF), and repeat revascularization were more frequent in Gr 4. Severe (CrCl < 30 ml/min) CRF is a significant risk factor for overall and MACE-free survival after OPCAB surgery. It is associated to cardiac death, CHF and repeat revascularization.