Multiple Risk Assessment of Cardiovascular Surgery in Chronic Renal Failure Patients

Background Chronic renal failure is a major risk factor in cardiovascular surgery. We evaluated results of cardiovascular surgery in chronic renal failure patients (s-creatinine > 200 μmol/L or established dialysis) at our center from 1990 to 2000. Methods One hundred and six chronic renal failure patients underwent cardiovascular surgery (56 coronary artery bypass operations, 25 valve replacements with or without coronary bypass, and 25 other major cardiovascular operations [8 thoracic aorta, 10 abdominal aorta, 7 other]). Matched controls were selected (n = 106) based on age, sex, year, and type of operation and occurrence of diabetes. Results There were 88 men and 18 women and mean age was 64 ± 10 years (standard deviation). Demographics did not differ between chronic renal failure and control patients, except for hypertension (more prevalent in chronic renal failure group, p< 0.05). Intraoperative hemorrhage, perfusion and ischemia time, and reoperation did not differ between groups. Chronic renal failure patients received more transfusions of red blood cells, plasma, and platelets (p< 0.02). Ventilation support (27.6 ± 59.3 hours), intensive care unit stay (7.7 ± 8.3 days), and hospital stay (12.3 ± 10.5 days) were longer (p< 0.02). Early mortality was 16% versus 6.6% (p = 0.04) and 5-year mortality was 79% versus 39% (p< 0.05) for chronic renal failure and control patients, respectively. Independent preoperative risk factors of mortality for chronic renal patients were age greater than 70 years (relative risk = 2.32, p = 0.001), chronic obstructive pulmonary disease (relative risk = 2.59, p = 0.001), diabetes (relative risk = 1.80, p = 0.037), and dialysis (relative risk = 2.03, p = 0.005). Conclusions Chronic renal failure patients suffered more postoperative complications and had substantially increased short-term and long-term mortality rates. Independent preoperative mortality risk factors for chronic renal failure patients were age, chronic obstructive pulmonary disease, diabetes, and chronic dialysis.