Long-term patient and allograft outcomes of renal transplant recipients undergoing cardiac surgery

Abstract

Objectives: Cardiovascular complications are a major cause of morbidity and mortality among renal transplant recipients. This study assessed perioperative risk factors for mortality and long-term outcomes in renal transplant recipients who underwent cardiac surgery.

Methods: From 1999 to 2010, 92 renal transplant recipients with a functioning allograft underwent cardiac surgery at our institution. Cardiac procedures included coronary artery bypass grafting (43 patients, 46%), isolated valve surgery (17 patients, 18%), combined coronary artery bypass grafting and valve surgery (18 patients, 19%), and aortic procedures (7 patients, 7%).

Results: Transient renal failure requiring dialysis occurred in 20 of 92 patients (21%), with 3 not recovering renal function and returning to a permanent dialysis regimen while in the hospital. After cardiac surgery 30-day, 1-year, 5-year, and 8-year survival rates were 89%, 72%, 47%, and 30%, respectively. Freedom from dialysis was 90% after 1 year, 66% after 5 years, and 49% after 8 years. Risk factors for 30-day mortality were age > 65 years, left ventricle ejection fraction < 35%, and a combined cardiac procedure. Pulmonary hypertension and diabetes were risk factors for death from a cardiac cause after discharge. Diabetes, dyslipidemia, preoperative use of an intra-aortic balloon pump, postoperative creatinine > 2 mg/dL, and transient renal failure requiring dialysis were associated with a permanent dialysis requirement after cardiac surgery.

Conclusions: Cardiac surgery in patients receiving renal transplant who have functioning allograft has acceptable outcomes. If combined procedures are required, patients should be carefully considered. Transient postoperative renal impairment, even if resolved at discharge, increases the risk for allograft failure during long-term follow-up.

Keywords: 23; 25; CABG; CPB; cardiopulmonary bypass; coronary artery bypass grafting.