Coronary artery bypass grafting in patients on maintenance dialysis: Is peritoneal dialysis a risk factor of operative mortality?

Increasing numbers of patients on dialysis are undergoing coronary artery bypass grafting (CABG). We undertook this retrospective study to identify risk factors of operative mortality in dialysis patients who underwent CABG. We performed retrospective analysis of 105 patients who were on dialysis for at least two months before surgery and who underwent CABG in Toronto General Hospital from 1997 to 2006. Using prospectively collected data from the Division of Cardiovascular Surgery Database of Toronto General Hospital, we collected data on comorbidities, procedures, modality change during hospitalization, and operative outcomes. Logistic regression was used to assess risk factors of operative mortality. One hundred and five maintenance dialysis patients (40 PD and 65 HD) who met the inclusion criteria were studied. Overall in-hospital mortality was 7.6%. Atrial fibrillation and pneumonia occurred in 16.2 and 9.5%, respectively, of all dialysis patients. Among PD patients, rates of post-operative dialysate leak and peritonitis were 10 and 12.5%, respectively. Among HD patients, 4.6% experienced post-operative AV access thrombosis. Logistic regression showed older age (a parts per thousand yen70 years) and peritoneal dialysis are independent risk factors of operative mortality. In this retrospective study, older patients on PD had higher operative mortality than HD patients. These findings suggest extra care should be taken when CABG is considered for PD patients over 70 years old. In this study we could not identify the reason(s) for the high mortality of elderly peritoneal dialysis patients undergoing CABG.