Minimised versus conventional cardiopulmonary bypass: outcome of high-risk patients.

BACKGROUND: Coronary artery bypass grafting (CABG) with extracorporeal circulation (ECC) is the gold standard for surgical coronary re-vascularisation. Recently, minimised extracorporeal circulation system (MECC) has been postulated a safe and advantageous alternative for multi-vessel CABG.
METHOD: Between January 2004 and December 2007, 244 high-risk patients (logistic EuroScore (ES)>10%) underwent CABG in our institution. ECC was used in 139 (57%) and MECC in 105 (43%) patients. Demographic data including age (MECC: 73.4+/-7.4 years; ECC: 73.3+/-6.4 years), ES (MECC: 19.2+/-9.8%; ECC: 21.4+/-11.9%), left-ventricular ejection fraction (MECC: 45.6+/-16.1%; ECC: 43.1+/-15.3%), diabetes mellitus (MECC: 14.3%; ECC: 15.1%) and COPD (MECC: 6.7%; ECC: 7.9%) did not differ between the two groups. Preoperative end-stage renal failure was an exclusion criterion. The clinical course and serological/haematological parameters in the ECC and MECC patients were compared in a retrospective manner.
RESULTS: Although the numbers of distal anastomoses did not differ between the two groups (MECC: 3.0+/-0.9; ECC: 2.9+/-0.9), ECC time was significantly shorter in the MECC group (MECC: 96+/-33 min; ECC: 120+/-50 min, p<0.01). Creatinine kinase (CK) levels were significantly lower 6 h after surgery in the MECC group (MECC: 681+/-1505 U l(-1); ECC: 1086+/-1338 U l(-1), p<0.05) and the need of red blood cell transfusion was significantly less after MECC surgery (MECC: 3 [range: 1-6]; ECC: 5 [range: 2-9] p<0.05). Moreover, 30-day mortality was significantly lower in the MECC group as compared to the ECC group (MECC: 12.4%; ECC: 26.6, p<0.01). DISCUSSION: MECC is a safe alternative for CABG surgery. A lower 30-day mortality, lower transfusion requirements and less renal and myocardial damage encourage the use of MECC systems, especially in high-risk patients.