Influence of on-pump versus off-pump techniques and completeness of revascularization on long-term survival after coronary artery bypass

Off-pump coronary artery bypass graft surgery (OPCABG) may be associated with reduced morbidity and in-hospital mortality. In this study, we report the influence of surgery type, number of grafts, and the Index of Completeness of Revascularization (ICOR), namely, the number of grafts/number diseased vessel systems, on long-term survival.

From 1997 to 2006, 12,812 consecutive patients underwent isolated CABG at a single academic center. Ten-year survival data were obtained by cross-referencing patients with the national Social Security Death Index. A propensity score analysis of 46 preoperative characteristics balanced risk factors between surgical groups. A proportional hazards regression analysis modeled the hazard of death as a function of surgery type (on versus off), distal group (1 to 3 versus 4 to 7 vessels), ICOR, and propensity score.

Proportional hazards regression analysis showed no significant influence of surgery type or number of grafts on long-term survival within the four groups: OPCABG 1 to 3 grafts (n = 3,946; ICOR 1.11), OPCABG 4 to 7 grafts (n = 1,721; ICOR 1.56), on-pump CABG 1 to 3 grafts (n = 3,380; ICOR 1.21), and on-pump CABG 4 to 7 grafts (n = 3,765; ICOR 1.64). Irrespective of technique of revascularization, there was a survival advantage for patients with higher ICOR.

Long-term survival was similar for patients receiving 1 to 3 or 4 to 7 grafts by either on-pump or off-pump techniques. However, higher ICOR was associated with improved long- term survival within all groups.