European Journal of Cardio-Thoracic Surgery, Vol 12, 31-39, Copyright © 1997 by European Association for Cardio-thoracic Surgery
Predictors of early and overall outcome in coronary artery bypass without cardiopulmonary bypass
Y Moshkovitz, Y Paz, E Shabtai, G Cotter, G Amir, AK Smolinsky and R Mohr
Department of Cardiac Surgery, The Chaim Sheba Medical Center, Tel Hashomer, Israel.
OBJECTIVE: Cardiopulmonary bypass in coronary artery bypass graft
operations may adversely affect the outcome especially in high-risk
patients. The purpose of this study is to evaluate results of coronary
artery bypass performed without cardiopulmonary bypass, in a relatively
high-risk cohort, and to identify predictors of unfavorable outcome.
METHOD: Three hundred and thirteen (313) patients, 246 (79%) of whom had
high-risk conditions, who have a coronary anatomy suitable for coronary
artery bypass surgery without cardiopulmonary bypass, underwent this
procedure between December 1991 and July 1995. Mean number of
grafts/patient was 1.8 (1-5), and only 71 patients (23%) received a graft
to the circumflex coronary system. RESULTS: Early unfavorable outcome
events included operative mortality (12 patients, 3.8%), nonfatal
perioperative myocardial infarction (eight patients, 2.6%), emergency
reoperation (three patients, 0.9%), sternal infection (five patients,
1.6%), and nonfatal stroke (two patients, 0.6%). Multivariate analysis
revealed angina pectoris class IV (odds ratio 5.4) and age > or = 70
years (odds ratio 5.0) as independent predictors of early mortality.
Preoperative risk factors such as repeat coronary artery bypass grafting
(50 patients, 16%), ejection fraction < or = 0.35 (85 patients, 27%),
acute myocardial infarction (86 patients, 28%), cardiogenic shock (ten
patients, 3.2%), chronic renal failure (25 patients, 8%), chronic
obstructive pulmonary disease (20 patients, 6%), and peripheral vascular
disease (51 patients, 16%) did not increase early mortality. During 33
months of follow-up (range 1-57 months), there were 42 deaths, at least 16
cardiac-related (one and four years actuarial survival of 90% and 76%
respectively), and 39 patients (12.5%) in whom angina returned. Calcified
aorta (odds ratio 2.6) and old myocardial infarction (odds ratio 1.8) were
independent predictors of overall unfavorable events. CONCLUSIONS: Coronary
artery bypass grafting without cardiopulmonary bypass can be performed with
relatively low operative mortality in certain high-risk subgroups of
patients; however, an increased risk of graft occlusion is a potential
disadvantage. This procedure should therefore be considered only for
patients with suitable coronary anatomy, in whom cardiopulmonary bypass
poses a high risk. Although the risk of stroke is relatively low, the
procedure is still hazardous for patients aged 70 years and over.