European Journal of Cardio-Thoracic Surgery, Vol 11, 129-133, Copyright © 1997 by European Association for Cardio-thoracic Surgery
Reoperative coronary artery bypass procedures: risk factors for early mortality and late survival
JT Christenson, M Schmuziger and F Simonet
The Cardiovascular Surgery Unit, Hopital de la Tour, Meyrin-Geneva, Switzerland.
OBJECTIVES: The number of coronary artery disease reoperations is
increasing. The aim of this paper is to identify risk factors and evaluate
the results of REDO coronary artery bypass grafting (CABG). MATERIAL:
Between January 1984 and October 1994, 594 patients underwent REDO-CABG and
3157 underwent primary-CABG. The mean age was 62 years with 84% men.
Hypertension, hyperlipidemia, insulin dependent diabetes, smoking and renal
insufficiency were all more frequent in the REDO- group. A significantly
higher number of patients undergoing REDO-CABG were in the Canadian
Cardiovascular Society (CCS) angina class 3 and 4, had instable angina, had
left main stem stenosis of greater than 70% and 3-vessel disease compared
to those undergoing primary-CABG. The mean preoperative left ventricular
function (LVEF) was 49.8 (REDO) vs. 58.2%, with a P value of less than
0.001. RESULTS: The overall postoperative mortality rate for
REDO-operations was 9.6 (57/594) vs. 2.8% for primary-CABG. Patients with a
reoperative interval of more than 1 year had an 8.9% mortality rate,
compared to those reoperated less than 1 year after the initial CABG, where
the mortality was 21% with a P value of less than 0.05. Postoperative low
cardiac output syndrome, intraaortic balloon pump support, prolonged
ventilatory support (> 24 h), hemorrhage and gastrointestinal
complications were prominent features of the REDO-group (all P < 0.01).
Urgent operation, CCS class 3 and 4, LVEF of less than 40%, generalized
arteriosclerotic disease and advanced age (> 80 years) were independent
risk factors for postoperative death in both groups. Preoperative renal
insufficiency, diabetes and short interval from primary-CABG were added
risk factors in the REDO-group. The 5-years survival rate after REDO-CABG
was 89%, while the cardiac event-free survival rate was 79% and at 7 years
84 and 62%, respectively. CONCLUSIONS: Reoperative CABG is effective, but
has an increased operative mortality and morbidity. The long-term results
are encouraging. Unstable angina, poor preoperative left ventricular
function, renal insufficiency, insulin dependant diabetes and an interval
shorter than 1 year of the initial operation were independent riskfactors
for mortality.
