Conversion in off-pump coronary artery bypass grafting: an analysis of predictors and outcomes.
BACKGROUND
The incidence, predictive factors, and outcomes related to conversion from off-pump coronary artery bypass (OPCAB) to on-pump coronary artery bypass grafting (ONCAB) have not been well defined. We sought to determine the incidence of conversion, predictive factors, and any associated adverse consequences.


METHODS
From January 2000 through June 2002, 1,644 patients underwent nonemergent OPCAB with 61 patients requiring conversion from OPCAB to ONCAB. These groups were retrospectively compared by univariate and multivariate regression analysis. The converted group was then computer matched 1:3, to a cohort of ONCAB patients to determine differences in outcomes.


RESULTS
The overall conversion rate was 3.71%. Converted patients compared with a computer-matched ONCAB patients had a higher incidence of operative mortality (18.0% versus 2.7%, p < 0.001). Urgently converted patients had a higher incidence of postoperative cardiac arrest (25% versus 1.1%, p < 0.001), multisystem organ failure (10.7% versus 0.6%, p < 0.001), vascular complications (7.1% versus 1.1%, p = 0.03), and perioperative myocardial infarction (10.7% versus 1.1%, p = 0.02). Predictive factors for conversion were surgeon early in OPCAB experience (odds ratio [OR] 4.4), previous CABG (OR 2.8), and congestive heart failure (OR 2.0). The need for urgent-emergent conversion was highly predictive for operative mortality (OR 7.3) compared with elective conversion.


CONCLUSIONS
Patients undergoing urgent-emergent but not elective conversion from OPCAB to ONCAB had a significantly higher risk of mortality and morbidity compared with patients whose procedure was initially ONCAB. Variables predictive of conversion included previous CABG, congestive heart failure, and surgeons early in OPCAB experience.
Edgerton
James R
JR
Cardiopulmonary Research Science and Technology Institute, USA and Medical City Dallas Hospital, Dallas, Texas, USA. edgertonjr@aol.com
Dewey
Todd M
TM
Magee
Mitchell J
MJ
Herbert
Morley A
MA
Prince
Syma L
SL
Jones
Katherine K
KK
Mack
Michael J
MJ
D002315:Cardiopulmonary Bypass / Q000706:statistics & numerical data; D002983:Clinical Competence; D001026:Coronary Artery Bypass / Q000379:methods* / Q000401:mortality; D017558:Elective Surgical Procedures; D004630:Emergencies; D006323:Heart Arrest / Q000209:etiology; D006333:Heart Failure / Q000150:complications; D006754:Hospital Restructuring; D006801:Humans; D009102:Multiple Organ Failure / Q000209:etiology; D011183:Postoperative Complications; D012189:Retrospective Studies; D016896:Treatment Outcome