Reexploration for hemorrhage following coronary artery bypass grafting: incidence and risk factors. Northern New England Cardiovascular Disease Study Group.

OBJECTIVE

To assess mortality and risk factors associated with reexploration for hemorrhage in patients undergoing coronary artery bypass grafting (CABG).

DESIGN

Regional cohort study. Patient characteristics, treatment variables, and outcome measures were collected prospectively.

SETTING

All 5 centers performing cardiac surgery in Maine, New Hampshire, and Vermont.

PATIENTS: A consecutive cohort of 8586 patients undergoing isolated CABG between 1992 and 1995.

MAIN OUTCOME MEASURES: Postoperative hemorrhage leading to reexploration, in-hospital mortality, and length of stay.

RESULTS

A total of 305 patients (3.6%) underwent reexploration for bleeding. In these patients, in-hospital mortality was nearly 3 times higher (9.5% vs 3.3% for patients not requiring reoperation, P<.001) and average length of stay from surgery to discharge was significantly longer (14.5 days vs 8.6 days, P<.001). High rates of reexploration for hemorrhage were observed in patients with prolonged (> 150 minutes) cardiopulmonary bypass (39 [11.1%] of 351) and in those requiring an intra-aortic balloon pump intraoperatively (12 [8%] of 139). In multivariate analysis, older age, smaller body surface area, prolonged cardiopulmonary bypass, and number of distal anastomoses were associated with increased bleeding risks. The use of thrombolytic therapy within 48 hours of surgery was weakly but not significantly associated with the need for reexploration. Factors not significantly associated with reexploration included patient sex, preoperative ejection fraction, surgical priority, history of liver disease, myocardial infarction, prior CABG, renal failure, and diabetes mellitus.

CONCLUSIONS

Hemorrhage requiring reexploration after CABG is associated with markedly increased mortality and length of stay. Patients predicted to have increased risks of bleeding may benefit from prophylactic use of aprotinin, aminocaproic acid, or other agents shown to reduce hemorrhage.