Influence of Old Age, Gender, and Internal Mammary Artery Grafting on Operative Mortality and Morbidity in Coronary Artery Bypass Grafting

Guo-Wei He; Tea E. Acuff; William H. Ryan; Yang-Hui He; Michael J. Mack

Influence of Old Age, Gender, and Internal Mammary Artery Grafting on Operative Mortality and Morbidity in Coronary Artery Bypass Grafting

Am J Geriatr Cardiol. 1996 Nov;5(6):22-35.

Authors

Guo-Wei He¹, Tea E. Acuff, William H. Ryan, Yang-Hui He, Michael J. Mack

Affiliation

¹ Department of Surgery, University of Hong Kong, The Grantham Hospital and The Albert Starr Academic Center for Cardiac Surgery, St. Vincent Hospital and Medical Center, Portland, OR.

PMID: 11416399

Abstract

Operative risk may change its pattern from time to time. To investigate determinants for operative mortality in patients undergoing CABG since the mid 1980s and the influence of age, gender, and IMAG on mortality, the data of 6,360 patients who underwent CABG from January 1986 through June 1993 were analyzed. Of these patients, 2,153 had SVG alone and 4,207 had IMAG including UIMAG (3,957) and BIMAG (250). Overall mortality was 4.34%. OM (in hospital death) for IMAG (2.69%) was lower than for SVG (7.57%, p is less than 0.0001). There was no difference in mortality between BIMAG (3.2%) and UIMAG patients (2.65%, p equals 0.6) or UIMAG/SVG patients (4.29%, p equals 0.36). Fewer IMAG patients had postoperative complications (LCO, insertion of IABP, prolonged ventilation, reoperation for bleeding, neurological complications, perioperative MI, and infection of legs) than SVG patients. There was no difference in the incidence of sternal infection. To determine risk factors for mortality and the influence of IMAG on the outcome, 82 variables (31 preoperative, 17 intraoperative, and 34 postoperative) were analyzed by univariate analysis. Significant variables or the variables having a trend (p is less than 0.2) to be associated with mortality were included in stepwise multiple logistic regression analyses. Two regression analyses were separately performed. Regression 1 only included pre- and intraoperative variables whereas regression 2 included postoperative variables as well. The logistic regressions demonstrate that preoperative (low EF, age at or above 70, female gender, history of CHF or arrhythmia, and functional Class), intraoperative (emergency operation, reoperation, long perfusion time, and lack of IMAG), and postoperative (complications) variables are independently associated with higher mortality. Female gender is an independent determinant for mortality and not dependent on small body surface area. Neither use of BIMAG or right IMAG, nor number of grafts is associated with the OM. The identification of these risk factors may have important implications in further improvement of the results for CABG.