Predictors of operative risk for coronary bypass operations in patients with left ventricular dysfunction

Objectives: The prevalence of ventricular dysfunction in patients undergoin g coronary operations, as well as the prevalence of other risk factors in t hese patients, has been increasing. We identified the predictors of mortali ty and morbidity in patients with ventricular dysfunction to permit more ac curate evaluation of risk and to direct future strategies to improve outcom es. Methods: Demographic, intraoperative, and outcome data were collected p rospectively on 20,614 patients undergoing isolated coronary operations at our institution from 1982-1997. Multivariable regression analyses were used to identify the independent predictors of mortality and low-output syndrom e. Results: Moderate ventricular dysfunction (ejection fraction, 20%-40%) w as noted in 4107 (19.9%) patients, and severe dysfunction (ejection fractio n, <20%) was noted in 680 (3.3%) patients. Patients with worse ventricular function had an increasing prevalence of other risk factors with time. Mort ality decreased between the 1982-1986 and 1987-1991 cohorts but did not dec rease further. Low-output syndrome was less common in the 1992-1997 cohort than in previous years. The predictors of mortality were ventricular dysfun ction, age, reoperation, year of operation, urgency, female sex, and left m ain stenosis. Low-output syndrome was predicted by ventricular dysfunction, reoperation, year of operation, female sex, urgency, extensive coronary di sease, age, left main stenosis, and symptom class. Conclusions: Despite the increasing prevalence and risk profile of patients with ventricular dysfun ction, mortality rates and incidence of low-output syndrome declined with t ime. Patients with severe dysfunction were at greatest risk when facing reo peration or urgent operation. Earlier intervention and more aggressive preo perative optimization may improve outcomes in these high-risk patients.