Effects Of Obesity On Outcomes In Elderly Patients Undergoing Cardiac Valve Replacement

Background and objective: Obesity is an epidemic disease in modern society. It is related to aging and as the population ages, there will be more and more obese patients. The average age of patients undergoing cardiac surgery is increasing and thus, cardiac surgeons will see more and more obese elderly patients. Obesity is a well known operative risk in general, but there has been little research regarding it as a risk factor specifically in cardiac valve replacement in the elderly patients. This study attempts to delineate this risk more precisely.Methods: A retrospective chart review was carried out on 219 elderly patients (age≥60 years) who underwent cardiac valve replacement at Fujian Provincial Hospital in Fuzhou , China between January, 1996 and December, 2006. The patients were divided into three groups: control group, overweight group, and obese group according to body mass index (BMI). Operative details, the pathological changes of auricular muscle, postoperative complications, and mortality were compared between the three groups, and some of the clinical data were analyzed with logistic regression method.Results: The LVPW, LVEDD, and E/A ratio of the obese group were significantly greater,larger,and lower than those in the control and overweight groups (P<0.05) and correlated with the degree of obesity. There was no statistical difference in the degree of myocardial fatty infiltration between the three groups (P>0.05) .Postoperative complications such as respiratory failure, pulmonary infection, low cardiac output, duration of ventilator use , wound infection, and delayed wound healing in the obese group were significantly higher than those in the control and overweight groups (P<0.05). The hospital mortality of control, overweight and obese groups were 4.50%, 10.45% and 17.07% respectively (P<0.05). Logistic regression showed that preoperative heart failure (NYHA grade IV ) , obesity, infective endocarditis , concomitant CABG, prior cardiac operation, low LVEF, and aortic cross-clamp time were all independent predictors of postoperative mortality.Conclusions: Obesity is an independent predictor of postoperative mortality. Increasing obesity is associated with an increase in postoperative complications and operative mortality. Obesity is not a contraindication for cardiac valve replacement for elderly patients but should be considered along with other operative risk factors before making a recommendation for surgery.