Impact of obesity in morbity and mortality of patients submitted to myocardial revascularization surgery <b>[Abstract in English]</b>

Abstract

Aims: To evaluate if obesity increase the incidence of post-operative complications and mortality after myocardial revascularization surgery. Methods: Hystorical cohort of 2.445 patients who underwent isolated coronary artery bypass grafting surgery between January 1996 and December 2006 at Hospital São Lucas da PUCRS. The pre-operative variables were: age, sex, functional class of angina (Canadian Heart Association), functional class of heart failure, diabetes, prior cerebral vascular accident (stroke), hypertension, renal dysfunction, chronic obstructive pulmonary disease, smoking, use of Intra-aortic Ballon, use of betablocker, and left ventricular ejection fraction. In the intraoperative, the cardiopulmonary bypass time was evaluated. The postoperative variables included: death, mediastinitis, stroke, respiratory infection, mechanical ventilation time, sepsis, vasoactive drugs, systemic inflammatory response syndrome, myocardial infarction, pulmonary embolism, acute renal disfunction, atrial fibrillation, hypertension, bleeding and lenght of hospital stay. The analysis was performed with statistical software SPSS 10.5, using the Student t test for continuous variables and x square test for categorical variables. Univariate and multivariate analysis were made and the odds ratio (OR) calculated with a 95% confidence interval (CI) and a 0.05 level of significance Results: From the total of 2.445 patients, 11.5% were obese and 56.2% were males. Diabetes, diabetes insulindependent and hypertension were more prevalent in the obese group. There were no differences in relation to death between the two groups: (10.7% in the obese x 8.6% in the non-obese) p = 0.14. In the multivariate analysis obesity was associated with mediastinitis OR=2.7 (95% CI 1.6-4.5), systemic inflammatory response syndrome OR= 2.7 (95% CI 1.8-3.8 ) and pulmonary embolism OR= 2.3 (95% CI 1.3-4.2) Conclusions: In this study obesity increased the risk of the following post-operative complications of myocardial revascularization surgery: mediastinitis, pulmonary embolism an systemic inflammatory response syndrome. There was not a statistically significant increase in mortality. KEY WORDS: MYOCARDIAL REVASCULARIZATION/ mortality; CORONARY ARTERY BYPASS/mortality; CORONARY ARTERY DISEASE/surgery; POSTOPERATIVE PERIOD; OBESITY/complications; MEDIASTINITIS; PULMONARY EMBOLISM; SYSTEMIC INFLAMMATORY RESPONSE SYNDROME.