8 Even though the existing literature contains information on the role of seasonal variations in the effects of some drugs on patients prepared for coronary artery bypass grafting GW4064 supplier surgery (CABG),9 precious little is currently available on the possible effects of seasonal variations on the outcome of patients
following CABG.1 The aim of this study was to assess the short-term outcome of post-CABG patients in the four seasons to seek any possible correlation between seasonal variations and CABG outcome. Patients and Methods The data on all patients who underwent CABG between January 2007 and December 2009 Inhibitors,research,lifescience,medical in two private hospitals in Shiraz, Iran were analyzed. The seasons were defined Inhibitors,research,lifescience,medical as spring (March 21 to June 21), summer (June 22 to September 22), autumn (September 23 to December 21), and winter (December 22 to March 20). In-hospital mortality, length of Intensive Care Unit (ICU) stay, and length of hospital stay were considered as outcome measures. The EuroSCORE (European System for Cardiac Operative Inhibitors,research,lifescience,medical Risk Evaluation) was calculated for all the patients. The EuroSCORE is a risk model which can calculate the risk of death after cardiac
surgery. In this model, 17 different questions (regarding age, sex, arteriopathy, previous surgery, serum creatinine, pulmonary disease, etc.) are asked, and specific software is utilized to calculate the risk via logistic regression. SPSS software version 17
was used for statistical analysis. The continuous variables are reported as Inhibitors,research,lifescience,medical mean±standard deviation or median, and the categorical variables are reported as frequencies and proportions. The Kruskal-Wallis, chi square, and ANOVA tests were employed as appropriate. The effect of seasonal variations on hospital mortality, length Inhibitors,research,lifescience,medical of ICU stay, and length of hospital stay was assessed using multiple logistic regressions in the presence of the EuroSCORE to adjust for the other confounding factors that could affect the outcome of operations. Results Of all the patients who underwent CABG between January 2007 and December 2009 in our centers, only 436 patients had complete archived files to permit the required analysis. Of the 436 patients, 402 received CABG and the remaining 32 patients had CABG combined with some other types of cardiac surgery. The latter group was excluded from Fossariinae the analysis. There were no differences as regards the mean age and the sex ratio of the patients between the four seasons (table 1). Table 1 Characteristics of the patients who underwent coronary artery bypass grafting surgery in various seasons In the mentioned period, only 3 deaths occurred: 2 deaths in spring and one in summer. None of the mortalities occurred in the ICU. No statistical differences could be found between the seasons for the death variable. The mean EuroSCORE was not different between the patients in the four seasons (P=0.