Data analysis. Descriptive statistics (mean (SD), median, frequency as appropriate) will be used to summarize the demographic, procedural and clinical characteristics of the study group. To evaluate the success of randomization, the investigator will describe demographic and clinical data both overall and after stratification by surgery type and by treatment type. As intra-operative conditions can direct modification in the actual surgery performed (e.g. CABG may become CABG plus valve replacement), the investigator will also describe the proportion of subjects who were misclassified by surgery type during randomization and if necessary will assess randomization balance according to the actual surgery type received.