The purpose of this study is to identify measures of obesity, functional capacity, and specific biomarkers that may be predictive of obesity and post-operative outcomes.

Background: Increasing levels of obesity worldwide have led to a rise in the prevalence of obesity-related complications including cardiovascular disease, diabetes, cancers etc. Health care providers believe that obesity has a negative effect on patients undergoing cardiac surgery, with overweight and obese patients being more likely to experience adverse post-operative outcomes. The body mass index (BMI) is the single most used measure for determining obesity classification in clinical practice, without accounting for a patient's level of cardiopulmonary fitness or muscle mass.

Study Design: Patients between the ages of 18 and 75 years undergoing elective cardiac surgery will be consented to participate in this prospective observational trial. Patients are invited to participate in measures of obesity, functional capacity and exercise capacity assessments, quality of life questionnaires, and blood and tissue sampling for biomarker analysis.

Endpoints: Measures other than BMI that could be predictive of short-term and long-term post-operative outcomes. Outcomes of interest include: prolonged length of ventilation, hospital length of stay and all-cause mortality.

Summary: The results of this trial will potentially identify an improved definition of fitness capacity for obese cardiac surgical patients and biomarkers alone or in combination that could identify the potential for adverse outcomes in patients undergoing cardiac surgery. This study will help clinicians better segregate and treat patients pre-operatively based on fitness levels and associated biomarkers.

Inclusion Criteria:

• · Provide informed consent

  • Male or female patients who are > 18 years of age
  • Patients must be scheduled to undergo elective, first-time cardiac surgery during routine scheduling times

Exclusion Criteria:

• Patients who are > 75 years of age
• BMI is less than 18.5 kg/m2 and classified as underweight according to the World Health Organization
• Any non-elective first time cardiac surgery patient (eg. in-house urgent patients; emergent patients)
• Any cardiac patients to undergo re-operation
• Simultaneous participation in another study with an investigational study agent

All patients scheduled to undergo elective, first-time cardiac surgery will be considered for eligibility to participate in the study. As well, a patient whose BMI is less than 18.5 kg/m2 and classified as underweight by the World Health Organization will be excluded. Only those patients who are classified as being normal weight range or overweight and/or obese may be considered for eligibility to participate as defined by the study objectives regarding post-operative cardiac surgery outcomes in obese patients. Patients in the normal weight range classification will be included as a baseline control participant cohort. Finally, patients over the age of 75 will be excluded so as to eliminate the role that advanced age may play in affecting functional capacity.