Impact of Obesity on Postoperative Outcomes following cardiac Surgery (The OPOS study): rationale and design of an investigator-initiated prospective study

Abstract

IntroductionIncreasing levels of obesity worldwide have led to a rise in the prevalence of obesity-related complications including cardiovascular risk factors such as diabetes, hypertension and dyslipidaemia. Healthcare providers believe that overweight and obese cardiac surgery patients are more likely to experience adverse postoperative outcomes. The body mass index (BMI) is the primary measure of obesity in clinical practice, without accounting for a patient’s level of cardiopulmonary fitness or muscle mass. The objective of this study is to determine whether fitness capacity of obese cardiac surgical patients and biomarkers, alone or in combination, will help identify patients at risk for adverse outcomes when undergoing cardiac surgery.Methods and analysisPatients between the ages of 18 and 75 years undergoing elective cardiac surgery are consented to participate in this prospective observational study. Patients will be 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. The endpoints evaluated are measures other than BMI that could be predictive of short-term and long-term postoperative outcomes. Clinical outcomes of interest are prolonged ventilation, hospital length of stay, renal failure and all-cause mortality. Biomarkers of interest will largely focus on metabolism (lipids, amino acids) and inflammation (adipokines, cytokines and chemokines).Ethics and disseminationThis study has been approved by the institutional review board at the Horizon Health Network. On completion of the study, the results shall be disseminated through conference presentations and publications in peer-reviewed journals. Additionally, the report shall also be diffused more broadly to the general public and the cardiovascular community.Trial registration numberNCT03248921.

Influence of Obesity on Short-Term Surgical Outcomes in HFrEF Patients Undergoing CABG: A Retrospective Multicenter Study

“…The prolonged hospital length of stay and increased ventilation time in the obese group of HFrEF patients are consistent with the literature, which often reports extended recovery periods for obese patients [22,23] following CABG. This could be attributed to a higher burden of comorbidities, increased surgical complexity, and the challenges in postoperative care, including ventilation management.…”

“…The trend toward higher mortality in the obese group echoes the sentiments of several studies that implicate obesity as a factor in increased short-term mortality following CABG. However, the 'obesity paradox'-where obesity, in certain contexts, appears to confer a survival advantage after cardiac events-remains a contentious topic, with some studies suggesting a protective effect of increased BMI in the postoperative period [22,[27][28][29], but is contradicted in other studies [30,31].…”

The Obesity Paradox in Cardiothoracic Surgery

“…In conclusion, the impact of BMI has been consistently analysed in studies that aim to identify risk factors for increased early complications and extended length of stay to enhance quality and provide cost-effective means of patient centered care. An ongoing study by Aguiar, et al [16]. (The impact of Obesity on Postoperative…”

“…Outcomes following cardiac Surgery (OPOS) study) aims to better differentiate obese patients who experience fewer complications from those with increased rates of adverse events [16].…”

The Rate of Postoperative Mortality and Renal and Respiratory Complications are Increased in Patients with Extreme Obesity Undergoing Cardiac Surgery – A Retrospective Observational Cohort Study of 8848 Patients

“…Previous research regarding this association has shown a correlation between acute renal failure and extreme obesity. [13][14][15][16] It is necessary to mention that obesity, by itself, has a negative effect on renal function due to fluid retention, which predisposes to a state of chronic and acute renal insufficiency. 17,18 Serra et al observed that excess adipose tissue correlated with the insulin resistance mechanism.…”