Obesity Paradox in Off-Pump Coronary Artery Bypass Surgery: Does It Benefit the Elderly?

Relation of body mass index to long-term survival and cardiac remodelling for patients undergoing mitral valve replacement surgery

BACKGROUND AND AIMS

Studies have demonstrated that obesity is paradoxically associated with reduced mortality following cardiac surgery. However, these studies have treated various types of cardiac surgery as a single entity. With mitral valve (MV) surgeries being the fastest-growing cardiac surgical interventions in North America, the purpose of this study was to identify the impact of body mass index (BMI) on long-term survival and cardiac remodelling of patients undergoing MV replacement (MVR).

METHODS AND RESULTS

In this retrospective, single-center study, 1071 adult patients who underwent an MVR between 2004 and 2018 were stratified into five BMI groups (<20, 20-24.9, 25-29.9, 30-34.9, >35). Cox proportional hazard regression models were used to determine the association between BMI and all-cause mortality. Patients who were underweight had significantly higher all-cause mortality rates at the longest follow-up (median 8.2 years) than patients with normal weight (p = 0.01). Patients who were in the obese group had significantly higher readmission rates due to myocardial infarction (MI) at the longest follow-up (p = 0.017). Subgroup analysis revealed a significant increase in long-term all-cause mortality for female patients who were underweight. Significant changes in left atrial size, mitral valve peak and mean gradients were seen in all BMI groups.

CONCLUSIONS

For patients undergoing mitral valve replacement, BMI is unrelated to operative outcomes except for patients who are underweight.

Multidimensional Approach to Frailty

The concept of frailty syndrome (FS) was first described in the scientific literature three decades ago. For a very long time, we understood it as a geriatric problem, recently becoming one of the dominant concepts in cardiology. It identifies symptoms of FS in one in 10 elderly people. It is estimated that in Europe, 17% of elderly people have FS. The changes in FS resemble and often overlap with changes associated with the physiological aging process of the body. Although there are numerous scientific reports confirming that FS is age correlated, it is not an unavoidable part of the aging process and does not apply only to the elderly. FS is a reversible clinical condition. To maximize benefits of frailty-reversing activities for patient with frailty, identification of its determinants appears to be fundamental. Many of the determinants of the FS have already been known: reduction in physical activity, malnutrition, sarcopenia, polypharmacy, depressive symptom, cognitive disorders, and lack of social support. This review shows that insight into FS determinants is the starting point for building both the comprehensive definition of FS and the adoption of the assessment method of FS, and then successful clinical management.

Perioperative Heart-Brain Axis Protection in Obese Surgical Patients: The Nutrigenomic Approach

The number of obese patients undergoing cardiac and noncardiac surgery is rapidly increasing because they are more prone to concomitant diseases, such as diabetes, thrombosis, sleep-disordered breathing, cardiovascular and cerebrovascular disorders. Even if guidelines are already available to manage anesthesia and surgery of obese patients, the assessment of the perioperative morbidity and mortality from heart and brain disorders in morbidly obese surgical patients will be challenging in the next years. The present review will recapitulate the new mechanisms underlying the Heart-brain Axis (HBA) vulnerability during the perioperative period in healthy and morbidly obese patients. Finally, we will describe the nutrigenomics approach, an emerging noninvasive dietary tool, to maintain a healthy body weight and to minimize the HBA propensity to injury in obese individuals undergoing all types of surgery by personalized intake of plant compounds that may regulate the switch from health to disease in an epigenetic manner. Our review provides current insights into the mechanisms underlying HBA response in obese surgical patients and how they are modulated by epigenetically active food constituents.

Adiposity in relation to readmission and all-cause mortality following coronary artery bypass grafting: A systematic review and meta-analysis

This study systemically reviewed evidence linking adiposity to readmission and all-cause mortality in post-coronary artery bypass grafting (CABG) patients. Keyword/reference search was performed in PubMed, Web of Science, CINAHL, and Cochrane Library for articles published before June, 2018. Eligibility criteria included study designs: experimental/observational studies; subjects: adult patients undergoing CABG; and outcomes: hospital/clinic readmissions, and short-term (≤30 days) and mid-to-long-term (>30 days) all-cause mortality. Seventy-two studies were identified. Meta-analysis showed that the odds of post-CABG readmission among patients with overweight was 30% lower than their normal-weight counterparts and the odds of mid-to-long-term post-CABG mortality among patients with overweight were 20% lower than their normal-weight counterparts. In contrast, no difference in post-CABG readmission rate was found between patients with obesity and their nonobese counterparts; no difference in short-term or in-hospital post-CABG mortality rate was found between patients with overweight or obesity and their normal-weight counterparts; and no difference in mid-to-long-term post-CABG mortality rate was found between patients with obesity and their normal-weight counterparts. In conclusion, patients with overweight but not obesity had a lower readmission and mid-to-long-term mortality rate following CABG relative to their normal-weight counterparts. Preoperative weight loss may not be advised to patients with overweight undergoing CABG.

Impact of body mass index on outcomes following mitral surgery: does an obesity paradox exist?

OBJECTIVES

This study was conducted to clarify the relationship between body mass index and mitral valve (MV) surgery and to determine whether an 'obesity paradox' exists in the context of surgery for degenerative MV disease.

METHODS

In this retrospective single-centre study, we analysed data from 715 patients who underwent mitral surgery for degenerative disease from 2000 to 2015. Patients were classified according to body mass index: underweight (<20 kg/m2), normal weight (20-24.99 kg/m2), overweight (25-29.99 kg/m2) and obese (≥30 kg/m2). Early and long-term results were investigated. Multivariable analysis was conducted to identify risk factors for long-term mortality.

RESULTS

Mean follow-up was 67 ± 44 months (range 0-190 months). There were no differences between groups regarding 30-day mortality (P = 0.35), stroke (P = 0.45), reoperation for bleeding (P = 0.9) and length of hospital stay (P = 0.31). Obese patients were at increased risk of acute kidney injury when compared with normal weight patients (17% vs 5%; P = 0.03) but not when compared with the other groups; this was confirmed within the subgroup with depressed ejection fraction (42% vs 10%, P = 0.02). No differences in long-term survival were found across groups for all patients (P = 0.62) and for patients with depressed ejection fraction (P = 0.6), with a trend towards worse survival in obese patients undergoing MV repair (P = 0.06). Survival in obese patients undergoing repair was significantly worse than that in obese patients undergoing replacement (P = 0.04).

CONCLUSIONS

An 'obesity paradox' was not demonstrated after surgery for degenerative MV disease. Obese patients are more prone to acute kidney injury and have worse late survival after MV repair.