Ct-based diagnosis of sarcopenia as a prognostic factor for postoperative mortality after elective open-heart surgery in older patients: a cohort-based systematic review and meta-analysis

Background

Cardiac open-heart surgery, which usually involves thoracotomy and cardiopulmonary bypass, is associated with a high incidence of postoperative mortality and adverse events. In recent years, sarcopenia, as a common condition in older patients, has been associated with an increased incidence of adverse prognosis.

Methods

We conducted a search of databases including PubMed, Embase, and Cochrane, with the search date up to January 1, 2024, to identify all studies related to elective cardiac open-heart surgery in older patients. We used the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach to assess the certainty of evidence.

Results

A total of 12 cohort studies were included in this meta-analysis for analysis. This meta-analysis revealed that patients with sarcopenia had a higher risk of postoperative mortality. Furthermore, the total length of hospital stay and ICU stay were longer after surgery. Moreover, there was a higher number of patients requiring further healthcare after discharge. Regarding postoperative complications, sarcopenia patients had an increased risk of developing renal failure and stroke.

Conclusion

Sarcopenia served as a tool to identify high-risk older patients undergoing elective cardiac open-heart surgery. By identifying this risk factor early on, healthcare professionals took targeted steps to improve perioperative function and made informed clinical decisions.Systematic review registration: https://www.crd.york.ac.uk/prospero/, identifier CRD42023426026.

Association between overweight and obesity with coronary artery bypass graft failure: an individual patient data analysis of clinical trials

OBJECTIVES

The association between obesity and graft failure after coronary artery bypass grafting has not been previously investigated.

METHODS

We pooled individual patient data from randomized clinical trials with systematic postoperative coronary imaging to evaluate the association between obesity and graft failure at the individual graft and patient levels. Penalized cubic regression splines and mixed-effects multivariable logistic regression models were performed.

RESULTS

Six trials comprising 3928 patients and 12 048 grafts were included. The median time to imaging was 1.03 (interquartile range 1.00-1.09) years. By body mass index (BMI) category, 800 (20.4%) patients were normal weight (BMI 18.5-24.9), 1668 (42.5%) were overweight (BMI 25-29.9), 983 (25.0%) were obesity class 1 (BMI 30-34.9), 344 (8.8%) were obesity class 2 (BMI 35-39.9) and 116 (2.9%) were obesity class 3 (BMI 40+). As a continuous variable, BMI was associated with reduced graft failure [adjusted odds ratio (aOR) 0.98 (95% confidence interval (CI) 0.97-0.99)] at the individual graft level. Compared to normal weight patients, graft failure at the individual graft level was reduced in overweight [aOR 0.79 (95% CI 0.64-0.96)], obesity class 1 [aOR 0.81 (95% CI 0.64-1.01)] and obesity class 2 [aOR 0.61 (95% CI 0.45-0.83)] patients, but not different compared to obesity class 3 [aOR 0.94 (95% CI 0.62-1.42)] patients. Findings were similar, but did not reach significance, at the patient level.

CONCLUSIONS

In a pooled individual patient data analysis of randomized clinical trials, BMI and obesity appear to be associated with reduced graft failure at 1 year after coronary artery bypass grafting.

Utility of growth differentiation factor-15 as a predictor of cardiovascular surgery outcomes: Current research and future directions

In a world increasingly confronted by cardiovascular diseases (CVDs) and an aging population, accurate risk assessment prior to cardiac surgery is critical. Although effective, traditional risk calculators such as the Japan SCORE, Society of Thoracic Surgeons score, and EuroSCORE II may not completely capture contemporary risks, particularly due to emerging factors such as frailty and sarcopenia. These calculators often focus on regional and ethnic specificity and rely heavily on evaluations based on age and underlying diseases. Growth differentiation factor-15 (GDF-15) is a stress-responsive cytokine that has been identified as a potential biomarker for sarcopenia and a tool for future cardiac risk assessment. Preoperative plasma GDF-15 levels have been associated with preoperative, intraoperative, and postoperative factors and short- and long-term mortality rates in patients undergoing cardiac surgery. Increased plasma GDF-15 levels have prognostic significance, having been correlated with the use of cardiopulmonary bypass during surgery, amount of bleeding, postoperative acute kidney injury, and intensive care unit stay duration. Notably, the inclusion of preoperative levels of GDF-15 in risk stratification models enhances their predictive value, especially when compared with those of the N-terminal prohormone of brain natriuretic peptide, which does not lead to reclassification. Thus, this review examines traditional risk assessments for cardiac surgery and the role of the novel biomarker GDF-15. This study acknowledges that the relationship between patient outcomes and elevated GDF-15 levels is not limited to CVDs or cardiac surgery but can be associated with variable diseases, including diabetes and cancer. Moreover, the normal range of GDF-15 is not well defined. Given its promise for improving patient care and outcomes in cardiovascular surgery, future research should explore the potential of GDF-15 as a biomarker for postoperative outcomes and target therapeutic intervention.

Sarcopenia Adversely Affects Outcomes following Cardiac Surgery: A Systematic Review and Meta-Analysis

BACKGROUND

Sarcopenia is a degenerative condition characterised by the loss of skeletal muscle mass and strength. Its impact on cardiac surgery outcomes remains poorly investigated. This meta-analysis aims to provide a comprehensive synthesis of the available evidence to determine the effect of sarcopenia on cardiac surgery outcomes.

METHODS

A systematic review and meta-analysis followed PRISMA guidelines from inception to April 2023 in EMBASE, MEDLINE, Cochrane database, and Google Scholar. Twelve studies involving 2717 patients undergoing cardiac surgery were included. Primary outcomes were early and late mortality; secondary outcomes included surgical time, infection rates, and functional outcomes. Statistical analyses were performed using appropriate methods.

RESULTS

Sarcopenic patients (906 patients) had a significantly higher risk of early mortality (OR: 2.40, 95% CI: 1.44 to 3.99, p = 0.0007) and late mortality (OR: 2.65, 95% CI: 1.57 to 4.48, p = 0.0003) compared to non-sarcopenic patients (1811 patients). There were no significant differences in overall surgical time or infection rates. However, sarcopenic patients had longer ICU stays, higher rates of renal dialysis, care home discharge, and longer intubation times.

CONCLUSION

Sarcopenia significantly increases the risk of early and late mortality following cardiac surgery, and sarcopenic patients also experience poorer functional outcomes.

Sarcopenia and Cardiovascular Diseases

Sarcopenia is the loss of muscle strength, mass, and function, which is often exacerbated by chronic comorbidities including cardiovascular diseases, chronic kidney disease, and cancer. Sarcopenia is associated with faster progression of cardiovascular diseases and higher risk of mortality, falls, and reduced quality of life, particularly among older adults. Although the pathophysiologic mechanisms are complex, the broad underlying cause of sarcopenia includes an imbalance between anabolic and catabolic muscle homeostasis with or without neuronal degeneration. The intrinsic molecular mechanisms of aging, chronic illness, malnutrition, and immobility are associated with the development of sarcopenia. Screening and testing for sarcopenia may be particularly important among those with chronic disease states. Early recognition of sarcopenia is important because it can provide an opportunity for interventions to reverse or delay the progression of muscle disorder, which may ultimately impact cardiovascular outcomes. Relying on body mass index is not useful for screening because many patients will have sarcopenic obesity, a particularly important phenotype among older cardiac patients. In this review, we aimed to: (1) provide a definition of sarcopenia within the context of muscle wasting disorders; (2) summarize the associations between sarcopenia and different cardiovascular diseases; (3) highlight an approach for a diagnostic evaluation; (4) discuss management strategies for sarcopenia; and (5) outline key gaps in knowledge with implications for the future of the field.

Muscle strength trajectories and their association with postoperative health-related quality of life in patients undergoing coronary artery bypass grafting surgery: a prospective cohort study

BACKGROUND

Patients with sarcopenia have a higher risk of poor recovery after coronary artery bypass grafting (CABG). Little is known about the impact of changes in muscle strength (the primary indicator for sarcopenia) on health-related quality of life (HR-QoL). This study aimed to (1) identify subgroups with different muscle strength trajectories, (2) identify differences in preoperative risk factors among trajectory group membership, and (3) explore their prognostic value on postoperative HR-QoL in patients undergoing CABG.

METHODS

In this prospective observational study 131 patients undergoing elective CABG completed grip strength tests and HR-QoL questionnaires. Latent Class Growth Mixture Modelling (LCGMM) was used to identify clinically relevant trajectories (> 5% of study population) for weight-normalised grip strength, measured at admission, 3 days, and 6 months after surgery. Differences between trajectory group membership at baseline were evaluated. The impact of trajectory group membership on postoperative HR-QoL was evaluated with multiple linear regression models.

RESULTS

Due to low numbers (n = 15), female patients were excluded from LCGMM and subsequent statistical analyses. In males (n = 116), we identified two main weight-normalised grip strength trajectories: a "stable average" trajectory with a slight decline immediately post-surgery and recovery to preoperative levels (n = 85) and a "high" trajectory with a considerable immediate decline after surgery but followed towards a higher level of recovery compared to preoperative level (n = 27). The "stable average" patients were older (68 vs. 57 years; P = 0.003), had more diabetes (27% vs. 4%; P = 0.01) and had a higher BMI (27.8 vs. 24.8; P = 0.005) compared to the "high" group. After correction for age, diabetes, and baseline HR-QoL, group trajectory membership was not associated with postoperative HR-QoL, yet an increase in individual change scores of weight-normalised grip strength was associated with a better postoperative HR-QoL. We also identified one small trajectory group (n = 4, ≤ 5%).

CONCLUSIONS

This study showed two relevant weight-normalised grip strength trajectories in male patients undergoing CABG, varying in important preoperative risk factors. While change scores of grip strength per weight did predict postoperative HR-QoL, the trajectory subgroups could not predict postoperative HR-QoL. Future research should focus on female patients, reacting potentially different on CABG and/or rehabilitation treatment. Trial registration NCT03774342, 12-12-2018.

Sarcopenia with co-existent type 2 diabetes mellitus is associated with worse clinical outcomes among hospitalised cardiac patients

BACKGROUND & AIMS

Sarcopenia has been shown associated with functional decline, disability, poorer quality of life and mortality. However, there are limited studies among hospitalised cardiac patients in Malaysia. This study aimed to identify the association of sarcopenia and type 2 diabetes mellitus (T2DM) with clinical outcomes among hospitalised cardiac patients.

METHODS

This prospective observational study assessed 100 patients who were admitted to the general wards at the National Heart Institute. We measured handgrip strength, body composition using bioelectrical impedance analysis (BIA) and recorded the length of stay (LOS), unplanned readmission and incidence of infection within 90 days after discharge. Logistic regression analysis at a significant level p < 0.05 was used to identify the association between sarcopenia and clinical outcomes.

RESULTS

The prevalence of sarcopenia was 63%, and this was similar in patients with or without T2DM. After adjustment, sarcopenia was significantly associated with 90-day unplanned readmission (adjusted OR 3.5; 95%CI 1.40-8.77; p = 0.007) and LOS (AOR 0.4; 95%CI 0.16-0.88; p = 0.026). After adjustment, the co-existent of T2DM and sarcopenia was significantly associated with 90-day unplanned readmission (AOR 7.3; 95%CI 1.82-29.66; p = 0.005) and 90-day incidence of infection (AOR 4.4; 95%CI 1.12-17.52; p = 0.033).

CONCLUSION

Sarcopenia with co-existent T2DM was associated with increased risk for readmission and infection among hospitalised cardiac patients. Early identification of sarcopenia is important for timely intervention to improve prognosis in hospitalised cardiac patients with T2DM.

Sarcopenia in cardiac surgery: Dual X-ray absorptiometry study from the McGill frailty registry

BACKGROUND

To determine the prevalence and prognostic value of sarcopenia measured by dual x-ray absorptiometry (DXA) and physical performance tests in patients undergoing coronary artery bypass surgery or heart valve procedures.

METHODS

Adults undergoing cardiac surgery were prospectively enrolled and completed a questionnaire, physical performance battery, and a DXA scan (GE Lunar) to measure appendicular muscle mass indexed to height² (AMMI). Patients were categorized as sarcopenic based on European Working Group 2 guidelines if they had low AMMI defined as <7 kg/m² for men or <5.5 kg/m² for women, and low muscle strength defined as 5 chair rise time ≥15 seconds. Cox proportional hazards regression was used to test the association between sarcopenia and all-cause mortality over a median follow-up of 4.3 years.

RESULTS

The cohort consisted of 141 patients with a mean age of 69.7 ± 10.0 years and 21% females. The prevalence rates of low AMMI, slow chair rise time, and sarcopenia (low AMMI and slow chair rise time) were 24%, 57%, 13%, respectively. The 4-year survival rate was 79% in the non-sarcopenic group as compared to 56% in the sarcopenic group (Log-rank P = 0.01). In the multivariable model, each standard deviation of decreasing AMMI and increasing chair rise time was associated with a hazard ratio for all-cause mortality of 1.84 (95% CI 1.18, 2.86) and 1.79 (95% CI 1.26, 2.54), respectively.

CONCLUSION

Lower-extremity muscle strength and DXA-based muscle mass are objective indicators of sarcopenia that are independently predictive of all-cause mortality in older cardiac surgery patients.

Effects of Slowness, Frailty, Insufficient Intake, and Delirium in Patients Following Cardiac Surgery: A Cohort Study

BACKGROUND

Slow gait, frailty, insufficient postoperative caloric intake, and delirium, although seemingly distinct, can appear simultaneously in patients who underwent cardiac surgery.

OBJECTIVES

The aim of this study was to evaluate how these 4 factors overlap and how they individually and cumulatively affect cardiac surgery outcomes.

METHODS

The effects of slowness (gait speed <0.83 m/s), frailty (≥3/5 Fried criteria), insufficient postoperative intake (<800 kcal/d), and delirium (defined by the Confusion Assessment Method) on hospital length of stay (LOS) and 3-month mortality were analyzed in 308 adult patients.

RESULTS

Slowness, frailty, insufficient intake, and delirium affected 27.5%, 29.5%, 31.5%, and 13.3% of participants, respectively; only 42.2% (130/308) were free from these risks. Risk overlap was prevalent, as 26.3% (n = 81) had 2 or more risk factors. The most obvious overlap was in delirium (80% of delirious participants had other risks), suggesting that delirium cannot be managed in isolation. Individually, whereas slowness was associated only with longer LOS, frailty, insufficient intake, and delirium all led to longer LOS and higher mortality. When equally weighting each risk factor to analyze their cumulative effects, LOS increased by 4.4 days (95% confidence interval, 3.0-5.7) and 3-month mortality increased by 2.6-fold (95% confidence interval, 1.4-4.6), with each risk factor added, independent of participants' educational level, body mass index, and risk for cardiac surgery (EuroSCORE II ≥6).

CONCLUSIONS

Because a clinical overlap of slowness, frailty, insufficient postoperative intake, and delirium was evident in patients who underwent cardiac surgery, and risk of death and longer hospital stay increased with each factor added, care should be revised to consider these overlapping factors to maximize patient outcomes.

Propensity weighting: how to minimise comparative bias in non-randomised studies?

Non-randomised study designs are frequently used by researchers in cardiovascular nursing and allied professions. Baseline differences between the groups to be compared may introduce bias in the results. Methods for causal inference address this issue. One such method is propensity weighting, in which two or more treatments/exposure groups are weighted to make the groups as comparable as possible. As such, it mimics a randomised controlled trial design. In this article, the Twang package is presented for propensity weighting, and its use is exemplified in a study on smoking and cannabis consumption in adults with congenital heart disease.

Sarcopenia in open heart surgery patients: A cohort study

Background

Sarcopenia is a condition characterized by loss of muscle mass, muscle strength, or physical performance. It has been reported that cardiac surgery causes systemic inflammatory response, which leads to sarcopenia. In addition, open-heart surgery (OHS) has been associated with length of hospital stay, prolonged mechanical ventilation, and postoperative pulmonary complications. However, very few studies have explored the association of sarcopenia with OHS. Thus, this study explores the prevalence of sarcopenia in OHS patients as well as their relationship.

Methods

This cohort study included 160 patients; it was designed to assess sarcopenia during preoperative OHS and before patient discharge from the hospital. Sarcopenia was defined according to Asian Working Group for Sarcopenia (AWGS) criteria as low muscle mass plus low muscle strength and/or slow gait speed. Participants were requested to perform exercises to test their handgrip strength, gait speed, and bioelectrical impedance. In addition, their medical history (e.g., duration of hospitalization and mechanical ventilation) was recorded.

Results

The prevalence of sarcopenia during preoperative OHS was 26.9%, with affected men comprising 11.9% and affected women comprising 15% of the total sample. Participants with sarcopenia had a significantly lower body mass index (BMI) than those without. Further, patients who had longer stays in the hospital and prolonged mechanical ventilation time showed significantly higher rates of developing sarcopenia. During postoperative OHS, the incidence of sarcopenia rose by 20.92%, increasing the total prevalence of sarcopenia to 46.41%. Moreover, advanced age emerged as one of the most significant risk factors of sarcopenia. Participants in the age group >55 years had an increased risk of sarcopenia (odds ratio [OR]: 3.90). It was also found that patients with a low BMI (<23 kg∗m⁻²) and a history of diabetes mellitus (DM) had an increased risk of sarcopenia (ORs: 2.11 and 1.47, respectively). Moreover, longer hospital stays and mechanical ventilation times were important risk factors (ORs: 1.58 and 2.07, respectively).

Conclusion

The prevalence of sarcopenia was observed to be high during postoperative OHS. Participants with sarcopenia who underwent OHS had a history of DM, longer length of hospital stays, and prolonged mechanical ventilation times, compared with patients without sarcopenia.

Clinical trial registration number

TCTR20190509003.

Surviving and Thriving 1 Year After Cardiac Surgery: Frailty and Delirium Matter

BACKGROUND

We compared 1-year functional outcomes for 4 cardiac surgery patient groups: comparison (without preoperative frailty or postoperative delirium [POD]), frailty only (with preoperative frailty only), POD only (with POD only), and frailty-POD (combined frailty and POD).

METHODS

Consecutive cardiac surgery patients (n = 298) at a university hospital were assessed for preoperative frailty using Fried's phenotype, and POD was assessed daily for 10 days after surgery using the Confusion Assessment Method. Functional outcomes (Barthel Index for activities of daily living [ADL]) and all-cause mortality were evaluated 1-year after surgery.

RESULTS

Preoperative frailty presented in 85 of participants (28.5%) and POD in 38 (12.8%). Frail participants were at increased risk for POD (odds ratio = 4.9; P < .001). Overall, 1-year mortality was 4.0% (n = 12) and functional change was 0.4 ± 11.0 Barthel points. Controlling for age, cardiac risk, and baseline ADL, frailty-only and comparison participants had comparable 1-year functional outcomes. The POD-only group had greater mortality (adjusted hazard ratio = 23.9; P = .01), whereas the combined frailty-POD group had the greatest ADL decline (β = -23.7; P = .01) and the highest mortality (adjusted hazard ratio = 30.2; P = .006) compared with the comparison group.

CONCLUSIONS

Preoperative frailty alone did not negatively affect cardiac surgery patients' functional outcomes up to 1 year, but coexisting frailty and POD led to substantial loss of independence on 3 to 4 ADLs and a 30.2-fold higher likelihood of dying 1 year after surgery. Because frailty led to a 4.9-fold increase in POD risk, frailty may serve as a presurgical screen to identify patients who would likely benefit from delirium prevention and functional recovery programs to maximize 1-year postsurgical outcomes.

Preoperative Treatment of Malnutrition and Sarcopenia in Cardiac Surgery: New Frontiers

Cardiac surgery is performed more often in a population with an increasing number of comorbidities. Although these surgeries can be lifesaving, they disturb homeostasis and may induce a temporary overall loss of physiologic function. The required postoperative intensive care unit and hospital stay often lead to a mid- to long-term decline of nutritional and physical status, mental health, and health-related quality of life. Prehabilitation before elective surgery might be an opportunity to optimize the state of the patient. This article discusses current evidence and potential effects of preoperative optimization of nutrition and physical status before cardiac surgery.