A Novel Model Incorporating Pectoralis Muscle Measures to Predict Mortality After Ventricular Assist Device Implantation

The Association Between Preoperative Pectoralis Muscle Quantity and Outcomes After Cardiac Transplantation

BACKGROUND

Sarcopenia is underappreciated in advanced heart failure and is not routinely assessed. In patients receiving a left ventricular assist device, preoperative sarcopenia, defined by using computed-tomography (CT)-derived pectoralis muscle-area index (muscle area indexed to body-surface area), is an independent predictor of postoperative mortality. The association between preoperative sarcopenia and outcomes after heart transplant (HT) is unknown.

OBJECTIVES

The primary aim of this study was to determine whether preoperative sarcopenia, diagnosed using the pectoralis muscle-area index, is an independent predictor of days alive and out of the hospital (DAOHs) post-transplant.

METHODS

Patients who underwent HT between January, 2018, and June, 2022, with available preoperative chest CT scans were included. Sarcopenia was diagnosed as pectoralis muscle-area index in the lowest sex-specific tertile. The primary endpoint was DAOHs at 1 year post-transplant.

RESULTS

The study included 169 patients. Patients with sarcopenia (n = 55) had fewer DAOHs compared to those without sarcopenia, with a median difference of 17 days (320 vs 337 days; P = 0.004). Patients with sarcopenia had longer index hospitalizations and were also more likely to be discharged to a facility other than home. In a Poisson regression model, sarcopenia was a significant univariable and the strongest multivariable predictor of DAOHs at 1 year (parameter estimate = -0.17, 95% CI -0.19 to -14; P = < 0.0001).

CONCLUSIONS

Preoperative sarcopenia, diagnosed using the pectoralis muscle-area index, is an independent predictor of poor outcomes after HT. This parameter is easily measurable from commonly obtained preoperative CT scans and may be considered in transplant evaluations.

Validation of the Minnesota Pectoralis Risk Score to predict mortality in the HeartMate 3 population

BACKGROUND

The Minnesota Pectoralis Risk Score (MPRS) utilizes computed tomography-quantified thoracic muscle and clinical variables to predict survival after left ventricular assist device (LVAD) implantation. The model has not been prospectively tested in HeartMate 3 recipients.

METHODS

A single-center HeartMate 3 cohort from July 2016 to July 2021 (n = 108) was utilized for this analysis. Cohort subjects with complete covariates for MPRS calculation (pectoralis muscle measures, Black race, creatinine, total bilirubin, body mass index, bridge to transplant status, and presence/absence of contrast) implanted after MPRS development were included. MPRS were calculated on each subject. Receiver operating characteristic curves were generated to test model discrimination at 30-day, 90-day, and 1-year mortality post-LVAD. Next, the performance of the 1-year post-LVAD outcome was compared to the HeartMate 3 survival risk score (HM3RS).

RESULTS

The mean age was 58 (15 years), 80% (86/108) were male, and 26% (28/108) were destination therapy. The area under the curve (AUC) for the MPRS model to predict post-LVAD mortality was 0.73 at 30 days, 0.78 at 90 days, and 0.81 at 1 year. The AUC for the HM3RS for the 1-year outcome was 0.693. Each 1-unit point of the MPRS was associated with a significant increase in the hazard rate of death after LVAD (hazard ratio 2.1, 95% confidence interval 1.5-3.0, p < 0.0001).

CONCLUSIONS

The MPRS had high performance in this prospective validation, particularly with respect to 90-day and 1-year post-LVAD mortality. Such a tool can provide additional information regarding risk stratification to aid informed decision-making.

Frailty in the Advanced Heart Failure Patient: A Challenging, Neglected, Yet Potentially Modifiable Risk Factor

Purpose of review

There is an increasing push for frailty assessment to become a routine part of the evaluation of potential candidates for advanced heart failure (AHF) therapies. The aim of this review is to highlight the importance of frailty in the care of the AHF patient.

Recent findings

This review focuses on some of the available data for the assessment of frailty specifically in the AHF, durable mechanical circulatory support (MCS), and heart transplant (HT) patients, and explores some of the challenges in assessing frailty in these patient populations.

Summary

As the presence of frailty can significantly impact outcomes after HT and durable MCS implantation, there should be an increased recognition of this entity during routine evaluation and management of the AHF patient.

CT-derived psoas muscle area and density are associated with length of stay and discharge disposition after liver transplantation

BACKGROUND & AIMS

Prolonged length of stay (LOS) and discharge disposition following liver transplantation are associated with postoperative complications and increased healthcare utilization. This study evaluated the relationship between CT-derived psoas muscle measurements and hospital LOS, intensive care unit (ICU) LOS, and discharge disposition after liver transplant. The psoas muscle was chosen given its ease of measurement with any radiological software. A secondary analysis assessed the relationship between the American Society for Parenteral and Enteral Nutrition and the Academy of Nutrition and Dietetics (ASPEN/AND) malnutrition diagnosis criteria and CT-derived psoas muscle measures.

METHODS

CT-derived measures of psoas muscle density (mHU) and cross-sectional area at the level of the third lumbar vertebrae were obtained from preoperative CT scans of liver transplant recipients. Cross-sectional area measures were corrected for body size to generate a psoas area index variable (cm²/m²; PAI).

RESULTS

Each 1-unit increase in PAI was associated with a reduced hospital LOS of 4 days (R² = 0.07). Each 5-unit increase in mean Hounsfield units (mHU) was associated with a reduced hospital and ICU LOS of 5 and 1.6 days, respectively (R² = 0.22 and 0.14, respectively). Mean PAI and mHU were higher in patients who discharged to home. PAI was reasonably identified through ASPEN/AND malnutrition criteria, but there was no difference in mHU between those with and without malnutrition.

CONCLUSION

Measures of psoas density were associated with both hospital and ICU LOS and discharge disposition. PAI was associated with hospital LOS and discharge disposition. CT-derived measures of psoas density may be a valuable complement to preoperative liver transplant nutrition assessment using traditional ASPEN/AND malnutrition criteria.

Prognostic Value of Frailty for Heart Failure Patients Undergoing Left Ventricular Assist Device Implantation: A Systematic Review

Frailty is associated with poor clinical outcomes in heart failure patients. The impact of frailty on outcomes following left ventricular assist device (LVAD) implantation, however, is less clearly defined. We therefore sought to conduct a systematic review to evaluate current frailty assessment strategies and their significance for patients undergoing LVAD implantation. We conducted a comprehensive electronic search of PubMed, Embase, and CINAHL databases from inception until April 2021 for studies examining frailty in patients undergoing LVAD implantation. Study characteristics, patient demographics, type of frailty measurement, and outcomes were extracted. Outcomes were organized into 5 basic categories: implant length of stay (iLOS), 1-year mortality, rehospitalization, adverse events, and quality of life (QOL). Of the 260 records retrieved, 23 studies involving 4935 patients satisfied the inclusion criteria. Approaches to measuring frailty varied, with the 2 most common being sarcopenia determined by computed tomography and Fried's frailty phenotype assessment. Outcomes of interest were also widely variable, with iLOS stay and mortality being the most frequently reported, albeit with differing definitions of both between studies. The heterogeneity among included studies precluded quantitative synthesis. Narrative synthesis showed that frailty by any measure is more likely to be associated with higher mortality, longer iLOS, more adverse events and worse QOL post-LVAD implant. Frailty can be a valuable prognostic indicator in patients undergoing LVAD implantation. Further studies are needed to determine the most sensitive frailty assessment, as well as the ways in which frailty may serve as a modifiable target to improve outcomes following LVAD implantation.

Is pectoralis muscle index a risk factor for mortality in left ventricular assist device patients?

OBJECTIVE

We aimed to investigate whether sarcopenia measured from pectoralis muscles is a risk factor for long-term mortality in left ventricular assist device patients.

METHODS

Patients aged >18 years implanted with a left ventricular assist device in a single center between 2013 and 2019 were retrospectively included. Patients without a thoracic computed tomography scan performed within 3 months of left ventricular assist device implantation and without computed tomography scans appropriate for pectoralis muscle measurement were excluded. Pectoralis muscle measurements were made on thoracic computed tomography slices, and pectoralis muscle indices were calculated for each patient. Sarcopenia was defined as being in the gender-specific lowest tertile of pectoralis muscle index. Survival was compared between patients with and without sarcopenia.

RESULTS

The study was conducted on 64 left ventricular assist device patients who met the inclusion criteria. Notably, 21 (32.8%) of the study patients were sarcopenic. Diabetes mellitus and sarcopenia were more common in patients with 2-year mortality in our cohort. Patients with sarcopenia had a worse 2-year survival (p<0.001). Sarcopenia had an adjusted hazard ratio of 4.04 (95% confidence interval (CI) 1.36-12.02, p=0.012), while diabetes mellitus was associated with an adjusted hazard ratio of 3.14 (95%CI 1.17-8.39, p=0.023).

CONCLUSION

Sarcopenia defined by low pectoralis muscle index increases the risk for 2-year mortality in left ventricular assist device patients.

Current Approach to the Diagnosis of Sarcopenia in Heart Failure: A Narrative Review on the Role of Clinical and Imaging Assessments

Sarcopenia has been established as a predictor of poor outcomes in various clinical settings. It is particularly prevalent in heart failure, a clinical syndrome that poses significant challenges to health care worldwide. Despite this, sarcopenia remains overlooked and undertreated in cardiology practice. Understanding the currently proposed diagnostic process is paramount for the early detection and treatment of sarcopenia to mitigate downstream adverse health outcomes.

Impact of psoas muscle evaluation on clinical outcomes in patients undergoing left ventricular assist device implantation

AIMS

The measurement of muscle mass reflects the physical components of frailty, which might affect postoperative outcomes in patients undergoing left ventricular assist device (LVAD) implantation. The aim of this study was to investigate the relationship between preoperative skeletal muscle evaluation and clinical outcomes in patients undergoing LVAD implantation.

METHODS

From January 2010 to December 2017, a total of 63 patients were enrolled in this single-centre study. A retrospective analysis of preoperative abdominal computed tomography (CT) for psoas muscle index (PSMI) and Hounsfield-Units of the Psoas Muscle (PSHU) at the level of the mid-L4 vertebra was performed.

RESULTS

Sixty-three patients (male; n = 49, 78%), with a mean age of 58.0 ± 11.8 years, were treated with LVAD due to dilated (32%) or ischemic cardiomyopathy (68%). Among them, 43 patients (68.3%) were categorized in the Interagency Registry for Mechanically Assisted Circulatory Support profile I. The survival rate was 73.0% at 30 days and 44.4% at 1 year. Receiver-operating characteristic (ROC) curve analyses revealed that PSMI was a significant numeric predictor of 1-year mortality (P = 0.04). In contrast, PSHU displayed a significant predictive potential for pericardial effusion (P = 0.03) and respiratory insufficiency (P = 0.01). In addition, comparative ROC curve analysis revealed no significant difference in the predictive potential of PSMI and PSHU.

CONCLUSION

Preoperative PSMI might be a predictor of 1-year mortality in patients undergoing LVAD implantation. In contrast, the PSHU seemed to potentially assume postoperative adverse events in this study. Thus, the evaluation of the preoperative psoas muscle using CT appears to be promising.

Myosteatosis as a Shared Biomarker for Sarcopenia and Cachexia Using MRI and Ultrasound

Purpose

Establish bedside biomarkers of myosteatosis for sarcopenia and cachexia. We compared ultrasound biomarkers against MRI-based percent fat, histology, and CT-based muscle density among healthy adults and adults undergoing treatment for lung cancer.

Methods

We compared ultrasound and MRI myosteatosis measures among young healthy, older healthy, and older adults with non-small cell lung cancer undergoing systemic treatment, all without significant medical concerns, in a cross-sectional pilot study. We assessed each participant's rectus femoris ultrasound-based echo intensity (EI), shear wave elastography-based shear wave speed, and MRI-based proton density fat-fraction (PDFF). We also assessed BMI, rectus femoris thickness and cross-sectional area. Rectus femoris biopsies were taken for all older adults (n = 20) and we analyzed chest CT scans for older adults undergoing treatment (n = 10). We determined associations between muscle assessments and BMI, and compared these assessments between groups.

Results

A total of 10 young healthy adults, 10 older healthy adults, and 10 older adults undergoing treatment were recruited. PDFF was lower in young adults than in older healthy adults and older adults undergoing treatment (0.3 vs. 2.8 vs. 2.9%, respectively, p = 0.01). Young adults had significantly lower EI than older healthy adults, but not older adults undergoing treatment (48.6 vs. 81.8 vs. 75.4, p = 0.02). When comparing associations between measures, PDFF was strongly associated with EI (ρ = 0.75, p < 0.01) and moderately negatively associated with shear wave speed (ρ = −0.49, p < 0.01) but not BMI, whole leg cross-sectional area, or rectus femoris cross-sectional area. Among participants with CT scans, paraspinal muscle density was significantly associated with PDFF (ρ = −0.70, p = 0.023). Histological markers of inflammation or degradation did not differ between older adult groups.

Conclusion

PDFF was sensitive to myosteatosis between young adults and both older adult groups. EI was less sensitive to myosteatosis between groups, yet EI was strongly associated with PDFF unlike BMI, which is typically used in cachexia diagnosis. Our results suggest that ultrasound measures may serve to determine myosteatosis at the bedside and are more useful diagnostically than traditional weight assessments like BMI. These results show promise of using EI, shear wave speed, and PDFF proxies of myosteatosis as diagnostic and therapeutic biomarkers of sarcopenia and cachexia.

Effect of preoperative erector spinae muscles mass on postoperative outcomes in patients with left ventricular assist devices

BACKGROUND

Frailty influences the postoperative outcomes in patients undergoing left ventricular assist device (LVAD) implantation. Recently, erector spinae muscle (ESM) mass has been proposed as a parameter to assess frailty accurately. Thus, the purpose of the present study was to evaluate whether preoperative ESM mass is associated with short- and long-term clinical outcomes in patients with LVAD.

METHODS

A total of 119 consecutive patients with LVAD were enrolled between January 2010 and October 2017 at a single heart center. The ESM area, ESM index, and Hounsfield units (HU) of the ESM were calculated by computed tomography for preoperative ESM mass evaluation. We then statistically evaluated the in-hospital mortality, major adverse cardiovascular events (MACE), duration of hospital stay, and long-term survival.

RESULTS

In a multivariate Cox regression analysis, ESM mass indicated no effect on all clinical outcomes. In addition, the ESM area presented a weak but significant negative linear correlation only with the duration of hospital stay (r = -0.21, p < .05). In contrast, the Model For End-stage Liver Disease (MELD) score and preoperative venous-arterial extracorporeal membrane oxygenation (va-ECMO) were significant predictive factors for in-hospital mortality (MELD score: p < .001, hazard ratio [HR] 1.1; preoperative va-ECMO: p < .01, HR 2.72) and MACE (MELD score: p < .001, HR 1.07; preoperative va-ECMO: p < .005, HR 2.62).

CONCLUSION

Preoperative ESM mass might predict the length of hospital stay in patients undergoing LVAD implantation. In contrast, it had no effect on MACE, in-hospital mortality, or long-term survival in this study.

Heart Failure Severity Stratification Beyond INTERMACS Profiles: A Step Toward Optimal Left Ventricular Assist Device Timing

The purpose of this analysis is to determine whether pectoralis muscle measures quantified on pre left ventricular assist device (LVAD) computerized tomography (CT) scans can identify subgroups of patients with differential disease severity within each Interagency Registry for Mechanical Circulatory Support (INTERMACS) profile. Patients with chest CTs performed ≤3 months before LVAD implantation at University of Minnesota (n = 143) and Houston Methodist Hospital (n = 133) were identified from the larger LVAD cohorts (University of Minnesota n = 353, Houston Methodist =278). Unilateral Pectoralis muscle mass indexed to body surface area and pectoralis muscle attenuation were measured on preoperative chest CT scans. Patients within each INTERMACS profile were separated into HIGH and LOW PEC muscle groups. Kaplan-Meier and multivariable cox regression analyses were performed to compare mortality among INTERMACS profiles by HIGH and LOW PEC muscle groups. INTERMACS 3 and 4 patients in the HIGH PEC groups had the highest survival on LVAD support (1 year survival 85% vs. 68%, log rank P = 0.0001). Being in this group was associated with a 60% reduction in the hazards rate (HR) of death after LVAD (adjusted HR 0.40, 95% confidence interval 0.25-0.62). Additionally, renal function deterioration in the year before LVAD was associated with lower INTERMACS profiles and lower measured pectoralis muscle tissue attenuation at the time of LVAD implantation. INTERMACS 3 and 4 patients with the highest pectoralis muscle measures had the best survival after LVAD. The association between renal function deterioration and sarcopenia suggests these muscle changes are progressive. Computerized tomography quantification of sarcopenia may help identify optimal LVAD implantation timing.