Usefulness of Psoas Muscle Area to Predict Mortality in Patients Undergoing Transcatheter Aortic Valve Replacement

Usefulness of Psoas Muscle Area to Predict Mortality in Patients Undergoing Transcatheter Aortic Valve Replacement Mike Saji, MDa,b, D. Scott Lim, MDa, Michael Ragosta, MDa, Damien J. LaPar, MD, MScc, Emily Downs, MDc, Ravi K Ghanta, MDc, John A. Kern, MDc, John M. Dent, MDa, and Gorav Ailawadi, MDc,* Frailty has become high-priority theme in cardiovascular diseases because of aging and increasingly complex nature of patients. Low muscle mass is characteristic of frailty, in which invasive interventions are avoided if possible because of decreased physiological reserve. This study aimed to determine if the psoas muscle area (PMA) could predict mortality and to investigate its utility in patients who underwent transcatheter aortic valve replacement (TAVR). We retrospectively reviewed 232 consecutive patients who underwent TAVR. Cross-sectional areas of the psoas muscles at the level of fourth lumbar vertebra were measured by computed tomography and normalized to body surface area. Patients were divided into tertiles according to the normalized PMA for each gender (men: tertile 1, 1,708 to 1,178 mm2/m2; tertile 2, 1,176 to 1,011 mm2/m2; and tertile 3, 1,009 to 587 mm2/m2; women: tertile 1, 1,436 to 962 mm2/m2; tertile 2, 952 to 807 mm2/m2; and tertile 3, 806 to 527 mm2/m2). Smaller normalized PMA was independently correlated with women and higher New York Heart Association classification. After adjustment for multiple confounding factors, the normalized PMA tertile was independently associated with mortality at 6 months (adjusted hazard ratio 1.53, 95% confidence interval 1.06 to 2.21). Kaplan eMeier analysis showed that tertile 3 had higher mortality rates than tertile 1 at 6 months (14% and 31%, respectively, p [ 0.029). Receiver-operating characteristic analysis showed that normalized PMA provided the increase of C-statistics for predicting mortality for a clinical model and gait speed. In conclusion, PMA is an independent predictor of mortality after TAVR and can complement a clinical model and gait speed. Ó 2016 Elsevier Inc. All rights reserved. (Am J Cardiol 2016;-:-e-) In the Placement of Aortic Transcatheter Valve (PARTNER) trial and the Transcatheter Valve Therapy (STS/ACC TVT) registry, mortality was quite high, particularly for inoperable patients who had transcatheter aortic valve replacement (TAVR), and appropriate patient selection is required.1 Frailty has become high-priority theme in cardiovascular diseases because of aging and increasingly complex nature of patients.2 Low muscle mass is characteristic of frailty, in which invasive interventions are avoided if possible because of decreased physiological reserve and vulnerability to stressors.3 Recently, the psoas muscle area (PMA), as measured on computed tomography (CT), has been shown to be related to poor outcomes after TAVR.4,5 However, according to the European Working Group on Sarcopenia in Older People (EWGSOP), low muscle mass defined as sarcopenia should be assessed by Divisions of aCardiovascular Medicine, Department of Medicine and Cardiothoracic Surgery, Department of Surgery, Advanced Cardiac Valve Center, University of Virginia, Charlottesville, Virginia; and bDepartment of Cardiology, Sakakibara Heart Institute, Tokyo, Japan. Manuscript received January 26, 2016; revised manuscript received and accepted April 26, 2016. See page 7 for disclosure information. *Corresponding author: Tel: (434) 924-5052; fax: (434) 244-7588. E-mail address: [email protected] (G. Ailawadi). c

0002-9149/16/$ - see front matter Ó 2016 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.amjcard.2016.04.043

muscle volume obtained by imaging study in combination of functional test such as gait speed, and its utility remains unclear in this population.6 The purpose of this study was to determine if PMA could predict mortality and to investigate its utility and relation between other frailty markers in patients undergoing TAVR. Methods The study population comprised 236 consecutive patients with severe aortic stenosis who underwent TAVR at the University of Virginia from March 2009 to May 2015. CT scans of the chest, abdomen, and pelvis were obtained for all patients to determine the appropriate method of access, and 232 of these were of sufficient quality to allow for comprehensive analysis of the PMA irrespective of the use of intravenous contrast. The treatment initially was determined according to the protocol defined by the PARTNER and PARTNER II trials. After the SAPIEN and SAPIEN XT valves (Edwards Lifesciences, Irvine, California) received the US commercial approval, treatment was performed with their use according to American Heart Association/American College of Cardiology (AHA/ACC) guidelines. Ninety patients received an experimental replacement valve as part of a trial; the other 142 received a commercially approved valve. After June 2012, gait speed was routinely evaluated www.ajconline.org

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Figure 1. The psoas muscles on computed tomography scans. Computed tomographic view of the psoas muscles (asterisks) at the level of the fourth lumbar vertebra (L4) (arrow).

before the procedure (n ¼ 121) and evaluated in a subanalysis. All cases were reviewed by a multidisciplinary team consisting of cardiac surgeons, interventional cardiologists, and imaging specialists and deemed to be high risk (n ¼ 115) or inoperable (n ¼ 117). The Society of Thoracic Surgeons (STS) risk score was calculated in each patient. Our institutional review board approved the study. All information was retrospectively obtained from patients’ medical records. In addition, the Social Security Death Index was searched to confirm all deaths and to check for patients lost to follow-up. Data analyses were completed before the procedure using images collected by SOMATOM Definition Flash (Siemens Healthcare, Erlangen, Germany) or LightSpeed (GE Healthcare, Little Chalfont, United Kingdom) CT scanners. PMA was analyzed in a blinded fashion by 2 experienced assessors (M.S. and S.L.). Specifically, the cross-sectional areas of the right and left psoas muscles were measured at the level of the fourth lumbar vertebra (L4) (Figure 1)4; the Carestream Vue Picture Archiving and Communication System radiology software program (version 11.3, Carestream Health, Rochester, New York) was used to manually outline the borders of the right and left psoas on individual CT image slices showing the superior aspect of the L4. The areas of the resulting enclosed regions were computed and summed to find the total cross-sectional area of the psoas muscles. To account for the potential inclusion of fat or other tissue within or around the PMA, density thresholds from 30 to 150 Hounsfield units, consistent with a previous study, were used.4 PMAs retrieved from 24 randomly selected data files were measured by another observer to determine the interobserver agreement and then again by the original observers (on a different day) to determine the intraobserver agreement; in both cases, the observers were blinded to the previous measurements. Participants were instructed to walk at a comfortable pace in a well-lit, unobstructed hallway for a distance of 5 m. Patients were permitted to use assist devices such as walkers and canes. Gait speed was calculated by dividing 5 m by the time needed to walk this distance in seconds. Patients

repeated the walk 3 times, if possible, and their mean speed was calculated. Patients unable to walk the distance due to shortness of breath or desaturation at rest were recorded as having a gait speed of 0 m/s.7 The primary end points were all-cause mortality at 30 days and 6 months. Echocardiographic findings were analyzed by full-time academic echocardiographers using AHA/ACC guidelines. Co-morbidities were defined according to the STS criteria, and procedural complications were defined according to the Valve Academic Research Consortium 2 Criteria. Device success was defined as the absence of procedural mortality, correct positioning of a single prosthetic valve, and intended performance of the prosthetic valve. The early combined safety end-point at 30 days includes all-cause mortality, all stroke, lifethreatening bleeding, acute kidney injury (stages 2 or 3), coronary obstruction requiring intervention, major vascular complications, and valve-related dysfunction requiring a repeat procedure. TAVR was performed as previously described.1 Continuous variables were expressed as the mean  standard deviation, and categorical variables as the number and percentage. Normality of distribution for continuous variables was tested using the ShapiroeWilk test. Because measured PMA values (mm2) were better correlated with body surface area (BSA; r ¼ 0.699) than other body component measurements such as body mass index (r ¼ 0.363), the measured PMA values (mm2) were normalized by dividing PMA by BSA (mm2/m2) to measure the relative muscle mass. Additionally, because normalized PMA was related to gender (shown in results section), patients were divided into tertiles according to normalized PMA for each gender (men: tertile 1, 1,708 to 1,178 mm2/m2; tertile 2, 1,176 to 1,011 mm2/m2; and tertile 3, 1,009 to 587 mm2/m2; women: and tertile 1, 1,436 to 962 mm2/m2; tertile 2, 952 to 807 mm2/m2; and tertile 3, 806 to 527 mm2/m2). The 3 groups were compared using the chi-square test (categorical covariates) or one-way analysis of variance and the KruskaleWallis test (continuous covariates; Tables 1 and 2. A 2-sided p value <0.05 was considered statistically

Valvular Heart Disease/Psoas Muscle Area in TAVR

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Table 1 Baseline patient characteristics Characteristic

Age (years) Men Body mass index (kg/m2) Normalized psoas muscle area (mm2/m2) NYHA classification III/IV STS score (%) Inoperable Diabetes mellitus Hypertension Dyslipidemia Coronary artery disease Previous MI Previous PCI Previous cardiac surgery Peripheral artery disease Previous stroke Previous pacemaker implantation Atrial fibrillation COPD (moderate/severe) Hemoglobin level (g/dL) eGFR (mL/min/1.73 m2) Albumin level (g/dL) Gait speed (m/s)* Excluding patients who cannot walk† Ejection fraction (%) AVA (cm2) Mean gradient (mm Hg) MR (moderate/severe) Pulmonary artery pressure (mm Hg)

Overall (n ¼ 232)

80.1  8.7 132 (57%) 28.1  7.1 1016  229 154 (66%) 8.5  4.6 117 (50%) 97 (42%) 171 (74%) 136 (59%) 145 (63%) 34 (15%) 56 (24%) 110 (47%) 61 (26%) 23 (9.9%) 35 (15%) 97 (42%) 47 (20%) 11.7  1.74 56.5  24.3 3.7  0.3 0.5  0.3 0.7  0.2 48.3  14.0 0.66  0.15 44.7  13.1 26 (11%) 43.6  14.2

Normalized psoas muscle area

p-value

Tertile 1 (n ¼ 77)

Tertile 2 (n ¼ 78)

Tertile 3 (n ¼ 77)

78.7  9.2 44 (57%) 28.5  7.5 1237  202 47 (61%) 8.2  4.7 39 (51%) 34 (44%) 55 (71%) 43 (56%) 51 (66%) 16 (21%) 22 (29%) 40 (52%) 15 (19%) 6 (7.7%) 11 (14%) 30 (39%) 18 (23%) 11.8  1.8 59.8  24.5 3.7  0.4 0.5  0.3 0.7  0.1 50.6  13.1 0.68  0.15 44.7  12.8 8 (10%) 43.6  15.0

81.6  7.2 44 (56%) 28.2  6.3 999  115 49 (63%) 9.2  5.2 39 (50%) 33 (42%) 59 (76%) 51 (65%) 49 (63%) 5 (6.4%) 13 (17%) 37 (47%) 18 (23%) 9 (12%) 11 (14%) 33 (42%) 18 (23%) 11.5  1.5 51.8  23.6 3.7  0.4 0.5  0.3 0.7  0.2 48.4  12.9 0.62  0.13 45.0  13.1 9 (12%) 45.3  15.3

79.8  9.4 44 (57% 27.7  7.7 813  119 58 (75%) 8.2  3.9 39 (51%) 30 (39%) 57 (74%) 42 (55%) 45 (58%) 13 (17%) 21 (27%) 33 (43%) 28 (36%) 8 (10%) 13 (17%) 34 (44%) 11 (14%) 11.8  1.8 57.9  24.5 3.8  0.4 0.5  0.3 0.7  0.2 45.9  15.7 0.66  0.16 44.3  13.7 9 (12%) 42.0  12.0

0.148 0.994 0.473 <0.001 0.123 0.429 0.996 0.803 0.835 0.326 0.606 0.032 0.164 0.528 0.043 0.727 0.864 0.803 0.280 0.416 0.087 0.648 0.884 0.658 0.156 0.066 0.912 0.948 0.648

Values are mean  SD or n (%). AVA ¼ aortic valve area; COPD ¼ chronic obstructive pulmonary disease; eGFR ¼ estimated glomerular filtration rate; MI ¼ myocardial infarction; MR ¼ mitral regurgitation; NYHA ¼ New York Heart Association; PCI ¼ percutaneous coronary intervention; PMA ¼ psoas muscle area; STS ¼ Society of Thoracic Surgeons. * Tertile 1, n ¼ 40, Tertile 2, n ¼ 43, Tertile 3, n ¼ 38 (total n ¼ 121). † Tertile 1, n ¼ 28, Tertile 2, n ¼ 33, Tertile 3, n ¼ 27.

significant. Associations between normalized PMA and all variables provided in Table 1 were assessed using univariate linear regression; variables with p values <0.15 on this analysis were entered into a multivariate regression model and further assessed to determine whether they were independently correlated with normalized PMA (Table 3). To determine the influence on the relation between mortality, variables (provided in Table 1) with p values <0.05 on univariate analysis were entered into multivariate Cox proportional hazards model. KaplaneMeier analysis was used to estimate the cumulative mortality in each PMA tertile. Receiver-operating characteristic (ROC) analysis was performed using mortality at 6 months, and the area under the curve (C-statistic) was assessed using the clinical model and the DeLong method. The clinical model included the variables that were identified as independent predictors in multivariate analysis, provided in Table 4. Because the characteristics of participants with gait speed were similar to those without gait speed (Supplementary Tables 1 and 2), the same tertile criteria were applied for the subanalysis.

Additionally, the patients were divided into 2 groups using a cutoff gait speed value of 0.5 m/s because the general cutoff value of 0.8 m/s was not validated in this study (best cut-off value: 0.5 m/s derived from ROC curve).2 Intraobserver and interobserver agreement values were evaluated by calculating the intraclass correlation coefficients (ICC), with excellent agreement defined as ICC >0.8. All analyses were performed using SPSS version 22.0 (IBM, Armonk, New York) and R version 2.13 (R Foundation for Statistical Computing). Results Patient demographic and clinical characteristics at baseline are provided in Table 1. The mean gait speed was 0.5 m/s overall and was not different across the tertiles, irrespective of whether patients who could not walk (n ¼ 33) were included or removed from analyses. Although BSA was not normally distributed, both PMA and PMA/ BSA (normalized PMA) were normally distributed in men

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Table 2 Procedural outcomes Outcome

Transfemoral approach Valve size ¼ 23 mm Valve size ¼ 26 mm Valve size ¼ 29 mm Length of stay after TAVR (days) Device success Mortality at 30 days Mortality at 6 months Early combined safety endpoint at 30 days All stroke Life-threatening bleeding Acute kidney injury (AKIN stage 2 or 3) Coronary obstruction requiring intervention Major vascular complication Valve-related dysfunction requiring repeat procedure Postprocedural AI (moderate/severe)

Overall (n ¼ 232)

141 (61%) 91 (39%) 120 (52%) 21 (9.0%) 6.9  7.0 225 (97%) 17 (7.3%) 48 (21%) 67 (29%) 11 (4.7%) 15 (6.4%) 35 (15%) 0 (0%) 22 (9.4%) 6 (2.5%) 14 (6.0%)

Psoas muscle area

p-value

Tertile 1 (n ¼ 77)

Tertile 2 (n ¼ 78)

Tertile 3 (n ¼ 77)

45 (58%) 27 (35%) 44 (57%) 6 (7.7%) 7.0  6.4 75 (97%) 4 (5.1%) 10 (13%) 21 (27%) 2 (2.5%) 2 (2.5%) 12 (16%) 0 (0%) 6 (7.7%) 2 (2.5%) 3 (3.8%)

50 (64%) 32 (41%) 34 (44%) 12 (15%) 6.7  7.1 74 (95%) 7 (8.9%) 16 (21%) 20 (26%) 3 (3.8%) 6 (7.6%) 9 (12%) 0 (0%) 6 (7.6%) 3 (3.8%) 6 (7.6%)

46 (60%) 32 (42%) 42 (55%) 3 (3.8%) 7.1  7.6 76 (99%) 6 (7.7%) 22 (29%) 26 (34%) 6 (7.7%) 7 (9.0%) 14 (18%) 0 (0%) 10 (13%) 1 (1.2%) 5 (6.4%)

0.751 0.657 0.201 0.040 0.863 0.409 0.653 0.058 0.499 0.093 0.070 0.507 1.000 0.438 0.402 0.308

Values are n (%). AI ¼ aortic insufficiency; TAVR ¼ transcatheter aortic valve replacement.

and women (Supplementary Figure 1). Mortality at 30 days and 6 months after TAVR were 7.3% and 21%, respectively, with a mean STS score of 8.5%. Other procedural outcomes are provided in Table 2. The STS score was lower in patients who underwent the gait speed test, compared to those who did not; however, there were more patients who were considered inoperable in the group that underwent the test. There were no differences between these 2 groups in normalized PMA or procedural outcomes, including mortality at 6 months (Supplementary Tables 1 and 2). In Figure 2, tertile 1 had the lowest mortality rate at 6 months, whereas tertiles 2 and 3 had higher mortality rates at 6 months (14%, 21%, and 31%, respectively). In univariate analyses of all variables provided in Table 1, Men, New York Heart Association (NYHA) classification, diabetes mellitus, coronary artery disease, previous cardiac surgery, and aortic valve area were correlated with normalized PMA, and these variables were entered into the multivariate linear regression model (Table 3). This analysis revealed that a smaller normalized PMA correlated with women and higher NYHA classification (analysis of variance p <0.001, adjusted R2 ¼ 0.26). Figure 3 demonstrates the relation between normalized PMA and frailty marker in this population (gait speed and albumin). Either gait speed or albumin was not correlated with normalized PMA in men and women. By univariate analyses of baseline variables (provided in Table 1), normalized PMA, NYHA classification, STS score, previous myocardial infarction, estimated glomerular filtration rate, and mean gradient were significantly associated with mortality at 6 months, and these variables were entered into the multivariate Cox proportional hazard model (Table 4). This analysis found normalized PMA was independently associated with mortality at 6 months (adjusted hazard ratio [HR] 1.53, 95% confidence interval 1.06 to 2.21). In sensitivity analysis, variables (all stroke and

Table 3 Results of the linear regression analysis of the associations between normalized psoas muscle area and other variables Sample (n ¼ 232)

Univariate analysis

Multivariate analysis

b Coefficient p-value b Coefficient p-value Men NYHA classification Diabetes mellitus Coronary artery disease Previous cardiac surgery AVA

0.49 -0.15 0.10 0.14 0.18 0.19

<0.001 0.020 0.098 0.025 0.004 0.004

0.48 -0.11

<0.001 0.043

AVA ¼ aortic valve area; CI ¼ confidence interval; NYHA ¼ New York Heart Association.

bleeding) trend toward greater incidence with normalized PMA tertiles were additionally put into a model, and results did not differ (adjusted HR 1.52, 95% confidence interval 1.04 to 2.23). In the ROC analysis, the addition of normalized PMA to a clinical model derived from the multivariate models slightly increased the C-statistics at 6 months; 0.73 (95% confidence interval 0.65 to 0.81) to 0.75 (95% confidence interval 0.67 to 0.83) by DeLong method (Supplementary Figure 2). In our subanalyses, gait speed alone (cut-off value of 0.5 m/s) was not associated with mortality (p ¼ 0.174); however, mortality rate was higher in patients with gait speed <0/5 m/s than those with gait speed 0.5 m/s in smaller normalized PMA (Figure 4). In ROC analysis, the gait speed in combination with PMA demonstrated greater discrimination ability than gait speed alone at 6 months by DeLong method; C-statistics 0.57 (95% confidence interval 0.46 to 0.68) to 0.65 (95% confidence interval 0.51 to 0.76; Supplementary Figure 2).

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Table 4 Cox proportional hazard analysis for the association between mortality and clinical characteristics Sample (n ¼ 232)

Normalized PMA (per tertile) NYHA classification (per class) STS score (<5, 5-10, 10-15, 15) Previous MI eGFR (per 15 mL/min/1.73 m2) Mean gradient (per 10 mm Hg)

Univariate analysis

Multivariate analysis

HR

95% CI

p value

Adjusted HR

95% CI

p value

1.51 1.87 1.40 2.12 0.77 0.76

1.05e2.18 1.23e2.85 1.04 e1.88 1.10e4.08 0.62e0.95 0.60e0.96

0.025 0.003 0.023 0.034 0.016 0.024

1.53 1.79

1.06e2.21 1.16e2.78

0.020 0.009

2.26 0.78

1.17e4.35 0.63e0.98

0.014 0.041

CI ¼ confidence interval; eGFR ¼ estimated glomerular filtration rate; HR ¼ hazard ratio; MI ¼ myocardial infarction; NYHA ¼ New York Heart Association; PMA ¼ psoas muscle area; STS ¼ Society of thoracic Surgeons.

ICCs of interobserver and intraobserver reproducibility for PMA assessment were satisfactory; the intraobserver coefficient was 0.98 and the interobserver coefficient was 0.95. Discussion The purpose of this study was to determine if PMA can predict mortality and to investigate its utility and relation between other frailty markers in patients undergoing TAVR. We found normalized PMA to be independently associated with mortality at 6 months. Moreover, in ROC analysis, the addition of normalized PMA to a clinical model derived from the multivariate models slightly increased the C-statistics at 6 months. In subanalysis, gait speed combined with normalized PMA showed greater discrimination ability than gait speed alone. Normalized PMA was independently associated with mortality at 6 months. As previously shown in patients with cardiovascular and gastrointestinal disease, PMA can predict poor prognosis in this study as well.4,5,8,9 Given that half the patients who undergo TAVR die within 1 year or fail to achieve improvement in their quality of life, the new marker, normalized PMA, is very useful for predicting whether TAVR will be beneficial in a relatively short-term period.10,11 In ROC analysis, the addition of normalized PMA to a clinical model derived from the multivariate models slightly increased the C-statistics at 6 months. Normalized PMA may be useful as an independent geriatric marker when determining the suitability of invasive procedures in patients who are difficult to perform a gait speed test (e.g., severe orthopedic disease or sedation with mechanical ventilation), handgrip strength, or questionnaire, however, increment of C-statistics is relatively small if you add normalized PMA to clinical model and is comparable to those of each frailty variable in a previous study, suggesting that combined geriatric assessment is more predictive in this population.12,13 In the subanalysis, gait speed combined with normalized PMA showed greater discrimination ability than gait speed alone. Gait speed, in the general population, is an easy and reliable way to begin frailty assessment or screening in practice.6,14,15 However, as patients undergoing TAVR are often already significantly debilitated, most patients met the frailty criteria commonly defined as gait speed <0.8 m/s.2 Although a more stringent cutoff of 0.5 m/s may fare

Figure 2. KaplaneMeier survival curves for normalized PMA. KaplaneMeier curves for mortality at 6 months in relation to normalized PMA (mm2/m2), stratified into tertiles for each gender.

slightly better as a predictor of increased risk,16 gait speed itself has had difficulty predicting mortality.2 In this study, 1/4 of the patients could not complete 5-m walk despite preserved psoas muscle. This confirms that the inability to walk 5 m in this population may not be predictive and should be further debated in large study.2 Nonetheless, Cstatistic of 0.65 in combination with normalized PMA and gait speed in this study is relatively high as a geriatric assessment, compared with other studies.14 Notably, relation between normalized PMA and gait speed was not linear in this study. This is consistent with a previous study reported by EWGSOP and may be explained for the following reasons: (1) muscle mass can be lost without functional decline and (2) a small change in physiological capacity may have substantial effects on performance in frail adults, whereas large change in capacity have little or no effect in nonfrail patients.6,17 For those reasons, according to EWGSOP, 2 criteria (imaging to evaluating

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Figure 3. Scatter point of PMA versus frailty scale in men and women. The lack of correlation between gait speed and normalized PMA in men (A) and women (B) and albumin and normalized PMA in men (C) and women (D).

Figure 4. Bar graph of each PMA tertile. Difference in mortality between patients with gait speed (GS) 0.5 m/s and those with GS <0.5 m/s in each tertile.

muscle mass and gait speed to evaluating function) are used to define sarcopenia. The relation between normalized PMA and albumin as a marker of malnutrition was also not linear in this study. This relation has not been investigated and should be confirmed in future studies.6 Unfortunately, handgrip strength and Katz Activities of Daily Living, 2 other tools to measure frailty in TAVR patients, were not routinely obtained. However, according to previous studies,

they appear to be nonlinear and independent of PMA, indicating that measurement of PMA adds more information to these tools in patients who had TAVR.3,6,7,13,18 From the standpoint of utility in daily practice, gait speed and normalized PMA as a marker of sarcopenia are more feasible to obtain than other tools as both are simple assessments.12,13 PMA is objectively and easily assessed regardless the use of contrast during the CT scan with good interobserver and intraobserver reproducibility. Given that smaller normalized PMA was correlated with higher NYHA class in this study, severe aortic stenosis or congestive heart failure may contribute to an increased risk of sarcopenia.6,19 Low body mass index, a concept similar to normalized PMA, has already been reported as a predictive factor for poor outcomes in patients with severe aortic stenosis.20 However, as weight change varies widely between subjects independent of the muscle volume, imaging study such as CT may be able to better identify sarcopenic obesity (a low lean body mass and high fat mass) than the simple body weight alone.6 The outcomes in the present study are comparable to those reported in the US registries.21 However, a larger number of inoperable patients and a greater mean STS score suggest that the present study included a sicker patient population than those in the US registries. This study has a number of important limitations to note. First, this study was limited by its retrospective nature and was performed at a single center with a relatively small number of patients. Second, psoas muscle measurements can only be obtained only in patients who had an abdomenepelvis CT because currently there is no bedside test to measure PMA. Third, PMA was not compared with other traditional frailty markers such as handgrip strength or Katz Activities of Daily Living.

Valvular Heart Disease/Psoas Muscle Area in TAVR

Despite these limitations, our study has some important conclusions. Herein, we demonstrate that PMA, which can be reliably and easily measured, is an independent predictor of 6-month mortality after TAVR. Moreover, PMA can complement clinical models and gait speed in the overall assessment of frailty. Disclosures

10.

11.

Dr. Ailawadi is a consultant for Edwards Lifesciences and is on the Advisory Board of Edwards Lifesciences. Supplementary Data

12.

Supplementary data associated with this article can be found, in the online version, at http://dx.doi.org/10.1016/j. amjcard.2016.04.043. 13. 1. Makkar RR, Fontana GP, Jilaihawi H, Kapadia S, Pichard AD, Douglas PS, Thourani VH, Babaliaros VC, Webb JG, Herrmann HC, Bavaria JE, Kodali S, Brown DL, Bowers B, Dewey TM, Svensson LG, Tuzcu M, Moses JW, Williams MR, Siegel RJ, Akin JJ, Anderson WN, Pocock S, Smith CR, Leon MB; PARTNER Trial Investigators. Transcatheter aortic-valve replacement for inoperable severe aortic stenosis. N Engl J Med 2012;366:1696e1704. 2. Afilalo J, Alexander KP, Mack MJ, Maurer MS, Green P, Allen LA, Popma JJ, Ferrucci L, Forman DE. Frailty assessment in the cardiovascular care of older adults. J Am Coll Cardiol 2014;638:747e762. 3. Fried LP, Tangen CM, Walston J, Newman AB, Hirsch C, Gottdiener J, Seeman T, Tracy R, Kop WJ, Burke G, McBurnie MA; Cardiovascular Health Study Collaborative Research Group. Frailty in older adults: evidence for a phenotype. J Gerontol A Biol Sci Med Sci 2001;56: M146eM156. 4. Mamane S, Mullie L, Piazza N, Martucci G, Morais J, Vigano A, Levental M, Nelson K, Lange R, Afilalo J. Psoas muscle area and allcause mortality after transcatheter aortic valve replacement: the Montreal-Munich Study. Can J Cardiol 2016;32(2):177e182. 5. Paknikar R, Friedman J, Cron D, Deeb GM, Chetcuti S, Grossman PM, Wang S, Englesbe M, Patel HJ. Psoas muscle size as a frailty measure for open and transcatheter aortic valve replacement. J Thorac Cardiovasc Surg 2016;151(3):745e751. 6. Cruz-Jentoft AJ, Landi F, Schneider SM, Zúñiga C, Arai H, Boirie Y, Chen LK, Fielding RA, Martin FC, Michel JP, Sieber C, Stout JR, Studenski SA, Vellas B, Woo J, Zamboni M, Cederholm T. Sarcopenia: European consensus on definition and diagnosis. Report of the European Working Group on Sarcopenia in Older People. Age Ageing 2010;39:412e423. 7. Green P, Arnold SV, Cohen DJ, Kirtane AJ, Kodali SK, Brown DL, Rihal CS, Xu K, Lei Y, Hawkey MC, Kim RJ, Alu MC, Leon MB, Mack MJ. Relation of frailty to outcomes after transcatheter aortic valve replacement (from the PARTNER trial). Am J Cardiol 2015;116: 264e269. 8. Lee JS, He K, Harbaugh CM, Schaubel DE, Sonnenday CJ, Wang SC, Englesbe MJ, Eliason JL; Michigan Analytic Morphomics Group (MAMG). Frailty, core muscle size, and mortality in patients undergoing open abdominal aortic aneurysm repair. J Vasc Surg 2011;53: 912e917. 9. Englesbe MJ, Patel SP, He K, Lynch RJ, Schaubel DE, Harbaugh C, Holcombe SA, Wang SC, Segev DL, Sonnenday CJ. Sarcopenia and

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