Osteosarcopenia and Mortality in Older Adults Undergoing Transcatheter Aortic Valve Replacement

Abstract

Importance: Osteosarcopenia is an emerging geriatric syndrome characterized by age-related deterioration in muscle and bone. Despite the established relevance of frailty and sarcopenia among older adults undergoing transcatheter aortic valve replacement (TAVR), osteosarcopenia has yet to be investigated in this setting.

Objective: To determine the association between osteosarcopenia and adverse outcomes following TAVR.

Design, setting, and participants: This is a post hoc analysis of the Frailty in Aortic Valve Replacement (FRAILTY-AVR) prospective multicenter cohort study and McGill extension that enrolled patients aged 70 years or older undergoing TAVR from 2012 through 2022. FRAILTY-AVR was conducted at 14 centers in Canada, the United States, and France between 2012 and 2016, and patients at the McGill University-affiliated center in Montreal, Québec, Canada, were enrolled on an ongoing basis up to 2022.

Exposure: Osteosarcopenia as measured on computed tomography (CT) scans prior to TAVR.

Main outcomes and measures: Clinically indicated CT scans acquired prior to TAVR were analyzed to quantify psoas muscle area (PMA) and vertebral bone density (VBD). Osteosarcopenia was defined as a combination of low PMA and low VBD according to published cutoffs. The primary outcome was 1-year all-cause mortality. Secondary outcomes were 30-day mortality, hospital length of stay, disposition, and worsening disability. Multivariable logistic regression was used to adjust for potential confounders.

Results: Of the 605 patients (271 [45%] female) in this study, 437 (72%) were octogenarian; the mean (SD) age was 82.6 (6.2) years. Mean (SD) PMA was 22.1 (4.5) cm2 in men and 15.4 (3.5) cm2 in women. Mean (SD) VBD was 104.8 (35.5) Hounsfield units (HU) in men and 98.8 (34.1) HU in women. Ninety-one patients (15%) met the criteria for osteosarcopenia and had higher rates of frailty, fractures, and malnutrition at baseline. One-year mortality was highest in patients with osteosarcopenia (29 patients [32%]) followed by those with low PMA alone (18 patients [14%]), low VBD alone (16 patients [11%]), and normal bone and muscle status (21 patients [9%]) (P < .001). Osteosarcopenia, but not low VBD or PMA alone, was independently associated with 1-year mortality (odds ratio [OR], 3.18; 95% CI, 1.54-6.57) and 1-year worsening disability (OR, 2.11; 95% CI, 1.19-3.74). The association persisted in sensitivity analyses adjusting for the Essential Frailty Toolset, Clinical Frailty Scale, and geriatric conditions such as malnutrition and disability.

Conclusions and relevance: The findings suggest that osteosarcopenia detected using clinical CT scans could be used to identify frail patients with a 3-fold increase in 1-year mortality following TAVR. This opportunistic method for osteosarcopenia assessment could be used to improve risk prediction, support decision-making, and trigger rehabilitation interventions in older adults.

Figure 1.. Bone and Muscle Status by Computed Tomography

Representative examples from a patient with preserved psoas muscle area (PMA) and vertebral bone density (VBD) (A), a patient with low VBD alone (B), a patient with low PMA alone (C), and a patient with low PMA and VBD (osteosarcopenia) (D). The measurements of VBD (in Hounsfield units [HU]) and PMA (in centimeters squared) are listed. The red mask denotes the segmented psoas muscles at the L4 vertebrae level; blue circle, the region of interest to assess trabecular attenuation.

Figure 2.. Kaplan-Meier Plot of Survival by Bone and Muscle Status

Normal indicates preserved psoas muscle area (PMA) and vertebral bone density (VBD). Osteosarcopenia indicates low PMA and VBD.