Effect of low skeletal muscle mass on long-term mortality after abdominal aortic aneurysm repair: A meta-analysis

OBJECTIVE: This meta-analysis was designed to assess if pre-operative low skeletal muscle mass impacts mortality rates of patients undergoing abdominal aortic aneurysm (AAA) repair. METHODS: Datasets of PubMed, CENTRAL, ScienceDirect, Embase, and Google Scholar were searched from 1(st) January 1980 to 15(th) December 2021 for studies assessing the role of low skeletal muscle mass on mortality rates of AAA repair. Studies measuring skeletal muscle mass on computed tomography scans and reporting long-term mortality (>1 year) were included. Multivariable adjusted ratios were combined in a random-effects model. RESULTS: Fifteen studies with 3776 patients were included. Meta-analysis showed a statistically significant increased risk of all-cause mortality in patients with low skeletal muscle mass (HR: 2.07 95% CI: 1.56, 2.74 I2=65% p<0.00001) as compared to normal muscle mass patients. Pooled data indicated that low skeletal muscle mass was associated with statistically significant increased risk of mortality in studies on endovascular repair (HR: 2.86 95% CI: 1.95, 4.20 I2=58% p<0.00001) as well as those including a mixed group of patients (HR: 1.39 95% CI: 1.06, 1.82 I2=31% p=0.02). CONCLUSION: Low skeletal muscle mass in AAA patients undergoing surgical repair is associated with increased risk of long-term mortality. Current evidence is limited by the retrospective nature of data and variability in defining and measuring low skeletal muscle mass. There is a need for future prospective studies defining the optimal cut-off of low skeletal muscle mass in different populations.