Sarcopenia is a Prognostic Biomarker for Long-Term Survival after Endovascular Aortic Aneurysm Repair: A Systematic Review and Meta-Analysis

Background: Sarcopenia is the loss of muscle mass and strength. It manifests as decreased core muscle area in axial abdominal computed tomography scans. The predictive value of sarcopenia in outcome research has been widely discussed. A systematic review was conducted to assess sarcopenia as a biomarker in patients undergoing endovascular abdominal aortic aneurysm repair (EVAR) and its association with long-term survival. Methods: A systematic search of the English medical literature, published from 1991 to 2021, was conducted, using PubMed, EMBASE, and CENTRAL, as per the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA, 2020) guidelines. The study protocol was registered to the International Prospective Register of Systematic Reviews (CRD 42021260192). Observational studies reporting on sarcopenic and nonsarcopenic patients undergoing EVAR were included. The Risk Of Bias In Non-Randomized Studies - of Interventions (ROBINS-I) risk of bias evaluation tool was used for the quality assessment. The outcomes were summarized as odds ratio (OR) along with their 95% confidence intervals (CI), through a paired meta-analysis. The primary outcome was 5-year survival following EVAR. Results: Eleven observational studies, including 2,385 patients (89.6% males) treated with EVAR, between 1999 and 2018, were included in the qualitative synthesis. The mean age was 72.9 years (range 70-76.4 years). Nine of the studies reported on a negative prognostic value of sarcopenia on survival during a long-term follow-up. Six studies stratified their cohorts in sarcopenic versus nonsarcopenic patients (40.3% sarcopenic). The cutoff values (mm(2) or mm(2)/m(2)) for defining sarcopenic patients were heterogeneous while ranging from 451 to 4,820 mm(2)/m(2) and 1,207 to 11,400 mm(2). Eight studies reported data on the mean follow-up duration, ranging from 27 to 101 months. Six studies reported on outcomes in terms of 5-year survival rates after EVAR, favoring nonsarcopenic over sarcopenic patients, with survival rates ranging from 58 to 93% and 24 to 60%, respectively. After a meta-analysis including 3 eligible studies, sarcopenia was associated with worse 5-year survival after EVAR (OR 0.77, 95% CI [0.58, 0.97], P < 0.001). Conclusions: The available data derived from observational studies suggest an association between sarcopenia and worse long-term survival in patients treated with EVAR. There is a lack of a universally accepted definition for sarcopenia and future reporting standards should address this issue. Prospective studies are necessary to establish this negative prognostic value of sarcopenia on long-term survival.