Assessment of skeletal muscle in patients with stable coronary artery disease: clinical significance and associations

Abstract

Aim. To assess skeletal muscle in patients with stable coronary artery disease (CAD) before coronary artery bypass grafting (CABG), the factors associated with its deterioration, and possible clinical significance. Material and methods. The study included 77 patients (68 men and 9 women, aged 51-69 years) who were admitted to the cardiology department for pre-CABG testing. All patients underwent routine laboratory and instrumental examination. In addition, the subjects underwent a six-minute walk test and lower limb muscle strength testing. Participants were divided into two groups: group 1 (n=45; 58,44%) — patients with mean strength score of lower limb extensor muscles less than the median (mean 20 kg/s), group 2 (n=32; 41,56%) — more than the median (mean 32,5 kg/s). The groups were comparable in main demographic and anthropometric parameters, risk factors for atherosclerosis, concomitant pathology, history of atherothrombotic events, laboratory and instrumental data, as well as CABG outcomes. Results. When assessing the skeletal muscle in CAD patients before surgery, the median lower limb extensor strength score was 25 kg/s. Patients from group 1 had a higher incidence of myocardial infarction (MI) in history (p=0,021), decreased left ventricle ejection fraction (p=0,025), increased heart rate (p=0,025) and leukocyte count (p=0,036). In such patients, there was a significant increase of postoperative complications of CABG surgery (p=0,003). According to multivariate regression analysis, MI history (p = 0.011) and a higher leukocyte count (p=0,042) were independent predictors of decrease in lower limb muscle strength. Conclusion. The obtained results can be used in the preparation of rehabilitation programs for patients before CABG surgery.