Evaluation of the Relationship Between Muscle Mass Measured by Bioelectrical Impedance Analysis and the Risk of Hemorrhagic Events Under Direct Oral Anticoagulants in the Elderly

Appendicular muscle mass expressed in kg is measured by an InBody S10 impedance meter (Appendix 3: InBody S10 impedance meter), during a visit, after stabilization of the patient's blood volume, within a limit of 7 days after inclusion.

This is the combination of:

• a "reduction in muscle strength" determined by a grip strength measurement and a Timed Chair Stand Test measurement
• a "reduction in muscle mass", determined by the primary endpoint

According to the High Authority of Health, the diagnosis of malnutrition requires the presence of at least one phenotypic criterion and one etiological criterion.

The phenotypic criteria are as follows (one criterion is sufficient):

• Weight loss ≥ 5% in 1 month or ≥ 10% in 6 months or ≥ 10% compared to usual weight before the onset of the disease;
• BMI < 22 kg/m²;
• Confirmed sarcopenia

The etiological criteria are as follows (one criterion is sufficient):

• Reduction in food intake of ≥ 50% for more than 1 week, or any reduction in intake for more than 2 weeks compared to: usual food consumption or protein-energy requirements;
• Reduced absorption (malabsorption/maldigestion);
• Pathological situation (with or without inflammatory syndrome): acute pathology or chronic pathology or progressive malignant pathology.

According to the High Authority of Health, the criteria for severe malnutrition are as follows (one criterion is sufficient):

• BMI < 20 kg/m²;
• Weight loss: ≥ 10% in 1 month, or ≥ 15% in 6 months, or ≥ 15% compared to the usual weight before the onset of the disease;
• Albumin level ≤ 30 g/L.

There is no definition expressing a threshold; we will consider that the lower the variation is from the median, the greater the loss of muscle mass.