- Factors that may impair the quality of the CAVI and /or the PWV measurement or make PWV recording unreliable: known significant peripheral vascular disease with proximal artery stenosis, ankle brachial index < 0.9, or limb amputation; history of vascular surgery at the level of the carotid artery, femoral artery or aorta; body mass index > 40 kg/m²; atrial fibrillation and/or other major arrhythmia.