Why traumatic leg amputees are at increased risk for cardiovascular diseases

Post-traumatic lower limb amputees have an increased morbidity and mortality from cardiovascular disease. Risk factors for this amplified morbidity and the involved pathophysiologic mechanisms have not been comprehensively studied.

The MEDLINE database was reviewed, with case-controlled studies and nested in cohort studies eligible for inclusion in this analysis.

Insulin resistance, psychological stress and patients' deviant behaviors are prevalent in traumatic lower limb amputees. Each of these factors may have systemic consequences on the arterial system and may contribute to the increased cardiovascular morbidity in traumatic amputees. Abnormalities of arterial flow proximal to the amputation site may hold the explanation for the linkage between the extent of leg amputation and the magnitude of the cardiovascular risk: proximal leg amputation is associated with greater risk than distal amputation and bilateral amputation with greater risk than unilateral amputation. This review focuses on hemodynamic culprits (shear stress, circumferential strain, reflected waves), hemodynamic consequences in proximity to the occluded femoral artery and hemodynamic consequences at a distance.

Coronary risk in lower limb amputees may be substantially greater than predicted by available algorithms, given that neither hemodynamic nor psychological factors concern the current prediction models. It seems reasonable to take early prophylactic measures in lower limb amputees by discouraging smoking, excessive alcohol consumption and adherence to a low fat diet. Studies are needed to evaluate the optimal intensity of physical exercise effects on reflected pulse waves and their possible long-term consequences. Guidelines for optimal blood pressure, blood glucose and lipid control in amputees need to be convened.