[Medial calcific sclerosis under long-term anticoagulation with vitamin K antagonists]

Vitamin K antagonists not only influence the synthesis of coagulation factors but also the activation of other vitamin K dependent proteins. Among other possible side effects, arterial calcification has been focused on in recent years.

Four patients under long-term anticoagulation for more than 10 years developed medial calcific sclerosis. In case 1 we identified an unexplained medial calcific sclerosis on x-ray after a trauma by chance. After that we examined the ankle-brachial index of blood pressure in all patients who had received long-term anticoagulation for more than 10 years. Where the index exceeded 1,3 we performed a x-ray-examination of the forefoot. Of the four described patients no one suffered from diabetes mellitus, renal failure or hyperparathyreoidism. Serum calcium was normal in all patients. The severity of the medial calcific sclerosis could not be explained by the initial vascular risk factors.

In certain patients, even at low vascular risk, a medial calcific sclerosis can appear under long-term anticoagulation with vitamin K antagonists. We conclude that vitamin K antagonists inhibit several proteins which protect the vessels from calcification leading to medial calcific sclerosis.