In this open, prospective, non-randomised, parallel group, unicentric pilot-study will be compared the progress of valvular and coronary calcification with regard to the therapy with either acetyl-salicylic acid or phenprocoumon. The progress of calcification is documented by comparison of cardial stratified computed tomography. It is supposed that treatment with phenprocumon leads to increased coronary and valvular calcification as well to decreased blood levels of carboxylated matrix-GLA-protein

Patients will be allocated to two groups with either

1. anticoagulation with phenprocoumon (needed for at least 1 year)
2. therapy with ASA

Both treatment groups should include to 50% patients with a glomerular filtration rate (GFR) < 60 ml/min and > 15 ml/min.

All patients will undergo a screening procedure with evaluation of calcium regulating proteins, echocardiography and stratified computed tomography of the heart. Medical check up's are planned after 1,3,6, 12 and 18 months.

Prior investigations concern diastolic ventricular function under long lasting therapy with phenprocoumon and the influence of long lasting therapy with phenprocoumon in patients suffering from aortic valve sclerosis.

Inclusion Criteria:

• 60 patients with new onset of anticoagulation therapy with phenprocoumon for the expectant duration of at least one year
• BMI 19-27 kg/qm
• Mental ability and capacity to understand and follow the instructions of the investigator
• Written informed consent

Exclusion Criteria:

• Patients not fulfilling the inclusion criteria or with:

  • renal failure grade IV or V
  • acute cardial or pulmonary decompensation
  • women of childbearing age, pregnant or breastfeeding women
  • psychiatric diseases
  • life expectancy < 1 year
  • acute lifethreatening situations
  • participation in other studies
  • persons in dependency from the sponsor or working with the sponsor

Patients with required therapy with either ASS or phenprocoumon