Is being in high altitudes a risk factor for pulmonary embolism?

High altitude: Pulmonary embolism is commonly from atrial fibrillation or from a deep vein thrombosis in the leg. I don't feel that high altitude alone per se is a common cause of those predisposing conditions although it may predispose somewhat to a hypercoagulable state in certain people. Dehydration would be a more common predisposing factor in dry high altitude conditions.