Patients considered at “low-risk”, in case of low PCP or moderate PCP with a negative D-dimer test result, will be discharged without anticoagulant therapy. Conversely, patients with moderate PCP and a positive D-dimer test or with high PCP , will be considered as being at “high risk” and will receive therapeutic doses of LMWHs as ‘protective anticoagulation’. Physicians have indeed the option of admitting patients to the hospital irrespective of PCP and D-dimer test results. All patients, either managed as in or out-patients, havo to undergo diagnostic imaging within 72 hours of PCP and D-dimer test assessment.