Inclusion Criteria:

1. Informed Consent as documented by signature
2. Age ≥18 years
3. Objective diagnosis of symptomatic or asymptomatic isolated SSPE

Exclusion Criteria:

1. Presence of leg deep vein thrombosis (DVT) or upper extremity DVT (subclavian vein or above)
2. Active cancer, defined as cancer treated with surgery, chemotherapy, radiotherapy, or palliative care during the last 6 months
3. ≥1 prior episode of unprovoked VTE (absence of a transient or permanent risk factor)
4. Clinical instability (systolic blood pressure <100 mm Hg or arterial Oxygen saturation <92% at ambient air) at the time of presentation
5. Active bleeding or at high risk of bleeding
6. Severe renal failure (creatinine clearance <30ml/min)
7. Severe liver insufficiency (Child-Pugh B or C)
8. Concomitant use of strong CYP3A4 inhibitors or strong CYP3A4 inducers
9. Known hypersensitivity to rivaroxaban
10. Need for therapeutic anticoagulation for another reason
11. Therapeutic anticoagulation for >72 hours for any reason at the time of screening
12. Hospitalized for >72 hours prior to the diagnosis of isolated SSP (hospital-acquired VTE)
13. Known pregnancy or breast feeding (pregnancy test to be performed for women of childbearing potential)
14. Lack of safe contraception in women of childbearing potential
15. Refusal or inability to provide informed consent
16. Prior enrolment in this trial