Diclofenac for Submassive PE

Inclusion Criteria: 1. Acute symptomatic PE confirmed by multidetector CT angiography, a high-probability V/Q scan, or by the presence of deep vein thrombosis confirmed by lower limb ultrasound testing in patients with nonconclusive V/Q scan; 2. first symptoms occurring ten days or less before randomization; 3. haemodynamic stability (systolic blood pressure \> 100 mm Hg, no need of inotropic support, pulmonary resuscitation, intubation or thrombolytic treatment); 4. right ventricular dysfunction assessed by transthoracic echocardiography within the first 12 hours after diagnosis of PE; 5. signed informed consent. Exclusion Criteria: 1. Previous diagnosis of chronic thromboembolic pulmonary hypertension; 2. active bleeding, or clinically relevant bleeding in the previous month before diagnosis of PE; 3. peptic ulcer; 4. major surgery, or severe trauma in the previous month before diagnosis of PE; 5. indication for chronic anticoagulation; 6. pregnancy or breast feeding; 7. renal insufficiency (serum creatinine \> 2 mg/dL) or severe hepatic impairment; 8. hypersensitivity to diclofenac, sodium metabisulfite, or acetylsalicylic acid; 9. bronchial asthma; 10. severe congestive heart failure; 11. inflammatory bowel disease.