Non-immunogenic recombinant staphylokinase or placebo will be administered intravenously at a dose of 15 mg as a single bolus for 10-15 seconds. All patients will be examined for 30 days. primaryPurpose: TREATMENT masking: DOUBLE maskingDescription: Neither patient nor investigator knows treatment assignment. All eligible patients will be randomized in two equal groups for administration of non-immunogenic recombinant staphylokinase or placebo. whoMasked: PARTICIPANT whoMasked: INVESTIGATOR count: 486 type: ESTIMATED name: Non-immunogenic recombinant staphylokinase name: Placebo measure: Composite of death from any cause or hemodynamic collapse or recurrent PE measure: Right/left ventricular (RV/LV) end-diastolic diameter ratio measure: RV/LV end-diastolic diameter ratio measure: RV/LV end-diastolic diameter ratio measure: Right ventricular (RV) end-diastolic volume measure: Qanadli index measure: Systolic pulmonary artery pressure measure: In hospital death from all causes (assessed up to day 7) measure: Death from all causes measure: Safety endpoint - hemorrhagic stroke measure: Safety endpoint - BARC type 3 and 5 bleeding measure: Safety endpoint - number and severity of adverse events (AEs) and serious AEs in organs and systems sex: ALL minimumAge: 18 Years stdAges: ADULT stdAges: OLDER_ADULT facility: V.F. Dolgopolov Vyselki Central District Hospital city: Vyselki state: Krasnodar Region zip: 353100 country: Russian Federation name: Valerii V. Makukhin, PhD role: CONTACT phone: (86199) 123-53 phoneExt: +7 email: makuhinv@mail.ru name: Valerii V. Makukhin, PhD role: PRINCIPAL_INVESTIGATOR lat: 45.58128 lon: 39.66409 facility: I.P. Pavlov Ryazan State Medical University city: Ryazan' state: Ryazan zip: 390026 country: Russian Federation name: Denis S. Yunevich, PhD role: CONTACT phone: (4912) 46-63-90 phoneExt: +7 email: yunevichden@ya.ru name: Denis S. Yunevich, PhD role: PRINCIPAL_INVESTIGATOR lat: 54.6269 lon: 39.6916 facility: Belgorod Regional Clinical Hospital of St. Joseph city: Belgorod zip: 308007 country: Russian Federation name: Sergei L Konstantinov, MD role: CONTACT email: konstantinov5@yandex.ru name: Sergei L Konstantinov, MD role: PRINCIPAL_INVESTIGATOR lat: 50.61074 lon: 36.58015 facility: Kuzbass Cardiology center city: Kemerovo zip: 650002 country: Russian Federation name: Vasilii V. Kashtalap, MD, PhD role: CONTACT phone: +7 (3842) 64-22-41 email: v_kash@mail.ru name: Vasilii V. Kashtalap, MD, PhD role: PRINCIPAL_INVESTIGATOR lat: 55.33333 lon: 86.08333 facility: City Clinical Hospital №1 city: Kirov zip: 610035 country: Russian Federation name: Oleg V. Solovyev, PhD role: CONTACT phone: (8332) 56-35-74 phoneExt: +7 email: ckn@medkirov.ru name: Oleg V. Solovyev, PhD role: PRINCIPAL_INVESTIGATOR lat: 58.59665 lon: 49.66007 facility: Regional Clinical Hospital №2 city: Krasnodar zip: 350012 country: Russian Federation name: Tamara A. Chirva, MD role: CONTACT phone: (861) 222-000-2 phoneExt: +7 email: makuhinv@mail.ru name: Tamara A. Chirva, MD role: PRINCIPAL_INVESTIGATOR lat: 45.04484 lon: 38.97603 facility: S.S. Yudin City Clinical Hospital city: Moscow zip: 115446 country: Russian Federation name: Bogdan B Orlov, MD, PhD role: CONTACT phone: 7 (499) 612-45-66 email: bborlov@mail.ru name: Bogdan B Orlov, MD, PhD role: PRINCIPAL_INVESTIGATOR lat: 55.75222 lon: 37.61556 facility: V.V. Vinogradov City Clinical Hospital city: Moscow zip: 117292 country: Russian Federation name: Imad Merai, MD, PhD role: CONTACT phone: +7 (495) 103 46 66 email: imadmerai@yahoo.com name: Imad Merai, MD, PhD role: PRINCIPAL_INVESTIGATOR lat: 55.75222 lon: 37.61556 facility: S.P. Botkin City Clinical Hospital city: Moscow country: Russian Federation name: Yuri V. Karabach, PhD role: CONTACT phone: (499) 490-03-03 phoneExt: +7 email: yu.karabach@ya.ru name: Yuri V. Karabach, PhD role: PRINCIPAL_INVESTIGATOR lat: 55.75222 lon: 37.61556 facility: N.N. Burdenko Penza Regional Clinical hospital city: Penza zip: 440026 country: Russian Federation name: Valentin E. Oleynikov, MD, PhD role: CONTACT phone: +7 (8412) 54-84-07 email: oleynikof@gmail.com name: Valentin E. Oleynikov, MD, PhD role: PRINCIPAL_INVESTIGATOR lat: 53.20066 lon: 45.00464 facility: G.A. Zakharyin Clinical hospital №6 city: Penza zip: 440071 country: Russian Federation name: Elena S. Panina, PhD role: CONTACT phone: (8412) 98-33-55 phoneExt: +7 email: panina.es@mail.ru name: Elena S. panina, PhD role: PRINCIPAL_INVESTIGATOR lat: 53.20066 lon: 45.00464 facility: City Clinical Hospital №4 city: Perm zip: 614107 country: Russian Federation name: Oleg M. Lapin, PhD role: CONTACT phone: 342-263-01-06 phoneExt: +7 email: heparin@yandex.ru name: Oleg M. Lapin, PhD role: PRINCIPAL_INVESTIGATOR lat: 58.01046 lon: 56.25017 facility: V.P. Polyakov Samara Regional Clinical Cardiology Dispensary city: Samara zip: 443070 country: Russian Federation name: Dmitrii V Duplyakov, MD, PhD role: CONTACT phone: 8 (846) 373-70-63 email: duplyakov@yahoo.com name: Dmitrii V Duplyakov, MD, PhD role: PRINCIPAL_INVESTIGATOR lat: 53.20007 lon: 50.15 hasResults: False