Pulmonary embolism (PE) is associated with serious morbidity and mortality. In this case report, we describe a hemodynamically stable patient with submassive PE and a large thrombus in the inferior vena cava (IVC) protruding into the right atrium (RA), complicated by severe respiratory failure, elevated troponin T (TnT), and right ventricular (RV) dysfunction. The patient was stratified as intermediate-high risk of early death. Important issues regarding the initial choice of anticoagulation, rescue thrombolytic therapy, and benefits of adding riociguat to stimulate the nitric oxide-soluble guanylate cyclase-cyclic guanosine monophosphate (NO-sGC-cGMP) pathway to improve the RV function are discussed. Finally, we address appropriate timing and the use of IVC filter in a situation of recurrent PE following anticoagulation and fibrinolytic therapy.