A 62-year-old woman from Mumbai presents with acute dyspnea and syncope. Vital signs: HR 128/min, BP 88/56 mmHg, RR 28/min, SpO₂ 88% on room air. CTPA performed emergently shows a large saddle embolism straddling the pulmonary artery bifurcation with bilateral pulmonary artery involvement. The right ventricle is severely dilated with a RV/LV diameter ratio of 1.8 on the axial image. Troponin is markedly elevated. The patient is in cardiogenic shock. What is the most appropriate immediate next step in management?