A 48-year-old woman from Mumbai presents with acute-onset dyspnea, orthopnea, and pink frothy sputum. On examination, she is tachycardic (110/min), hypotensive (90/60 mmHg), and has a loud holosystolic murmur at the apex radiating to the axilla. Chest X-ray shows bilateral pulmonary edema. Echocardiography confirms acute severe mitral regurgitation secondary to papillary muscle rupture. What is the most appropriate immediate management?