A 58-year-old man with a 5-day history of immobilization following a motor vehicle accident presents to the emergency department with acute onset dyspnea, chest pain, and syncope. His blood pressure is 82/56 mmHg, heart rate 118/min, and respiratory rate 28/min. CT pulmonary angiography (CTPA) shows the structure marked **A** — a thrombus straddling the main pulmonary artery bifurcation. His RV/LV diameter ratio is 1.3, and troponin is elevated. Which of the following is the most appropriate immediate management for this patient?
A. Systemic thrombolysis with alteplase 100 mg IV over 2 hours
B. Anticoagulation with unfractionated heparin and observation for hemodynamic stabilization
C. Surgical embolectomy under cardiopulmonary bypass
D. Catheter-directed thrombolysis with reduced-dose tPA
Explanation
Why Systemic thrombolysis with alteplase 100 mg IV over 2 hours is right
The clinical presentation — sustained hypotension (SBP 82 mmHg), syncope, and a saddle embolus at the main pulmonary artery bifurcation (marked A) — defines MASSIVE (HIGH-RISK) PULMONARY EMBOLISM. According to Harrison's Principles of Internal Medicine 21e and the 2019 ESC Guidelines on PE, systemic thrombolysis with alteplase 100 mg IV over 2 hours is FIRST-LINE therapy for high-risk PE with sustained hemodynamic compromise. The saddle thrombus straddling the MPA bifurcation is the radiologic hallmark of massive PE and carries 25–65% mortality if untreated. The elevated troponin and RV/LV ratio >1.0 confirm RV dysfunction, which is the key prognostic marker. Thrombolysis rapidly restores pulmonary perfusion and reduces 30-day mortality in this population.
Why each distractor is wrong
Anticoagulation with unfractionated heparin and observation for hemodynamic stabilization: This is appropriate for submassive or low-risk PE, but a patient with sustained hypotension and a saddle embolus requires immediate thrombolysis, not observation. Anticoagulation alone is insufficient and delays life-saving reperfusion therapy.
Catheter-directed thrombolysis with reduced-dose tPA: Catheter-directed thrombolysis is reserved for cases where systemic thrombolysis is contraindicated (e.g., active bleeding, recent hemorrhagic stroke) or has failed. This patient has no contraindications and requires first-line systemic thrombolysis.
Surgical embolectomy under cardiopulmonary bypass: Surgical embolectomy is a rescue therapy for refractory cardiogenic shock despite thrombolysis or when thrombolysis is absolutely contraindicated. It is not first-line and carries higher morbidity. Systemic thrombolysis should be attempted first.
High-YieldNEET PG
Massive PE with sustained hypotension and saddle embolus = systemic thrombolysis (alteplase 100 mg IV over 2 hours) is first-line; surgical embolectomy is rescue therapy for failure or contraindication.
Harrison's Principles of Internal Medicine 21e; ESC Guidelines on PE 2019; PEITHO trial NEJM 2014
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