A 58-year-old woman, 10 days post-total knee replacement, presents with sudden-onset dyspnea, pleuritic chest pain, hemoptysis, and syncope. Vitals: BP 92/60 mmHg, HR 128/min, RR 28/min, SpO₂ 86% on room air. Wells score is 7 (high probability). CT pulmonary angiogram (CTPA) is performed and shows the finding marked **A** in the diagram — a large intraluminal filling defect in the right main pulmonary artery extending into lobar branches. Bedside echocardiography demonstrates McConnell's sign, and troponin and BNP are elevated. Which of the following is the most appropriate immediate management for this patient?
A. Catheter-directed thrombolysis with delayed anticoagulation
B. Insertion of an inferior vena cava (IVC) filter without anticoagulation
C. Anticoagulation with unfractionated heparin alone and observation
D. Systemic thrombolysis with alteplase 100 mg IV over 2 hours
Explanation
Why Systemic thrombolysis with alteplase 100 mg IV over 2 hours is right
The intraluminal filling defect marked A in the CTPA, combined with hemodynamic instability (SBP 92/60 mmHg), elevated biomarkers (troponin, BNP), and signs of RV strain (McConnell's sign, elevated JVP, parasternal heave), defines MASSIVE PULMONARY EMBOLISM. According to Harrison's Principles of Internal Medicine (21e), hemodynamically unstable patients with massive PE require immediate systemic thrombolysis with alteplase 100 mg IV over 2 hours as the gold standard treatment. The large filling defect in the right main pulmonary artery is the anatomic hallmark of massive PE requiring urgent reperfusion therapy.
Why each distractor is wrong
Anticoagulation with unfractionated heparin alone and observation: This is appropriate for submassive PE (RV strain + biomarker elevation but normotensive) or low-risk PE, not for hemodynamically unstable massive PE. This patient requires immediate thrombolysis, not anticoagulation alone.
Insertion of an inferior vena cava (IVC) filter without anticoagulation: IVC filters are reserved only for patients with absolute contraindications to anticoagulation (e.g., active bleeding, recent hemorrhagic stroke). This patient has no such contraindication and requires immediate thrombolysis, not filter placement.
Catheter-directed thrombolysis with delayed anticoagulation: While catheter-directed thrombolysis is an alternative in select cases (e.g., if systemic thrombolysis is contraindicated), it is not the first-line immediate management for hemodynamically unstable massive PE. Systemic thrombolysis is faster and the standard of care in this scenario.
High-YieldNEET PG
Massive PE (hemodynamic instability + large filling defect on CTPA + RV strain) = systemic thrombolysis with alteplase 100 mg IV over 2 hours; submassive PE (RV strain + biomarkers but normotensive) = anticoagulation alone ± case-by-case lytics; low-risk PE = outpatient DOAC.
Harrison's Principles of Internal Medicine, 21e, Chapter on Pulmonary Embolism
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