Answer: A. V/Q scan
This is a middle-aged woman with prior miscarriages who presents with severe pulmonary arterial hypertension (PAH). Chronic thromboembolic pulmonary hypertension (CTEPH) is a relatively uncommon but potentially treatable cause of PAH that should be ruled out.
CTEPH is chronic process that may result in small scattered thromboembolic disease that maybe missed on routine computed tomographic angiography; hence, V/Q scanning is the first-line imaging test to rule out CTEPH.1
Options C, D, and E have little if any role in the workup of PAH. Once the diagnosis is confirmed, patients with CTEPH should be started on lifelong anticoagulation therapy and should be evaluated by a multidisciplinary team for pulmonary endarterectomy.1 Pulmonary endarterectomy has been shown to improve symptoms and normalize hemodynamics.1
Galiè N, Humbert M, Vachiery JL, et al. 2015 ESC/ERS guidelines for the diagnosis and treatment of pulmonary hypertension: the Joint Task Force for the Diagnosis and Treatment of Pulmonary Hypertension of the European Society of Cardiology (ESC) and the European Respiratory Society (ERS): endorsed by: Association for European Paediatric and Congenital Cardiology (AEPC), International Society for Heart and Lung Transplantation (ISHLT). Eur Heart J. 2016;37(1):67-119.