Pulmonary Vascular Disease
Pulmonary and Critical Care Medicine · Pulmonary Vascular Disease 🎯 Practice these cards
Normal resting mPAP is about ____ mm Hg; the 2018 Sixth World Symposium on PH lowered the diagnostic threshold to mPAP ≥____ mm Hg (historically ≥____ mm Hg).
Normal resting mean pulmonary artery pressure (mPAP) is about 14 mm Hg and rarely exceeds 20 mm Hg. PH was historically defined as a resting mPAP ≥25 mm Hg measured by right heart catheterization; the 2018 Sixth World Symposium on PH lowered the threshold to mPAP ≥20 mm Hg because patients above that level already face increased early mortality.
Per the 2022 ESC/ERS guidelines, pre-capillary PH requires mPAP >20 mm Hg plus PVR >____ Wood units and a pulmonary artery wedge pressure ≤____ mm Hg.
The 2022 ESC/ERS guidelines define pre-capillary PH as mPAP >20 mm Hg plus PVR >2 Wood units (lowered from the previous 3 WU) with a pulmonary artery wedge pressure ≤15 mm Hg; they also formally define exercise PH (mPAP/cardiac output slope >3 mm Hg/L/min) and mandate initial combination therapy for most newly diagnosed PAH.
PH Group 1 = ____, Group 2 = left heart disease, Group 3 = lung disease/hypoxia, Group 4 = ____, Group 5 = unclear/multifactorial; the most common causes of PH overall are ____.
PH is classified into five clinical groups: Group 1 = pulmonary arterial hypertension (PAH); Group 2 = PH due to left-sided heart disease; Group 3 = PH due to lung disease and/or hypoxia; Group 4 = chronic thromboembolic PH (CTEPH) and other pulmonary artery obstructions; Group 5 = unclear or multifactorial mechanisms. The majority of PH is attributable to left-sided heart disease and hypoxic lung disease (Groups 2 and 3), and management targets the underlying condition rather than the PH itself.
Heritable forms account for up to ____% of PAH, most often autosomal dominant mutations in ____.
Heritable forms account for up to 10% of PAH, most often autosomal dominant mutations in bone morphogenetic protein receptor type 2 (BMPR2), with variable penetrance and a roughly 2% per year conversion rate among carriers. Loss of BMPR2-mediated antiproliferative signaling tips the TGF-β balance toward proproliferative activin signaling — the mechanistic target of sotatercept.
About ____% of patients with systemic sclerosis develop PAH, most often the ____ cutaneous form.
About 10% of patients with systemic sclerosis develop PAH, most often the limited cutaneous form; disease is frequently treatment-refractory and outcomes are worse than in other PAH causes. In diffuse scleroderma, PH often coexists with interstitial lung disease.
Portopulmonary hypertension affects ____% of patients with portal hypertension and must be distinguished from ____, which features abnormal vasodilation with intrapulmonary shunting.
Portopulmonary hypertension affects 2–10% of patients with portal hypertension, independent of the cause of liver disease; the mechanism may involve impaired hepatic metabolism of vasoactive substances. It must be distinguished from hepatopulmonary syndrome, which features abnormal vasodilation with intrapulmonary shunting.
The first-line screening test for suspected PH is ____, but the diagnosis can only be confirmed by ____.
Transthoracic echocardiography is the first-line screening test for suspected PH, but echo-derived PA pressure estimates are often inaccurate. Right heart catheterization is essential to confirm the diagnosis, because it provides accurate hemodynamic data and helps distinguish the primary cause of the elevated PA pressure.
All patients being evaluated for PH should undergo a ____ scan to screen for CTEPH; its sensitivity for chronic thrombus approaches ____%, and a normal scan ____ the diagnosis.
Every patient being evaluated for PH should undergo ventilation/perfusion (V/Q) scanning to screen for CTEPH, even without a history of pulmonary embolism. V/Q scanning is more sensitive than CT angiography for chronic thromboembolic disease, with sensitivity for chronic thrombus approaching 100%; a normal V/Q scan is sufficient to exclude CTEPH.
A positive vasoreactivity test is a fall in mPAP of at least ____ mm Hg to an absolute level of ≤____ mm Hg without a drop in cardiac output; fewer than ____% of patients are vasoreactive, and only they should receive high-dose ____.
Vasoreactivity testing with a short-acting agent (inhaled nitric oxide or epoprostenol) is reserved for idiopathic or heritable PAH. A positive response is a fall in mPAP of at least 10 mm Hg to an absolute level of 40 mm Hg or less without a drop in cardiac output. Fewer than 5% of patients are vasoreactive, and only they should receive high-dose calcium channel blocker therapy.
Established PAH therapies target the endothelin, nitric oxide–cGMP, and ____ pathways; riociguat is a ____ stimulator that acts independently of endogenous nitric oxide.
PAH therapy targets three pathways: endothelin receptor antagonists (bosentan, ambrisentan, macitentan), phosphodiesterase-5 inhibitors (sildenafil, tadalafil) that prolong the vasodilator effect of cyclic GMP, and prostacyclin analogues (epoprostenol, treprostinil, iloprost). Riociguat is an oral soluble guanylate cyclase stimulator that works independently of endogenous nitric oxide and is also the only approved PAH-directed therapy for CTEPH.
In the AMBITION trial, upfront dual oral therapy with ____ plus ____ reduced the risk of clinical worsening by 50% versus monotherapy.
In the AMBITION trial, treatment-naïve patients started on ambrisentan plus tadalafil had a 50% lower risk of clinical worsening than those on either agent alone, without an increase in adverse events — making upfront dual oral combination therapy the recommended first-line approach for patients without high-risk features who can tolerate it.
____, FDA-approved in March 2024, is the first ____ inhibitor — a fourth PAH therapeutic pathway; in the STELLAR trial it improved 6-minute walk distance by ____ m and reduced death or clinical worsening by approximately ____%.
Sotatercept (Winrevair), an activin signaling inhibitor — a fourth therapeutic pathway beyond endothelin, nitric oxide, and prostacyclin — rebalances the BMPR2/TGF-β axis toward antiproliferative signaling. In the phase 3 STELLAR trial, added to background therapy it improved 6-minute walk distance by 34.4 m versus placebo at 24 weeks and reduced the risk of death or clinical worsening by approximately 84%. The FDA approved it on March 26, 2024; it is given subcutaneously every 3 weeks with hemoglobin and platelet monitoring.
Fewer than ____% of patients with acute PE develop CTEPH, yet more than 1 in ____ patients diagnosed with CTEPH has no documented history of PE.
Fewer than 5% of patients with acute pulmonary embolism develop CTEPH, yet more than 1 in 5 patients diagnosed with CTEPH has no documented history of PE, which makes it an underrecognized cause of PH requiring a high index of suspicion.
All patients with CTEPH require ____ anticoagulation; the only potentially curative therapy is ____, for which approximately ____ of patients are eligible.
Lifelong anticoagulation prevents further thromboembolism in all patients with CTEPH, but the only potentially curative therapy is pulmonary thromboendarterectomy (PEA). Every patient with CTEPH warrants surgical evaluation at an experienced center regardless of severity; about half of patients are eligible for surgery, and hemodynamics normalize in about one third of those who undergo it. Registry data support DOACs as an acceptable alternative to vitamin K antagonists for lifelong anticoagulation.
For inoperable CTEPH, options include balloon pulmonary angioplasty and ____, the only approved PH therapy for CTEPH; 3-year survival in the 2024 CTEPH Registry was ____% with BPA versus only ____% with neither PEA nor BPA.
For inoperable CTEPH or persistent PH after PEA, options include balloon pulmonary angioplasty (BPA) and riociguat — currently the only approved PH therapy for CTEPH. The 2024 Worldwide CTEPH Registry reported 3-year survival of 94% with PEA, 92% with BPA, and only 71% with neither, confirming that mechanical revascularization drives survival.
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