Pulmonary Hypertension Flashcards
Haemodynamic Definition of Pulmonary Hypertension
mPAP ≥20, PVR < 2 WU, PAWP < 15 mmHg –> “unclassified” pulmonary hypertension. May be increased pulmonary flow. Should be followed up
Echocardiographic Probability of Pulmonary Hypertension
Other echocardiographic features
The Ventricles
* RV/LV basal diameter/area ratio >1.0
* Flattening of the interventricular septum (LVEI >1.1 in systole and or diastole)
* TAPSE/sPAP ratio < 55mm/mmHg
The PA
* RVOT acceleration time < 105ms or midsystolic notching
* Early diastolic PR velocity >2.2m/s
* PA diameter > aortic room diameter, PA diameter >25mm
The IVC and RA
IVC >21mm with reduced collapse with inspiration (< 50% with sniff or < 20% with quiet breathing)
RA area end systole >18cm2
Overview of Pulmonay Hypertension
Echo Features of Pulmonary HTN
Vasoreactivity Testing in PAH
- Only do vasoreactivity testing in Idiopathic, Heritable or Drug Associated PAH
- Inhaled Nitric Oxide, inhaled iloprost or IV epoprostanol are recommended
- Positive Test = ≥10mmHg mPAP drop to reach an absolute value of ≤40mmHg with an unchanged or increased CO
- Treat responsive patients with high dose calcium channel blockers
Haemodynamic Measures Obtained During a Right Heart Cath
Diagnostic Algorithm for Pulmonary Hypertension
Warning signs:
rapid progression of symptoms
severely reduced exercise capacity
pre-syncope or syncope on exertion
right heart failure
PAH RFs:
FHx
Systemic sclerosis or other connective tissue disease
HIV
Portal HTN
CTEPH RFs:
- Hx PE
- Intravascular device
- High dose thyroxine
- Inflammatory bowel disease
- Splenectomy
- Essential thrombocythaemia
- Malignancy
Imaging in PH
- Echo is first line, non-invasive diagnostic tests
- After echo, assign a probability of PH based on TR velocity and other PH signs (low/intermiediate/high)
- V/Q scan or perfusion lung scan recommended for suspected CTEPH
- CTPA recommended in the work up of patients with suspected CTEPH
- Routine biochemistry, haematology, immunology, HIV and TFT in all patients with suspected PH to check for associated conditions
- Abdominal USS recommended for screening for portal hypertension
- PFTs with DLCO recommended in all patients suspected of PH
Screening in PH
Systemic Sclerosis
* * In patients with Systemic Sclerosis, annual assessment of PH risk is recommended
* If SSc >3 years, FVC ≥ 40% and DLCO < 60, use DETECT algorithm to identify asymptomatic patients with PAH
* In SSc,iIf SOB still unexplained after non-invawsive assessment, do RHC
CTEPH
* If new SOB following PE, check for CTEPH
* If >3months of anti-coagulation for PE and perfusion defect seen on V/Q - refer to PH centre
Other
* If mutation carrier and first degree relative of Hereditary PAP - annual screening
* Liver transplant - echo screenign for PH
Treatment - PAH with vasoreactivity on testing
- Only do vasoreactivity in idiopathic, heritable and drug related PAH (group 1)
- High dose CCBs (Amlodipine or Felodipine target dose 15-30mg (start 5mg), diltiazem120-360mg BD (start 60mg BD))
- Close follow up with repeat RHC in 3-4 months after starting treatment - continue for patients in functional class I or II who have a marked haemodynamic response (mPAP < 30, PVR < 4 WU)
- Start PAH therapy for those in functional class III or IV or no marked haemodynamic response after high dose CCBs.
Treatment - PAH without vasoreactivity testing
PAH Therapies
General
* Contraceptive adivce to young women - pregnancy high risk
* Oxygen in PaO2 < 8kPA (< 60mmHg, Sats < 92%)
* Diuretics if RF failure
* Consider anticoagulation on case by case basis
* Exercise training
**Endothelin Receptor Antagonists*
- Ambrisentan- Endothelin A blocker - 5-10mg OD - improves symptoms, exercise, haemodynamics and time to worsening - SE - peripheral oedema
- Bosentan - Endothelin A+B blocker - dose 125mg BD - improves symptoms, exercise, haemodynamics and time to worsening - raised ALT (LFTs monthly). Cytochrome P450 inducer
Macitentan - Endothelin A+B blocker - dose 10mg OD, SE - anaemia - ETAs not recommended in pregnancy
Phosphodiesterase 5 inhibitors
- Sildenafil - dose 20mg TDS- improves symptoms, exercise capacity and haemodynamics - dose 20mg TDS - SE headache, flushing, epistaxis
- Tadalafil - dose 40mg OD - symptoms, exercise capacity, haemodynamics and time to worsening - SE headache, flushing, epistaxis
Soluble Guanylate Cyclase Stimulators
* Riociguat - stimulates sGC, improves symptoms, exercise, haemodynamics and time to worsening - SE headache, flushing, epistaxis
* Not recommended in pregnancy
Prostacyclin Analogues and Prostacyclin Receptor Agonists
* Epoprostanol - short half life IV agent - needs tunnelled IV line and constant IV infusion. Associated with severe events related to line (line infection, sepsis, occlusion)
* Iloprost - inhaled administration. Improved symptoms, exercise capacity, PVR and clinical events
* Treprostanil - SC/IV. Inhaled/PO - not approved in Europe
* Beraprost - not approved in Europe
* Selexipag - oral prostacyclin receptor agonists. Improved symptoms, haemodynamics and events. SE- headaches, jaw pain, diarrhoea and nausea
PAH - 3 Strata Risk Stratification
PAH - 4 Strata Risk Stratification
PAH therapy recommendations
- In IPAH/HPAP/DHAH who present with intermedate/low risk of death - inital dual therapy with ETA and PDE5i is recommended. Ambrisentan and Tadalafil (1b). Macitentan and Tadalafil (1b). Consider others
- In IPAH/HPAP/DHAH who present with high risk of death - consider initial triple therapy with ETA/PDE5i and IV/SC prostacyclin analogue
- In IPAH/HPAP/DHAH who present with intermedate/low risk of death on ETA and PDE5i, consider adding Selexipag
- In IPAH/HPAP/DHAH who present with intermedate/low risk of death on ETA and PDE5i, consider switching PDE5i to Riociguat
- In IPAH/HPAP/DHAH who present with intermedate/high risk of death on ETA and PDE5i - consider IV/SC prostacyclin analogue and referal for lung transplant
PAH - Lung Transplantation
PAH with CHD (shunts)
- ASD/VSD/PDA and PVR < 3 with a shunt with Qp:Qs >1.5 - closure of shunt is recommended. PVR 3-5, consider shunt closure
- If PVR reduces to < 5 with PAH treatment, consider shunt closure
- PVR > 5, shunt closure not recommended
Group 2 Pulmonary Hypertension - PH-LHD
- Optimise Rx of underlying LHD before assessing PH
- RHC recommended if it aids management decisions
- RHC receommended prior to surgery or intervention in severe TR, with or without LHD
- If markers of pre-capillary component or RV failure, refer to PH centre
- Exercise or fluid challenge may reveal post capillary PH
- PAH drugs not recommended
Group 3 Pulmonary Hypertension - PH with Lung Diseases or Hypoxia
- Categeroised as severe (PVR >5 WU) or non-severe (≤ 5 WU)
- Echo, interpret in context of ABG, PFTs, CT
- Treat underlying lung disease (oxygen, NIV)
- Refer eligible patients for lung transplantation
- Inhaled treprostanil effective in RCTs
Group 4 Pulmonary Hypertension - CTEPH
- Consider in all PH as distintinct treatment
- Do APLS testing in all CTEPH
- V/Q –> CTPA–> DSA
- Lifelong anti-coagulation - VKA preferred
- Operable - Pulmonary Endarterectomy
- Inoperable or ongoing CTEPH post PEA - Balloon Pulmonary Angioplasty
- Inoperable CTEPH - consider off label ETA/PDE5/Riociguat
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Group 5 Pulmonary Hypertension - Unclear Mechanisms
Right Heart Cath Waveforms
PAH Genotype / Phenotype Associations
