MKSAP 6: Pulmonary Vascular Disease

Question 1

What is normal mean pulmonary artery pressure and what constitutes pulmonary HTN?

Answer 1

Normal: 15mmHg
PH: 25 mmHg

Question 2

Define the different groups of pulm HTN

Answer 2

Group 1: Pulmonary arterial HTN
- idiopathic, heritable, drug and toxin induced, connective tissue diseases, HIV infection, portal HTN and congenital heart disease
Group 2: Pulm HTN due left sided heart disease
Group 3: Pulm HTN due to lung disease and/or hypoxia
Group 4: CTEPH
Group 5: Pulm HTN with unclear or multifactorial causes
- hematologic disorders, systemic disorders, metabolic disorders

Question 3

The is the pathophysiologic basis for Group 2 Pulm HTN and Group 3 Pulm HTN?
What is the underlying issue for all causes of Pulm HTN?

Answer 3

Group 2: LV dysfunction and valvular disease lead to PH by volume and pressure overload
Group 3: Vasoconstriction brought on by alveolar hypoxia leading to pulmonary vascular remodeling
all causes: RV hypertrophy and dilatation develop over time in response to pulmonary artery pressure overload and mismatch of myocardial oxygen supply and demand resulting in ischemia, arrythmias and RV failure

Question 4

How does Pulm HTN initially present and then how does it present as it progresses?
What are some cardiovascular exam findings?

Answer 4

Initially: exertional dyspnea and fatigue
Progression: exertional chest pain, syncope and peripheral edema
JVD, a prominent jugular venous a wave, parasternal heave, a widened split S2 with a prominent pulmonic component or R sided regurgitant murmurs as RV dilates

Question 5

What is an initial helpful test and what is the confirmatory test?

Answer 5

TTE then RHC
**Remember that if you suspect lung disease as a cause, get tests to confirm that first before a RHC.
RHC should be considered after a normal TTE if the index of suspicion for Pulm HTN is high

Question 6

What are the general treatment guidelines for pulm HTN groups 2-5 and group 1?

Answer 6

Groups 2-5 treat the underlying condition

Group 1 can have advanced therapy with vasodilators

Question 7

What is the underlying pathophysiology in CTEPH?

Answer 7

The organized thrombus incorporates into the pulmonary artery endothelium thereby increasing pulmonary vascular resistance and pressures and eventually leading to right sided heart failure

Question 8

What are the diagnostic criteria for CTEPH?

Answer 8

1) Documentation of PH (pulm HTN - pulm art pressure > 25 mmHg by RHC in the absence of L heart pressure overload) and
2) compatible imaging evidence of chronic thromboembolism

Question 9

What are the imaging findings on CTPA compatible with CTEPH?

Answer 9

Vascular webs, intimal irregularities, and luminal narrowing

Question 10

What is the more sensitive testing modality for CTEPH?

Answer 10

V/Q scan

Question 11

What is the next diagnostic approach after imaging evidence of CTEPH?

Answer 11

Conventional pulmonary angiography to best characterize the extent and distribution of organized thrombus and to determine suitability for surgical intervention

Question 12

What is the medical treatment for CTEPH?

Answer 12

Anticoagulant therapy that is generally lifelong.

Question 13

What are the mechanical/surgical considerations for CTEPH?

Answer 13

IVC filter can be considered although its role in long term outcomes is not known.
Surgery in the form of pulmonary thromboendarterectomy is the only definitive therapy for CTEPH and evaluation even in mild disease is warranted.

Question 14

Define Group 1 PAH

Answer 14

Defined by a proliferative vasculopathy originating in the pulmonary artery endothelium, driven by imbalances in substances that affect vascular tone and endothelial/smooth muscle cellular growth (NO, prostacyclin, and endothelin)

Question 15

What are the 3 classifications of PAH

Answer 15

1) idiopathic
2) heritable
3) associated with other conditions

Question 16

What gene is involved in heritable form of Pulm HTN?

Answer 16

TGF-beta signaling system with most in BMPR2 which normally contributes to the apoptotic process

Question 17

What are the other conditions are encountered with and associated with PAH?

Answer 17

connective tissue diseases, portal HTN, HIV infection, illicit drug use, toxin exposure and congenital heart disease

Question 18

What is the diagnostic testing indicated for diagnosis of PAH?

Answer 18

RHC

Question 19

What are the goals of therapy for PAH?

Answer 19

Reduce vascular pressures
control symptoms
improve or maintain quality of life

Question 20

What supportive therapies can be considered in PAH?

Answer 20

Diuretic therapy 
Supplemental oxygen 
Anticoagulation is recommended 
Digoxin improves RV function
Exercise training

Question 21

What is the indication for calcium channel blockers in PAH?

Answer 21

Only prescribed for patients demonstrating a vasodilator response on RHC

Question 22

Sildenafil for PAH

Answer 22

phosphodiesterase 5 inhibitor - prolongs effect of intrinsic vasodilator cyclic GMP
initial therapy for mild to moderate disease

Question 23

tadalafil for PAH

Answer 23

phosphodiesterase 5 inhibitor - prolongs effect of intrinsic vasodilator cyclic GMP
initial therapy for mild to moderate disease

Question 24

Bosentan

Answer 24

endothelin - 1 receptor antagonist: blocks action of endogenous vasoconstrictor and smooth muscle mitogen endothelin
initial therapy for mild to moderate disease

Question 25

ambrisentan

Answer 25

endothelin - 1 receptor antagonist: blocks action of endogenous vasoconstrictor and smooth muscle mitogen endothelin
initial therapy for mild to moderate disease

Question 26

What are the side effects of endothelin 1 receptor antagonists and what screening is recommended?

Answer 26

class wide risk of liver injury and teratogenicity; LFT and pregnancy testing for reproductive age women are required

Question 27

Iloprost

Answer 27

an inhaled prostanoid: supplements endogenous levels of prostacyclin, a vasodilator with anti-smooth muscle proliferative properties

Question 28

epoprostenol

Answer 28

a parenteral prostacyclin analogue: supplements endogenous levels of prostacyclin, a vasodilator with anti-smooth muscle proliferative properties

Question 29

treprostinil

Answer 29

a parenteral prostacyclin analogue: supplements endogenous levels of prostacyclin, a vasodilator with anti-smooth muscle proliferative properties