Prevalence: at autopsy, PPH is found in 1% of Cor Pulmonale cases
Predisposing Factors: female sex (F:M ratio is 1.7:1 in younger cases/ ratio 1:1 in older pts.)
Mean Age at Presentation: 36 y/o (range 1-81 y/o)
Autosomal Dominant (with variable expression): 7% of cases
OCP Use:
Migraine
Variant angina
Physiology
Defined as persistent resting mean PA >25 mmHg (or mean PA >30 mmHg during exercise)
Increased resistance to pulmonary blood flow (initially responsive to vasodilators but later fixed) with eventual right-sided CHF (with decreased CO)
Pathologic Subtypes
Plexogenic pulmonary arteriopathy (30-60% of cases/ more common type in younger fe-males/ also seen in CHD, cirrhosis, collagen vascular disease/ Aminorex): medial hypertrophy, concentric laminar intimal fibrosis, plexiform lesions
Thrombotic pulmonary arteriopathy (40-50% of cases/ M:F ratio: 1:1/ also seen in ASD): eccentric intimal fibrosis, medial hypertrophy, fibroelastic intimal pads in arteries and arterioles, old recanalized thrombi
Diagnosis
ABG: hypocapnea/hypoxemia with increased A-a gradient (due to decreased CO, V/Q mismatch/intrapulmonary shunt/occasionally due to opening of PFO with intracardiac shunt)
PFT’s: usually normal, but mild restriction is occasionally seen/ decreased DLCO (usual)
Exercise test: exercise desaturation
VD/VT ratio: remains the same or increases
Lung Biopsy: not usually necessary
CXR: enlarged PA’s with clear lung fields/ cardiomegaly
V/Q scan:
Normal pattern (common in plexogenic subtype): presence of normal V/Q in presence of severe pulmonary HTN strongly suggests PPH
Mottled pattern (common in thrombotic subtype): subsegmental areas of decreased perfusion
Presence of lobar or segmental defects suggests CTPEH instead
Pulmonary Angiogram: “pruning” of peripheral vessels
Usually not necessary in presence of diagnostic V/Q pattern
ESR:
Serology
ANA: positive (>1:80 titer) in up to 30-40% of cases (most have speckled pattern)
Antiphospholipid Ab’s: may be seen in some cases
CBC: polycythemia (may be seen)/ MAHA (seen in a few cases, due to plexiform lesions)
EKG
RAD with RVH (R in V1 >5, etc.)
RAE
Echo: RVE with decreased LV cavity size/ abnormal septum/ dependence on atrial systole for RV filling
TR (by Doppler): jet peak vel squared x 4 + CVP estimates PA-SYS pressure
Bubble study: excludes intracardiac shunt (VSD/ ASD/ etc.)/ PFO seen in 20% of PPH cases
Swan
RA and RV-SYS: elevated
PA-Mean: elevated >25 mm Hg at rest or >30 mm Hg during exercise
PA-SaO2: lack of “step-up” excludes intracardiac shunt
PCWP: normal (due to normal LA, LV-EDP)
CO: normal-decreased at rest (does not rise appropriately with exercise)
SVR: normal
PVR: elevated
Cardiac Cath: PFO may occur due to pulmonary HTN, but L-to-R shunt suggests congenital defect
Angioscopy: may be necessary to rule out CTEPH in some cases
Clinical
Dyspnea (95%): insidious (no correlation with degree of pulmonary HTN): average duration from onset to diagnosis is 2.5 years
Symptoms of right-sided CHF: ascites,etc.
Hemoptysis (due to ruptured vessels)
Fatigue
Angina (due to RV ischemia, PA stretch)
Syncope (decreased CO)
Raynaud’s phenomenon (10-30%):
Hoarseness (PA impingement on recurrent laryngeal)
Signs of right-sided CHF: peripheral edema, right-sided S3 and S4
Signs of pulmonary HTN: split S2, accentuated P2/ RV heave, etc.
Low pulse pressure
Peripheral cyanosis
Absence of clubbing
Sudden death (occurs late)
Central PA Thrombi: may occur (probably later) secondary to low flow state with in situ thrombosis (Circ, 1995)
The removal of these by PTE does not treat underlying PPH and these patients do not come off CPB
Treatment
Avoidance of the following:
Exercise: increases PA pressures (and workload on RV
Hypoxia:
Smoking:
NSAIDS: due to effect of prostaglandins
Pregnancy:
PGF2a: increases PVR
Barbiturates: decrease CO
Oxygen: useful to ameliorate hypoxia
Diuretics: decrease RV preload
Pulmonary Vasodilator Trial (with Swan in place to avoid decrease in CO and BP):
Vasodilator Response (decrease in mean PA >10 to mean PA <40 with stable-increased CO):
Calcium-Channel Blockers (Nifedipine/Diltiazem):
No Vasodilator Response:
Avoid Calcium-Channel Blockers (due to risk of hypotension, acute right-sided heart failure, and death)
Prostacyclin (Flolan): indicated for class III patients and is the drug of choice for class IV patients
Improves exercise capacity, QOL, hemodynamics, and survival
Bosentan (Endothelin-1 Receptor Antagonist): indicated for NYHA III patients
Improves exercise tolerance, hemodynamics, functional class (over 1 year)
Monitor qmonthly LFT s and avoid pregnancy (teratogenic)
Sildenafil (): may be used
Anticoagulation: documented (retrospectively only) to prolong survival
Does not affect disease process
Heart-Lung Transplant: for patients with <1 year survival
Prognosis
Mean survival is 2-3 years (range: 0.5-3.5 years)
RA mean>15, CI <2, NYHA 3-4, presence of Raynaud’s, elev mean PA, decreased DLCO, more elevated JVP: poorer prognosis (prognosis not correlated with pO2)
