Portopulmonary Hypertension (PAH in the setting of liver disease)
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Transcript of Portopulmonary Hypertension (PAH in the setting of liver disease)
Portopulmonary Hypertension(PAH in the setting of liver disease)
George T. Kondos, MD
Associate Professor of Medicine
Department of Medicine
Section of Cardiology
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Classification of Pulmonary Hypertension
• 1975 WHO Classification – Primary pulmonary hypertension (PPH)
• Diagnosis of exclusion
– Secondary pulmonary hypertension• Presence of identifiable risk factors
• 1998 Evian Classification – Clinical classification system
– Different categories sharing similarities in pathophysiological mechanisms, clinical presentations, therapeutic options
• 2003 Revised Clinical Classification of Pulmonary Hypertension
• Other classification systems– Pathological
– Functional based on the severity of symptoms
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Clinical Classification of Pulmonary HypertensionVenice 2003Evian 1998
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Evolution of PAH Classification from 1998-2003
• The need for a genetic classification system– BMPR2 (50% of cases of FPAH)
– <70 mutations
• Discontinuing the term PPH
• Reclassification of PVOD and PCH
• Update on new RFs for PAH
• Reassessment of the classification of congenital systemic-to-pulmonary shunts
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Risk Factors Associated with PAH
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Associate Liver and Lung Disease
Advanced Liver Disease/Dysfunction
Hepatopulmonary syndrome Portopulmonary Hypertension
Pulmonary vascular dilatation
Severe arterial hypoxemia
May totally resolve after Tx
Pulmonary vasoconstrictive and proliferative
Leading to pulmonary hypertension
Right heart failure
Frequently not reversible by liver Tx
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Hepatopulmonary Syndrome
Liver disease
Hypoxemia (A-a >20mmHg or PAO2< 70mmHG
Intrapulmonary vascular dilatations (dilated capillaries)
Diffusion-perfusion impairment
Anatomic R->L shunt
Admin of 02 - partial improvement
Admin 02 in pure R->L - no improvement
Admin 02 in pure diffusion - may normalize PO2 at rest
8 µm 100 µm
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Differential Diagnosis of Hypoxemia
• Normal A-a 02 gradient– Hypoventilation
– Inhalation of gas with decreased FIO2
• Elevated A-a 02 gradient– Ventilation-perfusion
mismatch
– Anatomic R->L shunt
– Diffusion impairment
– Diffusion perfusion impairment
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Hepatopulmonary Syndrome• Worsened by
– Inc. C.O. in chronic liver disease– Inc. pulmonary capillary dilatations
• Associated clinically with– Orthodeoxia (dec in P02 4mmHg, or dec in P02 5%)
• Diagnostic studies– Contrast-enhanced echocardiography– Tc 99m pyrophosphate lung scan with detection over brain or
abdominal organs– ABG after breathing 100% 02 (shunt study)
• Treatment– Liver Tx if PaO2 50-60 mmHg– Individualize Rx if PaO2 <50mmHg– Garlic, Nitric Oxide, portosystemic shuynts, intrapulmonary embolization
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Portopulmonary Hypertension(The Challenge)
• Difficult to make precise comparative evaluations between Tx candidates– Limited amount accurate data available– Conclusions often conflicting– Failure of development of evidenced based
strategies• Different pathological presentations• Various comorbidities• Lack of complete hemodynamic and
echocardiographic data
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Portopulmonary Hypertension
• Definition– Presence of portal hyhpertension (ascites, varices,
splenomegaly)– Resting mPAP >25mmHg– Exercise mPAP>30mmHg– PCWP <15mmHG– >240 dynes.s.cm-5
• Incidence– 2-20% of cirrhotic patients– Prevalence may be greater (pts asymptomatic early
in the disease)
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Survival in PAH (Krowka, Clin Chest Med 2005)
Multicenter study: 10 OLT transplant centersDespite strong slection criteria 36% in-hospital mortality
- 13 deaths due to right heart failure
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Survival in IPAH(McGlaughlin, Chest 2004)
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
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Portopulmonary Hypertension Pathology
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Portopulmonary Hypertension(Clinical Presentation)
• Subtle
• Exertional dyspnia (most common, nonspecific)
• Fatigue
• Leg edema
• Chest pain or pressure
• syncope
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Portopulmonary Hypertension(Physical Examination)
• Carotid - decreased volume
• JVP - elevated, a >> v, possible a<v if TR is present +/- HJR if JVP normal
• Chest - unremarkable
• CVS - +RVI, S1 nl, S2 increased murmur of TR common, PI uncommon
• Extremities - edema
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Risks of Liver Tx in Portopulmonary HTN
• High risk surgery• 43 pts with portopulmonary HTN 35%
perioperative mortality (Krowka, Liver Transpl 2004)
– Right heart failure
– Cardiopulmonary collapse
– Intrapoperative death 5 pts
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Portopulmonary HTN(Screening)
• CxR and EKG insufficient– Enlarged pulmonary arteries, cardiomegaly pulmonary
hemodynamics are markdely abnormal
– RAD, RBBB, Twv inversions in the precordial leads - late findings
• Transthoracic doppler does not differentiate causes of elevated PAP– Hyperdynamic circulatory state
– Increased central volume
– Pulmonary vasculopathy of portopulmonary HTN
• RHC mandatory for definitive diagnosis– Inc. Rvsys (30-50mmHg) no elevated PVR via RHC
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Reliability of TTD in Detecting and Quantifying PAH
• TR jets analyzable in 39-86% of pts
• 10 studies have reported correlation coefficients between RVSP estimated from TR jets and RHC– 1 study - 51 pts poor correlation (r=0.31)
– 9 studies - >500 pts, significant correlations (0.83, 0.57, 0.95, 0.78, 0.85, 0.76, 0.93, 0.90, 0.89)
• Sensitivity and specificity estimating sPAP ranges: 0.79-1 and 0.6-0.98
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Differential Diagnosis of RHC Findings
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
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PVR in Portopulmonary HTN
• Debate regarding PVR >120, or > 240 dynes.s.cm-5
• Subgroup of Liver Dx pts with– PVR between 120-240 dynes.s.cm-5 and inc. PCWP– Pts have increased TPG (mPAP-PCWP) >15mmHg– Consider as having mild portopulmonary HTN– Follow very carefully - natural history unclear– Report CO and PVR as indices– Administration of 1L NS over 10 minutes to identify
individuals susceptible of liver ventricular failure during liver allograft reperfusion
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Screening Algorithm for Portopulmonary HTN
Transthoracic DopplerEcho
Rvsys >50mmHG and/or
Abn RV size/function
Observe; repeat echo12 months if Liver Tx
candidate
Right Heart Cathfor hemodynamic data
MeasureRAmPAPPCWPCOPVR
Characterize PulmonaryHemodynamics
PortopulmonaryHTN diagnosis established
mPAP <25mmHgmPAP >25 mmHg
and PVR >240 dynes.s.cm5mPAP >25 mmHgAnd PVR<240 dynes.s.cm5
Probable highflow state
Portopulmonary HTNDoes not exist
Other Patterns
Institute Treatment
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QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
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Acute Vasodilator Testing
• IV epoprostenol
• Inhaled NO
• IV adenosine
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Acute Vasodilator Testing• Continue until one of the following criteria is met
– Drop in SBP by 30% or >, or < 85mmHg
– Increased in HR by 40% or >100 bpm
– Intolerable side effects: HA, nausea, lightheadedness
– Target response achieved
– Maximum dose of vasodilator
• Responsiveness– Decrease of mPAP at least 10mmHG AND mPAP decreasing to
40mmHG or less AND normal or high CO
– ALL THREE CRITERIA NEED TO BE SATISFIED
• When should left heart catheterization be done?– Validation of abn PCWP
– Evaluation of LV diastolic dysfunction
– Syspected left-sided valvular dz (aortic, mitral)
– Suspected CAD
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Medical Treatment for Portopulmonary HTN
• Prostacycline - (Epoprostenol) - IV, inhaled• Prostacycline Analogs
– Treprostinil (SQ)
– Iloprost (inhaled)
– Beraprost
• Inhaled Nitric Oxide• Phosphodiesterase inhibitors
– Sildenafil
• Endothelian Receptor Antagonists (ET1 potent vasoconstrictor)– Bosentan (ET-A&B)
– Sitaxsentan (ET-A)
– Ambrisentan (ET-A)
• L-arginine • Combination therapy
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Prostacycline
• Potent vasodilator produced in endothelial and smooth-muscle cells
• Antiproliferative and antiplatelet effects• Improvement in survival well documented
compared to historical controls• Efficacy in Rx of portopulmonary HTN
– Therapeutic bridge to liver Tx
• Central venous catheter administration• Side-effects: flushing, HA, jaw pain, leg pain,
diarrhea, nausea
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Inhaled NO
• Endogenous endothelium derived vasodilator
• Directly relaxes vascular smooth muscle by inc. cGMP
• Variable response in pts with liver dz– Inc. levels of endogenous NO in liver dz
• Utility in predicting acute hemodynamic responsiveness
• Continuous inhalation device
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Phosphodiesterasse Inhibitors
• Improve pulmonary hemodynamics by enhancing endogenous NO effects by inhibiting the breakdown of cGMP
• Sildenafil: PDE type-5 inhibitor
• Dosage adjustments necessary in cirrhotics because of extensive hepatic metabolism
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Entothelin Receptor Antagonists
• Increased conc of ET-1 found in the plasma and lung tissue of pts with PAH
• Bosentan competitive inhibitor of ET A and B receptors
• Sitaxsentan selective ET-A
• Ambrisentan selective ET-A
• Limited use: hepatotoxicity
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L-arginine
• Endothelial derived vasodilation predominates over direct smooth muscle cell constriction
• EDRF produced by intact endothelium
• EDRF mediates Ach vasodilation
• EDRF is the NO radical derived from L-arginine
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
Vasodilator Agonists:
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PAH out of proportion of Left Heart Disease
• Definition:– Severely elevated PAP >35-40mmHG– PCWP or LVEDP <22 mmHG and– TPG >18-20
• Treatment– Main concern in treating with pts with elevated
LVEDP/CPWP with pulmonary vasodilators is an inc. in CO and venous return to the LV -> pulmonary edema
– Few studies looking and pulmonary vasodilators in DD– Optimize diuretics, nitrates, HR control– DO NOT use pulmonary vasodilators if PCWP or
LVEDP >16mmHG
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Postoperative Acute Right Heart Failure
• Inc CO seen in 5-18% after reperfusion of the new graft
• If there is resistance of PBF then pressure must increase
• This leads to systemic increases in PAPs• Leading to acute right ventricular failure• Increase in CO is unpredicatable therefore reduce
mPAP to a MILD level• Mechanism:
– Removal of the obstruction to portal flow, systemic vasodilation via washout of acid metabolites and other vasodilator substances from the new graft
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Portopulmonary Hypertension(Summary)
• Classification– mPAP 25-30 MILD
– mPAP >35-40 MODERATE
– MPAP >45 SEVERE
• PVR >240 dynes.sec.cm-5 (>120)• Management mPAP >35
– Determine cause• Volume overload -> Rx (effective with normal LV function) -> Tx • Poor cardiac function and elevated filling pressures -> ionotropic
agents if no improvement -> no Tx• PVR low, LV function hyperdynamic -> Tx
– If mPAP and PVR remain elevated - survial depends on RV function and the stressors applied during the perioperative period
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Pretransplantation issues with Portopulmonary Hypertension
• Does the degree of PAH warrant therapy before OLT is attempted?– mPAP <35 mmHG
• What therapy should be selected?– No studies address which agent is efficacious and safe
– IV epoprostenol (concerns with thrombycytopenia and splenomegaly), other prostacyclin analogues, silfandil
– MD experience, drug availability and safety concerns
• What pulmonary hemodynamic goals will facilitate a safe OLT– mPAP 35-50 with PVR 240-400, 50% perioperative mortality
– mPAP >50 exclude OLT at most centers
– Repeat doppler echos annually
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High Risk Pulmonary Hemodynamic Profile
Krowka, Liver Tranplantation2000
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Mayo Clinic Intra-op Guidelines(Guidelines for Canceling Surgery)
Krowka, Liver Tranplantation2000