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Treatment of PAH Associated with IPF/SSc. Dr.Özlem Özdemir Kumbasar. Clinical Classification of Pulmonary Hypertension. 1-Pulmonary arterial hypertension 2-Pulmonary hypertension associated with left heart diseases 3-Pulmonary hypertension associated with respiratory diseases and/or hypoxia
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Treatment of PAH Associated with IPF/SSc Dr.Özlem Özdemir Kumbasar
Clinical Classification of Pulmonary Hypertension • 1-Pulmonary arterial hypertension • 2-Pulmonary hypertension associated with left heart diseases • 3-Pulmonary hypertension associated with respiratory diseases and/or hypoxia • 4-Pulmonary hypertension due to chronic thrombotic and/or embolic disease • 5-Miscellaneaus
1.Pulmonary Arterial Hypertension • 1.1.Idiopathic • 1.2.Familial • 1.3.Associated with • 1.3.1.Connective tissue diseases • 1.3.2.Congenital systemic to pulmonary shunts • 1.3.3.Portal hypertension • 1.3.4.HIV infection • 1.3.5.Drugs and toxins • 1.3.6.Other (tyroid disorders, hematological problems….) • 1.4.Associated with significant venous or capillary involvement • 1.5.Persistant pulmonary hypertension of the newborn
3.Pulmonary hypertension associated with respiratory diseases and/or hypoxia • 3.1.Chronic obstructive pulmonary diseases • 3.2.Interstitial lung diseases • 3.3.Sleep disordered breathing • 3.4.Alveolar hypoventilation disorders • 3.5.Chronic exposure to high altitude • 3.6.Developmental abnormalities
Systemic sclerosis-Scleroderma • American Rheumatism Association (American College of Rheumatology): Major criterion or two or more minor criterion • Major criterion: symmetrical thickening, thightening and induration of the skin of the fingers and skin proximal to the metacarpophalangeal, or metatarsophalengeal joints • Minor criteria: • Sclerodactily: the changes of the major criterion, but limited to the fingers • Digital pitting scars or loss of substance from the finger pad: depressed areas at tips of fingers or loss of digital pad tissue as a result of ischemia • Bibasilar pulmonary fibrosis
SSc has two subgroups according to the extent of skin involvement: • Diffuse SSc-dSSc • Limited SSc-lSSc
Pulmonary manifestations of scleroderma • Most common manifestations: • Interstitial lung disease • Pulmonary hypertension • Others: • Pleural disease • Chronic aspiration • Airway disease • Lung cancer • Extrinsic restriction
PH in SSc • ILD hypoxemia PH • ILD+PH (PH out of proportion to the degree of fibrosis) • Isolated PH • Myocardial inflammation and fibrosis left and right ventricular disfunction PH -PH due to unrelated lung disease (COPD, CTEPH)
PAH is a leading cause of mortality in SSC. • SSc-associated PAH has got a worse prognosis than idiopathic PAH. • PAH related to SSc is common but its true prevelance is not known (4.9-38%)
Risk factors for PAH in SSc • Genetic???: HLA-B*13; HLA-B*65 • Increased age of SSc onset; postmenopausal age • Severe Raynaud phenomenon and digital tip ulcers • Absence of anti-Scl-70 • Predominance of nucleolar auto-antibodies
A decrease of DLCO during the early stages of the disease is a predictor of subsequent development of PAH during the course of SSc.
Pathogenesis • Pathogenesis of SSc-PAH resemble those of iPAH: • Endothelial injury dysfunction activated myofibroblasts • Overproduction of endothelin • Decreased production of vasodilators • Vascular smooth muscle cell proliferation and hypertrophy • Inflammation and adventitial fibrosis in medium sized to small sized pulmonary arteries • Vasoconstriction and hypertrophic changes increased pulmonary vascular resistance
Clinical features • Symptoms are often nonspecific: • dyspnea • fatigue • chest pain • syncope • In the early stages symptoms are evident only on exertion.
Diagnosis-baseline • History • Examination • Blood tests • Autoantibodies • Chest x-ray • PFT (spirometry, DLCO, ABG) • Doppler Echo
Scleroderma patient with respiratory symptoms • PFT : spirometry, DLCO, ABG • Isolated reduction in DLCO or a proggressive decline in DLCO suggest PAH • A ratio of percentage of predicted FVC and the percentage of predicted DLCO >1.4 is a predictor of PAH; and a value >2 predicts worse survival. • Normal PFT results do not rule out PAH. Serial DLCO testing has been recommended
Doppler Echo • sPAP>35mmHg ? - >40mmHg • N-terminal proBNP • CT-pericardial disease, main pA daimeter >29mm • Right heart catheterization-gold standard
Treatment • Patients with combined PAH and diastolic dysfunction and/or interstitial lung disease are often exclude from clinical trials. Therefore it is not known how best to treat them. • Treatment may be complicated with worsening hypoxemia due to increased ventilation-perfusion mismatch or pulmonary edema in patients with severe honeycombing or diastolic dysfunction.
Treatment • There are no specific guidelines for the treatment of SSc-PAH. • Treatment guidelines for iPAH cover PAH associated with connective tissue diseases; most experts use these recommendations.
Treatment • All patients with documented hypoxemia should be on supplemental oxygen to maintain SaO2 above 90%. • Patients with evidence of right ventricular failure should be given diuretics. • Oral anticoagulant- can be given if complication risk is low. Bleeding complications are more frequent in SSc.
Treatment • CCB: • Less than 10% of patients with iPAH are true responders to high dose calcium channel blokers. • Even fewer patients with SSc-PAH are true responders. • Acute vasoreactivity testing for Patients with SSc-PAH (weak recommendation based on expert opinion only)
Treatment • PAH specific agents: • Prostanoids • Endothelin antagonists • Phosphodiesterase inhibitors
Treatment • Prostanoids: • Epoprostenol: • Continuous iv epoprostenol improved exercise capacity, symptoms and hemodynamics in patients with SSc-PAH, in a multicenter, randomised, controlled, open label study . A survival advantage was not demonstrated.
Treatment • Prostanoids: • Treprostinil: • Sc infusion of treprostinil improved symptoms, exercise capacity and hemodynamics in patients with CTD related PAH • Inhaled iloprost: • Inhaled iloprost trial included patients with CTD, but subgroup analysis for thie group was not reported.
Treatment • Endothelin antagonists: • Bosentan: • It is approved for the treatment of iPAH and CTD-PAH. • Bosentan prevented walk distance deterioration in patients with SSc when compared with placebo. But exercise improvement was less marked than that seen in iPAH population.
Treatment • Bosentan: • In a retrospective single center study of iPAH and SSc-PAH patients, firs-line bosentan monotherapy was associated with long term improvement in functional class and good overall survival in patients with class III iPAH. Bur SSc-PAH patients showed stability or decline in functional class and tended to have a higher mortality. • In a second retrospective study of SSc-PAH patients bosentan was associated with an early improvement in functional class, but this benefit was lost after 9 months.
Treatment • Efficacy of selective ETA receptor antagonists sitaxsentan and ambrisentan in SSc-PAH patients remains to be determined
Treatment • Phosphodiesterase inhibitors: • Sildenafil: • In a randomised, double-blind, placebo controlled study of 278 patients with PAH sildenafil improved exercise capacity, functional class and hemodynamics. 30% of these patients had CTD, mainly SSc; but subgroup analysis was not reported.
PAH is a leading cause of mortality in patients with SSc. • In the current treatment era, 1 year survival for patients with SSc-PAH improved from 68 to 81%; and 2 year survival from 47 to 71%. • But SSc-PAH is associated with a poorer response to therapy and worse outcome when compared with iPAH.
Idiopathic Pulmonary Fibrosis • IPF has a poor prognosis. • Median survival is 2-5 years. • Mortality is usually related to progressive restriction or acute exacerbations. • PH may complicate the course of IPF and potentially impact prognosis.
Prognostic factors in IPF • 10% decrements in FVC • Exercise capacity • 6 MW distance • Desaturation during 6 MWT • PH
PH in IPF • Prevalence: 32-85% • Serial progression in PAP • Retrospective studies: • Initial prevelance: 33-41% • Follow-up prevalence:85-90%
PH in IPF • Lung volumes PH • Exercise capacity PH • Interstitial remodeling • Vascular remodeling • Down-regulation of prostanoid synthases in the interstitium and pulonary arteries of patients with IPF??? • IPF lungs show increased ET-1 and ET converting enzyme as compared with normal lungs • PDGF • TGF-beta
PH in IPF • Presence of PH correlated with lower DLCO and requirement for supplemental oxygen. • PH appears to be an important prognostic factor in IPF. • sPAP>50mmHg was found correlated with poorer survival. • Patients with mean PAP>35 had 1.5 fold increased post lung transplant mortality.
Treatment • Supplemental oxygen-beneficial effects on survival? • CCB-no role • Anticoagulation-better outcomes with long term anticoagulation??
Treatment • Bosentan • BUILD-1:A randomized placebo controlled trial of bosentan in idiopathic pulmonary fibrosis • No improvment over placebo with respect to 6MWD • A trend to delayed time to death or disease progression • Patients with echocardiographic evidence of severe PH (sPAP>50) were excluded.
Treatment • iv epoprostenol: • Decreases mPAP but increases pulmonary shunt flow • Current data do not support the use of iv epoprostenol in PH related to IPF
Treatment • Inhaled iloprost • Decreases mPAP without changes in shunt flow in patients with PH related to lung fibrosis. (8 patients, only one of them IPF). • Inhaled iloprost in IPF+PH-this study was completed (www.clinicaltrials.gov) Results?
Treatment • Sildenafil • A sigle dose of sildenafil decreased mPAP and shunt flow • A study with 14 patients: sildenafil improved 6MWD
Treatment • There are potential therapies: Et antagonists, inhaled prostanoids, phosphodiesterase inhibitors • But long term randomized, controlled trials are necessary to make strict conclusions. • Supplemental oxygen (when necessary) the most important therapy according to current data.