Localized versus systemic granulomatosis with polyangiitis: data from the French Vasculitis Study Group Registry.

OBJECTIVE: To describe the main features at diagnosis and evolution over time of patients with localized granulomatosis with polyangiitis (L-GPA) compared with those of systemic GPA (S-GPA). METHODS: EULAR definitions of L-GPA, i.e. upper and/or lower respiratory tract involvement, and S-GPA were applied to patients from the French Vasculitis Study Group Registry. L-GPA and S-GPA patients' characteristics at diagnosis and long-term outcomes were analysed and compared. RESULTS: Among the 795 Registry patients, 79 (10%) had L-GPA. Their main clinical manifestations were rhinitis, lung nodules, sinusitis and otitis. L-GPA vs S-GPA patients at diagnosis, respectively, were younger, more frequently had saddle nose deformity or subglottic stenosis and were less often PR3-ANCA-positive. L-GPA vs S-GPA induction therapy less frequently included CYC but more often a combination of MTX and glucocorticoids; 64% of MTX-treated patients experienced disease progression within 18 months post-diagnosis. L- and S-GPA patients' estimated relapse-free-survival probabilities, relapse rates and refractory disease rates at each time point were comparable, but L-GPA patients had more frequent ENT and lung relapses, and higher overall survival rates (P<0.02). Over a median follow-up of 3.5 years, 18 (22.8%) L-GPA progressed to S-GPA, either as a relapse after a period in remission or more frequently in the context of refractory disease. L-GPA patients experienced more ENT-related damage. CONCLUSIONS: The relapse risks of L-GPA and S-GPA were similar, but relapse patterns differed and L-GPA overall survival rate was higher. About one-quarter of L-GPA patients developed S-GPA over time, but without end-stage organ involvement.

Microscopic polyangiitis: Clinical characteristics and long-term outcomes of 378 patients from the French Vasculitis Study Group Registry.

OBJECTIVE: To describe characteristics and long-term outcomes of patients with microscopic polyangiitis (MPA), an antineutrophil cytoplasm antibody (ANCA)-associated small-vessel necrotizing vasculitis. METHODS: MPA patients from the French Vasculitis Study Group Registry satisfying the European Medicines Agency algorithm were analyzed retrospectively. Characteristics at diagnosis, treatments, relapses and deaths were analyzed to identify factors predictive of death or relapse. RESULTS: Between 1966 and 2017, 378 MPA patients (median age 63.7 years) were diagnosed and followed for a mean of 5.5 years. At diagnosis, the main clinical manifestations included renal involvement (74%), arthralgias (45%), skin (41%), lung (40%) and mononeuritis multiplex (32%), with less frequent alveolar hemorrhage (16%), cardiomyopathy (5%) and severe gastrointestinal signs (4%); mean serum creatinine was 217 µmol/L. ANCA were detected in 298/347 (86%) patients by immunofluorescence and/or enzyme-linked immunosorbent assay (ELISA). Among the 293 patients with available ELISA specificities, 272 (92.8%) recognized myeloperoxidase and 13 (4.4%) proteinase-3. During follow-up, 131 (34.7%) patients relapsed and 78 (20.6%) died, mainly from infections. Respective 5-year overall and relapse-free survival rates were 84.2% and 60.4%. Multivariable analyses retained age >65 years, creatinine >130 µmol/L, severe gastrointestinal involvement and mononeuritis multiplex as independent risk factors for death. Renal impairment was associated with a lower risk of relapse. CONCLUSION: Non-renal manifestations and several risk factors for death or relapse were frequent in this nationwide cohort. While mortality was low, and mainly due to treatment-related complications, relapses remained frequent, suggesting that MPA management can be further improved.

Long-term efficacy of remission-maintenance regimens for ANCA-associated vasculitides.

OBJECTIVE: To compare long-term efficacy of remission-maintenance regimens in patients with newly diagnosed or relapsing antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitides. METHODS: The 28-month Maintenance of Remission using Rituximab in Systemic ANCA-associated Vasculitis trial compared rituximab with azathioprine to maintain remission in patients with newly diagnosed or relapsing granulomatosis with polyangiitis, microscopic polyangiitis or renal-limited ANCA-associated vasculitis. Thereafter, prospective patient follow-up lasted until month 60. The primary endpoint was the major-relapse rate at month 60. Relapse and serious adverse event-free survival were also assessed. RESULTS: Among the 115 enrolled patients, only one was lost to follow-up at month 60. For the azathioprine and rituximab groups, respectively, at month 60, the major relapse-free survival rates were 49.4% (95% CI 38.0% to 64.3%) and 71.9% (95% CI 61.2% to 84.6%) (p=0.003); minor and major relapse-free survival rates were 37.2% (95% CI 26.5% to 52.2%) and 57.9% (95% CI 46.4% to 72.2%) (p=0.012); overall survival rates were 93.0% (95% CI 86.7% to 99.9%) and 100% (p=0.045) and cumulative glucocorticoid use was comparable. Quality-adjusted time without symptoms and toxicity analysis showed that rituximab-treated patients had 12.6 months more without relapse or toxicity than those given azathioprine (p<0.001). Antiproteinase-3-ANCA positivity and azathioprine arm were independently associated with higher risk of relapse. HRs of positive ANCA to predict relapse increased over time. CONCLUSION: The rate of sustained remission for ANCA-associated vasculitis patients, following rituximab-based or azathioprine-based maintenance regimens, remained superior over 60 months with rituximab, with better overall survival. TRIAL REGISTRATION NUMBER: NCT00748644.

Pulmonary arteriovenous malformations in hereditary haemorrhagic telangiectasia: Correlations between computed tomography findings and cerebral complications.

OBJECTIVES: Computed tomography (CT) is the modality of choice to characterise pulmonary arteriovenous malformations (PAVMs) in patients with hereditary haemorrhagic telangiectasia (HHT). Our objective was to determine if CT findings were associated with frequency of brain abscess and ischaemic stroke. METHODS: This retrospective study included patients with HHT-related PAVMs. CT results, i.e. PAVM presentation (unique, multiple, disseminated or diffuse), the number of PAVMs and the largest feeding artery size, were correlated to prevalence of ischaemic stroke and brain abscess. All CTs were reviewed in consensus by two radiologists. RESULTS: Of 170 patients, 73 patients had unique (42.9 %), 49 multiple (28.8 %), 36 disseminated (21.2 %) and 12 diffuse (7.1 %) PAVMs. Fifteen patients presented with brain abscess; 26 patients presented with ischaemic stroke. The number of PAVMs was significantly correlated with brain abscess (11.5 vs. 6.2, respectively; p=0.025). The mean diameter of the largest feeding artery was significantly correlated with ischaemic stroke frequency (4.9 vs. 3.2 mm, respectively; p=0.0098). CONCLUSIONS: The number of PAVMs correlated significantly with risk of brain abscess, and a larger feeding artery significantly with more ischaemic strokes. These findings can lead to a better recognition and management of the PAVMs at risk of cerebral complications. KEY POINTS: • Chest CT helps clinicians to facilitate appropriate PAVM management strategies. • Pulmonary arteriovenous malformation CT findings are correlated with risk of cerebral complications. • Risk of brain abscess is significantly correlated with number of PAVMs. • Risk of ischaemic stroke is significantly correlated with large feeding artery PAVMs. • Prevalence of observed of brain abscess and ischaemic stroke is 26 %.

Rituximab versus azathioprine for maintenance in ANCA-associated vasculitis.

BACKGROUND: The combination of cyclophosphamide and glucocorticoids leads to remission in most patients with antineutrophil cytoplasm antibody (ANCA)-associated vasculitides. However, even when patients receive maintenance treatment with azathioprine or methotrexate, the relapse rate remains high. Rituximab may help to maintain remission. METHODS: Patients with newly diagnosed or relapsing granulomatosis with polyangiitis, microscopic polyangiitis, or renal-limited ANCA-associated vasculitis in complete remission after a cyclophosphamide-glucocorticoid regimen were randomly assigned to receive either 500 mg of rituximab on days 0 and 14 and at months 6, 12, and 18 after study entry or daily azathioprine until month 22. The primary end point at month 28 was the rate of major relapse (the reappearance of disease activity or worsening, with a Birmingham Vasculitis Activity Score >0, and involvement of one or more major organs, disease-related life-threatening events, or both). RESULTS: The 115 enrolled patients (87 with granulomatosis with polyangiitis, 23 with microscopic polyangiitis, and 5 with renal-limited ANCA-associated vasculitis) received azathioprine (58 patients) or rituximab (57 patients). At month 28, major relapse had occurred in 17 patients in the azathioprine group (29%) and in 3 patients in the rituximab group (5%) (hazard ratio for relapse, 6.61; 95% confidence interval, 1.56 to 27.96; P=0.002). The frequencies of severe adverse events were similar in the two groups. Twenty-five patients in each group (P=0.92) had severe adverse events; there were 44 events in the azathioprine group and 45 in the rituximab group. Eight patients in the azathioprine group and 11 in the rituximab group had severe infections, and cancer developed in 2 patients in the azathioprine group and 1 in the rituximab group. Two patients in the azathioprine group died (1 from sepsis and 1 from pancreatic cancer). CONCLUSIONS: More patients with ANCA-associated vasculitides had sustained remission at month 28 with rituximab than with azathioprine. (Funded by the French Ministry of Health; MAINRITSAN ClinicalTrials.gov number, NCT00748644; EudraCT number, 2008-002846-51.).

Respiratory manifestations of eosinophilic granulomatosis with polyangiitis (Churg-Strauss).

The respiratory manifestations of eosinophilic granulomatosis with polyangiitis (EGPA) have not been studied in detail.In this retrospective multicentre study, EGPA was defined by asthma, eosinophilia and at least one new onset extra-bronchopulmonary organ manifestation of disease.The study population included 157 patients (mean±sd age 49.4±14.1 years), with a mean±sd blood eosinophil count of 7.4±6.4×109 L-1 at diagnosis. There was a mean±sd of 11.8±18.2 years from the onset of asthma to the diagnosis of EGPA, of 1.4±8.4 years from the first onset of peripheral eosinophilia to the diagnosis of EGPA, and of 7.4±6.4 years from EGPA diagnosis to the final visit. Despite inhaled and oral corticosteroid treatment, the severity of asthma increased 3-6 months before the onset of the systemic manifestations. Asthma was severe in 57%, 48%, and 56% of patients at diagnosis, at 3 years, and at the final visit, respectively. Persistent airflow obstruction was present in 38%, 30%, and 46% at diagnosis, at 3 years, and at the final visit, respectively.In EGPA, asthma is severe, antedates systemic manifestations by a mean of 12 years, and progresses to long-term persistent airflow obstruction despite corticosteroids in a large proportion of patients, which affects long-term management and morbidity.

Rituximab versus azathioprine for ANCA-associated vasculitis maintenance therapy: impact on global disability and health-related quality of life.

OBJECTIVES: To investigate the effects on health-related quality of life (HRQOL) and functional capability of rituximab vs azathioprine for ANCA-associated vasculitis (AAV) maintenance therapy. METHODS: In a 24-month phase III randomised-controlled trial, 115 patients over time received rituximab or azathioprine for AAV maintenance therapy. Mean changes of 36-item Short-form Health Survey (SF-36) and Health Assessment Questionnaire (HAQ) scores from baseline were analysed. RESULTS: Mean improvements of HAQ scores, from baseline to month 24 were significantly better for the rituximab (0.16 points lower) than the azathioprine group (p=0.038). As demonstrated by SF-36, study patients' baseline HRQOL was significantly impaired compared with age- and sex-matched US norms. At month 24, mean changes from baseline of SF-36 physical component score tended to be better for the rituximab group (+3.95 points, p=0.067) whereas mean changes from baseline of the SF-36 mental component score were significantly better for the azathioprine group (+4.23 points, p=0.041). CONCLUSIONS: Azathioprine-treated patients' for AAV maintenance therapy showed a decline in physical abilities when compared to RTX at M24 in the MAINRITSAN trial. TRIAL REGISTRATION: ClinicalTrials.gov, http://clinicaltrials.gov/, NCT00748644.

Risk of Direct Oral Anticoagulant Bioaccumulation in Patients with Pulmonary Hypertension.

BACKGROUND: Patients treated for pulmonary arterial hypertension (PAH) frequently receive vitamin K antagonists (VKAs) for PAH or validated indications (such as atrial fibrillation or venous thromboembolism). In these latter indications, VKAs are challenged by direct oral anticoagulants (DOAs). Decreased dosage of DOAs has been proposed in patients at risk of bioaccumulation. OBJECTIVES: We aimed to evaluate the frequency of bioaccumulation risks in patients treated with PAH-targeted therapy, particularly regarding the presence of validated indications. METHODS: We conducted a retrospective study in three different PAH referral centers. All patients receiving PAH-targeted therapy were classified according to demographics, prescription and indications of VKAs, and the presence of major bioaccumulation risk factors (renal failure, low body weight, strong P-glycoprotein or cytochrome P3A4 inhibitors). RESULTS: Two hundred and thirty-nine of the 366 patients included received VKAs, 94 for validated indications. At least one major risk factor was found in 231 (63.1%) of the whole study population, and in 54 (57.4%) of the patients anticoagulated for a validated indication. No specific patient phenotype could be individualized. CONCLUSIONS: About 1 in 2 patients treated with PAH therapy has at least one of the three major risk factors for DOA bioaccumulation. DOAs in the PH setting could be associated with bioaccumulation and should be individualized, mainly in patients with confirmed indication.

Prognostic value of right ventricular ejection fraction in pulmonary arterial hypertension.

Right ventricle ejection fraction (RVEF) evaluated with magnetic resonance imaging is a strong determinant of patient outcomes in pulmonary arterial hypertension. We evaluated the prognostic value of RVEF assessed with conventional planar equilibrium radionuclide angiography at baseline and change 3-6 months after initiating pulmonary arterial hypertension-specific therapy. In a prospective cohort of newly diagnosed patients with idiopathic, heritable or anorexigen-associated pulmonary arterial hypertension, RVEF was measured at baseline (n=100) and 3-6 months after initiation of therapy (n=78). After a median follow-up of 4.1 years, 41 deaths occurred, including 35 from cardiovascular causes. Patients with a (median) baseline RVEF >25% had better survival than those with a RVEF <25% using Kaplan-Meier analysis (p=0.010). RVEF at baseline was an independent predictor of all-cause and cardiovascular mortality in adjusted Cox regression model (p=0.002 and p=0.007, respectively; HR 0.93 for both). Patients with stable or increased RVEF at 3-6 months had a trend for improved all-cause survival (HR 2.43, p=0.086) and had less cardiovascular mortality (HR 3.25, p=0.034) than those in whom RVEF decreased despite therapy. RVEF assessed with conventional planar equilibrium radionuclide angiography at baseline and change in RVEF 3-6 months after therapy initiation independently predict outcomes in patients with pulmonary arterial hypertension.

Severe pulmonary hypertension associated with COPD: hemodynamic improvement with specific therapy.

BACKGROUND: There is no recommendation for treating pulmonary hypertension (PH) when associated with chronic obstructive pulmonary disease (COPD). OBJECTIVE: To evaluate the effect of PH-specific therapy in patients with COPD. METHODS: All successive patients with severe PH [mean pulmonary arterial pressure (mPAP) ≥35 mm Hg] and COPD, who received specific PH medication and who underwent right heart catheterization at baseline and after 3-12 months of treatment, were analyzed from a prospective database. RESULTS: Twenty-six patients were included with a median follow-up of 14 months. Mean forced expiratory volume in 1 s was 57 ± 20% of predicted, and mean forced expiratory volume in 1 s/forced vital capacity was 47 ± 12%. Dyspnea was New York Health Association classification stage (NYHA) II in 15%, NYHA III in 81% and NYHA IV in 4%. First-line treatments were endothelin receptor antagonists in 11 patients, phosphodiesterase-5 inhibitors in 11 patients, calcium blocker in 1 patient, combination therapy in 3 patients including 2 with a prostanoid. After 6 ± 3 months, pulmonary vascular resistance decreased from 8.5 ± 3 to 6.6 ± 2 Wood units (p < 0.001), with significant improvement of cardiac index from 2.44 ± 0.43 to 2.68 ± 0.63 liters × min × m-2 (p = 0.015) and mPAP from 48 ± 9 to 42 ± 10 mm Hg (p = 0.008). There was no significant difference in dyspnea, 6-min walking distance, echocardiographic parameters or N-terminal pro-brain natriuretic peptide levels. There was no significant difference in arterial oxygen saturation after 3-12 months of treatment. CONCLUSIONS: Specific PH medications may improve hemodynamic parameters in COPD patients with severe PH. Appropriate prospective randomized studies are needed to evaluate the potential long-term clinical benefit of treatment.

Hypereosinophilic obliterative bronchiolitis: a distinct, unrecognised syndrome.

Biopsy-proven cases of eosinophilic bronchiolitis have only been reported in isolation, and all come from Japan. We present six patients with hypereosinophilic obliterative bronchiolitis (HOB), defined by the following criteria: 1) blood eosinophil cell count >1 G·L(-1) and/or bronchoalveolar lavage eosinophil count >25%; 2) persistent airflow obstruction despite high-dose inhaled bronchodilators and corticosteroids; and 3) eosinophilic bronchiolitis at lung biopsy (n=1) and/or direct signs of bronchiolitis (centrilobular nodules and branching opacities) on computed tomography (n=6). Chronic dyspnoea and cough which was often severe, without the characteristic features of asthma, were the main clinical manifestations. Atopy and asthma were present in the history of three and two patients, respectively. One patient met biological criteria of the lymphoid variant of idiopathic hypereosinophilic syndrome. Mean blood eosinophil cell count was 2.7 G·L(-1) and mean eosinophil differential percentage at bronchoalveolar lavage was 63%. Mean initial forced expiratory volume in 1 s/forced vital capacity ratio was 50%, normalising with oral corticosteroid therapy in all patients. HOB manifestations recurred when oral prednisone was decreased to 10-20 mg·day(-1), but higher doses controlled the disease. HOB is a characteristic entity deserving to be individualised among the eosinophilic respiratory disorders. Thorough analysis is needed to determine whether unrecognised and/or smouldering HOB may further be a cause of irreversible airflow obstruction in chronic eosinophilic respiratory diseases.

Churg-Strauss syndrome presenting with acute myocarditis and cardiogenic shock.

Churg-Strauss syndrome (CSS) is a multisystem disorder characterised by asthma, prominent peripheral blood eosinophilia, and vasculitis signs. We report the case of a 22 year-old man admitted to the intensive care unit for acute myocarditis complicated with cardiogenic shock. Eosinophilia, history of asthma, lung infiltrates, paranasal sinusitis, glomerulonephritis, and abdominal pain suggested the diagnosis of CSS. Cardiac MRI confirmed cardiac involvement with a diffuse subendocardial delayed enhancement of the left ventricular wall, and a left ventricular ejection fraction (LVEF) of 30%. Acute myocarditis was confirmed with myocardial biopsy. The patient was successfully treated with systemic corticosteroids, intravenous cyclophosphamide, vasopressor inotropes, intra-aortic balloon pump and mechanical ventilation, and was discharged 21 days later. One year after diagnosis, the patient was asymptomatic. The eosinophilic cell count was normal. Follow-up MRI at one year showed LVEF of 40% with persistent delayed enhancement. Cardiac involvement by CSS requires immediate therapy with corticosteroids and cyclophosphamide, which may allow recovery of the cardiac function.

Comparative study of granulomatosis with polyangiitis subsets according to ANCA status: data from the French Vasculitis Study Group Registry.

OBJECTIVE: To investigate whether antineutrophil cytoplasm antibody (ANCA)-negative and myeloperoxidase (MPO)-ANCA-positive granulomatosis with polyangiitis (GPA) differ from proteinase-3 (PR3)-ANCA-positive GPA. METHODS: Diagnostic characteristics and outcomes of newly diagnosed French Vasculitis Study Group Registry patients with ANCA-negative, MPO-ANCA-positive or PR3-ANCA-positive GPA satisfying American College of Rheumatology criteria and/or Chapel Hill Conference Consensus Nomenclature were compared. RESULTS: Among 727 GPA, 62 (8.5%) were ANCA-negative, 119 (16.4%) MPO-ANCA-positive and 546 (75.1%) PR3-ANCA-positive. ANCA-negative patients had significantly (p<0.05) more limited disease (17.7% vs 5.8%) and less kidney involvement (35.5% vs 58.9%) than those PR3-ANCA-positive or MPO-ANCA-positive, with comparable relapse-free (RFS) and overall survival (OS). MPO-ANCA-positive versus PR3-ANCA-positive and ANCA-negative patients were significantly more often female (52.9% vs 42.1%), older (59.8 vs 51.9 years), with more frequent kidney involvement (65.5% vs 55.2%) and less arthralgias (34.5% vs 55.1%), purpura (8.4% vs 17.1%) or eye involvement (18.5% vs 28.4%); RFS was similar but OS was lower before age adjustment. PR3-positive patients' RFS was significantly lower than for ANCA-negative and MPO-positive groups combined, with OS higher before age adjustment. PR3-ANCA-positivity independently predicted relapse for all GPA forms combined but not when comparing only PR3-ANCA-positive versus MPO-ANCA-positive patients. CONCLUSIONS: Based on this large cohort, ANCA-negative versus ANCA-positive patients more frequently had limited disease but similar RFS and OS. MPO-ANCA-positive patients had similar RFS but lower OS due to their older age. PR3-ANCA-positive GPA patients' RFS was lower than those of the two other subsets combined but that difference did not persist when comparing only PR3 versus MPO-ANCA-positive patients.

Granulomatosis with polyangiitis: Study of 795 patients from the French Vasculitis Study Group registry.

OBJECTIVE: To describe the characteristics and long-term outcomes of patients with granulomatosis with polyangiitis (GPA) from the French Vasculitis Study Group database. METHODS: Patients' clinical and laboratory characteristics, Birmingham Vasculitis Activity Score (BVAS)-assessed disease activity, malignancies, opportunistic infections, and vital status were collected at diagnosis and each visit. Estimated probabilities and predictors of overall (OS) and relapse-free survival (RFS) were analyzed by Cox regression. RESULTS: We enrolled 795 newly diagnosed patients, followed for a median of 3.5 years. Initial clinical manifestations involved ear, nose & throat (ENT; 80%), lungs (68%) and kidneys (56%). Among the 728 available ELISA results, 75.0% were PR3-ANCA-positive, 16.5% MPO-ANCA-positive and 62 (8.5%) ANCA-negative. Relapses occurred in 394 (50%) patients, involving ≥1 organ(s) affected at onset in 179 (46%), mainly ENT, lungs and kidneys, with mean BVAS 10.2 points below that at diagnosis (p<0.001). Five- and 10-year RFS rates were 37% and 17%, respectively. PR3-ANCA-positivity independently predicted relapse (p = 0.05) and prolonged survival (p = 0.038). OS-but not RFS-improved significantly over time (p<0.001); 10-year OS reached 88.2% (95% CI 83.9 to 92.7) for the 660 patients diagnosed after 2000. Infections were the main causes of death. Malignancy or opportunistic infection each occurred in ≤5% of the patients. CONCLUSION: Survival has improved dramatically over the last decades but the high relapse rate remains a major concern for GPA patients, once again stressing the need for therapeutic strategy optimization to lower it. PR3-ANCA-positivity was associated with increased probability of relapse and survival.

4D time-resolved magnetic resonance angiography for noninvasive assessment of pulmonary arteriovenous malformations patency.

PURPOSE: To assess the capability of four-dimensional (4D) time-resolved magnetic resonance angiography (MRA) to assess pulmonary arteriovenous malformations (PAVMs) patency by analyzing pulmonary arterial and venous enhancement kinetics. MATERIALS AND METHODS: Seven patients with eight documented patent PAVMs underwent a 4D-MRA with keyhole and viewsharing compression at 3T with the following parameters: spatial resolution 0.87 × 0.87 × 1.4 mm(3); field of view 500 × 350 × 238 mm(3); dynamic scan time (temporal resolution) 1.2 seconds; total acquisition time 18.1 seconds for six dynamic datasets (6 × 1.2 sec + reference scan: 10.9 sec). All images were reviewed by two experienced radiologists. Image quality was rated on a qualitative 5-point scale (1: not assessable to 5: excellent). Signal value was measured on cross-sectional planes for the afferent arteries and efferent veins of the PAVM, and for normal reference healthy arteries and veins. The difference in time to peak for each coupled artery/vein (dTTPav) was calculated and compared with a Mann-Whitney test between PAVMs and reference vessels. RESULTS: Mean image quality was 3.2 ± 0.9. dTTPav was significantly smaller in PAVMs (0.15 ± 0.76 sec) than in reference vessels (3.75 ± 1.62 sec), P < 0.001. CONCLUSION: 4D-MRA is a promising tool for noninvasive assessment of PAVM patency.

Right-to-left shunt with hypoxemia in pulmonary hypertension.

BACKGROUND: Hypoxemia is common in pulmonary hypertension (PH) and may be partly related to ventilation/perfusion mismatch, low diffusion capacity, low cardiac output, and/or right-to-left (RL) shunting. METHODS: To determine whether true RL shunting causing hypoxemia is caused by intracardiac shunting, as classically considered, a retrospective single center study was conducted in consecutive patients with precapillary PH, with hypoxemia at rest (PaO2 < 10 kPa), shunt fraction (Qs/Qt) greater than 5%, elevated alveolar-arterial difference of PO2 (AaPO2), and with transthoracic contrast echocardiography performed within 3 months. RESULTS: Among 263 patients with precapillary PH, 34 patients were included: pulmonary arterial hypertension, 21%; PH associated with lung disease, 47% (chronic obstructive pulmonary disease, 23%; interstitial lung disease, 9%; other, 15%); chronic thromboembolic PH, 26%; miscellaneous causes, 6%. Mean pulmonary artery pressure, cardiac index, and pulmonary vascular resistance were 45.8 +/- 10.8 mmHg, 2.2 +/- 0.6 L/min/m2, and 469 +/- 275 dyn.s.cm-5, respectively. PaO2 in room air was 6.8 +/- 1.3 kPa. Qs/Qt was 10.2 +/- 4.2%. AaPO2 under 100% oxygen was 32.5 +/- 12.4 kPa. Positive contrast was present at transthoracic contrast echocardiography in 6/34 (18%) of patients, including only 4/34 (12%) with intracardiac RL shunting. Qs/Qt did not correlate with hemodynamic parameters. Patients' characteristics did not differ according to the result of contrast echocardiography. CONCLUSION: When present in patients with precapillary PH, RL shunting is usually not related to reopening of patent foramen ovale, whatever the etiology of PH.