Claire Dromer

Survival in Patients With Idiopathic, Familial, and Anorexigen-Associated Pulmonary Arterial Hypertension in the Modern Management Era

Background— Novel therapies have recently become available for pulmonary arterial hypertension. We conducted a study to characterize mortality in a multicenter prospective cohort of patients diagnosed with idiopathic, familial, or anorexigen-associated pulmonary arterial hypertension in the modern management era. Methods and Results— Between October 2002 and October 2003, 354 consecutive adult patients with idiopathic, familial, or anorexigen-associated pulmonary arterial hypertension (56 incident and 298 prevalent cases) were prospectively enrolled. Patients were followed up for 3 years, and survival rates were analyzed. For incident cases, estimated survival (95% confidence intervals [CIs]) at 1, 2, and 3 years was 85.7% (95% CI, 76.5 to 94.9), 69.6% (95% CI, 57.6 to 81.6), and 54.9% (95% CI, 41.8 to 68.0), respectively. In a combined analysis population (incident patients and prevalent patients diagnosed within 3 years before study entry; n=190), 1-, 2-, and 3-year survival estimates were 82.9% (95% CI, 72.4 to 95.0), 67.1% (95% CI, 57.1 to 78.8), and 58.2% (95% CI, 49.0 to 69.3), respectively. Individual survival analysis identified the following as significantly and positively associated with survival: female gender, New York Heart Association functional class I/II, greater 6-minute walk distance, lower right atrial pressure, and higher cardiac output. Multivariable analysis showed that being female, having a greater 6-minute walk distance, and exhibiting higher cardiac output were jointly significantly associated with improved survival. Conclusions— In the modern management era, idiopathic, familial, and anorexigen-associated pulmonary arterial hypertension remains a progressive, fatal disease. Mortality is most closely associated with male gender, right ventricular hemodynamic function, and exercise limitation.

Deciphering complement interference in anti-human leukocyte antigen antibody detection with flow beads assays.

Background Anti–human leukocyte antigen (HLA) antibody detection in solid-phase flow beads assays can be quenched by complement activation, but the precise mechanism of this interference is not fully elucidated yet. Methods Using the Luminex flow beads screening assay for detection of anti-HLA antibodies, we analyzed the binding of high concentrations of the pan class I anti-HLA monoclonal antibody W6/32 in neat normal, ethylenediaminetetraacetic acid–treated normal and complement factors C1q, C4/C3, C2, C3, factor B or C5-depleted human sera, using anti-mouse immunoglobulin G as the detection antibody. Complement activation and binding to beads were revealed using anti-human C1q, C4d, and C3d antibodies. To translate our findings to the human setting, we used the class I and class II HLA single-antigen flow beads assays and sera from four patients with high titers of antibodies. Results Detection of W6/32 did not suffer any interference with C1q and C4/C3–depleted sera. A partial quenching was observed with C2, C3, and factor B-depleted sera, but was more pronounced with the factor B-depleted serum. W6/32 was undetectable in presence of C5-depleted serum. The binding of activation products derived from C3 principally, and also from C4, impaired immunoglobulin G and C1q detection. Accordingly, C4d detection was hindered by deposition of activated C3. Similar findings were obtained with patients’ sera. Conclusion Binding of C4 and C3 activation products is the main responsible for complement interference in flow beads assays. A complete quenching requires complement activation through C3 cleavage and its amplification by the alternative pathway.

Dual-energy CT perfusion and angiography in chronic thromboembolic pulmonary hypertension: diagnostic accuracy and concordance with radionuclide scintigraphy

ObjectivesTo evaluate the diagnostic accuracy of dual-energy computed tomography (DECT) perfusion and angiography versus ventilation/perfusion (V/Q) scintigraphy in chronic thromboembolic pulmonary hypertension (CTEPH), and to assess the per-segment concordance rate of DECT and scintigraphy.MethodsForty consecutive patients with proven pulmonary hypertension underwent V/Q scintigraphy and DECT perfusion and angiography. Each imaging technique was assessed for the location of segmental defects. Diagnosis of CTEPH was established when at least one segmental perfusion defect was detected by scintigraphy. Diagnostic accuracy of DECT perfusion and angiography was assessed and compared with scintigraphy. In CTEPH patients, the per-segment concordance between scintigraphy and DECT perfusion/angiography was calculated.ResultsFourteen patients were diagnosed with CTEPH and 26 with other aetiologies. DECT perfusion and angiography correctly identified all CTEPH patients with sensitivity/specificity values of 1/0.92 and 1/0.93, respectively. At a segmental level, DECT perfusion showed moderate agreement (κ = 0.44) with scintigraphy. Agreement between CT angiography and scintigraphy ranged from fair (κ = 0.31) to slight (κ = 0.09) depending on whether completely or partially occlusive patterns were considered, respectively.ConclusionsBoth DECT perfusion and angiography show satisfactory performance for the diagnosis of CTEPH. DECT perfusion is more accurate than angiography at identifying the segmental location of abnormalities.Key Points• Chronic thromboembolic pulmonary hypertension (CTEPH) is potentially treatable by surgery.• Dual-energy computed tomography (DECT) allows angiography and perfusion using a single acquisition.• Both DECT perfusion and angiography showed satisfactory diagnostic performance in CTEPH.• DECT perfusion was more accurate than angiography in identifying segmental abnormalities.

Pulmonary hypertension associated with benfluorex exposure

Benfluorex was marketed in France until 2009, despite its similar pharmacological properties with fenfluramine and its derivatives known to be a cause of pulmonary arterial hypertension (PAH). The aim of this study is to report clinical and haemodynamic characteristics for patients suffering from pulmonary hypertension (PH) associated with benfluorex exposure that had been identified by the French PAH Network. 85 cases of PH associated with benfluorex exposure were identified by the French PAH Network from June 1999 to March 2011. Of these, 70 patients had confirmed pre-capillary PH. The median duration of exposure was 30 months, with a median of 108 months between start of exposure and diagnosis of the pulmonary vascular disease. 33% of all patients also had prior exposure to fenfluramine or dexfenfluramine, and an additional risk factor for PH was identified in 20 (30%) out of 70 patients with pre-capillary PH. A quarter of patients in this current series showed coexisting PH and mild-to-moderate cardiac valve involvement. The results of our study, together with the accumulated data regarding the known toxic effects of fenfluramine and dexfenfluramine, strongly suggest that benfluorex exposure is a potent trigger for PAH.

Lung transplantation for lymphangioleiomyomatosis: the French experience.

Background. Lymphangioleiomyomatosis (LAM) is a rare disease, leading in some cases to end-stage respiratory failure. Lung transplantation (LT) represents a therapeutic option in advanced pulmonary LAM. Methods. We conducted a retrospective multicenter study of 44 patients who underwent LT for LAM at 9 centers in France between 1988 and 2006. Results. All patients were women with a mean age of 41±10 years at LT. There were 34 single-lung transplants and 11 bilateral transplants (one retransplantation). Prior clinical events related to LAM were present in 75% of the patients and previous thoracic surgical procedures were noted in 86.6% of cases. At the latest preoperative evaluation, 30 patients had an obstructive pattern (mean forced expiratory volume in 1 second: 26%±14% of predicted) and 15 had a combined restrictive and obstructive pattern, with a mean KCO=27%±8.8% of predicted, PaO2=52.8±10.4 and PaCO2=42.6±9.8 mm Hg. Intraoperative cardiopulmonary bypass was required in 13 cases. The length of mechanical ventilation was 7.5±12.8 days. The median duration of follow-up was 37 months. The 1, 2, 5, and 10 years survival rates were 79.6%, 74.4%, 64.7%, and 52.4%, respectively. Extensive pleural adhesions were found in 21 patients leading to severe intraoperative hemorrhage. Postoperative LAM-related complications were pneumothorax in the native lung in five patients, chylothorax in six, bronchial dehiscence or stenosis in seven. There were two cases of recurrence of LAM. Conclusion. Despite a high morbidity mainly caused by previous surgical interventions and disease-related complications, LT is a satisfactory therapeutic option for end-stage respiratory failure in LAM.

Pulmonary hypertension in patients with neurofibromatosis type I.

Neurofibromatosis type I (NF1) is a rare genetic disease caused by mutations in the NF1 gene, which codes for tumor suppressor neurofibromin. NF1 is transmitted as an autosomal dominant and fully penetrant trait with no sex predominance. Precapillary pulmonary hypertension (PH) is a severe complication of NF1, initially described in patients with advanced parenchymal lung disease, which may complicate the course of NF1. We conducted this study to describe clinical, functional, radiologic, and hemodynamic characteristics and outcome of patients with NF1-associated PH.We identified 8 new cases of NF1-associated PH in patients carrying a NF1 gene mutation. No bone morphogenic protein receptor 2 (BMPR2) point mutation or large size rearrangements were identified. Seven female patients and 1 male patient were reported, suggesting a possible female predominance. PH occurred late in the course of the disease (median age, 62 yr; range, 53-68 yr). Dyspnea and signs of right heart failure were the major symptoms leading to the diagnosis of PH. At diagnosis, patients had severe hemodynamic impairment with low cardiac index (median, 2.3 L/min per m2; range, 1.9-4.7) and elevated indexed pulmonary vascular resistance (median, 15.1 mm Hg/L/min per m2; range, 4.5-25.9). All patients were in New York Heart Association functional class III with severe exercise limitation (median 6-min walk distance, 180 m; range, 60-375 m). Most patients had associated parenchymal lung disease, but some had no or mild lung involvement with disproportionate pulmonary vascular disease. Overall, the impact of PH therapy was limited and outcomes were poor.In conclusion, PH represents a rare but severe complication of NF1, characterized by female predominance, late onset in the course of NF1, and severe functional and hemodynamic impairment. Because of poor outcome and limited impact of specific PH therapy, eligible patients require early referral for lung transplantation. Further studies are needed to better understand the pathophysiology and the role, if any, of neurofibromin in NF1-associated PH.Abbreviations: 6MWD = 6-minute walk distance, ACVRL1 = activin A receptor type II-like kinase-1, BMPR2 = bone morphogenic protein receptor 2, CI = cardiac index, CT = computed tomography, DLCO = diffusion capacity of carbon monoxide, FEV1 = forced expiratory volume in one second, FVC = forced vital capacity, GAP = GTPase-activating protein, GTP =guanosine triphosphate, GTPase = guanosine triphosphotase, HIV = human immunodeficiency virus, HRCT = high-resolution computed tomography, mPAP = mean pulmonary arterial pressure, mTOR = mammalian target of rapamycin, NF1 = neurofibromatosis type I, NIH = National Institutes of Health, NYHA: New York Heart Association, PAH = pulmonary arterial hypertension, PCWP = pulmonary capillary wedge pressure, PFT = pulmonary function test, PH = pulmonary hypertension, PVRi = indexed pulmonary vascular resistance, RAP = right atrial pressure, SpO2 = pulse arterial oxygen saturation, TLC = total lung capacity, TPRi = indexed total pulmonary resistance, VEGF = vascular endothelial growth factor, VSMC = vascular smooth muscle cells.

Dehydroepiandrosterone (DHEA) improves pulmonary hypertension in chronic obstructive pulmonary disease (COPD): a pilot study.

OBJECTIVES It was previously shown that dehydroepiandrosterone (DHEA) reverses chronic hypoxia-induced pulmonary hypertension (PH) in rats, but whether DHEA can improve the clinical and hemodynamic status of patients with PH associated to chronic obstructive pulmonary disease (PH-COPD) has not been studied whereas it is a very severe poorly treated disease. PATIENTS AND METHODS Eight patients with PH-COPD were treated with DHEA (200mg daily orally) for 3 months. The primary end-point was the change in the 6-minute walk test (6-MWT) distance. Secondary end-points included pulmonary hemodynamics, lung function tests and tolerance of treatment. RESULTS The 6-MWT increased in all cases, from 333m (median [IQR]) (257; 378) to 390m (362; 440) (P<0.05). Mean pulmonary artery pressure decreased from 26mmHg (25; 27) to 21.5mmHg (20; 25) (P<0.05) and pulmonary vascular resistance from 4.2UI (3.5; 4.4) to 2.6UI (2.5; 3.8) (P<0.05). The carbon monoxide diffusing capacity of the lung (DLCO % predicted) increased significantly from 27.4% (20.1; 29.3) to 36.4% (14.6; 39.6) (P<0.05). DHEA treatment did not change respiratory parameters of gas exchange and the 200mg per day of DHEA used was perfectly tolerated with no side effect reported. CONCLUSION DHEA treatment significantly improves 6-MWT distance, pulmonary hemodynamics and DLCO of patients with PH-COPD, without worsening gas exchange, as do other pharmacological treatments of PH (trial registration NCT00581087).

One-year experience with high-emergency lung transplantation in France.

Background The continuing significant number of patients who die while on a waiting list for lung transplantation (LTx) has led several countries to modify their lung allocation rules in recent years. France has implemented high-emergency allocation rules to allow patients at imminent risk of death to undergo priority transplantation within several days. The aim of this study was to report on the early (2-year) experience of high-emergency LTx (HELTx) in France. Methods From July 1, 2007, to June 30, 2008, 186 patients underwent LTx in France in nine centers. Among them, 32 patients (17.2%) underwent HELTx (19 with cystic fibrosis, 7 pulmonary fibrosis, and 6 other diagnoses). The reasons for HELTx were risk of invasive mechanical ventilation (n=20), invasive mechanical ventilation (n=8), and extracorporeal membrane oxygenation (n=4). Results The median time between being placed on the HELTx waiting list and LTx was 3 days (interquartile range: 1–8 days). Survival rates in the HELTx group were 90.5%, 71%, 64.5%, 55%, and 51.5% at 1, 3, 6, 12, and 24 months, respectively, which were significantly lower than for 154 patients who underwent regular, nonurgent LTx during the study period (88.5%, 83%, 79%, 77%, and 71%, respectively). Conclusions Our data demonstrate that the new LTx allocation rules implemented in France since 2007 allow for rapid organ procurement for patients at imminent high risk of death. HELTx is feasible but yields poorer survival than elective LTx. Further studies are needed to assess implications of this organ allocation policy on the long run.

Relative Impact of Human Leukocyte Antigen Mismatching and Graft Ischemic Time After Lung Transplantation

BACKGROUND Recent data strongly suggest that human leukocyte antigen (HLA) mismatching has a negative impact on development of bronchiolitis obliterans syndrome (BOS) and survival after lung transplantation (LTx). Because HLA matching is sometimes achieved by extending ischemic time in other solid-organ transplantation models and ischemic time is a risk factor per se for death after LTx, we sought to compare the theoretical benefit of HLA matching with the negative impact of lengthened ischemic time. METHODS In this collaborative study we compared the relative impact of HLA mismatching and ischemic time on BOS and survival in 182 LTx recipients. RESULTS Using multivariate analyses, we observed a lower incidence of BOS (hazard ratio [HR] = 1.70, 95% confidence interval [CI]: 1.1 to 2.7, p = 0.03) and enhanced survival (HR = 1.91, 95% CI: 1.24 to 2.92, p = 0.01) in patients with zero or one HLA-A mismatch compared with those having two HLA-A mismatches. This beneficial effect on survival was equivalent to a reduction of ischemic time of 168 minutes. CONCLUSIONS We observed a reduced incidence of BOS and a better survival rate in patients well-matched at the HLA-A locus, associated with an opposite effect of an enhanced ischemic time. This suggests that graft ischemic time should be taken into account in future studies of prospective HLA matching in LTx.

Computed Tomographic Measurement of Airway Remodeling and Emphysema in Advanced Chronic Obstructive Pulmonary Disease. Correlation with Pulmonary Hypertension

RATIONALE Pulmonary hypertension (PH) is an established complication of advanced chronic obstructive pulmonary disease (COPD) associated with increased mortality. The mechanisms coupling PH and bronchial obstruction are unknown; in particular, PH appears to be unrelated to emphysema. We hypothesized that computed tomographic (CT) measurement of airway remodeling instead of emphysema may correlate with PH in COPD. OBJECTIVES We aimed to describe the clinical and CT characteristics of patients with COPD with or without PH and to correlate CT measurements of airway remodeling and emphysema with PH. METHODS Data were retrieved from 60 COPD patients who underwent both right heart catheterization and computed tomography in a period of stability and had no other disease known to cause PH. CT measurement of airway wall thickness (WT-Pi10) was used to assess airway remodeling and low lung area percentage (LAA%) to quantify emphysema extent. MEASUREMENTS AND MAIN RESULTS Thirty-four of the sixty patients with COPD had PH (mean pulmonary arterial pressure [PAPm] ≥ 25 mm Hg). There was no difference between the two groups regarding age, sex, and spirometric results, whereas there was more profound hypoxemia in the PH group. WT-Pi10 was increased in the patients with COPD and PH and correlated with PAPm (ρ = 0.62; P < 0.001). Conversely, there was no difference or correlation between PAPm and LAA% (ρ = 0.12; P = 0.33). In multivariate analysis (R(2) = 0.53), WT-Pi10 was the independent predictor most associated with PAPm elevation, as compared to hypoxia (PaO2) or pulmonary arterial enlargement (diameter ratio between the pulmonary arterial truncus and the ascending aorta). CONCLUSIONS This study demonstrates, for the first time to our knowledge, an association between structural alterations of bronchi and PH in COPD. Unlike quantification of emphysema, CT measurement of airway remodeling correlates with PAPm and could be used to estimate the severity of PH in COPD. Airway remodeling burden is not limited to airflow limitation in the assessment of COPD severity and mortality.