Introduction Hyperammonemia is a rare complication post solid organ transplant, with a high mortality. We report a case of hyperammonemic encephalopathy in separate cardiac and lung transplant recipients, likely related to donor derived infection acquired from the same donor. Case Report A 63-year-old male with sarcoid cardiomyopathy on LVAD support and no known hepatic disease received cardiac transplantation. He was extubated on day (D) 4 with normal allograft function and mentation. He received basiliximab induction, steroids, mycophenolate (MMF) and tacrolimus (TAC) on D6. He developed hallucinations on D8 followed by paranoia and reduced GCS on D9, with no focal neurological deficit. Cranial CT/MRI and CSF were unremarkable. Initial blood results showed raised CRP, WCC with mildly elevated urea, creatinine, bilirubin & transaminase. Serum ammonia (NH3) was 549µmol/L. He was intubated and diagnosed with hyperammonemic encephalopathy. Hyperammonemic encephalopathy had also been diagnosed in the lung transplant recipient, a 65-year-old male with COPD, from the same donor. He received basiliximab induction, steroids, MMF and Cyclosporine A (CSA) on D1. He developed right sided hypertonia and reduced consciousness on D6, with elevated NH3 (177µmol/L). Both received Mycoplasma / Ureaplasma combination antibiotics - moxifloxacin and azithromycin (lung), moxifloxacin and minocycline (cardiac); metronidazole, rifaximin, lactulose, ammonia scavengers and dialysis. NH3 normalised by D12 (lung) and D15 (cardiac) with improvement in mental state. At D30, both remain dependent on dialysis with ongoing antibiotics, steroids, and moderate immunosuppression. Both patients required tracheostomy for critical illness myopathy. The aetiology of hyperammonemia is putative, however both recipients had Mycoplasma hominis identified on blood cultures. M. hominis and Ureaplasma spp. were present in bronchial washings in the lung recipient, and sputum, pleural and pericardial fluid from cardiac recipient. The donor had culture negative urethritis at donation with Mycoplasma and Ureaplasma spp. confirmed on retrospective bronchial washing PCR. Summary Hyperammonemia should be suspected in transplant recipients with altered mental state. Transplant units need increased awareness of the potential impact of infection by urease-producing organisms.

The relationship between initial treatment strategy and survival in pulmonary arterial hypertension (PAH) is uncertain, although early combination therapy is proposed by current guidelines for majority of patients.

Purpose Impairment of left ventricular (LV) relaxation is associated with increased mortality after surgical treatment of pulmonary hypertension (PH). We sought to describe the pathophysiology of LV diastolic dysfunction in a porcine model of chronic thromboembolic pulmonary hypertension (CTEPH). The reversibility of LV diastolic dysfunction was investigated in patients with CTEPH after pulmonary endarterectomy (PEA). Methods CTEPH was induced in 2-month-old Large White piglets (PH group, n=6) by ligation of the left pulmonary artery (PA) followed by weekly embolization of right lower lobe for 5 weeks using a strong tissue glue (N-acetyl cyanoacrylate). These animals were compared to sham-operated animals (controls, n=6). LV diastolic function was assessed using echocardiography and conductance catheter measurements. LV fibrosis was investigated at 6 weeks using red Sirius staining of myocardial tissues. Echocardiographic measurements for LV diastolic function were retrospectively analyzed in 102 patients, before and after PEA. Results Mean PA pressure was higher at 6 weeks in PH animals compared to controls (28.5 [28.0; 34.2] vs. 14.0 [12.5; 14.0] mmHg, p<0.01). Increased end-diastolic LV pressure was observed in PH group (21.9 [18.1; 22.7] vs. 12.2 [11.7; 13.8] mmHg, p=0.013), along with a marked decrease in the curve-fitting constant (c) and the maximum rate of LV filling (dV/dtmax), respectively by 49% (p=0.03) and 74% (p=0.014). Stiffness constant ß was strongly correlated with Doppler imaging index E/A (r=-0.94, p=0.015). Mean LV fibrosis score was significantly higher in PH group at 6 weeks (5.11±0.89% vs. 3.29±1.14%, p<0.01). Pre-operative impairment of LV filling pattern was remarkable in patients with CTEPH (E/A = 0.81±0.32; E/E'=6.42±2.84), and significantly improved at 7 days post PEA (+30%, p<0.001). At 6 months, E/A ratio was significantly higher (0.91 [0.75; 1.20] vs. 0.76 [0.66; 0.94], p=0.05) but remained abnormal, despite significant decrease in mean pulmonary vascular resistance (7.3 ±3.1WU vs. 3.8±1.5WU, p<0.001). Conclusion Impaired myocardial stiffness was associated with LV fibrosis in our piglet model of CTEPH. Mild LV diastolic dysfunction was observed at 6 months in patient with CTEPH despite significant decrease in RV pressure overload after PEA. Myocardial fibrosis may be responsible for persistent abnormal LV relaxation.

Paediatric pulmonary arterial hypertension is a rare disease but causes significant morbidity and mortality where it is found. Literature on survival and response to therapy is scant.

Purpose Chronic thromboembolic pulmonary hypertension (CTEPH) is defined as pulmonary hypertension resulting from non-resolving fibro-thrombotic obstructions of pulmonary arteries. Pulmonary endarterectomy (PEA) remains the treatment of choice for disease that is technically operable. The epidemiology and long-term outcomes of CTEPH has not been previously described in Australia and New Zealand. Methods Using PHSANZ registry, data was extracted for all CTEPH patients diagnosed between January 2004 and March 2020. We analysed baseline characteristics, treatment strategies, outcome data, and long-term survival. Results A total of 404 patients were included with 146 (36.1%) undergoing PEA and 258 (63.9%) in the non-PEA group. PEA patients were younger (55±16yr vs. 62±16yr) with higher baseline 6MWD (405±122m vs. 323±146m), whilst both groups had similar baseline pulmonary haemodynamics. Pulmonary vasodilator therapy was used in 50% of patients post-PEA, and 76% in the non-PEA group. Actual 1, 5, and 10-yr transplant-free survivals were 93%, 84% and 74% for the PEA group compared to 87%, 63% and 42% for the non-PEA group (log rank test, p < 0.001). Similar survival trends were found in an incident-only cohort. Multivariate survival analysis is shown in Table 1 for a cohort of patients with full data available (total n=342). Conclusion In this first multicentre report of CTEPH in Australia and New Zealand, long-term survival is comparable to other contemporary registries. However, PEA was only offered to a minority of CTEPH patients and significantly less than overseas reports. Greater awareness and improved patient access to experienced CTEPH surgical centres are important priorities. Multivariate survival analysis showed baseline 6MWD was an independent predictor of survival in both operated and medically managed patients.

Pulmonary vascular resistance (PVR) >3 Wood units is a criterion of the haemodynamic definition of pulmonary arterial hypertension (PAH). However, this cut-off is conservative and arbitrarily defined. Data is lacking on the natural history, response to therapy and survival of patients diagnosed with precapillary pulmonary hypertension (PH) with mild or borderline elevation of PVR. In Australia, PAH therapy could be prescribed solely on mean pulmonary arterial pressure (PAP) and pulmonary arterial wedge pressure (PAWP) criteria. Using the Australian and New Zealand Pulmonary Hypertension Registry, we aimed to study a population diagnosed with PAH between January 2004 and December 2017 with the pre-defined haemodynamic characteristics of mean PAP ≥25 mmHg, PAWP ≤15 mmHg and PVR <3 Wood units. Eighty-two patients met the pre-defined haemodynamic inclusion criteria (mean age 63±11 years; 67 females). Underlying aetiologies included idiopathic disease (n=39), connective tissue disease (CTD; n=42) and HIV infection (n=1). At diagnosis, mean PAP was 27 mmHg (interquartile range (IQR) 25–30 mmHg), PAWP 13 mmHg (IQR 11–14 mmHg) and PVR 2.2 Wood units (IQR 1.9–2.7 Wood units). Baseline 6-min walk distance (6MWD) was 352 m (IQR 280–416 m) and 77% of subjects were in New York Heart Association (NYHA) functional class 3 or 4. All patients were commenced on initial monotherapy with an endothelin receptor antagonist (ERA; n=66) or phosphodiesterase type-5 inhibitor (PDE5i; n=16). At first re-evaluation, 6MWD increased by 46 m (IQR 7–96 m) and 35% of subjects demonstrated improvement in NYHA functional class. After a median follow-up of 65 months (IQR 32–101 months), 18 out of 82 subjects (22.0%) had died, with estimated 1-year and 5-year survival rates of 98% and 84%, respectively. Death attributed to PAH occurred in six out of these 18 patients (33.3%, 7% of total cohort). Patients with precapillary PH and “borderline” PVR falling outside the current definition have adverse outcomes. Such patients appear to respond to PAH therapy; however, this requires further study in randomised trials.

Making Australia the benchmark in echocardiography databases: The National Echo Database Australia (NEDA) D Playford, G. Strange, G. Scalia, S. Stewart, T. Marwick, A. Keogh, D. Prior, P. Steele, M. Ilton, E. Gabbay, J. Codde, B. Sheehan and D. Celermajer University of Notre Dame, Fremantle, Australia The Prince Charles Hospital, Brisbane, Australia Mary MacKillop Institute for Health Research, Melbourne, Australia Baker IDI, Melbourne, Australia St Vincents Hospital, Sydney, Australia St Vincents Hospital, Melbourne, Australia NT Heart Centre, Darwin, Australia University of Notre Dame, Fremantle, Australia Pulmonary Hypertension Society of ANZ, Australia Royal Pri

SESSION TITLE: Interventional Pulmonary Cases SESSION TYPE: Affiliate Case Report Slide PRESENTED ON: Sunday, October 25, 2015 at 10:45 AM - 11:45 AM INTRODUCTION: We describe a patient with severe pneumonia complicated by acute respiratory distress syndrome (ARDS), lung abscess and bilateral pneumothoraces with pneumomediastinum secondary to a bronchopleural fistula. The bronchopleural fistula was managed by bronchoscopic insertion of endobronchial valves to collapse the left lower lobe. CASE PRESENTATION: A 35 year old alcoholic man was admitted to intensive care with severe sepsis, bilateral pneumonia and alcoholic ketoacidosis. He developed ARDS requiring mechanical ventilation and subsequently extracorporeal membrane oxygenation (ECMO) for 10 days and tracheostomy formation. Following ECMO wean, the patient developed a left intra-parenchymal lung abscess and possible empyema for which an intercostal chest catheter was inserted. He then developed pneumomediastinum, pneumoretroperitoneum and pneumothorax secondary to a bronchopleural fistula (see Figure 1). This compromised effective mechanical ventilation with the patient requiring airway pressure release ventilation (APRV) on FiO2 0.8 and peak pressures 27-33 cm H2O, with a PaO2 of 60 mm Hg and PaCO2 of 64 mm Hg. A temporary bronchial blocker was inserted to collapse the left lower lobe. Definitive therapy with bronchoscopic insertion of 7 endobronchial valves (PulmonX Inc Zephyr® valves) was achieved. The patient required 3 months in intensive care and 4 months in hospital. He was transferred to a rehabilitation unit before return to independent living. The endobronchial valves were removed 6 months after insertion with good clinical and radiological outcomes. DISCUSSION: We describe the successful use of endobronchial valve insertion in a septic patient with ARDS and profound hypoxaemia on mechanical ventilation with a bronchopleural fistula. Radiological differentiation between intra-parenchymal abscess and empyema can be difficult but is important to guide appropriate therapy. CONCLUSIONS: Bronchoscopic insertion of endobronchial valves to treat bronchopleural fistulae has been described in a variety of settings.1 This case illustrates its potential usage in a critically unwell and hypoxaemic patient who would not have tolerated surgical intervention. Reference #1: Travaline et al (2009). Treatment of persistent pulmonary air leaks using endobronchial valves. Chest; 136: 355-360. DISCLOSURE: The following authors have nothing to disclose: Kuan Pin Lim, Melanie Lavender, Michael Musk, Jeremy Wrobel Endobronchial valve (Zephyr, PulmonX) insertion for bronchopleural fistula.