G. Strange

Pulmonary hypertension: prevalence and mortality in the Armadale echocardiography cohort

Background Pulmonary hypertension (PHT) lacks community prevalence and outcome data. Objective To characterise minimum ‘indicative’ prevalences and mortality data for all forms of PHT in a selected population with an elevated estimated pulmonary artery systolic pressure (ePASP) on echocardiography. Design Observational cohort study. Setting Residents of Armadale and the surrounding region in Western Australia (population 165 450) referred to our unit for transthoracic echocardiography between January 2003 and December 2009. Results Overall, 10 314 individuals (6.2% of the surrounding population) had 15 633 echo studies performed. Of these, 3320 patients (32%) had insufficient TR to ePASP and 936 individuals (9.1%, 95% CI 8.6% to 9.7%) had PHT, defined as, ePASP>40 mm Hg. The minimum ‘indicative’ prevalence for all forms of PHT is 326 cases/100 000 inhabitants of the local population, with left heart disease-associated PHT being the commonest cause (250 cases/100 000). 15 cases of pulmonary arterial hypertension/100 000 inhabitants were identified and an additional 144 individuals (15%) with no identified cause for their PHT. The mean time to death for those with ePASP >40 mm Hg, calculated from the first recorded ePASP, was 4.1 years (95% CI 3.9 to 4.3). PHT increased mortality whatever the underlying cause, but patients with PHT from left heart disease had the worst prognosis and those with idiopathic pulmonary arterial hypertension receiving disease-specific treatment the best prognosis. Risk of death increased with PHT severity: severe pulmonary hypertension shortened the lifespan by an average of 1.1 years compared with mild pulmonary hypertension. Conclusions In this cohort, PHT was common and deadly. Left heart disease was the most common cause and had the worst prognosis and treated pulmonary arterial hypertension had the best prognosis.

Prevalence of pulmonary arterial hypertension in an Australian scleroderma population: screening allows for earlier diagnosis

Background:  We sought to determine the prevalence of pulmonary complications and especially pulmonary arterial hypertension (PAH) in an Australian scleroderma population.

Evaluation of a tissue-engineered bovine pericardial patch in paediatric patients with congenital cardiac anomalies: initial experience with the ADAPT-treated CardioCel® patch

OBJECTIVES This study evaluated the safety, efficacy and clinical performance of the tissue-engineered ADAPT® bovine pericardial patch (ABPP) in paediatric patients with a range of congenital cardiac anomalies. METHODS In this single-centre, prospective, non-randomized clinical study, paediatric patients underwent surgery for insertion of the ABPP. Primary efficacy measures included early (<30 day) morbidity; incidence of device-related complications; haemodynamic performance derived from echocardiography assessment at 6- and 12-month follow-up and magnetic resonance imaging findings in 10 randomly selected patients at 12 months. Secondary measures included device-handling characteristics; shape and sizing characteristics and perioperative implant complications. The Aristotle complexity scoring system was used to score the complexity level of all surgical procedures. Patients completing the 12-month study were eligible to enter a long-term evaluation study. RESULTS Between April 2008 and September 2009, the ABPP was used in 30 paediatric patients. In the 30-day postoperative period, no graft-related morbidity was observed. In total, there were 5 deaths (2 in the 30-day postoperative period and 3 within the first 6 postoperative months). All deaths were deemed due to comorbid non-graft-related events. Echocardiography assessment at 6 and 12 months revealed intact anatomical and haemodynamically stable repairs without any visible calcification of the patch. Magnetic resonance imaging assessment in 10 patients at 12 months revealed no signs of calcification. Fishers exact test demonstrated that patients undergoing more complex, higher risk surgical repairs (Aristotle complexity score >8) were significantly more likely to die (P = 0.0055, 58% survival compared with 100% survival for less complex surgical repairs). In 19 patients, echocardiographic data were available at 18-36 months with no evidence of device calcification, infection, thromboembolic events or device failure. CONCLUSIONS This study demonstrates the safety and efficacy of this engineered bovine pericardial patch as a cardiovascular substitute for surgical repair of both simple and more complex congenital cardiac defects.

The bosentan patient registry: long-term survival in pulmonary arterial hypertension

Background/Aims: The Bosentan Patient Registry (BPR) was a prospective, multicentre, Australian registry funded by Actelion Pharmaceuticals. The primary aim of the registry was to collect survival data in patients with pulmonary arterial hypertension (PAH) treated with bosentan.

Survival after the initiation of combination therapy in patients with pulmonary arterial hypertension: an Australian collaborative report.

Background:  Several cellular pathways are implicated in the pathogenesis of pulmonary arterial hypertension (PAH) and attempts to arrest disease progression with a single drug would not be expected to succeed in the medium term. In clinical practice, combination therapy is often used in patients deteriorating on monotherapy, despite the absence of firm evidence from randomized controlled controls.

Time from symptoms to definitive diagnosis of idiopathic pulmonary arterial hypertension: The delay study

Survival rates for patients with idiopathic pulmonary arterial hypertension (IPAH) have improved with the introduction of PAH-specific therapies. However, the time between patient-reported onset of symptoms and a definitive diagnosis of IPAH is consistently delayed. We conducted a retrospective, multi-center, descriptive investigation in order to (a) understand what factors contribute to persistent diagnostic delays, and (b) examine the time from initial symptom onset to a definitive diagnosis of IPAH. Between January 2007 and December 2008, we enrolled consecutively diagnosed adults with IPAH from four tertiary referral centers in Australia. Screening of patient records and “one-on-one” interviews were used to determine the time from patient-described initial symptoms to a diagnosis of IPAH, confirmed by right heart catheterization (RHC). Thirty-two participants (69% female) were studied. Mean age at symptom onset was 56 ± 16.4 years and 96% reported exertional dyspnea. Mean time from symptom onset to diagnosis was 47 ± 34 months with patients subsequently aged 60 ± 17.3 years. Patients reported 5.3 ± 3.8 GP visits and 3.0 ± 2.1 specialist reviews before being seen at a pulmonary hypertension (PH) center. Advanced age, number of general practitioner (GP) visits, heart rate, and systolic blood pressure at the time of diagnosis were significantly associated with the observed delay. We found a significant delay of 3.9 years from symptom onset to a diagnosis of IPAH in Australia. Exertional dyspnea is the most common presenting symptom. Current practice within Australia does not appear to have the specific capacity for timely, multi-factorial evaluation of breathlessness and potential IPAH.

Bosentan therapy in patients with pulmonary arterial hypertension: The relationship between improvements in 6 minute walk distance and quality of life

Background and objective:  Bosentan, an oral, dual endothelin receptor antagonist, significantly improves functional status, haemodynamic measures and survival in patients with pulmonary arterial hypertension (PAH). However, there are limited data on the effect of bosentan on quality of life (QOL) and its relationship to changes in functional status, as measured by the 6 minute walk distance (6MWD).

Efficacy, safety and tolerability of bosentan in Chinese patients with pulmonary arterial hypertension.

BACKGROUND Bosentan has an established role in the management of pulmonary arterial hypertension (PAH). This clinical trial assessed the benefits of bosentan in the Chinese population. METHODS We investigated the efficacy and safety of bosentan in 92 Chinese citizens (mean +/- standard deviation age, 29.0 +/- 3.8 years) with PAH for a minimum of 12 weeks. All received bosentan (62.5 mg twice daily) for 4 weeks; then, patients who weighed <40 kg received 62.5 mg bosentan twice daily and patients who weighed >40 kg received 125 mg twice daily. All patients were eligible to continue bosentan beyond 12 weeks. The primary end point was a change in exercise capacity from baseline to 12 and 24 weeks. Secondary end points included a change in World Health Organization (WHO) functional class and changes in cardiopulmonary hemodynamics. RESULTS At baseline, 66 patients (72%) were in WHO functional class III; presentation was 37 (40%) with idiopathic PAH (iPAH), 34 (37%) with PAH related to congenital heart disease (CHD), and 21 (23%) with PAH related to connective tissue disease (CTD). Exercise capacity increased to 67.8 m after 12 weeks and 92.6 m after 24 weeks (p < 0.001). After 24 weeks, WHO functional class decreased (-0.8 +/- 0.6; p < 0.001), mean pulmonary artery pressure and pulmonary vascular resistance decreased (p < 0.01), and cardiac output increased (p < 0.001). Twelve patients (13%) experienced at least 1 adverse event. CONCLUSIONS Bosentan improved exercise capacity, functional class, and cardiopulmonary hemodynamics in this patient cohort and was well tolerated.

The manifestations of vasculopathy in systemic sclerosis and its evidence-based therapy.

Fibrosis, inflammation and vascular dysfunction are major features of systemic sclerosis and the multiple organ‐specific complications that characterize this disease. Several manifestations of systemic sclerosis, including Raynaud’s phenomenon, digital ulceration, scleroderma renal crisis and pulmonary arterial hypertension, contribute significantly to morbidity and mortality and are understood to share similarities in their underlying vasculopathy. In recent years, a number of treatment options have become available that ease the burden of these manifestations, including calcium channel blockers, angiotensin converting enzyme inhibitors, prostanoids and prostacyclin analogs, endothelin receptor antagonists, and phosphodiesterase type‐5 inhibitors. Several of these treatments have demonstrated beneficial effects against more than one complication, as a result of the similarities in the pathology underlying these manifestations. However, physicians involved in the management of patients with systemic sclerosis are faced with differing levels of evidence supporting these treatments, and historically little international consensus on the treatment of some manifestations, such as digital ulcers. The aim of this article is to evaluate the level of evidence supporting each intervention in systemic sclerosis, thereby facilitating decision‐making in the clinic.

An evaluation of Admedus' tissue engineering process-treated (ADAPT) bovine pericardium patch (CardioCel) for the repair of cardiac and vascular defects

Tissue engineers have been seeking the ‘Holy Grail’ solution to calcification and cytotoxicity of implanted tissue for decades. Tissues with all of the desired qualities for surgical repair of congenital heart disease (CHD) are lacking. An anti-calcification tissue engineering process (ADAPT® TEP) has been developed and applied to bovine pericardium (BP) tissue (CardioCel®, AdmedusRegen Pty Ltd, Perth, WA, Australia) to eliminate cytotoxicity, improve resistance to acute and chronic inflammation, reduce calcification and facilitate controlled tissue remodeling. Clinical data in pediatric patients, and additional pre-market authorized prescriber data demonstrate that CardioCel performs extremely well in the short term and is safe and effective for a range of congenital heart deformations. These data are supported by animal studies which have shown no more than normal physiologic levels of calcification, with good durability, biocompatibility and controlled healing.