WEDNESDAY,SEPTEMBER 28 TH 2011 509. Clinical features of human pulmonary hypertension 4909 Late-breaking abstract: Demographic trends and changes In long term outcome of incident idiopathic, heritable and anorexigen-associated pulmonary arterial hypertension between 2001 to 2009. Results from the Pulmonary Hypertension Registry of the United Kingdom and Ireland Yi Ling 1 , Martin Johnson 1 , David Kiely 2 , Robin Condliffe 2 , Charlie Elliot 2 , Simon Gibbs 3 , Luke Howard 3 , Joanna Pepke-Zaba 4 , Karen Sheares 4 , Paul Corris 5 , Andrew Fisher 5 , Jim Lordan 5 , Sean Gaine 6 , Gerry Coghlan 7 , John Wort 8 , Michael Gatzoulis 8 , Andrew Peacock 1 . 1 Scottish Pulmonary Vascular Unit, Golden Jubilee National Hospital, Clydebank, United Kingdom; 2 Pulmonary Vascular Unit, Royal Hallamshire Hospital, Sheffield, United Kingdom; 3 Pulmonary Hypertension Service, Hammersmith Hospital, London, United Kingdom; 4 Pulmonary Vascular Disease Unit, Papworth Hospital, Papworth, United Kingdom; 5 Northern Pulmonary Vascular Unit, Freeman Hospital, Newcastle, United Kingdom; 6 Pulmonary Hypertension Unit, Mater Misericordiae Hospital, Dublin, Ireland; 7 Pulmonary Hypertension Unit, Royal Free Hospital, London, United Kingdom; 8 Royal Brompton Pulmonary Hypertension and Adult Congenital Heart Centre, Royal Brompton Hospital, London, United Kingdom Background: There have been significant changes in the management of pul- monary arterial hypertension (PAH) over the past decade. In the UK and Ireland, care of pulmonary hypertension (PH) is centralised to designated PH centres. This provides an excellent opportunity to study changes in demographic and survival trends of the disease within an entire region with a common healthcare system. Aim: To determine whether baseline characteristics and survival of incident IPAH, heritable and anorexigen-associated PAH has changed over the past decade. Methods: Retrospective observational study of all incident cases of IPAH, herita- ble and anorexigen-associated PAH diagnosed in the UK and Ireland between 1st January 2001 and 31st December 2009. Results: Total of 646 patients were diagnosed (22% in 2001-2003, 33% in 2004- 2006 and 45% in 2007-2009). In recent years, patients were older, had higher BMI, lower % predicted diffusion capacity for carbon monoxide (DLCO) and had more co-morbidities (COPD, ischaemic heart disease and diabetes). There is no difference in unadjusted overall survival from 2001 to 2009. However, after adjusting for age, % DLCO, 6 minute walk distance and cardiac index, patients diagnosed in the 2001-2003 period were likely to have a shorter survival time compared to those diagnosed in 2007-2009 (hazard ratio 1.7, 95% CI 1.1-2.6) Conclusion: After adjusting for potential confounders, survival of incident IPAH, heritable and anorexigen-associated PAH in the UK and Ireland has improved over the last decade. 4910 Right ventricular (RV) remodelling in PAH: Impact of RV mass/volume ratio on survival Carmine Dario Vizza 1 , Roberto Badagliacca 1 , Roberto Poscia 1 , Marco Francone 2 , Serena Marcon 1 , Cristina Gambardella 1 , Silvia Papa 1 , Ilaria Iacucci 2 , Beatrice Pezzuto 1 , Alfred Nona 1 , Francesco Fedele 1 . 1 Cardiovascular & Respiratory Disease, La Sapienza University of Rome, Rome, Italy; 2 Radiology, La Sapienza University of Rome, Rome, Italy Pulmonary arterial hypertension (PAH) is characterized by an impressive increase in pulmonary vascular resistances (PVR) that causes severe right ventricular (RV) dysfunction. Because the pathophysiologic model is an afterload mismatch we hypotisize that the best RV adaptation is a concentric hypertrophy (high RV mass/volume ratio (RV M/V)). Methods: 63 consecutive patients with PAH (50 idiopathic, 13 associated to SSc) who underwent clinical (NYHA class) effort capacity (6MWT, six-minute walk- test) hemodynamic and heart magnetic resonance evaluation as routine work-up at the time of diagnosis. Population was divided in two groups on the basis of median value of RV M/V (cut-off 0,6) and followed-up for deaths (average 2.3 years). Results: Patients with RV M/V>0.6 have lower RV systolic and diastolic volumes but similar RV mass compared to patients with RV M/V<0,6. Despite no sig- nificant differences in clinical status, effort capacity and hemodynamics between the two groups, patients with RV M/V>0,6 have a lower mortality compared to patients with RV M/V<0,6. RV M/V < 0,6 RV M/V > 0,6 p< n=32 n=31 Age 50±16 54±14 0,05 NYHA 2,4±0,6 2,3±0,6 ns 6MWT,m 412±122 426±118 ns RV EDV, ml 172±65 131±32 0,002 RV ESV, ml 116±64 86±31 0,02 RV EF, % 35±14 35±12 ns RV mass 78±29 91±23 0,04 Pra, mmHg 7±3 7±4 ns Ppa, mmHg 53±19 52±16 ns CI, l/m’/m 2 2,3±0,8 2,3±0,7 ns PVR, WU 12±9 12±9 ns Death, n 7/32 1/31 0,007 EDV = end-diastolic volume; ESV = end-systolic volume. Conclusion: In PAH it is possible to identify a subgroup of patients with RV hypertrophy and moderate diastolic volume increase (i.e. high RV mass/volume ratio) which has a low rate of deaths, suggesting a better RV adaptation to the increased afterload. 4911 Pulmonary arterial hypertension in patients with chronic kidney disease on dialysis and without dialysis: Results of the PEPPER-study Stefan Pabst 1 , Christoph Hammerstingl 1 , Felix Hundt 2 , Thomas Gerhardt 3 , Christian Grohé 4 , Georg Nickenig 1 , Rainer Woitas 2 , Dirk Skowasch 1 . 1 Department of Pneumology/Cardiology, University of Bonn, Bonn, Germany; 2 Department of Nephrology, University of Bonn, Bonn, Germany; 3 Praxis für Nieren- und Hochdruckkrankheiten, Praxis für Nieren- und Hochdruckkrankheiten, Bonn, Germany; 4 Abteilung fuer Pneumologie, Evangelische Lungenklinik Berlin-Buch, Berlin, Germany Background: Pulmonary hypertension (PH) is common in patients with dialysis- dependent chronic kidney disease (CKD) and is an independent predictor of mortality. However, specific hemodynamics of the pulmonary circulation, changes induced by hemodialysis and prevalence of pulmonary arterial hypertension (PAH) have not been evaluated in patients with CKD. Methods and results: We assessed consecutive patients with CKD on hemodialysis (group 1, n=31) or without dialysis (group 2, n=31), in World Health Organization functional class ≥II with dyspnea unexplained by other causes, using right heart catheterization (RHC). In group 1 RHC was performed before and after dialysis. PAH was diagnosed if mean pulmonary arterial pressure (mPAP) was ≥25 mmHg and pulmonary capillary wedge pressure (PCWP) ≤15 mmHg (after dialysis in group 1) and if other causes of PH were excluded. In CKD patients after dialysis, prevalence of PH was 24/31 (77%; 20/31 postcapillary PH, 4/31 precapillary PH); prevalence of PAH was 3/31 (10%). After dialysis, there were significant decreases in mPAP and PCWP; all four cases of precapillary PH were unmasked by dialysis. In group 2, postcapillary PH was diagnosed in 22 cases (71%); no cases of PAH were detected. Conclusions: The finding that the prevalence of PAH was 10% in CKD patients on hemodialysis who have unexplained dyspnea suggests careful screening for PH in this patient population is warranted. The possibility that dialysis might be a trigger for the development of PAH is plausible given that there were no instances of PAH in the nondialysis CKD patient group. RHC should be performed after dialysis to unmask precapillary PH. 4912 Left atrial volume to distinguish idiopathic pulmonary arterial hypertension from pulmonary hypertension due to left heart disease Stephen Crawley, Martin Johnson, Andrew Peacock. Scottish Pulmonary Vascular Unit (SPVU), Golden Jubilee National Hospital, Glasgow, United Kingdom Introduction: It can be difficult to distinguish pulmonary arterial hypertension (which will respond to disease targeted therapy) from pulmonary hypertension due to left heart disease (PHLHD). Current practice is to use right heart catheterisation (RHC) to distinguish between the two conditions. We explored the use of left atrial volume (LAV) obtained via cardiac magnetic resonance imaging (CMR) as an alternative to RHC. Methods: Patients being admitted for diagnostic assessment underwent CMR and RHC. LA volume was assessed using standard 2- and 4-chamber CMR views and the biplane area-length method, and indexed to the body surface area. RHC was then performed within 72 hours. IPAH was defined as per current guidelines. Pa- tients with mean PAP >25mmHg and PAWP >15mmHg at RHC were considered to have PHLHD. Results: Between Jan 2009 and Feb 2011 we diagnosed 31 patients with IPAH (mPAP 47±10, PAWP 7±4 mmHg) and 19 patients with PHLHD (mPAP 43±8, PAWP 22±6 mmHg). LAV was significantly lower in IPAH compared with PHLHD (24±9 ml/m 2 vs 66±19 ml/m 2 ,p<0.0001). Using an LAV threshold of 43 ml/m 2 895s Oral Presentation Room D203-204 - 10:45-12:45 Abstract printing supported by . Visit Chiesi at Stand D.30