Conference: 2012 International PHA Conference and Scientific Sessions
Release Date: 06.22.2012
Presentation Type: Abstracts
I. Schulze-Neick1, T. Humpl2, R.M.F. Berger3, G. Raskob4, R. Weintraub5, B. Saji6, D. Yung7, R.J. Barst8, M. Beghetti9
1. Great Ormond Street Hospital for Children - London - United Kingdom
2. Hospital for Sick Children, Division of Cardiology - Toronto - Canada
3. University Medical Center Groningen, Department of Pediatric Cardiology - Groningen - Netherlands
4. University of Oklahoma - Oklahoma City - United States of America
5. Royal Children's Hospital - Melbourne - Australia
6. Toho University Omori Medical Center - Tokyo - Japan
7. Children's Hospital and Regional Medical Center - Seattle - United States of America
8. Columbia University - New York - United States of America
9. University of Geneva Children's Hospital - Geneva – Switzerland
BACKGROUND: PH with elevated pulmonary vascular resistance index (PVRI) is rare in children. With increasing treatment options available, accurate characterization by contemporary epidemiologic, diagnostic, clinical and outcome data of the disease is needed to provide optimal care.
PATIENTS/METHODS: Data on PH including right heart catheterization (RHC) at diagnosis were collected in 456 children aged 3mos to 18yrs by the TOPP registry (31 sites, 20 countries) between January 2008 and February 2010. All individual RHC datasets (n=435,95%) underwent blind review to confirm PH. Cardiac output was measured in 414 RHCs by thermodilution (n=165, 40%) or by Fick method (n=249, 60%), and acute vasodilator testing (AVT) was performed in 89% of the RHC to assess pulmonary vascular response.
RESULTS: At diagnostic RHC, the majority of the children (58%) were in functional class I/II. RHC- associated complications occurred in 6%, without procedure-related deaths. With complete hemodynamic data, PVRI was calculated in 368 (81%) RHC, excluding 6 patients with flow-related PH (PVRI<3 WU m2). In the remaining 362 children, mean pulmonary arterial pressure was 58 (95% CI 56, 59) mmHg, cardiac index was 3.7 L/min/m2 (95%CI 3.48, 3.83); right atrial pressure was normal, and mean mixed venous oxygen saturation was 66% (95%CI 65, 67). Average PVRI was 16.0 (95%CI 14.9, 17.0) WU m2, and PVRI/systemic vascular resistance index ratio was 0.85 (95%CI 0.80, 0.90). 36% of the reported AVTs were considered to be acute responders by the investigators. There was a significant worsening of hemodynamic disease parameters with increasing age at diagnosis (p<0.001).
CONCLUSIONS: In the TOPP Registry, PH in the children was overall severe and progressing with age despite maintained functional capacity. Hemodynamic assessment was remarkable for preserved right ventricular function ensuring adequate oxygen delivery despite the severely elevated PVRI, and for a significant number of acute responders to AVT, which may be both features being characteristic for pediatric PH. As adult-based non-invasive criteria for severity of PH such as functional status may lead to underestimation of the severity of pediatric PAH, reproducible, reliable and timely hemodynamic investigations are crucial to provide adequate therapy as early as possible.