Clinical Impact of Main Pulmonary Artery Dilatation on Outcome in Pediatric Idiopathic and Heritable Pulmonary Arterial Hypertension

Abstract

at diagnosis were excluded. The diagnosis of idiopathic and heritable PAH was established according to echocardiography, blood test including autoantibodies and liver function, pulmonary function tests, pulmonary ventilationperfusion scan, genetic test, and catheterization. We included patients with mean PAP >25 mmHg, with normal PA occlusion pressure ≤15 mmHg on catheterization. In addition, we also included patients with tricuspid regurgitant velocity >3.5 m/s on echocardiography. The healthy control group consisted of 166 age-and gender-matched children.We measured MPA protrusion, which is the distance between the protrusion of the MPA and the vertebral line (A); and thorax diameter (B). MPA/T ratio is expressed as A/B×100 (Figure 1). We used thorax diameter instead of body surface area because of the different physical build. Normal MPA/T ratio was obtained from 166 age-and gender-matched healthy children. To assess the clinical impact of higher MPA/T ratio on disease severity and prognosis, we compared clinical data in patients with higher and lower MPA/T ratio. The MPA/T ratio range in the control group was 4.2-14.2 (median, 7.7), thus, the upper limit of normal MPA/T ratio was defined as 14.2. P ulmonary artery hypertension (PAH) is characterized by dilatation of the main pulmonary artery (MPA) and narrowing of the peripheral PA. In case reports, progressive dilatation has led to PA dissection, rupture and left main coronary artery compression in patients with PAH. 1-3 Alterations in endothelial function and shear stress lead to structural changes including marked MPA dilatation and peripheral PA occlusions. 4,5Early investigators found significant correlation between MPA/thorax (MPA/T) ratio on chest radiography and PA pressure (PAP). 6,7 Although MPA dilation may be a potential risk factor of adverse events in PAH, the clinical impacts of marked PA dilatation have not been fully investigated. The aim of this study was therefore to assess the clinical differences in manifestations, disease severity, vasoreactivity, and outcomes between pediatric PAH with and without marked PA dilatation. MethodsBetween 1998 and 2013, we enrolled children with idiopathic or heritable PAH who were followed at Toho University Omori Medical Center. Children older than 19 years of age Received February 7, 2017; revised manuscript received July 20, 2017; accepted August 7, 2017; released online September 13, 2017Time for primary review: 24 days Department of Pediatrics, Toho University Omori Medical Center, Tokyo, Japan Mailing address: Satoshi Ikehara, MD, Department of Pediatrics, Toho University Omori Medical Center, 6-11-1 Omori-nishi, Ota-ku, Tokyo 143-8541, Japan. E-mail: ikepon114@yahoo.co.jp ISSN-1346-9843 All rights are reserved to the Japanese Circulation Society. For permissions, please e-mail: cj@j-circ.or.jp Clinical Impact of Main Pulmonary Artery Dilatation on Outcome in Pediatric Idiopathic and Heritable Pulmonary Arterial HypertensionSatoshi Ikehara, MD; Shinichi Takatsuki, MD; Tomotaka Nakayama, MD; Kazuyuki ...

Bosentan for Treatment of Pediatric Idiopathic Pulmonary Arterial Hypertension: State-of-the-Art

“…Yung et al (31) performed a cohort study of 77 children with IPAH, indicating that the use of calcium channel blockers (CCB) in 31 children positive for acute vascular response (AVR-positive) resulted in 1, 5, and 10 year survival rates of 97, 97 and 81%, and treatment success rates of 84, 68, and 47%, respectively. Following the rise of the “New Drug Age” after 1995 (32, 33), drugs such as bosentan and sildenafil appeared on the market, yielding 1, 5, and 10 year survival rates of 97, 97, and 78%, and the treatment success rates of 93, 86, and 60%, respectively. These data support the view that new targeted drugs can improve the survival rate and quality of life of patients.…”