title: PET imaging may provide a novel biomarker and understanding of right ventricular dysfunction in patients with idiopathic pulmonary arterial hypertension.
abstract: BACKGROUND
  The clinical course in pulmonary arterial hypertension (PAH) is variable, and there is limited information on the determinants and progression of right ventricular (RV) dysfunction. The objective is to develop PET metabolic imaging of the RV as a noninvasive tool in patients with PAH.
  
  
  RESULTS
  We performed PET scanning in 16 patients with idiopathic PAH (age, 41±14 years, 82% women) using (13)N-NH(3) for perfusion imaging and (18)F-fluorodeoxyglucose for metabolic imaging. The myocardium was divided into 6 regions of interest (3 left ventricular [LV], 3 RV), and time-activity curves were generated. A 2- compartment model was used to calculate myocardial blood flow (MBF), and Patlak analysis was used to calculate the rate of myocardial glucose uptake (MGU). All patients underwent cardiac catheterization, cardiac MRI, and cardiopulmonary exercise testing with gas exchange. MBF, MGU, and the ratio of RV/LV MGU were correlated to clinical parameters. Pulmonary artery (PA) pressure was 79±19/30±8 mm Hg (mean, 48±10 mm Hg). MBF was 0.84±0.33 mL/g per minute for the LV and 0.45±0.14 mL/g per minute for the RV. Mean MGU was 136±72 nmol/g per minute for the LV and 96±69 nmol/g per minute for the RV. The ratio of RV/LV MGU correlated significantly with PA systolic (r=0.75, P=0.0085) and mean (r=0.87, P=0.001) pressure and marginally with maximum oxygen consumption (r=-0.59, P=0.05). RV free wall MGU also correlated well with mean PA pressure (r=0.66, P=0.03).
  
  
  CONCLUSIONS
  PET scanning with (13)N-NH(3) and (18)F-fluorodeoxyglucose is a feasible modality for quantifying RV blood flow and metabolism in patients with idiopathic PAH.
authors.affiliation: Division of Cardiology, Department of Medicine, New York Presbyterian Hospital at Columbia University Medical Center, New York, NY 10032, USA. sb605@columbia.edu
authors.forename: Sabahat
authors.initials: S
authors.lastname: Bokhari
authors.forename: Amresh
authors.initials: A
authors.lastname: Raina
authors.forename: Erika Berman
authors.initials: EB
authors.lastname: Rosenweig
authors.forename: P Christian
authors.initials: PC
authors.lastname: Schulze
authors.forename: Justin
authors.initials: J
authors.lastname: Bokhari
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Einstein
authors.forename: Robyn J
authors.initials: RJ
authors.lastname: Barst
authors.forename: Lynne L
authors.initials: LL
authors.lastname: Johnson
mesh_terms: D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000378:metabolism; D015331:Cohort Studies; D003287:Contrast Media; D003952:Diagnostic Imaging / Q000379:methods; D018450:Disease Progression; D018618:Echocardiography, Doppler, Color; D004562:Electrocardiography / Q000379:methods; D065627:Familial Primary Pulmonary Hypertension; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D006976:Hypertension, Pulmonary / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000401:mortality; D007089:Image Enhancement / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D011237:Predictive Value of Tests; D011379:Prognosis; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D015996:Survival Rate; D018497:Ventricular Dysfunction, Right / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000401:mortality; D055815:Young Adult
chemical_list: D015415:Biomarkers; D003287:Contrast Media; D019788:Fluorodeoxyglucose F18