Real-time magnetic resonance assessment of septal curvature accurately tracks acute hemodynamic changes in pediatric pulmonary hypertension.
BACKGROUND
This study assesses the relationship between septal curvature and mean pulmonary artery pressure and indexed pulmonary vascular resistance in children with pulmonary hypertension. We hypothesized that septal curvature could be used to estimate right ventricular afterload and track acute changes in pulmonary hemodynamics.


RESULTS
Fifty patients with a median age of 6.7 years (range, 0.45-16.5 years) underwent combined cardiac catheterization and cardiovascular magnetic resonance. The majority had idiopathic pulmonary arterial hypertension (n=30); the remaining patients had pulmonary hypertension associated with repaired congenital heart disease (n=17) or lung disease (n=3). Mean pulmonary artery pressure and pulmonary vascular resistance were acquired at baseline and during vasodilation. Septal curvature was measured using real-time cardiovascular magnetic resonance. There was a strong correlation between mean pulmonary artery pressure and SCmin at baseline and during vasodilator testing (r=-0.81 and -0.85, respectively; P<0.01). A strong linear relationship also existed between pulmonary vascular resistance and minimum septal curvature indexed to cardiac output both at baseline and during vasodilator testing (r=-0.88 and -0.87, respectively; P<0.01). Change in septal curvature metrics moderately correlated with absolute change in mean pulmonary artery pressure and pulmonary vascular resistance, respectively (r=0.58 and -0.74; P<0.01). Septal curvature metrics were able to identify vasoresponders with a sensitivity of 83% (95% confidence interval, 0.36-0.99) and a specificity of 91% (95% confidence interval, 0.77-0.97), using the Sitbon criteria. Idiopathic pulmonary arterial hypertension subgroup analysis revealed 3 responders with ΔSCmin values of 0.523, 0.551, and 0.568. If the middle value of 0.551 is taken as a cutoff, the approximate sensitivity would be 67% and the specificity would be 93%.


CONCLUSIONS
Septal curvature metrics are able to estimate right ventricular afterload and track acute changes in pulmonary hemodynamics during vasodilator testing. This suggests that septal curvature could be used for continuing assessment of load in pulmonary hypertension.
From the Centre for Cardiovascular Imaging, UCL Institute of Cardiovascular Science, London, United Kingdom (B.P., M.A.Q., J.A.S., A.M.T., V.M.); Cardiorespiratory Division, Great Ormond Street Hospital for Children, London, United Kingdom (I.S.-N., G.D., S.M.); Adult Congenital Heart Disease Department, The Heart Hospital, University College London Hospitals, London, United Kingdom (B.P.); Pediatric Respiratory Medicine, The Royal Brompton Hospital, London, United Kingdom (A.M.); INSERM, U947, Nancy, France (F.O.); and IADI, Universite de Lorraine, Nancy, France (F.O.).
Bejal
B
Pandya
From the Centre for Cardiovascular Imaging, UCL Institute of Cardiovascular Science, London, United Kingdom (B.P., M.A.Q., J.A.S., A.M.T., V.M.); Cardiorespiratory Division, Great Ormond Street Hospital for Children, London, United Kingdom (I.S.-N., G.D., S.M.); Adult Congenital Heart Disease Department, The Heart Hospital, University College London Hospitals, London, United Kingdom (B.P.); Pediatric Respiratory Medicine, The Royal Brompton Hospital, London, United Kingdom (A.M.); INSERM, U947, Nancy, France (F.O.); and IADI, Universite de Lorraine, Nancy, France (F.O.).
Michael A
MA
Quail
From the Centre for Cardiovascular Imaging, UCL Institute of Cardiovascular Science, London, United Kingdom (B.P., M.A.Q., J.A.S., A.M.T., V.M.); Cardiorespiratory Division, Great Ormond Street Hospital for Children, London, United Kingdom (I.S.-N., G.D., S.M.); Adult Congenital Heart Disease Department, The Heart Hospital, University College London Hospitals, London, United Kingdom (B.P.); Pediatric Respiratory Medicine, The Royal Brompton Hospital, London, United Kingdom (A.M.); INSERM, U947, Nancy, France (F.O.); and IADI, Universite de Lorraine, Nancy, France (F.O.).
Jennifer A
JA
Steeden
From the Centre for Cardiovascular Imaging, UCL Institute of Cardiovascular Science, London, United Kingdom (B.P., M.A.Q., J.A.S., A.M.T., V.M.); Cardiorespiratory Division, Great Ormond Street Hospital for Children, London, United Kingdom (I.S.-N., G.D., S.M.); Adult Congenital Heart Disease Department, The Heart Hospital, University College London Hospitals, London, United Kingdom (B.P.); Pediatric Respiratory Medicine, The Royal Brompton Hospital, London, United Kingdom (A.M.); INSERM, U947, Nancy, France (F.O.); and IADI, Universite de Lorraine, Nancy, France (F.O.).
Andrea
A
McKee
From the Centre for Cardiovascular Imaging, UCL Institute of Cardiovascular Science, London, United Kingdom (B.P., M.A.Q., J.A.S., A.M.T., V.M.); Cardiorespiratory Division, Great Ormond Street Hospital for Children, London, United Kingdom (I.S.-N., G.D., S.M.); Adult Congenital Heart Disease Department, The Heart Hospital, University College London Hospitals, London, United Kingdom (B.P.); Pediatric Respiratory Medicine, The Royal Brompton Hospital, London, United Kingdom (A.M.); INSERM, U947, Nancy, France (F.O.); and IADI, Universite de Lorraine, Nancy, France (F.O.).
Freddy
F
Odille
From the Centre for Cardiovascular Imaging, UCL Institute of Cardiovascular Science, London, United Kingdom (B.P., M.A.Q., J.A.S., A.M.T., V.M.); Cardiorespiratory Division, Great Ormond Street Hospital for Children, London, United Kingdom (I.S.-N., G.D., S.M.); Adult Congenital Heart Disease Department, The Heart Hospital, University College London Hospitals, London, United Kingdom (B.P.); Pediatric Respiratory Medicine, The Royal Brompton Hospital, London, United Kingdom (A.M.); INSERM, U947, Nancy, France (F.O.); and IADI, Universite de Lorraine, Nancy, France (F.O.).
Andrew M
AM
Taylor
From the Centre for Cardiovascular Imaging, UCL Institute of Cardiovascular Science, London, United Kingdom (B.P., M.A.Q., J.A.S., A.M.T., V.M.); Cardiorespiratory Division, Great Ormond Street Hospital for Children, London, United Kingdom (I.S.-N., G.D., S.M.); Adult Congenital Heart Disease Department, The Heart Hospital, University College London Hospitals, London, United Kingdom (B.P.); Pediatric Respiratory Medicine, The Royal Brompton Hospital, London, United Kingdom (A.M.); INSERM, U947, Nancy, France (F.O.); and IADI, Universite de Lorraine, Nancy, France (F.O.).
Ingram
I
Schulze-Neick
From the Centre for Cardiovascular Imaging, UCL Institute of Cardiovascular Science, London, United Kingdom (B.P., M.A.Q., J.A.S., A.M.T., V.M.); Cardiorespiratory Division, Great Ormond Street Hospital for Children, London, United Kingdom (I.S.-N., G.D., S.M.); Adult Congenital Heart Disease Department, The Heart Hospital, University College London Hospitals, London, United Kingdom (B.P.); Pediatric Respiratory Medicine, The Royal Brompton Hospital, London, United Kingdom (A.M.); INSERM, U947, Nancy, France (F.O.); and IADI, Universite de Lorraine, Nancy, France (F.O.).
Graham
G
Derrick
From the Centre for Cardiovascular Imaging, UCL Institute of Cardiovascular Science, London, United Kingdom (B.P., M.A.Q., J.A.S., A.M.T., V.M.); Cardiorespiratory Division, Great Ormond Street Hospital for Children, London, United Kingdom (I.S.-N., G.D., S.M.); Adult Congenital Heart Disease Department, The Heart Hospital, University College London Hospitals, London, United Kingdom (B.P.); Pediatric Respiratory Medicine, The Royal Brompton Hospital, London, United Kingdom (A.M.); INSERM, U947, Nancy, France (F.O.); and IADI, Universite de Lorraine, Nancy, France (F.O.).
Shahin
S
Moledina
From the Centre for Cardiovascular Imaging, UCL Institute of Cardiovascular Science, London, United Kingdom (B.P., M.A.Q., J.A.S., A.M.T., V.M.); Cardiorespiratory Division, Great Ormond Street Hospital for Children, London, United Kingdom (I.S.-N., G.D., S.M.); Adult Congenital Heart Disease Department, The Heart Hospital, University College London Hospitals, London, United Kingdom (B.P.); Pediatric Respiratory Medicine, The Royal Brompton Hospital, London, United Kingdom (A.M.); INSERM, U947, Nancy, France (F.O.); and IADI, Universite de Lorraine, Nancy, France (F.O.). v.muthurangu@ucl.ac.uk.
Vivek
V
Muthurangu
D000208:Acute Disease; D000293:Adolescent; D006328:Cardiac Catheterization; D002648:Child; D002675:Child, Preschool; D065627:Familial Primary Pulmonary Hypertension; D005260:Female; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D006976:Hypertension, Pulmonary / Q000175:diagnosis* / Q000503:physiopathology; D007223:Infant; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D011237:Predictive Value of Tests; D011669:Pulmonary Wedge Pressure / Q000502:physiology; D015203:Reproducibility of Results; D014655:Vascular Resistance / Q000502:physiology; D014664:Vasodilation / Q000502:physiology; D016278:Ventricular Function, Right / Q000502:physiology; D054088:Ventricular Septum / Q000473:pathology*
hypertension, pulmonary; pediatrics; vasodilator agents