title: Beyond Pressure Gradients: The Effects of Intervention on Heart Power in Aortic Coarctation.
abstract: BACKGROUND
  In aortic coarctation, current guidelines recommend reducing pressure gradients that exceed given thresholds. From a physiological standpoint this should ideally improve the energy expenditure of the heart and thus prevent long term organ damage.
  
  
  OBJECTIVE
  The aim was to assess the effects of interventional treatment on external and internal heart power (EHP, IHP) in patients with aortic coarctation and to explore the correlation of these parameters to pressure gradients obtained from heart catheterization.
  
  
  METHODS
  In a collective of 52 patients with aortic coarctation 25 patients received stenting and/or balloon angioplasty, and 20 patients underwent MRI before and after an interventional treatment procedure. EHP and IHP were computed based on catheterization and MRI measurements. Along with the power efficiency these were combined in a cardiac energy profile.
  
  
  RESULTS
  By intervention, the catheter gradient was significantly reduced from 21.8±9.4 to 6.2±6.1mmHg (p<0.001). IHP was significantly reduced after intervention, from 8.03±5.2 to 4.37±2.13W (p < 0.001). EHP was 1.1±0.3 W before and 1.0±0.3W after intervention, p = 0.044. In patients initially presenting with IHP above 5W intervention resulted in a significant reduction in IHP from 10.99±4.74 W to 4.94±2.45W (p<0.001), and a subsequent increase in power efficiency from 14 to 26% (p = 0.005). No significant changes in IHP, EHP or power efficiency were observed in patients initially presenting with IHP < 5W.
  
  
  CONCLUSIONS
  It was demonstrated that interventional treatment of coarctation resulted in a decrease in IHP. Pressure gradients, as the most widespread clinical parameters in coarctation, did not show any correlation to changes in EHP or IHP. This raises the question of whether they should be the main focus in coarctation interventions. Only patients with high IHP of above 5W showed improvement in IHP and power efficiency after the treatment procedure.
  
  
  BACKGROUND
  clinicaltrials.gov NCT02591940.
authors.affiliation: Department of Congenital Heart Disease, German Heart Centre Berlin, Augustenburger Platz 1, Berlin, Germany.
authors.forename: Joao Filipe
authors.initials: JF
authors.lastname: Fernandes
authors.affiliation: Department of Congenital Heart Disease, German Heart Centre Berlin, Augustenburger Platz 1, Berlin, Germany.|Biofluid Mechanics Laboratory, Charité-Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Leonid
authors.initials: L
authors.lastname: Goubergrits
authors.affiliation: Biofluid Mechanics Laboratory, Charité-Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Jan
authors.initials: J
authors.lastname: Brüning
authors.affiliation: Biofluid Mechanics Laboratory, Charité-Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Hellmeier
authors.affiliation: Department of Congenital Heart Disease, German Heart Centre Berlin, Augustenburger Platz 1, Berlin, Germany.
authors.forename: Sarah
authors.initials: S
authors.lastname: Nordmeyer
authors.affiliation: Department of Congenital Heart Disease, German Heart Centre Berlin, Augustenburger Platz 1, Berlin, Germany.
authors.forename: Tiago Ferreira
authors.initials: TF
authors.lastname: da Silva
authors.affiliation: Department of Congenital Heart Disease, German Heart Centre Berlin, Augustenburger Platz 1, Berlin, Germany.
authors.forename: Stephan
authors.initials: S
authors.lastname: Schubert
authors.affiliation: Department of Congenital Heart Disease, German Heart Centre Berlin, Augustenburger Platz 1, Berlin, Germany.|Pediatric Cardiology, Charite-Universitätsmedizin Berlin, Berlin, Germany.|DZHK (German Centre for Cardiovascular Research), partner site Berlin, Berlin, Germany.
authors.forename: Felix
authors.initials: F
authors.lastname: Berger
authors.affiliation: Department of Congenital Heart Disease, German Heart Centre Berlin, Augustenburger Platz 1, Berlin, Germany.|Pediatric Cardiology, Charite-Universitätsmedizin Berlin, Berlin, Germany.|DZHK (German Centre for Cardiovascular Research), partner site Berlin, Berlin, Germany.
authors.forename: Titus
authors.initials: T
authors.lastname: Kuehne
authors.affiliation: Department of Congenital Heart Disease, German Heart Centre Berlin, Augustenburger Platz 1, Berlin, Germany.|Pediatric Cardiology, Charite-Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Marcus
authors.initials: M
authors.lastname: Kelm
mesh_terms: D000293:Adolescent; D000328:Adult; D001017:Aortic Coarctation / Q000503:physiopathology / Q000601:surgery; D001794:Blood Pressure; D006328:Cardiac Catheterization; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D009206:Myocardium