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. Objectives 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. Conclusion 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. Trial
Registration clinicaltrials.gov NCT0259194
