Coarctation of the aorta (CoA) is associated with decreased exercise capacity despite successful repair, though the hemodynamic mechanism remains unknown.
In this study, they studied aortic flow patterns during simulations of exercise in repaired CoA using 4D flow cardiovascular magnetic resonance (CMR) using aortic replicas connected to an in vitro flow pump and correlated findings with exercise stress test results to identify biomarkers of exercise intolerance.
As result, This study identified important associations between secondary flow characteristics and exercise capacity in repaired CoA not captured by traditional pressure gradient, likely due to increased turbulence and inefficient flow.

Jason G. Mandell, Yue-Hin Loke, Paige N. Mass, Vincent Cleveland, Marc Delaney, Justin Opfermann, Seda Aslan, Axel Krieger, Narutoshi Hibino & Laura J. Olivieri , "Altered hemodynamics by 4D flow cardiovascular magnetic resonance predict exercise intolerance in repaired coarctation of the aorta: an in vitro study", Journal of Cardiovascular Magnetic Resonance, Published Online (2021) .