title: Hemodynamic performance of fresh and calcified aortic valve prostheses in critical low stroke volume.
abstract: OBJECTIVE
  Heart failure is common following aortic valve replacement, and optimal prosthesis function is crucial in this critical clinical setting. The study aim was to investigate the hemodynamic performance and leaflet kinematics of fresh and calcified biological aortic valves in a simulated low stroke volume situation.
  
  
  METHODS
  Edwards Perimount Magna (PM) and Medtronic Mosaic Ultra (MU) valves were investigated in an artificial circulation system (130 beats/min, stroke volume 19 ml), and the results compared to normal output (70 beats/min, stroke volume 70 ml). Leaflet kinematics were visualized using a high-speed camera. All valves were exposed to a calcifying solution for six weeks.
  
  
  RESULTS
  In the low- and normal-output situation, the PM valve initially demonstrated lower pressure gradients compared to the MU valve (low output 2.4 +/- 0.16 versus 3.4 +/- 0.19 mmHg), but showed a significantly higher closing volume (up to 19% of stroke volume) leading to an increased total energy loss. Regurgitation for the PM valve was explained by progressively longer opening and closing times. The PM valve calcified faster and more severely, leading to increasing gradients and closure volume.
  
  
  CONCLUSIONS
  In the low stroke volume situation pericardial valves demonstrated superior systolic performance, but inferior diastolic performance, leading to a higher total energy loss compared to porcine valves. This finding may have clinical relevance in heart-failure patients.
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Johann Wolfgang Goethe University Hospital, Frankfurt/Main, Germany. dzemali@em.uni-frankfurt.de
authors.forename: Omer
authors.initials: O
authors.lastname: Dzemali
authors.forename: Farhad
authors.initials: F
authors.lastname: Bakhtiary
authors.forename: Ulrich
authors.initials: U
authors.lastname: Steinseiffer
authors.forename: Christof
authors.initials: C
authors.lastname: Schmitz
authors.forename: Brigit
authors.initials: B
authors.lastname: Glasmacher
authors.forename: Anton
authors.initials: A
authors.lastname: Moritz
authors.forename: Peter
authors.initials: P
authors.lastname: Kleine
mesh_terms: D000818:Animals; D001021:Aortic Valve / Q000502:physiology*; D001696:Biomechanical Phenomena; D002114:Calcinosis / Q000503:physiopathology*; D009202:Cardiomyopathies / Q000503:physiopathology*; D003971:Diastole; D006350:Heart Valve Prosthesis; D066298:In Vitro Techniques; D023421:Models, Animal; D008955:Models, Cardiovascular; D013318:Stroke Volume / Q000502:physiology*; D013552:Swine; D013599:Systole