title: Haemodynamic performance of a new pericardial aortic bioprosthesis during exercise and recovery: comparison with pulmonary autograft, stentless aortic bioprosthesis and healthy control groups.
abstract: OBJECTIVE
  Since blood flow impairment by aortic valve prosthesis is characteristically dynamic, this dynamic component is best and thoroughly appreciated by exercise Doppler echocardiography. We sought to determine the haemodynamics of a new pericardial aortic bioprosthesis [Trifecta™-aortic valve bioprosthesis (T-AVB), St Jude Medical, MN, USA] at rest and during exercise and a 10-min recovery period in comparison with alternative aortic valve prostheses, e.g. Ross operation (RO), stentless aortic valve [Medtronic freestyle-aortic valve bioprosthesis (MF-AVB)] and a healthy control group (CO).
  
  
  METHODS
  Haemodynamics at rest and during supine exercise stress testing and a 10-min recovery period were evaluated in 32 patients (mean age: 70.8 ± 6.7 years) with T-AVB (mean follow-up: 5 ± 2 months), 49 with RO (mean age: 43.5 ± 13.7 years), 39 with an MF-AVB (mean age: 64.6 ± 9.4 years) and 26 healthy patients (mean age: 39 ± 9 years). Measurements included mean outflow tract gradient (δp mean, mmHg), effective orifice area index (EOAI, cm(2)/m(2)) and valvular resistance (vR, dyn s cm(-5)).
  
  
  RESULTS
  Mean body surface area for T-AVB was 1.93 ± 0.24 m(2) (median 1.97 m(2)). Mean δp mean at rest was 7.2 ± 3.4 mmHg, mean EOAI 0.86 ± 0.23 cm(2)/m(2) and mean vR 50.7 ± 23.2 dyn s cm(-5). Supine stress testing did increase the mean EOAI to 0.98 ± 0.27 cm(2)/m(2), the mean vR to 62.6 ± 25.3 dyn s cm(-5) and the mean δp mean to 10.21 ± 4.7 mmHg, respectively (P < 0.05 for all comparisons). During the post-exercise recovery period, δp mean, EOAI and vR showed a prompt normalization within 5 min of cessation of exercise. At all the three measurement points, T-AVB and MF-AVB revealed low gradients, satisfactory EOAI and low vR. Compared with the RO and a healthy control group, both groups showed significantly inferior performance throughout the exercise and post-exercise study protocol (P < 0.05). In comparison with T-AVB, patients with an MF-AVB only showed significant inferior performance throughout series with respect to a higher vR, indicating a smaller increase in the EOAI during exercise. During the 10-min post-exercise period, T-AVB recovered significantly earlier than MF-AVB.
  
  
  CONCLUSIONS
  When comparing two different types of aortic valve bioprostheses with a gold standard group (RO) and a healthy population, both aortic valve bioprostheses perform inferior but reveal promising haemodynamics during exercise. During post-exercise haemodynamic recovery, only the T-AVB revealed a nearly physiological recovery pattern compared with the RO and a healthy control group.
authors.affiliation: Clinic for Cardiac and Thoracic Vascular Surgery, University Clinic of Schleswig-Holstein, Lübeck, Germany.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Hanke
authors.forename: Efstratios I
authors.initials: EI
authors.lastname: Charitos
authors.forename: Hauke
authors.initials: H
authors.lastname: Paarmann
authors.forename: Ulrich
authors.initials: U
authors.lastname: Stierle
authors.forename: Hans-H
authors.initials: HH
authors.lastname: Sievers
mesh_terms: D000328:Adult; D000368:Aged; D001021:Aortic Valve / Q000601:surgery*; D001705:Bioprosthesis; D016009:Chi-Square Distribution; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D006350:Heart Valve Prosthesis; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged
keywords: Aortic valve bioprosthesis; Exercise stress test; Haemodynamics