Randomized comparison of exercise haemodynamics of Freestyle, Magna Ease and Trifecta bioprostheses after aortic valve replacement for severe aortic stenosis

Abstract

Objectives: The purpose of this study was to compare haemodynamics at rest and during exercise after clinically indicated aortic valve replacement (AVR) for aortic stenosis among patients randomly assigned to one of three haemodynamically excellent bioprostheses.

Methods: In a single-centre, prospective trial, 60 patients undergoing clinically indicated AVR were randomly assigned to Freestyle, Magna Ease or Trifecta bioprostheses. Six months after surgery, patients underwent supine bicycle stress echocardiography for the assessment of aortic valve haemodynamics.

Results: There were 5 protocol deviations from random valve assignments, and 4 patients did not return for follow-up stress echo, yielding a study group of 56 patients {17 Freestyle, 21 Magna Ease, 18 Trifecta; median age 70 [interquartile range (IQR) 63-78 years], 37 (66%) men}. There were no statistically significant differences between groups in valve size, concomitant procedures or exercise variables. Resting haemodynamics revealed significant differences between groups in mean gradient [Freestyle 7 (IQR 5-9) mmHg, Magna Ease 9 (IQR 7-11) mmHg, Trifecta 5 (IQR 4-8) mmHg; P = 0.04], effective orifice area (EOA) [2.5 (IQR 2.2-2.7), 2.1 (IQR 1.7-2.3) and 2.6 (IQR 2.3-2.8), respectively; P = 0.02] and EOA index [1.22 (IQR 1.11-1.32), 1.02 (IQR 0.89-1.14) and 1.31 (IQR 1.00-1.42), respectively; P = 0.03]; in each case, Trifecta had better haemodynamics compared with Magna Ease. With exercise, significant differences between groups were evident in peak velocity at 50 watts and peak exercise; mean gradient at 25 watts, 50 watts and maximal exercise; and EOA at 25 watts and at peak exercise; all with haemodynamic superiority of Trifecta compared with Magna Ease. There were no statistically significant differences between Trifecta and Freestyle haemodynamics at rest or with exercise.

Conclusions: In a prospective, randomized study comparing haemodynamics after Freestyle, Magna Ease and Trifecta, all three valves exhibited good haemodynamics at rest and with exercise. There were small but significant differences between groups, with favourable haemodynamics associated with Trifecta compared to Magna Ease, and no significant differences between Trifecta and Freestyle. The Trifecta valve appears to offer haemodynamics similar to a stentless valve without the technical complexity of stentless valve implantation.

Clinicaltrialsgov identifier: NCT01635244.

Keywords: Aortic valve replacement; Bioprosthesis; Echocardiography/Doppler; Exercise testing; Haemodynamics.