Haemodynamics and left ventricular mass regression: a comparison of the stentless, stented and mechanical aortic...

Our objective was to compare the degree of change in hemodynamics and left ventricular mass (LVM) regression after aortic valve replacement (AVR) with stentless, stented and mechanical valves.

Patients greater than 59 years of age had AVR for aortic stenosis with the stentless xenograft (Cryolife-O'Brien, CLOB), stented xenograft (Carpentier-Edwards, C-E) or mechanical valve (ATS). One-hundred and forty-two patients received stentless, 40 stented, and 69 mechanical valves (mean age 74 +/- 6 vs. 72 +/- 7 and 67 +/- 6 years, respectively). Serial echocardiography was performed.

The left ventricular outflow tract diameter was similar pre-operatively in the stentless versus the stented versus the mechanical groups (2.2 +/- 0.4 vs. 2.3 +/- 0.2 vs. 2.2 +/- 0.3 cm; P, n.s). The effective orifice area was larger immediately post-operatively in the stentless versus the stented or the mechanical group (2.4 +/- 0.4 vs. 2.0 +/- 0.6 vs. 2.0 +/- 0.7 cm2, P = 0.0001 for both comparisons). The peak aortic gradient at 6 months was significantly less in the stentless versus the stented and mechanical groups (15 +/- 7 vs. 25 +/- 9 vs. 22 +/- 9 mmHg, P < 0.0001). LVM regressed over 6 months in all subgroups: stentless 272 +/- 64 g vs. 220 +/- 72 g, P = 0.0001, stented 257 +/- 58 vs. 230 +/- 74 g, P = 0.02, and mechanical 267 +/- 95 vs. 204 +/- 54 g, P = 0.003. The reduction in LVM was greater in the stentless versus the stented (P = 0.05) but similar to the mechanical group.

AVR with the stentless xenograft results in superior hemodynamics compared to the stented and mechanical valve replacements. AVR in all three groups leads to a significant regression of left ventricular hypertrophy within 6 months. However the reduction in LVM is greater in subjects with stentless and mechanical valves, which may have prognostic significance.