Does the type of prosthesis influence early left ventricular mass regression after aortic valve replacement? Assessment with magnetic resonance imaging.

BACKGROUND

Debate exists regarding selection of the prosthesis type most likely to maximize early left ventricular (LV) mass regression after aortic valve replacement (AVR) for stenotic valvular disease. The aim of this study was to compare the degree of LV mass regression measured by MRI 6 months after prospectively randomized valve implantation for two biological prostheses, stented and stentless, and for two mechanical valves, tilting disc and bileaflet.

METHODS

Thirty-nine consecutive patients with predominant aortic stenosis accepted for elective AVR were studied. Twenty patients requiring a tissue prosthesis were randomly assigned to receive either a Freestyle or Mosaic valve. The remaining 19 patients in whom mechanical prosthesis was indicated were randomly assigned to receive either an Ultracor or an ATS valve.

RESULTS

There was no difference in valve size implanted between the compared groups. LV mass measurements were performed with MRI (1.5-T Vision, Siemens, Germany) immediately before and 6 months after surgery. All valve types produced significant postoperative reduction in LV mass compared with preoperative values (P <.01). Percent change in LV mass regression was similar between the two porcine valve types, Mosaic (24.4% +/- 11.1%) and Freestyle (21.1% +/- 16.7%), and between the two mechanical valve designs, Ultracor (19.3% +/- 9.5%) and ATS (26.3% +/- 10.8%), respectively.

CONCLUSIONS

Significant LV remodeling occurs early after AVR for aortic stenosis. The degree of regression in LV mass is independent of prosthesis type implanted.