Clinical and hemodynamic performance of the 19-mm medtronic mosaic bioprosthesis.

BACKGROUND AND AIM OF THE STUDY: The Medtronic Mosaic valve (MMV) is a latest generation supra-annular stented porcine valve, which combines a low-profile stent, leaflet fixation at zero pressure in a predilated aortic root, and amino-oleic acid anti-mineralization treatment for improved hemodynamics and durability. A study was conducted to evaluate the clinical and hemodynamic performances of the MMV in patients with a small aortic root (19 mm aortic annulus).

METHODS: Between 1998 and 2004, 81 consecutive patients (69 females, 12 males; mean age 78.0 +/- 5.5 years) underwent aortic valve replacement using the 19-mm MMV. Concomitant coronary artery bypass grafting was performed in 28 patients (29.2%), and mitral valve surgery in one patient (1.2%).

RESULTS: The 30-day mortality rate was 9.9% (eight deaths). Postoperative actuarial survival estimates were 90.1 +/- 3.3%, 78.5 +/- 4.6% and 69.1 +/- 5.5% at one month, one year and two years, respectively. After a mean follow up of 2.7 +/- 1.9 years, no cases of structural dysfunction, non-structural dysfunction or valve thrombosis were noted. Four ischemic cerebral complications (2.0% per patient-year (pt-yr)), five bleeding complications (2.0%/pt-yr) and two prosthetic valve infections (1.0%/pt-yr) were observed. No reoperation on a MMV was performed. Postoperatively, the mean systolic gradient was 23.4 +/- 7.0 mmHg, and the effective orifice area (EOA) 1.06 +/- 0.33 cm2. Valve prosthesis-patient mismatch (VP-PM) was moderate (indexed EOA > 0.65 cm2/m2 and < or = 0.85 cm2/m2) in 40 patients (49.4%), and severe (indexed EOA < or = 0.65 cm2/m2) in 41 (50.6%).

CONCLUSION: Although providing acceptable clinical results, implantation of the 19-mm MMV resulted in a high incidence of postoperative VP-PM. Hence, this valve should be reserved for patients in whom the projected indexed EOA calculated preoperatively is deemed acceptable, given the patient's clinical condition.