Background: The Perimount Magna valve (Edwards Lifesciences, Irvine, CA) was designed to minimize the amount of obstruction to blood flow across the valve. We compared hemodynamic performance of the Perimount Magna valve with the Hancock II valve (Medtronic, Minneapolis, MN), a second-generation porcine bioprosthesis with proven long-term results.
Methods: The 57 patients who received a Magna valve at our institution from 2003 to 2005 were matched 1:1 with 57 patients who received a Hancock II valve on variables known to affect hemodynamic measurements: size of implanted valve, age, sex, and body surface area. Early postoperative transthoracic echocardiography was performed in 100% of patients.
Results: In addition to the matched variables, patients in both groups were similar for all measured preoperative characteristics and perioperative clinical outcomes. One week postoperatively, Magna patients had significantly lower peak (22.1 +/- 7.4 mm Hg versus 32.3 +/- 15.1 mm Hg) and mean transvalvular gradients (10.4 +/- 4.0 mm Hg versus 18.5 +/- 15.5 mm Hg, both p < 0.001). The Magna group also had a trend towards a larger effective orifice area (1.40 +/- 0.24 cm2 versus 1.29 +/- 0.34 cm2, p = 0.07), despite a similar left ventricular outflow tract diameter (2.0 +/- 0.2 cm versus 2.0 +/- 0.1 cm, p = 0.7). Patient-prosthesis mismatch, as defined by measured effective orifice area of less than 0.65 cm2/m2, was significantly less common in the Magna group (30% versus 52%, p = 0.02).
Conclusions: The Magna valve has more favorable early postoperative hemodynamics than the Hancock II valve. Further studies should be performed comparing the Magna valve to newer-generation, low-profile porcine valves.