Hemodynamic evaluation and midterm outcome of aortic valve replacement with size 19 Perimount prosthetic valve

Strategy to avoid patient-prosthesis mismatch: aortic root enlargement

BACKGROUND

The choice of a valve with an effective orifice area matching the body surface area and providing efficient hemodynamics is an important factor affecting mortality and morbidity in patients undergoing aortic valve replacement.

PATIENTS AND METHODS

Our preventative strategy was to implant a larger prosthetic valve by aortic root enlargement using the Nunez procedure in 17 patients between February 2010 and January 2011. The decision to enlarge the aortic root was taken when the 19-mm sizer could not be negotiated easily through the aortic root, or on the basis of body surface area of the patient or type of prosthesis available.

RESULTS

Postoperative reductions in peak and mean pressure gradients across aortic valve of 12.8-16.5 and 10.2-12.6 mm Hg, respectively, were observed. Postoperative effective orifice areas of the aortic valves were 1.1-1.5 cm(2). By upsizing the aortic valve, we were able to eliminate patient-prosthesis mismatch in 5 patients, and reduce severe patient-prosthesis mismatch to moderate in 11.

CONCLUSION

Aortic root enlargement is a safe procedure. Therefore, cardiac surgeons should not be reluctant to enlarge the aortic root with an autologous pericardial patch to permit implantation of an adequate size of aortic valve prosthesis, with minimal additional aortic crossclamp time and no added cost.

Prosthesis-patient mismatch in aortic stenosis

BACKGROUND

The clinical impacts of prosthesis-patient mismatch (PPM) after aortic valve replacement (AVR) have been debated since Rahimtoola first reported PPM in 1978. Many reports discussing several aspects of PPM have been published to date, but the definitive clinical impacts of PPM have not yet been clarified.

PURPOSE

The purpose of this review is to evaluate recent articles regarding PPM and discuss the latest findings.

RESULTS

Moderate PPM (indexed effective orifice area ≤ 0.85 cm(2)/m(2)) did not affect the surgical outcomes in several papers, but severe PPM (indexed effective orifice area ≤ 0.65 cm(2)/m(2)) affected early and late mortality in almost of the all papers in which it was reported. PPM had a greater effect on younger patients and patients with left ventricular dysfunction than it did on elderly patients and patients with preserved left ventricular function.

CONCLUSION

Based on recent findings, it is difficult to define the impact of PPM after AVR. To some degree, PPM affects the clinical outcomes after AVR; therefore, it is important to avoid PPM, especially severe PPM.

Clinical outcomes and hemodynamics of the 19-mm Perimount Magna bioprosthesis in an aortic position: comparison with the 19-mm Medtronic Mosaic Ultra Valve

BACKGROUND

When aortic valve replacement is performed in patients with a small aortic annulus, prosthesis-patient mismatch (PPM) is of concern because it can affect postoperative clinical outcomes. Although larger bioprosthetic valves have been well studied, the hemodynamics of 19-mm bioprostheses have been reported in only a small number of patients. The effectiveness as well as the impact of PPM on outcomes are thus still unclear.

METHODS AND RESULTS

Postoperative clinical and hemodynamic variables were compared in 67 patients with a 19-mm Carpentier Edwards Perimount Magna bioprosthesis and in 10 patients with a 19-mm Medtronic Mosaic Ultra valve. Mean follow-up time was 13 months. There was no in-hospital mortality. Echocardiography 6.5±4.0 months after surgery showed significant decreases in the mean left ventricular (LV)-aortic pressure gradient, and decreases in the mean LV mass index. Reduction in LV mass index did not differ between the valve groups, despite a higher pressure gradient in the Mosaic group. Although PPM was detected in 21 patients in the Magna group, it did not affect regression of the LV mass index during the follow-up period.

CONCLUSIONS

Use of the 19-mm Magna bioprosthesis appears to provide satisfactory clinical results. LV-aortic pressure gradient was lower in the Magna group. The present data suggest that PPM is not related to reduction in the LV mass index.