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Doppler hemodynamic characteristics of four widely used aortic valve prostheses
C Masotti1, C De Castro, M Aquilina
1Department of Cardiology, G.B. Morgagni Hospital, Forlì, Italy.
Insights
Doppler-Echocardiography assessed mechanical aortic prosthetic heart valves, revealing distinct hemodynamic profiles. Starr-Edwards valves showed higher gradients, while St. Jude Medical valves had lower gradients but more regurgitation, guiding surgical selection.
Area of Science:
- Cardiovascular Medicine
- Biomedical Engineering
- Diagnostic Imaging
Background:
- Mechanical prosthetic heart valves are crucial for aortic valve replacement.
- Understanding their hemodynamic performance is vital for patient outcomes.
- Doppler-Echocardiography offers a noninvasive method for assessing prosthetic valve function.
Purpose of the Study:
- To evaluate type-related flow characteristics of four mechanical aortic prosthetic heart valves using Doppler-Echocardiography.
- To compare hemodynamic parameters including pressure gradients, effective orifice area, and regurgitation among different valve types.
- To determine the reliability of Doppler-Echocardiography for long-term follow-up of prosthetic heart valves.
Main Methods:
- Fifty-one patients with normofunctioning mechanical aortic prosthetic heart valves were studied.
- Doppler-Echocardiography was used to measure Peak (PG) and Mean (MG) Gradients, Cardiac Index (CI), Regurgitant Jets, and Effective Orifice Area (EOA).
- Patients with prosthetic dysfunction were excluded; data were analyzed for correlations with valve size and type.
Main Results:
- A significant inverse correlation was found between transvalvular pressure gradients and valve size (-0.70).
- A significant direct correlation was observed between Effective Orifice Area (EOA) and valve size (0.82), confirming the continuity equation's reliability.
- Starr-Edwards valves exhibited the highest gradients, while St. Jude Medical valves showed the lowest. Starr-Edwards valves had less regurgitation compared to the moderate incompetence often seen with St. Jude Medical valves.
Conclusions:
- Hemodynamic differences exist among mechanical aortic prosthetic heart valve types, influencing surgical selection.
- Doppler-Echocardiography provides reproducible, specific, and noninvasive data comparable to cardiac catheterization for prosthetic valve assessment.
- Due to its high sensitivity, specificity, and safety, Doppler-Echocardiography is recommended for the long-term follow-up of patients with aortic prosthetic heart valves.
Abstract:
Fifty-one patients with normofunctioning aortic prosthetic heart valves were evaluated by Doppler-Echocardiography to determine type-related flow characteristics. The four mechanical valves tested were: Starr-Edwards (1200-1260 aortic), Bjork-Shiley (60 degrees-60 degrees cc aortic), Medtronic-Hall (aortic) and St. Jude Medical (aortic). The most significant dynamic indexes were calculated: Peak (PG) and Mean (MG) Gradient across the valve, Cardiac Index (CI) or Cardiac Output (CO), Regurgitant Jets, Effective Orifice Area (EOA), Spectral Diagram Systolic Trend (SDST) and PVRT (time required to reach peak velocity during systole)/LVET (left ventricular ejection time) Ratio. Patients with Doppler assessed prosthetic dysfunction were dropped out of the study group. As expected, significant reverse correlation (-0.70) was found when transvalvular pressure gradients were compared with valve size. Significant direct correlation (0.82) was found when EOA was compared with valve size, thus suggesting the high reliability of the continuity equation in the assessment of the real orifice area. The Starr-Edwards valve, when compared with the other prostheses of the same size, showed the highest calculated transvalvular gradient; the St. Jude Medical showed the lowest. On the other hand, the Starr-Edwards valve was not commonly associated with regurgitation, while the St. Jude valve was usually moderately incompetent. Those hemodynamic differences should guide the selection of the ideal prosthetic valve for elective surgical indications. Doppler measurements provided noninvasive information similar to that given by cardiac catheterisation, which was reproducible and specific for valve function. According to this high sensitivity and specificity and to the absolute innocuity of the procedure, Doppler-Echocardiography should be considered the elective technique for long-term follow-up in patients with aortic prosthetic heart valves.