In-Vitro Pulsatile Flow Testing of Prosthetic Heart Valves: A Round-Robin Study by the ISO Cardiac Valves Working Group
Hydrodynamic performance testing is one of the core in vitro assessments required by the ISO 5840 series of standards for all prosthetic heart valves. A round-robin study carried out in 2005 in accordance with ISO 5840:2005 revealed significant variabilities in prosthetic heart valve hydrodynamic performance measurements among the participating laboratories. In order to re-examine the inter-laboratory variability based on the “state-of-the-art” under ISO 5840-1 and 5840-2:2015, the ISO Cardiac Valve Working Groups decided in 2016 to repeat the round-robin study.
A total of 13 international laboratories participated in the study. The test valves were chosen to be the St. Jude Medical Masters Series mechanical valves (19 mm aortic, 25 mm aortic, 25 mm mitral, and 31 mm mitral), which were circulated among the laboratories. The testing was conducted according to a common test run sequence, with prespecified flow conditions.
The study revealed improved, yet still significant variability among different laboratories as compared to the 2005 study. The coefficient of variation ranged from 7.7 to 21.6% for the effective orifice area, from 10.1 to 32.8% for the total regurgitant fraction, and from 14.7 to 45.5% for the mean transvalvular pressure gradient.
The study revealed the ambiguities in the current versions of the ISO 5840 series of standards and the shortcomings of some participating laboratories. This information has allowed the ISO Working Group to incorporate additional clarifying language into the ISO 5840-1, -2, and -3 standards that are currently under revision to improve in vitro assessments. The results presented here can also be used by the testing laboratories to benchmark pulse duplicator systems and to train and certify testing personnel.
KeywordsProsthetic heart valves Hydrodynamic performance testing Effective orifice area Total regurgitant fraction Mean pressure gradient Waveform
We thank St. Jude Medical, Inc. (now part of Abbott) for providing the test valves. The findings and conclusions in this article have not been formally disseminated by the U.S. FDA and should not be construed to represent any agency determination or policy. The mention of commercial products, their sources, or their use in connection with material reported herein is not to be construed as either an actual or implied endorsement of such products by the U.S. Department of Health and Human Services.
The authors did not receive any funding to carry out the work.
The mention of commercial products, their sources, or their use in connection with material reported herein is not to be construed as either an actual or implied endorsement of such products by the U.S. Department of Health and Human Services.
Conflict of Interest
All authors declare that they have no conflicts of interest.
This article does not contain any studies with human participants or animals performed by any of the authors.
This article does not contain any studies with human participants.
- 3.Cornhill, J. F. An aortic-left ventricular pulse duplicator used in testing prosthetic aortic heart valves. J. Thorac. Cardiovasc. Surg. 4:550–558, 1977.Google Scholar
- 4.Davis K., J. H. Muller, C. J. Meyer, F. E. Smit. Evaluating the impact of air compliance chamber volumes on valve performance for three different heart valves. In: 2018 3rd Biennial South African Biomedical Engineering Conference (SAIBMEC), Stellenbosch, 2018, pp. 1–4.Google Scholar
- 5.ISO 5840-3:2013: Cardiovascular Implants—Cardiac Valve Prostheses—Part 3: Heart Valve Substitutes Implanted by Transcatheter Techniques. International Organization for Standardization, Geneva, Switzerland.Google Scholar
- 6.ISO 5840-2:2015. Cardiovascular Implants—Cardiac Valve Prostheses—Part 2: Surgically Implanted Heart Valve Substitutes. International Organization for Standardization, Geneva, Switzerland.Google Scholar
- 8.Retta, S. M., J. Kepner, S. Marquez, B. A. Herman, M. C. S. Shu, and L. W. Grossman. In-vitro pulsatile flow measurement in prosthetic heart valves: an inter-laboratory comparison. J. Heart Valve Dis. 26:72–80, 2017.Google Scholar