Commentary: Can in vitro valve testing reliably predict clinical outcomes?
Notice bibliographique
Résumé
Central MessageNew generations of aortic valve protheses should always aim at better clinical outcomes, whether physics, hemodynamic, or other parameters also mirror those changes.See Article page 43. New generations of aortic valve protheses should always aim at better clinical outcomes, whether physics, hemodynamic, or other parameters also mirror those changes. See Article page 43. Hatoum and colleagues1Hatoum H. Ahn S. Lilly S. Maureira P. Crestanello J. Thourani V.H. et al.Flow dynamics of surgical and transcatheter aortic valves: past to present.J Thorac Cardiovasc Surg Open. 2022; 9: 43-56Scopus (1) Google Scholar have published an elegant paper showing the hemodynamic parameters and flow characteristics downstream of various transcatheter and surgical aortic valve protheses. They included extensive fluid dynamic considerations by testing the valves in an in vitro environment, using a pulse duplicator. The authors measured the pressure gradient, effective orifice area (EOA), as well as the Reynolds shear stress (RSS) and viscous shear stress (VSS) (those last 2 are used to analyze the degree of turbulence in the downstream flow) among the protheses tested. They demonstrated that the SJM mechanical valve (Abbott Laboratories, Chicago, Ill) had the greatest EOA and that the Hancock II (Medtronic, Minneapolis, Minn) displayed the greatest range of RSS and VSS among the surgical valves. Regarding the transcatheter valves, the Evolut (Medtronic) displayed the greatest range of RSS and VSS compared with the SAPIEN 3 (Edwards Lifesciences, Irvine, Calif). The authors concluded that these features should be considered in the design of future aortic valves prothesis, and that the evolution of the aortic valve protheses have not kept up with improvements in physics.1Hatoum H. Ahn S. Lilly S. Maureira P. Crestanello J. Thourani V.H. et al.Flow dynamics of surgical and transcatheter aortic valves: past to present.J Thorac Cardiovasc Surg Open. 2022; 9: 43-56Scopus (1) Google Scholar The obvious question the reader should consider is whether better hemodynamic features translate into better clinical outcomes for patients undergoing aortic valve replacement? Better fluid dynamics do not always predict better clinical outcomes. For example, hemodynamics parameters of the Toronto SPV bioprothesis predicted excellent results; however, the valve was challenged by suboptimum durability, and reoperation was associated with a high complexity.2David T.E. Feindel C.M. Bos J. Ivanov J. Armstrong S. Aortic valve replacement with Toronto SPV bioprosthesis: optimal patient survival but suboptimal valve durability.J Thorac Cardiovasc Surg. 2008; 135: 19-24Abstract Full Text Full Text PDF PubMed Scopus (64) Google Scholar,3Dellgren G. Feindel C.M. Bos J. Ivanov J. David T.E. Aortic valve replacement with the Toronto SPV: long-term clinical and hemodynamic results.Eur J Cardiothorac Surg. 2002; 21: 698-702Crossref PubMed Scopus (41) Google Scholar Similarly, the Hancock II bioprothesis, despite of in vitro predictions of high pressure gradient, RSS, VSS, and low EOA, has demonstrated great durability.1Hatoum H. Ahn S. Lilly S. Maureira P. Crestanello J. Thourani V.H. et al.Flow dynamics of surgical and transcatheter aortic valves: past to present.J Thorac Cardiovasc Surg Open. 2022; 9: 43-56Scopus (1) Google Scholar,4David T.E. Armstrong S. Maganti M. Hancock II bioprosthesis for aortic valve replacement: the gold standard of bioprosthetic valves durability?.Ann Thorac Surg. 2010; 90: 775-781Abstract Full Text Full Text PDF PubMed Scopus (144) Google Scholar,5David T.E. Armstrong S. Sun Z. Clinical and hemodynamic assessment of the Hancock II bioprosthesis.Ann Thorac Surg. 1992; 54 (discussion 667-8): 661-667Abstract Full Text PDF PubMed Scopus (62) Google Scholar We are not implying that valve hemodynamics in such testing should be ignored; however, findings should be taken in context, and perhaps we should re-examine the implications of laboratory predictions. We have not yet reached the ideal aortic valve substitute. However, we have been improving clinical outcomes despite a possible lag on the physics features. Today, we can pick an aortic valve prothesis according to the preferences and characteristics of the patient, making each choice unique and individual. Patients at any age are able to choose the valve that best fits them, whether with a surgical or transcatheter approach, whether with a bioprothesis or a mechanical prothesis or a Ross procedure. And, for the future, the new generation of aortic valve protheses should always aim at better clinical outcomes, whether physics, hemodynamic, or other parameters mirror those changes. Flow dynamics of surgical and transcatheter aortic valves: Past to presentJTCVS OpenVol. 9PreviewTo perform an in vitro characterization of surgical aortic valves (SAVs) and transcatheter aortic valves (TAVs) to highlight the development of the flow dynamics depending on the type of valve implanted and assess the basic differences in the light of flow turbulence and its effect on blood damage likelihood and hemodynamic parameters that shed light on valve performance. Full-Text PDF Open Access
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,014 | 0,098 |
| Méta-épidémiologie (sens strict) | 0,002 | 0,001 |
| Méta-épidémiologie (sens large) | 0,003 | 0,002 |
| Bibliométrie | 0,002 | 0,002 |
| Études des sciences et des technologies | 0,003 | 0,005 |
| Communication savante | 0,004 | 0,006 |
| Science ouverte | 0,009 | 0,002 |
| Intégrité de la recherche | 0,056 | 0,043 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,013 | 0,016 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».