The On-X prosthetic heart valve at five years1
Section snippets
Patient population and surgery
From September 1996 to July 2001, a total of 532 patients had isolated valve replacement at 11 European and nine North American centers under a standardized protocol. Isolated aortic valve replacement (AVR) occurred in 303 (57%) patients, and isolated mitral valve replacement (MVR) in 229 (43%). In the AVR group, 68.6% of patients were male, whereas in the MVR group, 38% were male. The mean age at implant was 59.6 ± 9.1 years in AVR patients (range 20 to 85 years) and 59.2 ± 10.6 years in MVR
Mortality
Hospital mortality in the study was 2.44% (13/532) for the whole study, at 1.32% for AVR patients and 3.93% for MVR. One AVR patient died of multiple organ failure 6 weeks postoperatively without discharge from the hospital; thus, the 30-day mortality was 2.26% (0.99% for AVR and 3.93% for MVR). The 12 remaining deaths included 3 MVR patients from sepsis, 5 patients (2 AVR and 3 MVR) from arrhythmias determined by autopsy to be not related to the valve, 1 AVR patient from thromboembolism 10
Comment
As with all mechanical valves, a major concern is the long-term need for anticoagulation and the thrombogenic potential associated with these valves. Clinical studies of such valves rightly focus on thromboembolism, thrombosis, and bleeding rates, individually or as a collective index. In this study, patients were maintained on permanent anticoagulant therapy. The sum of the embolic and bleeding events in this study produced a freedom from these events at 2 years of 92.6% ± 1.2% AVR and 92.0% ±
Acknowledgements
The multicenter investigators in the On-X Prosthesis Heart Valve Trial are as follows: Europe: A. Laczkovics, Bochum, Germany; G. Laufer, Vienna, Austria; J. Pomar, Barcelona, Spain; D. Birnbaum, Regensburg, Germany; F. Hehrlein, Giessen, Germany; A. Haverich, Hannover, Germany; F. Mohr, Leipzig, Germany; H. Greve, Krefeld, Germany; H. Oelert, Mainz, Germany; D. Regensburger, Kiel, Germany; and G. Palatianos, Athens, Greece. North America: T. Ivey, Cincinnati, OH; G. Lemole, Newark, DE; S.
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Cited by (32)
The role of mechanical valves in the aortic position in the era of bioprostheses and TAVR: Evidence-based appraisal and focus on the On-X valve
2022, Progress in Cardiovascular DiseasesCitation Excerpt :This study was the first real-world demonstration of the exceptionally low incidence of valve thrombosis in On-X aortic valves.76 With the addition of other studies revealing low thromboembolic event rates,70,77 the path to the PROACT Trial was developed. The manufacturer-sponsored Prospective Randomized On-X Anticoagulation Clinical Trial (PROACT) study compared standard warfarin therapy (target INR 2.0 to 3.0) with either reduced warfarin (target INR 1.5 to 2.0) in the High-Risk arm, or dual antiplatelet therapy (DAPT) in the Low-Risk arm.27
Improving the hemocompatibility of heart valves
2018, Hemocompatibility of Biomaterials for Clinical Applications: Blood-Biomaterials InteractionsImproving the hemocompatibility of heart valves
2017, Hemocompatibility of Biomaterials for Clinical Applications: Blood-Biomaterials InteractionsClinical event rates with the On-X bileaflet mechanical heart valve: A multicenter experience with follow-up to 12 years
2013, Journal of Thoracic and Cardiovascular SurgeryCitation Excerpt :Trials are in progress to investigate the safety of low anticoagulation rates in the On-X valve (PROACT; US registration NCT00291525). No structural failures were found, and none have been reported by other studies.3-6,10,11 This is similar to other types of bileaflet mechanical valve other than the St Jude Medical valve, the discontinued Hemex-Duromedics valve (originally Hemex Scientific Inc, Austin, Tex), and the Tekna-Edwards valve (originally Baxter Healthcare Corp, Santa Ana, Calif), for which a small number of leaflet escapes have been reported.11-13
Influence of the On-X mechanical prosthesis on intermediate-term major thromboembolism and hemorrhage: A prospective multicenter study
2010, Journal of Thoracic and Cardiovascular SurgeryCitation Excerpt :Instead, patients were managed by either the primary physician or the treating cardiac surgeon according to practice guidelines.15 Patients in this study were comparable in age to those of other studies describing outcomes after mechanical valve replacement.3-13 Overall, 6% (38/682) of patients had preoperative left ventricular ejection fraction of less than 35%, whereas concomitant CABG was performed in 13% (80/682) of patients.
Immediate and Long-Term Echocardiographic Findings after Transcatheter Aortic Valve Implantation for the Treatment of Aortic Stenosis: The Cribier-Edwards/Edwards-Sapien Valve Experience
2010, Journal of the American Society of EchocardiographyCitation Excerpt :The mean pressure gradient for mechanical and tissue prostheses ranges from 13 to 17 mm Hg, and the mean pressure gradient for the Cribier-Edwards valve is 10 ± 2 mm Hg. Only the On-X (Medical Carbon Research Institute, LLC, Austin, TX) shows similar results with an effective orifice area of approximately 2 cm2.26 Hemodynamic differences with the Cribier-Edwards/Edwards-Sapien valve may be explained by its particular manufacture.
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The members of On-X Prosthesis Heart Valve Trial are listed in the Acknowledgments.