Acquired cardiovascular disease
Influence of the On-X mechanical prosthesis on intermediate-term major thromboembolism and hemorrhage: A prospective multicenter study

https://doi.org/10.1016/j.jtcvs.2009.10.068Get rights and content
Under an Elsevier user license
open archive

Objectives

Long-term thromboembolic and hemorrhagic outcomes after mechanical valve replacement have been well described; however, few studies have described these outcomes after valve replacement with the On-X mechanical prosthesis (On-X Life Technologies, Inc, Austin, Tex).

Methods

Between 2003 and 2008, 737 patients underwent either aortic valve replacement (n = 400), mitral valve replacement (n = 282), or double-valve replacement (n = 55). Longitudinal performance, freedom evaluation, and risk analysis were assessed with regard to major thromboembolism and hemorrhage. Risk modeling was performed with 16 variables inclusive of age, atrial fibrillation, concomitant coronary artery bypass grafting, New York Heart Association class, and ventricular dysfunction.

Results

Early mortality was 2.5% (n = 10) for aortic valve replacement and 3.2% (n = 9) for mitral valve replacement. Late mortality for aortic valve replacement was 4.8% per patient-year and 6.0% per patient-year for mitral valve replacement. Five-year freedom from major thromboembolism was 96.5% ± 1.2% for aortic valve replacement and 97.7% ± 0.9% for mitral valve replacement. Five-year freedom from hemorrhage was 93.6% ± 1.8% for aortic valve replacement and 95.7% ± 1.5% for mitral valve replacement. Concomitant coronary artery bypass grafting was predictive of major thromboembolism after aortic valve replacement (hazard ratio, 5.3; P = .02) and antithrombotic hemorrhage after mitral valve replacement (hazard ratio, 4.7; P = .03). No other independent predictors of major thromboembolism or hemorrhage were identified. One thrombosed mitral prosthesis was observed after deliberate discontinuation of anticoagulation. The major thromboembolic events occurred with variation of international normalized ratio levels inclusive of subtherapeutic levels. The majority of hemorrhagic events occurred with high international normalized ratio levels.

Conclusions

The On-X mechanical prosthesis provides favorable intermediate-term results with regard to major thromboembolism and hemorrhage.

CTSNet classification

35

Abbreviations and Acronyms

AVR
aortic valve replacement
CABG
coronary artery bypass grafting
CNS
central nervous system
HR
hazard ratio
INR
international normalized ratio
MVR
mitral valve replacement

Cited by (0)

Disclosures: On-X Life Technologies (formerly known as MCRI) provides unrestricted financial support to the University of Ottawa Heart Valve Clinic and the University of British Columbia Cardiac Valve Database. Dr Jamieson receives speakers' bureau support from On-X Life Technologies and does not receive financial support as the international principal investigator for the Prospective Randomized On-X Versus St. Jude Medical Evaluation Trial.