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DOI: 10.1055/a-2733-0889
Meta-Analysis of Low-Intensity versus Standard Anticoagulation for Mechanical Aortic Valves
Authors
Abstract
Background
This meta-analysis aimed to evaluate the long-term outcomes of a low-intensity anticoagulation (LA) strategy in patients undergoing mechanical aortic valve replacement.
Materials and Methods
A systematic search of the databases was conducted through October 2024. Single-arm meta-analysis was performed to estimate the pooled late outcomes associated with LA. The Kaplan–Meier survival curve was reconstructed using individual patient data from included studies to assess overall survival. A standard meta-analysis was then conducted to compare outcomes between LA and standard anticoagulation (SA).
Results
Eight studies, comprising 2,426 patients and 21,062.7 patient-years, were included. Five studies involved comparable groups, while three were single-arm studies. The pooled valve-related mortality rate with LA was 0.05 per 100 patient-year, with incidences of prosthetic valve thrombosis, composite of bleeding and thromboembolism, bleeding, and thromboembolism being 0.03, 1.5, 0.93, and 0.46 per 100 patient-year, respectively. The Kaplan–Meier analysis showed overall survival rates at 10 years of 88.5%. Compared with SA, LA was associated with significantly lower risks of all-cause mortality (hazard ratio [HR]: 0.50; 95% confidence interval [CI]: 0.37–0.68; p < 0.01), composite outcome (HR: 0.49; 95% CI: 0.37–0.66; p < 0.01), and bleeding (HR: 0.37; 95% CI: 0.26–0.52; p < 0.01). There were no significant differences in valve thrombosis (HR: 0.52; 95% CI: 0.13–2.11; p = 0.36) or thromboembolic event rates (HR: 0.88; 95% CI: 0.50–1.54; p = 0.65).
Conclusion
This meta-analysis suggests that LA is associated with reduced risks of all-cause mortality and bleeding compared with SA, while thromboembolic risks remain comparable.
Ethical Approval
Considering the nature of this study as a systematic review and meta-analysis of previously published articles, ethical approval was deemed unnecessary.
Publication History
Received: 16 June 2025
Accepted: 27 October 2025
Article published online:
10 November 2025
© 2025. International College of Angiology. This article is published by Thieme.
Thieme Medical Publishers, Inc.
333 Seventh Avenue, 18th Floor, New York, NY 10001, USA
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References
- 1 Yamak B, Iscan Z, Mavitas B. et al. Low-dose oral anticoagulation and antiplatelet therapy with St. Jude Medical heart valve prosthesis. J Heart Valve Dis 1999; 8 (06) 665-673
- 2 Van Nooten GJ, Taeymans Y, Van Belleghem Y. et al. Lower anticoagulation for mechanical heart valves: experience with the ATS bileaflet valve. Heart Lung Circ 2003; 12 (03) 164-171
- 3 Torella M, Torella D, Chiodini P. et al. LOWERing the INtensity of oral anticoaGulant Therapy in patients with bileaflet mechanical aortic valve replacement: results from the “LOWERING-IT” Trial. Am Heart J 2010; 160 (01) 171-178
- 4 Otto CM, Nishimura RA, Bonow RO. et al. 2020 ACC/AHA Guideline for the Management of Patients With Valvular Heart Disease: Executive Summary: A report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines. Circulation 2021; 143 (05) e35-e71
- 5 Puskas J, Gerdisch M, Nichols D. et al; PROACT Investigators. Reduced anticoagulation after mechanical aortic valve replacement: Interim results from the prospective randomized on-X valve anticoagulation clinical trial randomized Food and Drug Administration investigational device exemption trial. J Thorac Cardiovasc Surg 2014; 147 (04) 1202-1210 , discussion 1210–1211
- 6 Page MJ, McKenzie JE, Bossuyt PM. et al. The PRISMA 2020 statement: An updated guideline for reporting systematic reviews. BMJ 2021; 372 (71) n71
- 7 Guyot P, Ades AE, Ouwens MJ, Welton NJ. Enhanced secondary analysis of survival data: Reconstructing the data from published Kaplan-Meier survival curves. BMC Med Res Methodol 2012; 12: 9
- 8 Wei Y, Royston P. Reconstructing time-to-event data from published Kaplan-Meier curves. Stata J 2017; 17 (04) 786-802
- 9 Liu N, Zhou Y, Lee JJ. IPDfromKM: Reconstruct individual patient data from published Kaplan-Meier survival curves. BMC Med Res Methodol 2021; 21 (01) 111
- 10 Egger M, Davey Smith G, Schneider M, Minder C. Bias in meta-analysis detected by a simple, graphical test. BMJ 1997; 315 (7109): 629-634
- 11 Sterne JA, Hernán MA, Reeves BC. et al. ROBINS-I: A tool for assessing risk of bias in non-randomised studies of interventions. BMJ 2016; 355: i4919
- 12 Higgins JP, Altman DG, Gøtzsche PC. et al; Cochrane Bias Methods Group, Cochrane Statistical Methods Group. The Cochrane Collaboration's tool for assessing risk of bias in randomised trials. BMJ 2011; 343: d5928
- 13 Sterne JAC, Savović J, Page MJ. et al. RoB 2: A revised tool for assessing risk of bias in randomised trials. BMJ 2019; 366: l4898
- 14 Sawa S, Saito S, Morita K. et al. Thirty-year outcomes of low-intensity anticoagulation for mechanical aortic valve. Heart Vessels 2024; 39 (06) 549-555
- 15 Oo AY, Loubani M, Gerdisch MW. et al. On-X aortic valve replacement patients treated with low-dose warfarin and low-dose aspirin. Eur J Cardiothorac Surg 2024; 65 (05) 65
- 16 Rubino AS, Torella M, Della Ratta EE. et al. Safety of low intensity oral anticoagulant therapy in patients with bileaflet mechanical aortic valve prosthesis: A propensity weighted study. Int J Cardiol 2020; 317: 139-143
- 17 Puskas JD, Gerdisch M, Nichols D. et al; PROACT Investigators. Anticoagulation and antiplatelet strategies after On-X mechanical aortic valve replacement. J Am Coll Cardiol 2018; 71 (24) 2717-2726
- 18 Teshima H, Ikebuchi M, Miyamoto Y. et al. 10-year results of On-X bileaflet mechanical heart valve in the aortic position: low target INR regimen in Japanese. Gen Thorac Cardiovasc Surg 2017; 65 (08) 435-440
- 19 Bové T, Van Belleghem Y, François K. et al. Low target-INR anticoagulation is safe in selected aortic valve patients with the Medtronic Open Pivot mechanical prosthesis: long-term results of a propensity-matched comparison with standard anticoagulation. Interact Cardiovasc Thorac Surg 2017; 24 (06) 862-868