. 2013 Nov;101(5):466–471. doi: 10.5935/abc.20130202

Table 4.

Main comparative studies after bioprosthetic valve implantation with outcome focused on thromboembolic events, comparing warfarin with aspirin alone

Author-Year	N	Study design and follow-up (months)	Location and incidence of embolic events (%/person-year)	Stipulated therapy	Conclusion (embolic events)
Gonzalez-Lavin et al³³ 1984	528	Retrospective; 30.5	MBP	Group 1: WAR < 6 weeks 206 pts; Group 2: > 8 weeks 322 pts	Bovine pericardial bioprosthesis; low risk.
Gonzalez-Lavin et al³³ 1984	528	Retrospective; 30.5	Group 1 = 4.6 Group 2 = 0.36	Group 1: WAR < 6 weeks 206 pts; Group 2: > 8 weeks 322 pts	Bovine pericardial bioprosthesis; low risk.
Turpie et al³⁴ 1988	210	Randomized; 3	ABP	Group 1: INR 2.5-4.0 108 pts; Group 2: INR 2.0-2.25 102 pts	Less intensive regimen was similar for embolic events and had fewer bleeding episodes.
Turpie et al³⁴ 1988	210	Randomized; 3	MBP	Group 1: INR 2.5-4.0 108 pts; Group 2: INR 2.0-2.25 102 pts
Orszulak et al¹⁰ 1995	285	Retrospective;	MBP 2.5	Not informed	High risk of CVA (40%/ person-year) in the first month;
Goldsmith et al³⁵ 1998	145	Retrospective;	ABP 0.3	ASA	In the first three months there was no increased risk of thromboembolism;
Moinuddeen et al³⁶ 1998	185	Retrospective; 3	ABP 2.8 x 2.6	WAR 109 x NAT 76 pts	Early OA was not effective in reducing embolic events
Brueck et al³⁷ 2007	288	Retrospective; Observational; 12	ABP	ASA 132 x NAT 156 pts	No benefit of ASA versus nothing;
Duraes et al¹¹	184	Prospective. Observational	MBP and ABP	ASA 59 x NAT 125 pts	Low incidence. No benefit of ASA versus nothing.

N: sample size; AF: atrial fibrillation; ABP: aortic bioprosthesis; MBP: mitral bioprosthesis; NAT: No antithrombotic therapy; EF: ejection fraction; OA: oral anticoagulation; CVA: cerebrovascular accident; pts: Patients; ASA: aspirin.