Table 4.

Comparison among guidelines

	ACC/AHA 2006 guidelines/2008 focused update	ESC 2007 guidelines	ACCP 2008 guidelines
Target INR according to valve type and location	Mechanical Aortica,b 2–3 Mitral 2.5–3.5 Aortic + Mitral 2.5–3.5 Multiple 2.5–3.2	See Table 5	Mechanicalb Aorticc Mitral 2.5–3.5 Aortic + Mitral 2.5–3.5 Multiple 2.5–3.5
Adding ASA to VKA	If high-risk factors,a add ASA (75–100 mg/day) May be reasonable to give clopidogrel (75 mg/day) if ASA C/I	Add if concomitant CAD, PAD, or recurrent embolic event	Add ASA (50–100 mg/ day) for high-risk patients or previous embolic event
Bioprosthesis	ASA 75–100 mg/day Consider VKA if risk factorsa Risk factors with C/I to VKA consider a higher dose of ASA (75–325 mg/day)	No evidence to support the long-term use of antiplatelet agents in patients who do not have an indication other than the presence of the bioprosthesis itself	ASA 50–100 mg/day Consider VKA if high risk conditiona
Bioprosthesis–VKA during first 3 months after implant in patients without risk factor for thromboembolism	Reasonable Target INR = 2.5a	Yes (any position) Target INR = 2.5	Only in mitral valves Target INR = 2.5
Anticoagulation during early postoperative period	Early use of UFH after prosthetic valve replacement—before warfarin achieves therapeutic levels—is controversial	IV UFH until INR is therapeutic Oral anticoagulation should be started during the first postoperative days	IV UFH or subcutaneous LMWH until INR is therapeutic for 2 consecutive days
Bridge therapy	Should be considered in high-risk patients Preferably UFH Use of LMWH is not directly addressed	Hospital admission in advance and bridge with IV UFH Recommend against LMWH as outpatient	Unclear, though should be considered in high- risk patients Recommend considering use of LMWH as outpatient
Thromboembolic event during VKA	Add ASA and consider increasing INR target	Add ASA	Add ASA and consider increasing INR target

^aAtrial fibrillation, previous thromboembolism, left ventricular dysfunction, and hypercoagulable condition (target INR, 3.0; range, 2.5–3.5).

^bCaged-ball or caged-disk valve, VKA therapy (target INR, 3.0; range, 2.5–3.5).

^cAdditional risk factors for thromboembolism, such as atrial fibrillation, anterior-apical ST-segment elevation myocardial infarction, left atrial enlargement, hypercoagulable state, or low ejection fraction, we recommend VKA therapy (target INR, 3.0; range, 2.5–3.5). ACC indicates American College of Cardiology, ACCP American College of Chest Physicians, AHA American Heart Association, ASA aspirin, CAD coronary artery disease, C/I contraindicated, ESC European Society of Cardiology, INR international normalized ratio, IV intravenous, LMWH low molecular weight heparin, PAD peripheral artery disease, UFH unfractionated heparin, VKA vitamin K antagonist