Efficacy of oral anticoagulants compared with aspirin after infrainguinal bypass surgery (The Dutch Bypass Oral Anticoagulants or Aspirin Study): a randomised trial. Comparative effects of antiplatelet, anticoagulant, or combined therapy in patients with valvular and nonvalvular atrial fibrillation: a randomized multicenter study. Clopidogrel plus aspirin versus oral anticoagulation for atrial fibrillation in the Atrial fibrillation Clopidogrel Trial with Irbesartan for prevention of Vascular Events (ACTIVE W): a randomised controlled trial. A randomized comparison of antiplatelet and anticoagulant therapy after the placement of coronary-artery stents. Self-management of oral anticoagulation in the elderly: rationale, design, baselines and oral anticoagulation control after one year of follow-up. A randomized controlled trial.
Oral anticoagulants and aspirin are antithrombotic drugs that are commonly used in patients with vascular disease. We investigated whether either of these treatments prevented more effectively than the other bypass complications after infrainguinal bypass surgery.
                We did a multicentre, randomised, open trial. 2690 patients who had undergone infrainguinal grafting were randomly assigned oral anticoagulants (target international normalised ratio 3.0-4.5, n=1339) or aspirin (80 mg daily, n=1351). We followed up patients for a mean of 21 months. The primary outcome was graft occlusion.
                308 graft occlusions occurred in the oral-anticoagulants group compared with 322 in the aspirin group (hazard ratio 0.95 [95% CI 0.82-1.11]), which suggested no overall advantage for either treatment. Oral anticoagulants were beneficial in patients with vein grafts (0.69 [0.54-0.88]), whereas aspirin had better results for nonvenous grafts (1.26 [1.03-1.55]). The composite outcome of vascular death, myocardial infarction, stroke, or amputation occurred 248 times in the oral-anticoagulants group and 275 times in the aspirin group (0.89 [0.75-1.06]). Patients treated with oral anticoagulants had more major bleeding episodes than those treated with aspirin (108 vs 56; 1.96 [1.42-2.71]).
                Oral anticoagulation was better for the prevention of infrainguinal-vein-graft occlusion and for lowering the rate of ischaemic events. Aspirin was better for the prevention of non-venous graft occlusion, and was associated with fewer bleeding episodes. This trial evaluated the efficacy and safety of the combination of antiplatelet and moderate-intensity anticoagulation therapy in patients with atrial fibrillation associated with recognized risk factors or mitral stenosis.
                Warfarin was more effective than aspirin in preventing stroke in these patients; combined therapy with low anticoagulant intensity was ineffective. Mitral stenosis patients were not investigated.
                We performed a multicenter randomized trial in 1,209 patients at risk. The intermediate-risk group included patients with risk factors or age >60 years: 242 received the cyclooxygenase inhibitor triflusal, 237 received acenocumarol, and 235 received a combination of both. The high-risk group included patients with prior embolism or mitral stenosis: 259 received anticoagulants and 236 received the combined therapy. Median follow-up was 2.76 years. Primary outcome was a composite of vascular death and nonfatal stroke or systemic embolism.
                Primary outcome was lower in the combined therapy than in the anticoagulant arm in both the intermediate- (hazard ratio [HR] 0.33 [95% confidence interval (CI)0.12 to 0.91]; p = 0.02) and the high-risk group (HR 0.51 [95% CI 0.27 to 0.96]; p = 0.03). Primary outcome plus severe bleeding was lower with combined therapy in the intermediate-risk group. Nonvalvular and mitral stenosis patients had similar embolic event rates during anticoagulant therapy.
                The combined antiplatelet plus moderate-intensity anticoagulation therapy significantly decreased the vascular events compared with anticoagulation alone and proved to be safe in atrial fibrillation patients. Oral anticoagulation therapy reduces risk of vascular events in patients with atrial fibrillation. However, long-term monitoring is necessary and many patients cannot achieve optimum anticoagulation. We assessed whether clopidogrel plus aspirin was non-inferior to oral anticoagulation therapy for prevention of vascular events.
                Patients were enrolled if they had atrial fibrillation plus one or more risk factor for stroke, and were randomly allocated to receive oral anticoagulation therapy (target international normalised ratio of 2.0-3.0; n=3371) or clopidogrel (75 mg per day) plus aspirin (75-100 mg per day recommended; n=3335). Outcome events were adjudicated by a blinded committee. Primary outcome was first occurrence of stroke, non-CNS systemic embolus, myocardial infarction, or vascular death. Analyses were by intention-to-treat. This study is registered with ClinicalTrials.gov, number NCT00243178.
                The study was stopped early because of clear evidence of superiority of oral anticoagulation therapy. There were 165 primary events in patients on oral anticoagulation therapy (annual risk 3.93%) and 234 in those on clopidogrel plus aspirin (annual risk 5.60%; relative risk 1.44 (1.18-1.76; p=0.0003). Patients on oral anticoagulation therapy who were already receiving this treatment at study entry had a trend towards a greater reduction in vascular events (relative risk 1.50, 95% CI 1.19-1.89) and a significantly (p=0.03 for interaction) lower risk of major bleeding with oral anticoagulation therapy (1.30; 0.94-1.79) than patients not on this treatment at study entry (1.27, 0.85-1.89 and 0.59, 0.32-1.08, respectively).
                Oral anticoagulation therapy is superior to clopidogrel plus aspirin for prevention of vascular events in patients with atrial fibrillation at high risk of stroke, especially in those already taking oral anticoagulation therapy. The clinical benefit of coronary-artery stenting performed in conjunction with coronary angioplasty is limited by the risk of thrombotic occlusion of the stent as well as hemorrhagic and vascular complications of intensive anticoagulation. We compared antiplatelet therapy with conventional anticoagulant therapy with respect to clinical outcomes 30 days after coronary-artery stenting.
                After successful placement of Palmaz-Schatz coronary-artery stents, 257 patients were randomly assigned to receive antiplatelet therapy (ticlopidine plus aspirin) and 260 to receive anticoagulant therapy (intravenous heparin, phenprocoumon, and aspirin). The primary cardiac end point was a composite measure reflecting death from cardiac causes or the occurrence of myocardial infarction, aortocoronary bypass surgery, or repeat angioplasty. The primary noncardiac end point comprised death from noncardiac causes, cerebrovascular accident, severe hemorrhage, and peripheral vascular events.
                Of the patients assigned to antiplatelet therapy, 1.6 percent reached a primary cardiac end point, as did 6.2 percent of those assigned to anticoagulant therapy (relative risk, 0.25; 95 percent confidence interval, 0.06 to 0.77). With antiplatelet therapy, there was an 82 percent lower risk of myocardial infarction than in the anticoagulant-therapy group, and a 78 percent lower need for repeat interventions. Occlusion of the stented vessel occurred in 0.8 percent of the antiplatelet-therapy group and in 5.4 percent of the anticoagulant-therapy group (relative risk, 0.14; 95 percent confidence interval, 0.02 to 0.62). A primary noncardiac end point was reached by 1.2 percent of the antiplatelet-therapy group and 12.3 percent of the anticoagulant-therapy group (relative risk, 0.09; 95 percent confidence interval, 0.02 to 0.31). Hemorrhagic complications occurred only in the anticoagulant-therapy group (in 6.5 percent). An 87 percent reduction in the risk of peripheral vascular events was observed with antiplatelet therapy.
                As compared with conventional anticoagulant therapy, combined antiplatelet therapy after the placement of coronary-artery stents reduces the incidence of both cardiac events and hemorrhagic and vascular complications. Self-management is safe and reliable in patients with long-term oral anticoagulation (OAC). However, no study has yet assessed the safety and efficacy of OAC self-management in elderly patients with major thromboembolic and haemorrhagic complications as primary outcomes. In this multi-centre, open, randomised controlled trial, patients aged 60 years or more were randomised into the self-management group (SMG) (N = 99) or routine care group (RCG) (N = 96). We describe the rationale, design, baseline characteristics and interim analyses of oral anticoagulation control quality within the first year of follow-up. The medians of the squared international normalised ratio (INR) value deviations after six and 12 months were significantly lower in the SMG with medians of 0.16 and 0.16 compared to the RCG with medians of 0.25 and 0.25. The percentage of time within target range and the percentage of INR measurements within target range were significantly higher in the SMG versus the RCG within the first six months (medians 71% vs. 58% and 69% vs. 57%), and during the second six months of the study (75% vs. 67% and 72% vs. 57%). The numbers of all thromboembolic events requiring hospitalisation, major bleeding events, and deaths were similar in both groups. These preliminary results suggest that self-management of oral anticoagulation is safe and feasible for elderly patients willing to participate in a structured training programme.
Existing evidence does not suggest a mortality benefit from oral anticoagulation in patients with cancer while increasing the risk for bleeding.