Aspirin, Warfarin, or the Combination for Secondary Prevention of Coronary Events in Patients With Acute Coronary Syndromes and Prior Coronary Artery Bypass Surgery

Abstract

Background —Patients with a non–ST-elevation acute coronary syndrome and prior CABG are at high risk of a recurrent ischemic event despite aspirin therapy. This trial investigated the potential benefit of secondary prevention with warfarin. Methods and Results —In a double-blind randomized trial, 135 patients with unstable angina or non–ST-segment elevation myocardial infarction, with prior CABG, and who were poor candidates for a revascularization procedure received therapy with aspirin and placebo+warfarin, warfarin and placebo+aspirin, or aspirin and warfarin for 12 months. Warfarin was titrated to an international normalized ratio of 2.0 to 2.5. The primary end point (death or myocardial infarction or unstable angina requiring hospitalization 1 year after randomization) occurred in 14.6% of the patients in the warfarin-alone group, in 11.5% of patients in the aspirin-alone group, and in 11.3% of patients randomized to the combination therapy ( P =0.76). Subgroup analyses by risk features provided no indications that warfarin alone or in combination with aspirin could be of benefit over aspirin alone. Bleeding was more frequent in the 2 groups of patients administered warfarin. Conclusions —Moderate-intensity oral anticoagulation alone or combined with low-dose aspirin does not appear to be superior to low-dose aspirin in the prevention of recurrent ischemic events in patients with non–ST-elevation acute coronary syndromes and previous CABG.

Antithrombotic therapy in hypertension: a Cochrane Systematic review

“…Two of these trials evaluated the effects of aspirin as compared to placebo, 20,31 while one trial compared the effects of aspirin, warfarin and aspirin plus warfarin. 24 A further trial investigated the outcome of aspirin vs clopidogrel. 32 Currently, there is only one large RCT with antithrombotic therapy that recruited solely hypertensive patients.…”

“…In the majority of the studies, we were unable to retrieve the data, which was largely due to the fact of the length of time since publication of the original trials. However, details were successfully requested from two studies 24,32 and one study having published a subgroup analysis with a different definition hypertension (SBP4145 mmHg 19 ) than in the data set provided from the original trial. 20 Both sets of data have been considered separately.…”

“…There was no significant difference in the haemorrhagic complications (ASA, 0/14, warfarin, 0/15, aspirin þ warfarin, 1/14). 24 The single haemorrhagic event occurred in the group treated with aspirin and warfarin.…”

“…[21][22][23] One study remained for further analysis. 24 Five studies investigating ticlopidine and glycoprotein IIb/IIIa inhibitors and their impact on cardiovascular and haemorrhagic events lacked sufficient follow-up data. [25][26][27][28][29] A further publication was excluded due to the inability to acquire the relevant data.…”

Treatment of Coronary Artery Bypass Graft Failure

“…[103] However, in a smaller randomized trial, moderate-intensity oral anticoagulation alone or combined with low-dose aspirin was not superior to low-dose aspirin in the prevention of recurrent ischemic events in patients with non-ST-elevation ACS and previous CABG. [104] Currently, the American College of Chest Physicians (ACCP) EvidenceBased Clinical Practice Guidelines recommended that oral anticoagulation in addition to aspirin can be considered only when it is indicated for other reasons. [105] Lipid lowering therapy -Clinical trials have shown that lipid lowering therapy (in particular statins) is beneficial in patients who have undergone CABG.…”