Combination Hemotherapy and Mortality Prevention (CHAMP) Study - CHAMP

Description:

Is the combination of aspirin and warfarin more effective than aspirin monotherapy in the secondary prevention of vascular events and death after acute myocardial infarction (AMI)?

Hypothesis:

The combination of aspirin and warfarin will be more effective than aspirin monotherapy in the secondary prevention of vascular events and death after acute myocardial infarction (AMI).

Study Design

Study Design:

Patient Populations:

Target/actual number of subjects in the trial: Age and age range: No cut off, all patients capable of giving consent Gender: Males and females (though veteran population is predominantly male) Diagnosis of acute MI as defined by the presence of two of the following: 1) Chest discomfort typical of acute MI 2) EKG changes typical of acute MI 3) Blood enzyme changes typical of acute MI

Primary Endpoints:

Mortality at a median follow-up duration of 2.7 years

Secondary Endpoints:

New angina pectoris, DVT, Claudication, PE, Angioplasty, Revascularization procedures, Hemorrhagic complications, Peptic ulcer, Abdominal pain, Gastritis, Nausea, Vomiting, Gout

Drug/Procedures Used:

Patients with AMI within 14 days of their event (n=5059) were randomly assigned in an open-labeled fashion to receive warfarin (target international normalized ratio 1.5 to 2.5 IU) plus aspirin (81 mg daily) (n=2537) or aspirin monotherapy (162 mg daily, n=2522) and followed for a median of 2.7 years.

Principal Findings:

Mortality at follow-up (primary end-point) was similar in the combination group compared to the group receiving aspirin alone (17.6% vs. 17.3%, log-rank p=0.76). Similarly, there was no difference between the combination therapy and monotherapy in the recurrence of AMI (13.3% vs. 13.1% respectively, log-rank p=0.78) or stroke (3.1% vs. 3.5%, respectively, log-rank p =0.52). Major bleeding, a majority being gastrointestinal, occurred more frequently in the combination therapy group than in the aspirin group (1.28 vs. 0.72 events per 100 person years of follow-up, respectively; p<0.001). Fourteen individuals had intracranial bleeds in both the aspirin and combination therapy groups.

Interpretation:

Among patients who have sustained an AMI, warfarin therapy (at a mean international normalized ratio of <1.8) combined with low-dose aspirin did not provide any additional clinical benefit beyond that achievable with aspirin monotherapy. This data supports findings from the Coumadin Aspirin Reinfarction Study (CARS) (median international normalized ratio range 1.04 to 1.19 IU) which suggested that warfarin plus aspirin does not provide any additional clinical advantage over aspirin alone in secondary prevention after AMI. Whether a higher target level of anticoagulation (> 1.80 IU) provides any advantage in combination with low dose aspirin over aspirin alone in secondary prevention after AMI is still uncertain but is being addressed in two ongoing clinical trials (Warfarin Reinfarction Study II [WARISII] and Anticoagulants in the Secondary Prevention of Events in Coronary Thrombosis II [ASPECT II]). Until the results of these trials are published, aspirin without routine warfarin is appropriate for secondary prevention after AMI.

References:

Fiore LD, Ezekowitz MD, Brophy MT, et al. for the Combination Hemotherapy and Mortality Prevention (CHAMP) Study Group. Department of Veterans Affairs Cooperative Studies Program Clinical Trial Comparing Combined Warfarin and Aspirin With Aspirin Alone in Survivors of Acute Myocardial Infarction: Primary Results of the CHAMP Study. Circulation 2002;105:557-63.

Clinical Topics: Anticoagulation Management, Prevention, Stable Ischemic Heart Disease

Keywords: Myocardial Infarction, Stroke, Recurrence, Platelet Aggregation Inhibitors, Secondary Prevention, Warfarin, Coronary Thrombosis, Electrocardiography, Hemorrhage


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