Nov. 14, 2003 (Orlando) -- Two studies bolster the integral role of clopidogrel in the treatment of patients with acute coronary syndromes (ACS), regardless of whether they are undergoing percutaneous coronary intervention (PCI), researchers reported here this week at the American Heart Association Scientific Sessions.
A new analysis of data from the Clopidogrel in Unstable Angina to Prevent Recurrent Events (CURE) trial suggests that platelet inhibition with clopidogrel for up to one year after presentation with ACS is highly cost-effective.
And a second analysis, using data from the Clopidogrel for Reduction of Events During Observation (CREDO) trial, shows that a loading strategy with clopidogrel prior to PCI is cost-effective both prior to PCI and for one year thereafter.
Presenting the CURE findings, William S. Weintraub, MD, director of the Emory Center for Outcomes Research at Emory University School of Medicine in Atlanta, said that about 94% of life-years gained through the use of clopidogrel for patients with ACS would cost less than $50,000 over a lifetime, the figure that Lambda estimates as societal willingness to pay.
The efficacy of clopidogrel was previously demonstrated in the CURE trial. That trial involved 12,562 patients presenting with unstable angina or a non-ST elevation myocardial infarction (MI) who were randomized to clopidogrel or placebo, said Dr. Weintraub. At a mean follow-up of 9 months, there were 20% fewer cardiovascular deaths, nonfatal MIs or strokes in the treated group compared with the placebo group ( P < .001).
For the cost-effectiveness analysis, the initial hospitalization and all rehospitalizations were assigned a diagnosis-related group (DRG). The DRGs were then converted to 2001 costs using Medicare average reimbursements. For purposes of the analysis, clopidogrel was priced at $3.22 per day, the average wholesale price in 2001.
Life expectancy associated with no event, MI, stroke, and death in trial survivors was estimated using published data on 5,070 patients from the Framingham Heart Study, and discounted 3%, Dr. Weintraub said.
Also, data on nearly 16,000 patients with ACS from the Saskatchewan Health database were analyzed using piecemeal regression to obtain death hazard functions over time. Life-years lost to an event were then calculated by subtracting the survival expected with a given event pattern from the life expectancy associated with no events.
For the cost-effectiveness analysis, 95% confidence intervals of differences in cost and efficacy were assessed by bootstrap.
Using the Framingham database, the cost of each extra year gained by clopidogrel treatment would be $6,318, Dr. Weintraub reported. Using the Saskatchewan database, it would be $6,475.
Analyses using private insurance or a blend of private insurance and Medicare yielded similar results, he said.
In comparison, aspirin for acute MI costs $2,400 per life-year gained and eptifibatide for ACS costs $16,491 per life-year saved, he noted.
Dr. Weintraub added that 94% of life-years gained using the Framingham database and 98% of those gained using the Saskatchewan database would cost less than $50,000.
The study was funded by Sanofi-Synthelabo and Bristol-Myers Squibb.
Charles A. Herzog, MD, Director of the Cardiovascular Special Studies Center at the United States Renal Data System in Minneapolis, called the analysis "robust."
"Economic analysis can be hazardous," he said. "But this one avoided pitfalls."
The data offer one more reason to offer clopidogrel to patients with ACS, he said. "It won't change my practice, as I was already prescribing clopidogrel based on the CURE effectiveness data," Dr. Herzog said. "But this gives another reason. The drug works and it is cost-effective."
The CREDO analysis yielded equally impressive results, said Dr. Weintraub, who was a coinvestigator.
In that trial, 2116 patients with coronary artery disease undergoing planned or probable PCI were randomized to clopidogrel loading before PCI plus 1 year of therapy or placebo. At 1 year, long-term clopidogrel therapy was associated with a 26.9% relative reduction in the combined risk of death, MI, or stroke compared with placebo (95% confidence interval, 3.9% - 44.4%), reported lead author Sean Beinart, MD, MsCR, a cardiologist at Emory University.
Using similar methodology to that used in the CURE analysis, the researchers found that the cost of each event prevented using a clopidogrel-loading strategy versus placebo based on 28-day outcomes was dominant, with 84.8% of life-years saved costing less than 50,000 per event prevented.
The study was funded by Sanofi-Synthelabo.
At 12 months, the cost-effectiveness of daily clopidogrel in addition to a clopidogrel-loading strategy prior to PCI compared with placebo was $3,685 per life-year saved, with 84.1% of life-years gained costing less than $50,000, the study showed.
Noting that another study showed that clopidogrel was cost-effective in the treatment of the subset of patients in the CURE trial who undergo PCI (PCI-CURE), Dr. Weintraub said, "The data consistently show that this is a very cost-effective therapy."
AHA Scientific Sessions 2003: Abstract 1925, presented Nov. 10, 2003; abstract 3495, presented Nov. 12, 2003.
Reviewed by Charlotte E. Grayson, MD
Medscape Medical News © 2003 Medscape
Cite this: Charlene Laino. CURE, CREDO Trials Demonstrate Clopidogrel Cost-Effective for ACS - Medscape - Nov 14, 2003.