Long-Term Cost Effectiveness of Early and Sustained Dual Oral Antiplatelet Therapy With Clopidogrel Given for Up to One Year After Percutaneous Coronary Intervention

Objectives

This study sought to evaluate the long-term cost effectiveness of a clopidogrel loading strategy before percutaneous coronary intervention (PCI) followed by continued treatment for one year.

Background

The Clopidogrel for the Reduction of Events During Observation (CREDO) trial, a randomized trial of 2,116 patients, showed the effectiveness of antiplatelet therapy with clopidogrel 300 mg before PCI and 75 mg daily for one year afterward compared with placebo load and placebo days 29 to 365 in reducing the combined risk of death, myocardial infarction, and stroke. All patients received clopidogrel on days 1 to 28 and aspirin on days 1 to 365.

Methods

All hospitalizations were assigned a diagnosis-related group. Associated costs were estimated three ways (including professional costs): 1) Medicare costs, 2) MEDSTAT costs, and 3) blend with Medicare for those age ≥65 years and MEDSTAT for those age <65 years. Clopidogrel 75 mg cost $3.22. Life expectancy in trial survivors was estimated using external data. Confidence intervals were assessed by bootstrap.

Results

The primary composite end point occurred in 89 (8.45%) clopidogrel patients and in 122 (11.48%) placebo patients (relative risk reduction [RRR] 26.9%; 95% confidence interval [CI] 3.9% to 44.4%). The number of life-years gained (LYG) with clopidogrel was 0.1526 (95% CI 0.0263 to 0.2838) using Framingham data and 0.1920 (95% CI 0.054 to 0.337) using Saskatchewan data. Average total costs were $664 higher for the clopidogrel arm (95% CI −$461 to $1,784). The incremental cost-effectiveness ratios (ICERs) based on Framingham data ranged from $3,685/LYG to $4,353/LYG, with over 97% of bootstrap-derived ICER estimates below $50,000/LYG. The ICERs based on Saskatchewan data were $2,929/LYG to $3,460/LYG, with over 98% of estimates below $50,000/LYG.

Conclusions

Platelet inhibition with clopidogrel loading before PCI followed by therapy for one year is highly cost effective.