Elsevier

American Heart Journal

Volume 158, Issue 6, December 2009, Pages 917-924
American Heart Journal

Clinical Investigation
Acute Ischemic Heart Disease
Underutilization of clopidogrel and glycoprotein IIb/IIIa inhibitors in non–ST-elevation acute coronary syndrome patients: The Canadian Global Registry of Acute Coronary Events (GRACE) experience

https://doi.org/10.1016/j.ahj.2009.09.016Get rights and content

Background

There are limited contemporary data on the early use of clopidogrel or glycoprotein (Gp) IIb/IIIa inhibitors, alone versus combination therapies, in non–ST-elevation acute coronary syndrome (NSTE-ACS).

Methods

This study included 5,806 Canadian NSTE-ACS patients with elevated cardiac biomarker and/or ST deviation on presentation in the prospective GRACE between 2003-2007. We stratified the study population according to the management strategy (non-invasive vs invasive) and into low-(GRACE risk score ≤108), intermediate- (109-140), and high-risk groups (≥141).

Results

Overall, 3,893 patients (67.1%) received early (≤24 hours of admission) antiplatelet therapy; the rates of use were 76%, 73%, and 57% in the low-, intermediate-, and high-risk groups, respectively (P for trend < .001). Only 54% of the conservatively managed patients and 12% of the invasively managed patients received early clopidogrel and GpIIb/IIIa inhibitors, respectively. High-risk patients were less likely (adjusted odds ratio = 0.48, 95% CI 0.39-0.59, P < .001) to receive early clopidogrel or GpIIb/IIIa inhibitors, whereas in-hospital catheterization was an independent positive predictor (adjusted odds ratio = 2.02, 95% CI 1.74-2.34, P < .001) of use.

Conclusions

In this contemporary NSTE-ACS population, both clopidogrel and GpIIb/IIIa inhibitors were targeted toward patients treated with an invasive strategy but paradoxically toward the lower-risk group. In particular, clopidogrel appeared to be underused among conservatively managed patients despite its proven efficacy, whereas GpIIb/IIIa inhibitors were administered to only a minority of the high-risk patients with elevated cardiac biomarkers. Our findings emphasize the ongoing need to promote the optimal use of evidence-based antiplatelet therapies among high-risk patients with NSTE-ACS.

Section snippets

Study population

GRACE was established as a multinational, prospective registry to describe the epidemiology, treatment patterns, and clinical outcomes of an unselected population of patients with the entire spectrum of ACS. Details of GRACE have been published.12

In brief, patients entered in the registry had to be 18 years or older, alive at the time of presentation, and admitted with a presumptive diagnosis of ACS based on the history and at least one of the following: abnormal cardiac biomarkers,

Patient characteristics

Table I shows the baseline characteristics, medical history, and presenting clinical features of the study population (n = 5,806). Despite having a normal initial biomarker level, patients with unstable angina (UA) had a slightly but significantly higher GRACE RS on presentation, as compared with non–ST-elevation myocardial infarction (NSTEMI) patients (P < .001). Overall, 40.4% and 31.0% of the study patients were in the GRACE high-risk and intermediate-risk categories, respectively. With

Discussion

In this study of high-risk NSTE-ACS patients in Canada, we found considerable underutilization of GpIIb/IIIa inhibitors and clopidogrel despite published randomized trials and clinical practice guidelines. In particular, clopidogrel was underused in the conservatively managed patients, whereas GpIIb/IIIa inhibitors were infrequently administered early even among high-risk patients who subsequently underwent PCI.

Several randomized clinical trials have evaluated the efficacy of antiplatelet

Conclusion

In this contemporary NSTE ACS population, both clopidogrel and GpIIb/IIIa inhibitors were targeted toward patients treated with an invasive strategy but paradoxically toward the lower-risk group. In particular, clopidogrel appeared to be underused among conservatively managed patients despite its proven efficacy in this CURE-like population, whereas GpIIb/IIIa inhibitors were administered to only a minority of the high-risk patients with elevated biomarkers. Our findings emphasize the ongoing

Disclosures

Dr. Shaun G. Goodman, Speaker and consulting honoraria and research grant support from Key Pharmaceuticals, Bristol-Myers Squibb, Sanofi Aventis, Pfizer, and Key Schering. Dr. Robert C. Welsh, Honoraria from Astra Zeneca, Eli Lilly, Boeringher Ingelheim, sanofi-aventis, Johnson and Johnson, Hoffman LaRoche, Schering Plough. Dr. Shamir R. Mehta, Honoraria and research grants from GlaxoSmithKline and Sanofi-Aventis. Dr. Gilles Montalescot, Research Grants from: Bristol Myers Squibb,

Acknowledgements

We thank all the study coordinators, investigators, and patients who participated in GRACE and GRACE2. Dr Andrew Yan is supported by the Canadian Institutes of Health Research and a New Investigator Award from the Heart and Stroke Foundation of Canada.

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