Comparative Effectiveness of Clopidogrel in Medically Managed Patients with Unstable Angina and non-ST Segment Elevation Myocardial Infarction.
J Am Coll Cardiol. 2014 Mar 21;
Authors: Solomon MD, Go AS, Shilane D, Boothroyd DB, Leong TK, Kazi DS, Chang TI, Hlatky MA
OBJECTIVES: To examine the effectiveness of clopidogrel in real-world, medically-managed patients with unstable angina (UA) or non-ST segment elevation MI (NSTEMI).
BACKGROUND: Although clinical trials have demonstrated the efficacy of clopidogrel to reduce cardiovascular morbidity and mortality in medically-managed patients with UA/NSTEMI, its effectiveness in actual clinical practice is less certain.
METHODS: We conducted a retrospective cohort study of Kaiser Permanente members without known coronary disease or prior clopidogrel use who presented with UA/NSTEMI between 2003-2008 and were medically managed. Over two years of follow-up, we measured the association between clopidogrel use and all-cause mortality, hospitalization for MI, and a composite endpoint of death or MI using propensity-matched multivariable Cox analyses.
RESULTS: We identified 16,365 patients with incident UA (35%) or NSTEMI (65%), 36% of who were prescribed clopidogrel within 7 days of discharge. In 8,562 propensity score matched patients, clopidogrel users had lower rates of all-cause mortality (8.3% vs 13.0%, p < 0.01; adjusted hazard ratio (HR) = 0.63, 95% confidence interval (CI) = 0.54 to 0.72) and the composite of death or MI (13.5% vs 17.4%, p < 0.01; HR = 0.74, CI = 0.66 to 0.84), but not of MI alone (6.7% vs. 7.2%, p=0.30; HR= 0.93, CI = 0.78 to 1.11) compared with non-users of clopidogrel. The association between clopidogrel use and the composite of death or MI was significant only among patients presenting with NSTEMI (HR = 0.67, CI = 0.59 to 0.76; pint < 0.01), and not among those presenting with UA (HR = 1.25, CI = 0.94 to 1.67).
CONCLUSION: In a large, community-based cohort of patients medically managed after UA/NSTEMI, clopidogrel use was associated with a lower risk of death and MI, particularly among NSTEMI patients.
PMID: 24703914 [PubMed - as supplied by publisher]