Clopidogrel in non-ST segment elevation acute coronary syndromes: an overview of the submission by the British Cardiac Society and the Royal College of Physicians of London to the National Institute for Clinical Excellence, and beyond

Rates and causes of death from non-ST elevation acute coronary syndromes: ten year follow-up of the PRAIS-UK registry

BACKGROUND

Long term nationally representative mortality rates following acute coronary syndrome (ACS) admissions are lacking beyond 5 years. We report rates and causes of mortality at approximately 10 years from PRAIS-UK.

METHODS

PRAIS-UK was a prospective registry of 1046 non-ST-elevation ACS admissions to 56 UK hospitals between 1998 and 1999. 493 patients surviving to 6 months were consented to long term follow-up. We identified deaths and causes (ICD codes) via the UK central death register and examined the influence of baseline characteristics and early revascularisation procedures. A modified GRACE risk score was constructed to determine the association of baseline score with long term risk of death.

RESULTS

The mean age was 66 years and 40% were women. After a median follow-up of 11.6 years (IQR 6.3-11.9), 46% (225) of patients had died with 55% being classified as cardiovascular. In a multivariate analysis, the following variables were associated with higher mortality (hazard ratio [HR] and 95% confidence intervals [CI]): age (10 years increase) 2.14 (1.87 to 2.45), ST depression or bundle branch block (compared to normal ECG) 1.68 (1.06 to 2.67), and history of heart failure (compared to no HF) 1.81 (1.28 to 2.56). The HR for risk of death in patients who received a revascularisation procedure (versus those who did not) in the first 6 months was 0.41 (0.24 to 0.69). The mean adapted GRACE score was 99.3 ± 26.4, associated with approximately 50% mortality at 10 years.

CONCLUSIONS

Non-ST elevation ACS is associated with about 50% mortality over 10 years that may be improved by early revascularisation. Well designed long-term registries can provide key data to determine prognosis and burden of disease.

Efficacy and safety of optimized antithrombotic therapy with aspirin, clopidogrel and enoxaparin in patients with non-ST segment elevation acute coronary syndromes in clinical practice

In randomized clinical trials enoxaparin in non ST-elevation acute coronary syndromes (NSTE-ACS) has been shown to be more effective than unfractionated heparin in preventing the combined endpoint of death and myocardial infarction. Clopidogrel in combination with aspirin reduced the combined endpoint of death, myocardial infarction and stroke in NSTE-ACS patients compared to aspirin alone. Aim of the present study was to determine the clinical impact of optimized antithrombotic therapy with enoxaparin, clopidogrel and aspirin compared to standard therapy with unfractionated heparin (UFH) and aspirin in NSTE-ACS in clinical practice. We analyzed data of 2,956 consecutive patients with NSTE-ACS and either antithrombotic therapy with enoxaparin, clopidogrel and aspirin or with aspirin and UFH, which were prospectively enrolled in the acute coronary syndromes registry (ACOS) from July 2000 until the end of November 2002. After adjustment for baseline characteristics and PCI the combined endpoint of hospital death and non-fatal reinfarctions was lower in the group with optimized antithrombotic therapy including clopidogrel, enoxaparin and aspirin compared to the control-group with aspirin and UFH (odds ratio 0.30, 95% confidence interval 0.16-0.53). There was no significant difference in major bleedings between the two treatment groups (1.5% vs. 0.9%, P = 0.35), while overall there were more bleeding complications in the group with optimized antithrombotic therapy (4.9% vs. 2.0%, P = 0.005). In clinical practice optimized antithrombotic therapy with aspirin, clopidogrel and enoxaparin in NSTE-ACS is associated with a reduction in the combined endpoint of death and non-fatal reinfarctions compared to standard therapy with aspirin and UFH without increase in major bleeding complications.

Clopidogrel in the treatment of ischaemic heart disease

Clopidogrel is an effective antiplatelet agent that has undergone rigorous assessment in the setting of ischaemic heart disease over the last decade. There is extensive evidence for the use of this drug in patients undergoing percutaneous coronary intervention, in those with stable ischaemic heart disease and also in those with acute coronary syndromes. This article examines the use of clopidogrel in patients with ischaemic heart disease.

Clopidogrel: a pharmacoeconomic review of its use in patients with non-ST elevation acute coronary syndromes

Clopidogrel (Plavix) is a selective inhibitor of adenosine diphosphate-induced platelet aggregation. In patients with acute coronary syndromes (ACS) [unstable angina or non-ST-segment elevation myocardial infarction], clopidogrel plus aspirin (acetylsalicylic acid) for up to 1 year significantly reduced the risk of cardiovascular events relative to placebo plus aspirin in the well designed clinical trial CURE (Clopidogrel in Unstable angina to prevent Recurrent Events) and its substudy in patients undergoing percutaneous coronary intervention (PCI) [PCI-CURE]. In pharmacoeconomic evaluations based on data from these trials conducted in a number of countries that used a variety of models, methods and/or type of costs, clopidogrel plus aspirin was consistently predicted to be cost effective relative to aspirin alone in the management of patients with ACS, including those undergoing PCI. Clopidogrel plus aspirin in patients with ACS reduced the incremental cost per cardiovascular event prevented and/or life-year gained (LYG) relative to aspirin alone in analyses using within-trial data (including longer-term analyses incorporating life-expectancy estimates) from the CURE or PCI-CURE studies. In Markov models of cost effectiveness with a lifetime horizon from a healthcare payer perspective based on the CURE trial, relative to aspirin alone, clopidogrel plus aspirin for 1 year was predicted to have incremental costs per LYG of 8132Euro in Spain (2003 values) and 1365Euro in Sweden (2000 values). In similar Swedish analyses from a healthcare payer perspective, clopidogrel plus aspirin for 1 year was predicted to have incremental costs per LYG of 10,993Euro (2004 values) relative to aspirin alone based on data from the PCI-CURE substudy. Broadly similar results have also been reported in modelled analyses from other countries. Cost-utility analyses based on the CURE trial suggest that, relative to lifelong aspirin alone, clopidogrel plus aspirin for 1 year followed by aspirin alone is associated with incremental costs per QALY gained that are below the traditional threshold of cost utility in Spain, the UK and the US. In patients with ACS, including those undergoing PCI, the addition of clopidogrel to standard therapy with aspirin is clinically effective in preventing cardiovascular events. Available pharmacoeconomic data from several countries, despite some inherent limitations, support the use of clopidogrel plus aspirin for up to 1 year as a cost-effective treatment relative to aspirin alone in this patient population.