Clopidogrel for the secondary prevention of stroke

Patients suffering a transient ischaemic attack (TIA) or ischaemic stroke (IS) have a high risk of recurrence. The inhibition of platelet function is effective in the reduction of secondary vascular events in patients with TIA or stroke. This is true for acetylsalicylic acid (ASA), clopidogrel, ticlopidine and the combination of ASA plus slow-release dipyridamole. This overview analyses the results of recent trials and presents ongoing or future trials with clopidogrel as well as the combination of clopidogrel plus ASA. Clopidogrel is superior to ASA in the prevention of vascular events in patients with IS, myocardial infarction (MI) or peripheral arterial disease (PAD). The difference is highest for high-risk patients such as diabetics, patients who underwent coronary bypass surgery and patients with a remote prior history of ischaemic events. A prediction model is presented which allows the identification of patients in whom clopidogrel is superior to ASA for the secondary prevention of stroke. The combination of clopidogrel and ASA is better than ASA alone in patients undergoing coronary stent implantations and patients with unstable angina or non-Q-wave MI. In high-risk patients with TIA or stroke, the addition of ASA to clopidogrel is not superior to ASA monotherapy but results in a higher rate of bleeding complications. The long-term combination therapy is currently investigated in several large trials in > 30,000 patients, with a large number of stroke patients.     

Efficacy and costs of secondary prevention with antiplatelets after ischaemic stroke

Ischaemic stroke and other atherothrombotic events substantially increase the medico-economic burden because of their high treatment costs and long-lasting disabilities with need for chronic care. Studies have shown that the cost of stroke represents approximately 3 - 5% of the annual health budget. Antiplatelet agents play a major role in secondary stroke prevention. Acetylsalicylic acid (ASA), ASA combined with extended-release dipyridamole (ER-Dip), and clopidogrel are all acceptable choices for first-line treatment in the secondary prevention of stroke. The newer antiplatelets, however, are more expensive than ASA, and their cost-effectiveness is not easily estimated. ASA has to be given to 33 stroke patients to prevent one future stroke, myocardial infarction (MI) or vascular death compared with placebo. Adding ER-Dip to ASA increases the benefit for the patients. A total of 33 stroke patients had to be treated with this combination, instead of ASA, to prevent one stroke. However, the combination of ASA plus ER-Dip does not prevent MI, vascular death or the combined end point of either stroke or death. Clopidogrel is more effective than ASA in preventing a combined end point of ischaemic stroke, MI, or vascular death, but it has not been shown to be superior to ASA in preventing recurrent stroke in transient ischaemic attack or stroke patients. Several subgroups, such as stroke patients with additional peripheral artery disease, patients with prior coronary artery bypass, patients with insulin-dependent diabetes, and patients with recurrent vascular events, were identified, in whom the benefit of clopidogrel is amplified. Taking economical aspects into account, the fixed combination of ASA and ER-Dip can be recommended for secondary stroke prevention as a first-line alternative to ASA in patients without major comorbidity. In patients with higher comorbidity, clopidogrel may be more effective for the individual patient compared with ASA, and might also be cost-effective. Furthermore, in patients with ASA intolerance clopidogrel is a useful, but expensive, alternative.     

Combination antiplatelet agents for secondary prevention of ischemic stroke

Stroke is a leading cause of death and the primary cause of serious, long-term disability in the United States. Joint guidelines from the American Heart Association (AHA) and American Stroke Association (ASA), as well as recent guidelines from the Eighth American College of Chest Physicians (ACCP) Conference on Antithrombotic and Antiplatelet Therapy, recommend aspirin, clopidogrel, or extended-release dipyridamole plus aspirin as acceptable first-line options for secondary prevention of ischemic events in patients with a history of ischemic stroke or transient ischemic attack (TIA). The ACCP strongly recommends the combination of extended-release dipyridamole plus aspirin over aspirin monotherapy (highest level of evidence) and suggests clopidogrel monotherapy over aspirin monotherapy (lower level of evidence). The AHA-ASA guidelines suggest that either extended-release dipyridamole plus aspirin or clopidogrel monotherapy should be used over aspirin monotherapy. Both guidelines recommend avoiding the combination of clopidogrel and aspirin for most patients with previous stroke or TIA. Results from recent trials evaluating combination antiplatelet therapy have been published that enhance the AHA-ASA recommendations and provide the foundation for the updated ACCP guideline. To identify pertinent combination antiplatelet trials, a MEDLINE search of the literature from 1967-2007 was performed. Two trials were identified--the European-Australasian Stroke Prevention in Reversible Ischemia Trial (ESPRIT) and Clopidogrel for High Atherothrombotic Risk and Ischemic Stabilization, Management, and Avoidance (CHARISMA). The ESPRIT compared aspirin monotherapy with the combination of aspirin plus extended-release dipyridamole for prevention of secondary ischemic events in patients with a history of TIA or minor stroke. The CHARISMA trial compared aspirin plus clopidogrel with aspirin alone in a population at high risk for atherothrombotic events using the composite outcome of myocardial infarction, stroke, and death from cardiovascular causes. Data from ESPRIT add to evidence that the combination of aspirin plus extended-release dipyridamole is superior to aspirin alone. The findings of the CHARISMA trial reinforce recommendations from both AHA-ASA and ACCP that the combination of aspirin and clopidogrel be reserved for special populations requiring this antiplatelet combination (e.g., those who have had coronary artery stenting).     

Drug evaluation of clopidogrel in patients with ischemic stroke

Clopidogrel is an effective antiplatelet medication used for the secondary prevention of ischemic events in patients with various cardiovascular, cerebrovascular and peripheral vascular disease conditions. The objective of this paper is to discuss the role of clopidogrel in ischemic stroke patients and to review the existing data from randomized trials supplemented by pilot and mechanistic studies that supports these indications for its use. An analysis of the mechanism of action and pharmacology of clopidogrel is provided. After Phase III trials, such as the CAPRIE (Clopidogrel versus Aspirin in Patients at Risk of Ischemic Events) and MATCH (Management of Atherothrombosis with Clopidogrel in High-risk patients) trials, the role of clopidogrel in secondary prevention is well defined. The role of clopidogrel in acute ischemic stroke and neurointerventional procedures is evolving based on new pilot trials. At present, there is insufficient data to recommend the use of clopidogrel in acute ischemic stroke. Clopidogrel may be a valuable alternative to aspirin. However, more studies are required to assess the role of clopidogrel in selected patient groups with respect to acute ischemic stroke.     

Drug evaluation of clopidogrel in patients with ischemic stroke

Clopidogrel is an effective antiplatelet medication used for the secondary prevention of ischemic events in patients with various cardiovascular, cerebrovascular and peripheral vascular disease conditions. The objective of this paper is to discuss the role of clopidogrel in ischemic stroke patients and to review the existing data from randomized trials supplemented by pilot and mechanistic studies that supports these indications for its use. An analysis of the mechanism of action and pharmacology of clopidogrel is provided. After Phase III trials, such as the CAPRIE (Clopidogrel versus Aspirin in Patients at Risk of Ischemic Events) and MATCH (Management of Atherothrombosis with Clopidogrel in High-risk patients) trials, the role of clopidogrel in secondary prevention is well defined. The role of clopidogrel in acute ischemic stroke and neurointerventional procedures is evolving based on new pilot trials. At present, there is insufficient data to recommend the use of clopidogrel in acute ischemic stroke. Clopidogrel may be a valuable alternative to aspirin. However, more studies are required to assess the role of clopidogrel in selected patient groups with respect to acute ischemic stroke.     

Antiplatelet therapy in cerebrovascular disorders

Antiplatelet treatment is a mainstay in acute and long-term secondary stroke prevention. Aspirin is still most widely used worldwide, however, there is increasing evidence from small randomised trials that dual antiplatelet therapy combining aspirin with dipyridamole or clopidogrel might be more effective in the acute and early chronic post-ischemic phase (i.e. first 90 days). Both clopidogrel and the combination of aspirin and extended-release dipyridamole are recommended by current guidelines in long-term secondary stroke prevention in patients who are at high risk for a recurrent ischemic stroke, since they are more effective compared with aspirin monotherapy.Antiplatelet agents are the therapy of choice in patients with ischemic stroke due to intracranial stenosis and patent foramen ovale. In contrast, oral anticoagulation is clearly superior to single or double antiplatelet therapy in patients with cardioembolic stroke, mainly caused by atrial fibrillation.Concerning newer antiplatelet agents, only cilostazol appears to be a promising therapeutic option in patients with ischemic stroke in the near future, but so far, only studies in Asian stroke patients have been performed.     

The basis of platelets: platelets and atherothrombosis: an understanding of the lack of efficacy of aspirin in peripheral arterial disease (PAD) and diabetic patients

Platelet activation subsequent to the adhesion of platelets to the vascular wall results in the release of mediators that promote platelet aggregation, which plays a pivotal role in the development of the polyvascular atherosclerotic disease that can be referred to by the acronym 'ATIS' (AtheroThrombosIS). The currently available antiplatelet drugs used to prevent vascular events in patients with cardiovascular disease, including peripheral arterial disease (PAD), include aspirin and thienopyridines such as clopidogrel. These drugs decrease platelet aggregability, each of them by inhibiting a different pathway of platelet activation and recruitment. Aspirin acts by inhibiting thromboxane A2 (TXA2) formation through the inhibition (acetylation) of cyclo-oxygenase. On the other hand, thienopyridines suppress the platelet aggregation adenosine diphosphate (ADP) pathway by inhibiting the platelet P2Y12 subtype of the ADP receptor. The results of the large ATT (Antithrombotic Trialists' Collaboration) meta-analysis of published clinical studies on aspirin, reported in 2002, confirmed the previous meta-analysis and major trials that treatment with aspirin (mixed with other antiplatelet agents in these large meta-analyses) can prevent vascular events in high-risk patients with cardiovascular disease. However, it must be stressed that specifically in PAD patients no significant effect of aspirin was demonstrated in a more recent meta-analysis. This was also the case for primary and secondary prevention in diabetic patients. In keeping with these observations, neither a five-year follow-up study of Japanese diabetic patients in the JPAD (Japanese Primary Prevention of Atherosclerosis with Aspirin for Diabetes) study, a seven-year follow-up study of UK diabetic patients with PAD in the POPADAD (Prevention of Progression of Arterial Disease and Diabetes) study, nor a very recent Scottish study in the same population of diabetics with PAD revealed a significant beneficial effect for aspirin in preventing ischaemic events. This failure may be a consequence of more rapid recovery of platelet aggregability following each dose of aspirin in these PAD or diabetic populations, with the accelerated platelet turnover resulting in a condition of aspirin resistance. Results of the large scale CAPRIE (Clopidogrel versus Aspirin in Patients at Risk of Ischaemic Events) trial that evaluated clopidogrel in patients with cerebral infarction, myocardial infarction or PAD have found clopidogrel to be significantly more effective than aspirin in preventing ischaemic events in patients with PAD. Furthermore, a subgroup analysis of the study has confirmed the efficacy of clopidogrel in diabetic patients with PAD, showing a significant reduction of events in clopidogrel-treated, compared with aspirin-treated, diabetic patients. These results are also likely to be attributable to the greater frequency of aspirin resistance in aspirin-treated patients in these populations (diabetics and/or PAD). Platelets, through activation and aggregation, have an important role in ATIS. However, although antiplatelet therapy with low-dose aspirin has been reported to prevent vascular events in high-risk patients with cardiovascular disease, recent studies in patients with PAD or diabetes mellitus have failed to support the efficacy of aspirin in preventing vascular events in these patient populations. In contrast, clopidogrel appears to be a useful antiplatelet agent in the prevention of vascular events in patients with PAD or diabetes.     

Antithrombotic treatment in the prevention of ischemic stroke

Approximately 5.7 million people died from stroke in 2005 [1]. According to World Health Organization estimates, figures are predicted to increase to 23 million first-ever strokes, 77 million stroke survivors, 61 million disability adjusted life years (DALYs) and 7.8 million deaths in the next 20 years [2]. Heart disease and stroke are leading causes of DALYs lost and deaths worldwide [3]. Over 70 % of ischemic strokes are first events, which makes primary prevention immensely important. The treatments for acute ischemic stroke have emerged during the last decade and there is growing evidence of efficacy and importance of secondary prevention. We foresee that patients at high risk of vascular events could reduce their risk by 75 to 80 % through optimal prevention strategies including a combination of lifestyle changes and medical therapy [4]. In this review, we will focus on the aspects of antithrombotic treatment of ischemic stroke (IS) in the primary and secondary prevention.     

The value of clopidogrel versus aspirin in reducing atherothrombotic events: the CAPRIE study

Atherothrombotic disease is a growing health problem, and is increasingly more costly to manage. Clopidogrel is an advanced, specific adenosine diphosphate receptor antagonist, which has been shown to be a highly potent antiplatelet agent. Data from the Clopidogrel versus Aspirin in Patients at Risk of Ischaemic Events (CAPRIE) study have demonstrated the significantly superior clinical benefit of clopidogrel over aspirin for secondary prevention of atherothrombotic disease, with a relative risk reduction in myocardial infarction, stroke or vascular death of 8.7% (95% confidence interval 0.3, 16.5; P = 0.043). Moreover, clopidogrel demonstrated an amplified clinical benefit versus aspirin in patients at high risk of atherothrombotic events, such as those with a previous history of symptomatic atherothrombotic disease or with major risk factors such as diabetes mellitus or hypercholesterolaemia. On the basis of commonly accepted threshold criteria (Euros 20000 per life-year gained; LYG), clopidogrel in comparison with aspirin is cost-effective for the secondary prevention of atherothrombotic disease (cost per LYG ranging from Euros 19462 to Euros 3256). Economic analyses have demonstrated consistent cost-effectiveness results with clopidogrel in different countries. Moreover, in high-risk patient subgroups the cost-effectiveness of clopidogrel in comparison with aspirin was evenbetter (cost per LYG ranging from Euros 5900 to Euros 6310). Compared with other treatment strategies used for the prevention of ischaemic or atherothrombotic events, the cost-effectiveness of clopidogrel in comparison with aspirin based on CAPRIE is favourable, with most analyses in the intermediate range of cost-effectiveness. The available data thus support the use of clopidogrel as a clinically efficient and cost-effective option for secondary prevention of atherothrombotic disease, particularly in high-risk patients.     

Clopidogrel hydrogen sulphate for atrial fibrillation

INTRODUCTION: Atrial fibrillation is a common cardiac rhythm abnormality with a considerable cardiovascular disease burden worldwide. It is an independent major risk factor for stroke. Stroke prevention with anticoagulation or antiplatelet agents has been an important area of clinical research. Warfarin is the most widely used antithrombotic therapy for stroke prophylaxis for last several years, and now dabigatran (150 mg b.i.d.) is more effective than warfarin in stroke prevention in individuals at increased of stroke. In addition, several studies have evaluated the efficacy of clopidogrel for stroke prophylaxis either alone or in combination with aspirin. AREAS COVERED: This review summarizes the key findings of the trials looking at the efficacy of clopidogrel in stroke prevention. A literature search was performed using PubMed and Google Scholar. The trials that evaluated the efficacy of clopidogrel in preventing atherothrombotic events or stroke were also included. EXPERT OPINION: Clopidogrel prevents more vascular events, including stroke, in patients with a recent myocardial infarction, stroke or peripheral vascular disease than aspirin. Combination of clopidogrel and aspirin provides a greater reduction of stroke than aspirin or clopidogrel monotherapy, but at an increased risk of bleeding. Dual antiplatelet therapy (clopidogrel and aspirin) is inferior to warfarin in primary stroke prevention for patient with atrial fibrillation and thus should be considered for stroke prophylaxis only in patients ineligible for warfarin. However, with the advent of newer agents, like direct thrombin inhibitors and Factor Xa inhibitors, the role of antiplatelet therapy for stroke prevention in atrial fibrillation remains unclear.     

Medical prevention of stroke and stroke recurrence in patients with TIA and minor stroke

Background: Secondary stroke prevention after transient ischemic stroke (TIA) or minor stroke is of major importance in order to avoid recurrent cerebrovascular events and decrease morbidity and mortality. Objective/methods: Systematically review of recently published, high-quality studies emphasizing the need for emergency assessment and treatment of patients with TIA and minor stroke and to give a comprehensive and distinct overview over medical secondary stroke prevention trials performed in these patients. Results/conclusions: Evaluation and implementation of preventive stroke therapy has to be immediate in patients with TIA and stroke. For patients with non-cardioembolic stroke, antiplatelet agents are the treatment of choice. Aspirin plus extended-release dipyridamole and clopidogrel are more effective than aspirin and should be used in patients with a high risk of recurrent stroke. Oral anticoagulation is highly effective in patients with a cardiac source of embolism. Treatment of risk factors such as arterial hypertension and high cholesterol is even more important in secondary stroke prevention than in primary prevention. Vitamin supplementation and lowering of elevated levels of homocysteine are not effective in stroke prevention.     

Modelling the long term cost effectiveness of clopidogrel for the secondary prevention of occlusive vascular events in the UK

OBJECTIVE: To assess the long term cost effectiveness of clopidogrel monotherapy compared with acetylsalicylic acid (aspirin; ASA) monotherapy in patients at risk of secondary occlusive vascular events (OVEs) in the UK. DESIGN: Cost utility analysis based on clinical data from CAPRIE (a multicentre randomised controlled trial, involving 19185 patients); long-term effects were extrapolated beyond the trial period using a Markov model populated with data from UK observational studies. Health economic evaluation carried out from the perspective of the UK National Health Service. PARTICIPANTS: A representative cohort of 1000 UK patients aged 60 years (approximate mean age of the CAPRIE population), with the qualifying diagnoses of myocardial infarction, ischaemic stroke and peripheral arterial disease, who are at risk of secondary OVEs (non-fatal myocardial infarction, non-fatal stroke or vascular death). INTERVENTIONS: Patients were assumed to receive treatment with either clopidogrel (75 mg/day) for 2 years followed by ASA (325 mg/day, average) for their remaining lifetime, or ASA alone (325 mg/day, average) for life. MAIN OUTCOME MEASURES: Incremental cost per life year gained and incremental cost per quality-adjusted life year (QALY) gained. RESULTS: In the base case, the incremental cost effectiveness of clopidogrel versus ASA in this population is estimated at 18888 pounds per life year gained and 21 489 pounds per QALY gained. Multiple deterministic and probabilistic sensitivity analyses suggest the model is robust to variations in a wide range of input parameters. CONCLUSION: Two years of treatment with clopidogrel can be considered a cost effective intervention in patients at risk of secondary OVEs in the UK.     

Clopidogrel hydrogen sulphate for atrial fibrillation

Introduction: Atrial fibrillation is a common cardiac rhythm abnormality with a considerable cardiovascular disease burden worldwide. It is an independent major risk factor for stroke. Stroke prevention with anticoagulation or antiplatelet agents has been an important area of clinical research. Warfarin is the most widely used antithrombotic therapy for stroke prophylaxis for last several years, and now dabigatran (150 mg b.i.d.) is more effective than warfarin in stroke prevention in individuals at increased of stroke. In addition, several studies have evaluated the efficacy of clopidogrel for stroke prophylaxis either alone or in combination with aspirin.

Areas covered: This review summarizes the key findings of the trials looking at the efficacy of clopidogrel in stroke prevention. A literature search was performed using PubMed and Google Scholar. The trials that evaluated the efficacy of clopidogrel in preventing atherothrombotic events or stroke were also included.

Expert opinion: Clopidogrel prevents more vascular events, including stroke, in patients with a recent myocardial infarction, stroke or peripheral vascular disease than aspirin. Combination of clopidogrel and aspirin provides a greater reduction of stroke than aspirin or clopidogrel monotherapy, but at an increased risk of bleeding. Dual antiplatelet therapy (clopidogrel and aspirin) is inferior to warfarin in primary stroke prevention for patient with atrial fibrillation and thus should be considered for stroke prophylaxis only in patients ineligible for warfarin. However, with the advent of newer agents, like direct thrombin inhibitors and Factor Xa inhibitors, the role of antiplatelet therapy for stroke prevention in atrial fibrillation remains unclear.     

P2Y12 receptor inhibitors for secondary prevention of ischemic stroke

Introduction: Ischemic stroke (IS) is a major cause of death and disability worldwide. The P2Y₁₂ receptor plays a critical role in the formation of a stable thrombus leading to ischemic complications. Therefore, P2Y₁₂ receptor inhibitors constitute a major antiplatelet strategy in the secondary prevention of IS.

Areas covered: We searched articles about P2Y₁₂ receptor inhibitors and stroke in PubMed published until December 2014. This is a comprehensive review of the role of P2Y₁₂ receptor inhibitors alone and in combination with aspirin in the secondary prevention of noncardioembolic stroke.

Expert opinion: The potential benefit of more potent antiplatelet therapy for secondary stroke prevention must be weighed against the risk of bleeding in patients with IS. Short-term (≤ 3 months) dual antiplatelet therapy with clopidogrel and aspirin that is initiated early after IS or transient ischemic attack due to large artery atherosclerosis appears most efficient.     

《2021 AHA/ASA指南:卒中和短暂性脑缺血发作患者的卒中预防》解读

2021年5月24日,美国心脏协会和美国卒中协会(AHA/ASA)发布《2021AHA/ASA指南:卒中和短暂性脑缺血发作患者的卒中预防》。该指南内容涉及继发性卒中预防的诊断评估、血栓风险因素的管理、病因学管理以及继发性卒中的系统护理等。该文拟对指南中药物治疗相关部分进行解读,并对抗栓药物与既往版本指南进行比较,以期为我国缺血性卒中和短暂性脑缺血发作生存者卒中的二级预防提供参考。     

Role of antiplatelet therapy in cardiovascular disease II: Ischemic stroke

The etiology of cerebrovascular disease is heterogeneous, with the majority of strokes being of ischemic origin. Transient ischemic attack is now considered to be an important precursor and long-term risk factor for ischemic stroke. Given the lack of acute therapies for ischemic stroke, current treatments focus on secondary prevention through risk-factor management, pharmacotherapy and interventional approaches. As illustrated in this paper, antiplatelet agents (e.g. clopidogrel, aspirin, dipyridamole) are the cornerstone of therapy for prevention of recurrent ischemic stroke.     

Antiplatelet therapy in peripheral arterial disease

Antiplatelet therapy significantly reduces the incidence of vascular death, nonfatal myocardial infarction, and nonfatal stroke in patients with peripheral arterial disease (PAD) and intermittent claudication, in patients undergoing peripheral grafting, in patients undergoing peripheral angioplasty, and in patients with carotid disease. Aspirin, aspirin plus dipyridamole, ticlodipine, and clopidogrel have been shown to be efficacious in the treatment of PAD. Data from the Clopidogrel versus Aspirin in Patients at Risk for Ischaemic Events (CAPRIE) trial demonstrated in 11,592 patients with PAD that patients randomized to clopidogrel 75 mg daily had a 24% significant (p=0.0028) reduction in vascular death, nonfatal myocardial infarction, and nonfatal stroke than patients randomized to aspirin 325 mg daily. These data favor the use of clopidogrel in patients with PAD.     

Safety of clopidogrel and aspirin for stroke prevention: implications of the CHARISMA trial.

Antiplatelet therapy is universally recommended for the prevention of recurrent events in patients with noncardioembolic ischaemic stroke or transient ischaemic attack (TIA), acute and chronic coronary artery disease, or peripheral arterial disease. However, choosing which antiplatelet agents to use in these situations remains controversial. The use of aspirin, aspirin plus extended-release dipyridamole, or clopidogrel is recommended as initial therapy in patients with noncardioembolic ischaemic stroke or TIA to reduce the risk of recurrent stroke and other cardiovascular events. Based on the results of the MATCH trial, combination therapy with aspirin plus clopidogrel is not recommended for patients with ischaemic stroke or TIA due to the increased risk of haemorrhage.The results of the CHARISMA trial support this recommendation; despite previous data demonstrating a favourable benefit-risk profile of aspirin plus clopidogrel in patients with acute coronary syndrome, this combination should not be used in patients at high risk for atherothrombosis and those with previous stroke or TIA. In these patients, the CHARISMA trial demonstrated a lack of significant clinical efficacy and an increased risk of bleeding with clopidogrel plus aspirin compared with aspirin alone.Further research is needed to assess the benefit-risk ratio of clopidogrel plus aspirin in specific subpopulations of patients at high risk for atherothrombotic events, and to determine the role of clopidogrel plus aspirin in preventing cardioembolic stroke or early recurrent stroke after symptomatic large-vessel atherostenosis. Recent and ongoing studies are seeking to better define the roles of different antiplatelet regimens in preventing recurrent stroke.     

Clopidogrel versus aspirin in patients with atherothrombosis: CAPRIE-based calculation of cost-effectiveness for Germany

ABSTRACT

Objectives: To model the 2-year cost-effectiveness of secondary prevention with clopidogrel versus aspirin (acetylsalicylic acid) (ASS) in German patients with myocardial infarction (MI), ischaemic stroke (IS) or diagnosed with peripheral arterial disease (PAD), based on CAPRIE trial data and from the perspective of German third party payers (TPP).

Methods: An existing Markov model was adapted to Germany by using German cost data. The model was extended by using different datasets for cardiovascular event survival times (Framingham vs. Saskatchewan health databases) and in two separate scenarios.

Results: The treatment with clopidogrel leads to a reduction of 13.19 vascular events per 1000 patients, of which 2.21 are vascular deaths. The overall incremental costs for the 2-year management of atherothrombotic patients with clopidogrel instead of ASS are calculated to be about €1 241 440 per 1000 patients. The number of life-years saved (LYS) has been calculated as the difference in the number of life-years lost due to vascular death or events with ASS versus clopidogrel: it is 86.35 LYS when analysis is based on Framingham data and 66.07 LYS with Saskatchewan-based survival data. The incremental costs per LYS are €14 380 and €18 790, respectively. Cost-effectiveness is sensitive to changes in survival data, discounting and daily costs of clopidogrel, but stable against substantial (± 25%) changes in all other cost data.

Conclusion: The findings for Germany are in line with published results for Belgium (€13 390 per LYS) and also with results for Italy (€17 500 per LYS), both based on Saskatchewan data, and with a French analysis based on Framingham data (€15 907 per LYS). Even if no officially accepted cost-effectiveness threshold exists for Germany at present, incremental cost-effectiveness results of less than €20 000 per LYS for the treatment with clopidogrel can be assumed to be acceptable for German third party payers.     

Role of antiplatelet therapy in cardiovascular disease II: Ischemic stroke

The etiology of cerebrovascular disease is heterogeneous, with the majority of strokes being of ischemic origin. Transient ischemic attack is now considered to be an important precursor and long-term risk factor for ischemic stroke. Given the lack of acute therapies for ischemic stroke, current

treatments focus on secondary prevention through risk-factor management, pharmacotherapy and interventional approaches. As illustrated in this paper, antiplatelet agents (e.g. clopidogrel, aspirin, dipyridamole) are the cornerstone of therapy for prevention of recurrent ischemic stroke.