Systematic review and meta-analysis of adverse events of low-dose aspirin and clopidogrel in randomized controlled trials

Antiplatelet agents do not impact the hospital course in patients with gastrointestinal bleeding

BACKGROUND

Use of antiplatelet agents (APAs) have been shown to increase the risk of gastrointestinal (GI) bleeding despite their cardiovascular benefits.

AIM

To understand the impact of APAs, we assessed the outcomes in patients admitted with acute GI bleeding to our hospital. We hypothesized there is no difference among GI bleeders admitted to the hospital while bleeding on or off APAs.

METHODS

In an observational prospective cohort study, 104 sequential patients admitted with a diagnosis of GI bleeding were followed. Patients were classified as either on APA or not.

RESULTS

Thirty of 104 (29%) patients were on long-term aspirin and/or clopidogrel on admission and 5 were taking nonaspirin nonsteroidal anti-inflammatory drugs, total of 35 (34%). There was no difference between patients using APA and those not using APA with regard to admission hemoglobin, age, presentation, source of bleed, total number of units transfused, intensive care unit admission rates, and overall length of stay. There was, however, a significant difference in the presence of hemodynamic compromise on initial presentation, with a higher proportion of APA users being orthostatic (51.4% vs 26% in nonusers, with P=0.02, by Fisher exact test). Clopidogrel was safely restarted in high-risk patients with significant cardiac history.

CONCLUSIONS

This study demonstrated that APA use did not significantly alter the course or outcome in GI bleeders admitted to our institution during their hospital stay.

Aspirin for the prevention of colorectal cancer

Over 600,000 people worldwide die of colorectal cancer (CRC) annually, highlighting the importance of developing effective prevention strategies. Among proposed chemopreventive interventions, aspirin is perhaps the agent with the strongest body of evidence that supports wider spread use to significantly reduce the population burden of CRC. Several epidemiological studies, four randomized controlled trials (RCTs) of colorectal polyp recurrence, and RCTs in patients with hereditary colorectal cancer syndromes, have shown that aspirin reduces incidence of colorectal neoplasia. Recently, in a pooled analysis of five cardiovascular-prevention RCTs linked to cancer outcomes, daily aspirin use at any dose reduced the risk of CRC by 24% and of CRC-associated mortality by 35% after a delay of 8-10 years. In an expanded meta-analysis of 8 cardiovascular-prevention RCTs, daily aspirin use at any dose was associated with a 21% lower risk of all cancer death, including CRC, with benefit only apparent after 5 years. In this review, we will summarize human studies of aspirin in CRC prevention as well as discuss the safety profile and mechanism of aspirin in CRC prevention.

Antiplatelets in secondary stroke prevention

The aim of this review is to provide evidence-based recommendations on the secondary prevention of atherothrombotic ischemic stroke. Antiplatelets are the major therapy for the secondary stroke prevention. The most commonly used antiplatelets agents are aspirin, clopidogrel, and extended-release dipyridamole. A lot of progress had been made in last years regarding aspirin resistance and genotyping of clopidogrel metabolism. According to the results of the accomplished studies it is difficult to broadly recommend one antithrombotic agent in favor of the other. Instead, a review of the currently published data suggests the importance of focusing on the individualizing approach in antiplatelet therapy.

Cost-effectiveness analysis: cardiovascular benefits of proton pump inhibitor co-therapy in patients using aspirin for secondary prevention

BACKGROUND

Many patients with cardiovascular (CV) disease will stop aspirin (ASA) because of ASA-related dyspepsia. Proton pump inhibitor (PPI) co-therapy may reduce ASA-related dyspepsia, enhancing ASA adherence and improving CV outcomes.

AIM

To explore the impact of PPI co-therapy on CV outcomes in long-term, low-dose ASA users.

METHODS

We modified a previously published Markov model to assess the long-term impact of PPI co-therapy on CV and upper gastrointestinal bleeding (UGIB) outcomes among patients using ASA for secondary CV prevention. UGIB events, recurrent myocardial infarctions (MIs) and incremental cost-effectiveness ratios (ICERs) were measured. The perspective taken was that of a long-term payer.

RESULTS

Compared with ASA alone, ASA plus PPI resulted in fewer lifetime UGIB events (3.4% vs. 7.2%) and increased ASA adherence (74% vs. 71%). Increased ASA adherence resulted in fewer recurrent MIs (26 fewer events per 10000 patients). On average, the ASA plus PPI strategy resulted in 38 additional days of life per patient, with the majority of this benefit (61%) because of a reduction in CV mortality (rather than UGIB-related mortality). ASA plus PPI was also more costly than ASA alone, with an ICER of $19000 per life-year saved. Results were sensitive to cost of PPI and impact of PPI on ASA adherence.

CONCLUSIONS

Proton pump inhibitor co-therapy has the potential to impact not only GI, but also CV outcomes in patients with CV disease using ASA and such co-therapy is likely to be cost-effective. Future studies should better quantify the CV benefits of PPI co-therapy.

Gastrointestinal effects of aspirin

Aspirin is being used as an effective analgesic and anti-inflammatory agent at doses >325 mg daily. At low doses (75-325 mg daily), aspirin is the key antiplatelet drug in the pharmacological prevention of cardiovascular diseases. Topical and systemic effects of aspirin in the gastrointestinal mucosa are associated with mucosal damage in the upper and lower gastrointestinal tract. The risk of upper gastrointestinal bleeding with aspirin is increased with old age, male sex, ulcer history and concomitant medication with NSAIDs, cyclooxygenase 2 selective inhibitors, corticosteroids or other antithrombotic agents. In some patients, the cardiovascular benefits of low-dose aspirin might be overcome by the risk of gastrointestinal complications, but withdrawal of aspirin therapy can precipitate a cardiovascular event. These patients will need concomitant therapy with antisecretory agents, especially PPIs, to reduce the gastrointestinal risk. Eradication of Helicobacter pylori infection might be an additional option in patients with a history of ulcer. Furthermore, there is growing evidence that long-term use of aspirin decreases the risk of colorectal cancer, even at low doses. As aspirin is one of the most prescribed drugs worldwide and its clinical impact is huge, physicians need to consider the benefits and harms for each individual patient in order to maximize the benefits of aspirin.

Clinical evidence of interaction between clopidogrel and proton pump inhibitors

Clopidogrel is approved for reduction of atherothrombotic events in patients with cardiovascular (CV) and cerebrovascular disease. Dual antiplatelet therapy with aspirin and clopidogrel decreases the risk of major adverse cardiac events after acute coronary syndrome or percutaneous coronary intervention, compared with aspirin alone. Due to concern about gastrointestinal bleeding in patients who are receiving clopidogrel and aspirin therapy, current guidelines recommend combined use of a proton pump inhibitor (PPI) to decrease the risk of bleeding. Data from previous pharmacological studies have shown that PPIs, which are extensively metabolized by the cytochrome system, may decrease the ADP-induced platelet aggregation of clopidogrel. Results from retrospective cohort studies have shown a higher incidence of major CV events in patients receiving both clopidogrel and PPIs than in those without PPIs. However, other retrospective analyses of randomized clinical trials have not shown that the concomitant PPI administration is associated with increased CV events among clopidogrel users. These controversial results suggest that large specific studies are needed. This article reviews the metabolism of clopidogrel and PPIs, existing clinical data regarding the interaction between clopidogrel and PPIs, and tries to provide recommendations for health care professionals.

Long-term use of aspirin and the risk of gastrointestinal bleeding

BACKGROUND

In short-term trials, aspirin is associated with gastrointestinal bleeding. However, the effect of dose and duration of aspirin use on risk remains unclear.

METHODS

We conducted a prospective study of 87,680 women enrolled in the Nurses' Health Study in 1990 who provided biennial data on aspirin use. We examined the relative risk (RR) of major gastrointestinal bleeding requiring hospitalization or blood transfusion.

RESULTS

During a 24-year follow-up, 1537 women reported a major gastrointestinal bleeding. Among women who used aspirin regularly (≥2 standard [325 mg] tablets/week), the multivariate RR of gastrointestinal bleeding was 1.43 (95% confidence interval [CI], 1.29-1.59) when compared with nonregular users. Compared with women who denied any aspirin use, the multivariate RRs of gastrointestinal bleeding were 1.03 (95% CI, 0.85-1.24) for women who used 0.5 to 1.5 standard aspirin tablets/week, 1.30 (95% CI, 1.07-1.58) for women who used 2 to 5 tablets/week, 1.77 (95% CI, 1.44-2.18) for women who used 6 to 14 tablets/week, and 2.24 (95% CI, 1.66-3.03) for women who used more than 14 tablets/week (P(trend)<.001). Similar dose-response relationships were observed among short-term users (≤5 years; P(trend)<.001) and long-term users (>5 years; P(trend)<.001). In contrast, after adjustments were made for dose, increasing duration of use did not confer a greater risk of bleeding (P(trend) = .28).

CONCLUSION

Regular aspirin use is associated with gastrointestinal bleeding. Risk seems more strongly related to dose than duration of aspirin use. Efforts to minimize adverse effects of aspirin therapy should emphasize using the lowest effective dose among both short- and long-term users.

The role of antiplatelets in hypertension and diabetes mellitus

Cardiovascular disease (CVD) remains the main cause of mortality and morbidity in patients with diabetes. Prevention of CVD in diabetes involves a multifactorial approach that aims to treat the cluster of risk factors including hyperglycemia, dyslipidemia, obesity, hypertension, and hypercoagulation associated with this condition. Antiplatelets reduce the prothrombotic environment in diabetes, but complications of this therapeutic approach include a general risk of bleeding, specifically intracranial hemorrhage, the risk of which increases in the presence of hypertension. Current guidelines recommend the use of antiplatelet agents after tight control of blood pressure, which, in clinical practice, is not always possible. In this review, the evidence for antiplatelet use in diabetes with particular emphasis on patients with associated hypertension is examined. Safe levels of blood pressure with antiplatelet therapy, various studies, and general recommendations for diabetes patients, in light of current evidence, are explored.

Safety and efficacy of triple antithrombotic therapy after percutaneous coronary intervention in patients needing long-term anticoagulation

Background: Optimal antithrombotic therapy after percutaneous coronary intervention (PCI) is currently undefined in patients requiring long-term anticoagulation. Previous studies comparing triple therapy (TT) of warfarin, aspirin and clopidogrel with standard dual therapy (DT) of aspirin and clopidogrel have yielded conflicting results. Meta-analysis of these studies was performed to evaluate safety and efficacy of TT.

Methods: A total of 1482 patients from 6 studies were analyzed using the Mantel–Haenszel random effect model to extract incidence of major bleeding. The secondary end point assessed by three of these studies was major adverse cardiac events (MACEs: cardiovascular death, myocardial infarction and thromboembolic complications). The incidence of MACEs was computed using the Mantel–Haenszel fixed effect model. Combined relative risks (RRs) across all of the studies and the 95% confidence intervals (CIs) were determined. A two-sided alpha error <0.05 was considered statistically significant.

Results: Baseline characteristics were similar in both groups. Compared with patients receiving DT, the risk of major bleeding was significantly higher in the TT group (RR: 2.74, CI: 1.08–6.98; p = 0.034). However, risk of MACE was significantly lower in the TT group (RR: 0.72, CI: 0.56–0.98; p = 0.014).

Conclusion: In patients requiring long-term anticoagulation after PCI, TT may be superior to DT in reducing the incidence of MACEs, however risk of major bleeding complications is increased significantly.

Antiplatelet drugs in the elderly: prescriptions often inappropriate and reduced tolerance by associated diseases and drugs

To assess the conditions of prescriptions and tolerance of antiplatelet drugs (APD) in the elderly and to detail the parameters that influence the tolerance of these drugs. Prospective survey in a Department of Geriatric Medicine. Two hundred nineteen patients 70 years and older treated with one or two APD prior to admission were included during 7 months in 2008. We recorded the type of APD, associated diseases, main associated or co-prescribed drugs which could interact with APD and the bleeding adverse events including cutaneous bleeding. The mean age of the 219 patients was 84.5 ± 6.7 years (70-101 years), women 59.4%. Among patients 64.8% received aspirin (mainly 75 mg), 28.3% received clopidogrel and 6.8% received their combination; 16.9% of prescriptions were off-label; 51.6% of patients had an associated disease and/or an associated drug which could have increased risk of bleeding event. Among the patients who received a gastric-protective drug, the prescription followed the recommendations of the French Health Authority in 38.9%. We recorded bleeding events in 24.2% of patients at admission and in 18.3% of patients during the hospitalization. Bleeding events were significantly more frequent in patients treated with aspirin than clopidogrel (40.8 vs. 24.2%, P < 0.05) and/or with an associated drug (OR = 2.36, 95% CI 1.34-4.14, P < 0.01) and/or an associated disease (OR = 1.22, 95% CI 1.01-3.42, P < 0.05). APD treatment was stopped in 28.8% of patients, mainly because lack of indication or bleeding adverse events. Off-label prescriptions of APD were not rare in the elderly, and adverse events are frequent. The results of this preliminary study evoke that medical situations at increased risk of bleeding are perhaps insufficiently evaluated, either in case of prescription of associated drugs with increased bleeding risk or during the follow-up of patients with associated diseases. Cutaneous bleeding events should be more taken into account in prospective studies.

Antiplatelet combinations for prevention of atherothrombotic events

Antiplatelet therapy plays a fundamental role in reducing atherothrombotic events by several pathways. The present work reviews available evidence on antiplatelet therapy both for primary prevention and in the presence of established peripheral, cerebral, or cardiac ischemic disease. Due to the importance of adherence to therapy to achieve optimal effects, special attention is given to the use of fixed-dose oral formulations in the clinical subset of patients in whom double antiplatelet therapy has proven indications.

Severe depression and behavioral disturbance, an unusual presentation of intracerebral hemorrhage in a 78-year-old man

We describe a case of a 78-year-old man who, on two occasions, had intracerebral hemorrhage with an atypical, predominantly psychiatric presentation: once with major depression without focal neurological signs and the second time with severe behavioral disturbance and only mild facial paralysis.

A prospective study of aspirin use and the risk of gastrointestinal bleeding in men

BACKGROUND AND AIMS

Data regarding the influence of dose and duration of aspirin use on risk of gastrointestinal bleeding are conflicting.

METHODS

We conducted a prospective cohort study of 32,989 men enrolled in the Health Professionals Follow-up Study (HPFS) in 1994 who provided biennial aspirin data. We estimated relative risk of major gastrointestinal bleeding requiring hospitalization or a blood transfusion.

RESULTS

During 14 years of follow-up, 707 men reported an episode of major gastrointestinal bleeding over 377,231 person-years. After adjusting for risk factors, regular aspirin use (≥2 times/week) had a multivariate relative risk (RR) of gastrointestinal bleeding of 1.32 (95% confidence interval [CI], 1.12-1.55) compared to non-regular use. The association was particularly evident for upper gastrointestinal bleeding (multivariate RR, 1.49; 95% CI, 1.16-1.92). Compared to men who denied any aspirin use, multivariate RRs of upper gastrointestinal bleeding were 1.05 (95% CI 0.71-1.52) for men who used 0.5-1.5 standard tablets/week, 1.31 (95% CI 0.88-1.95) for 2-5 aspirin/week, 1.63 (95% CI, 1.15-2.32) for 6-14 aspirin/week and 2.40 (95% CI, 1.10-5.22) for >14 aspirin/week (P(trend)<0.001). The relative risk also appeared to be dose-dependent among short-term users <5 years; P(trend)<.001) and long-term users (≥5 years; P(trend) = 0.015). In contrast, after controlling for dose, increasing duration of use did not appear to be associated with risk (P(trend) = 0.749).

CONCLUSIONS

Regular aspirin use increases the risk of gastrointestinal bleeding, especially from the upper tract. However, risk of bleeding appears to be more strongly related to dose than to duration of use. Risk of bleeding should be minimized by using the lowest effective dose among short-term and long-term aspirin users.

Inhibition of the antithrombotic effects of clopidogrel by proton pump inhibitors: facts or fancies?

Clopidogrel plus aspirin is considered the antiplatelet treatment of choice in patients with acute coronary syndrome, whether or not they are undergoing a percutaneous coronary intervention (PCI). The same treatment is mandatory in all patients undergoing a PCI with stent implantation. Clopidogrel is a pro-drug that needs metabolic activation through a cytochrome P450-dependent pathway, with an extensive involvement of the CYP 2C19 isoenzyme. Proton pump inhibitors (PPIs) reduce the risk of gastrointestinal bleeding in patients receiving dual antiplatelet therapy. In the past two years some scientific evidences have suggested a possible negative interference of PPIs on antiplatelet effect of clopidogrel because of the competitive inhibition of the CYP 2C19 isoenzyme. Few studies testing platelet reactivity in patients receiving both clopidogrel and a PPI have demonstrated a reduced inhibitory effect of the association on platelet aggregation. Moreover, results from retrospective observational studies have shown a higher incidence of major cardiovascular events in patients receiving both clopidogrel and PPIs. These data have not been confirmed neither by the only prospective randomized study comparing clopidogrel plus omeprazole with clopidogrel alone, nor by the retrospective analysis of the TRITON TIMI 38 trial, where PPIs did not affect the clinical outcome of patients given clopidogrel or prasugrel. Nevertheless both the US Food and Drug Administration (FDA) and the European Medicines Agency (EMEA) have discouraged the concomitant use of clopidogrel and PPIs. Important questions concerning a true interference between the two classes of drugs still remain unanswered and need to be addressed by adequately powered studies.

Risk assessment and aspirin use in Asian and Western populations

Objective

The aim of this review was to examine aspirin utilization, cardiovascular risk estimation, and clinical evidence for aspirin prophylaxis in Asian versus Western countries.

Methods

A literature search was performed using PubMed and the key terms “aspirin” and “Asia” or “Western”.

Results

Despite the growing burden of cardiovascular disease (CVD), aspirin is underutilized in high-risk patients in both Asian and Western countries. A number of risk estimation scores are available; however, validation is needed in countries such as Japan, India, and in South Asia. Underutilization of aspirin in Asia may be linked to an overestimation of bleeding risks. It is possible that a higher prevalence of Helicobacter pylori infection and genetic differences may make Asians more susceptible to gastrointestinal bleeding. Very low aspirin doses and even the wider use of gastroprotective agents may be the optimal approach to high-risk patients in Asia.

Conclusions

Based on the current evidence, aspirin should be used for CVD prevention when the risk:benefit ratio is favorable. A number of trials are underway, including the Diabetic Atherosclerosis Prevention by Cilostazol and Japanese Primary Prevention Project, which will provide key data on the benefits of aspirin in Asian patients at risk of CVD, and may improve aspirin utilization and risk estimation.

Risk management of risk management: Combining proton pump inhibitors with low-dose aspirin

Low-dose aspirin is widely used in the primary and secondary prevention of cardiovascular events, but is associated with a range of upper gastrointestinal side effects. In this review, we summarize the rationale for low-dose aspirin therapy, quantify the risk for upper gastrointestinal side effects, identify the risk factors involved, and provide an overview of preventive strategies, thereby focusing on the rationale and clinical utility of combining proton-pump inhibitors with low-dose aspirin.

Is there an association between low dose aspirin and anemia (without overt bleeding)? Narrative review

Background

Overt bleeding associated with low dose aspirin (LDA) is well-recognized, little attention is given to the possibility of association between LDA and occult bleeding, although this is known to occur in healthy volunteers. LDA is used increasingly in primary and secondary prevention of a number of medical conditions, many of which are common in older people, as is anemia. Anemia in older people is associated with adverse outcomes including disability, morbidity and mortality. The purpose of this study was to review the evidence that LDA might cause anemia without overt bleeding.

Methods

An extensive narrative review was carried out. Electronic searching (including database links) and reference lists of reports were used to identify studies reporting on use of aspirin ≤325 mg/day and anemia or change in hemoglobin (Hb) without overt bleeding. Data were extracted from reports of trials, adverse drug reactions (ADRs) and prevalence studies of adults aged ≥18 years, published since 1980.

Results

There are few relevant data, with considerable heterogeneity among trial designs, duration, and patient characteristics in studies of LDA. In five randomised trials (n = 5879) in (mostly secondary) prevention, the majority of patients were men without peptic ulcer disease aged 50-70 years and no consistent association between LDA and change in Hb was found. In two smaller studies (n = 609) of primary prevention in healthy patients aged ≥70 years, there was a small but statistically significant fall in Hb with LDA. Observational studies, and data from trials in which use of LDA was not a primary focus of the study, were inconclusive.

Conclusions

It is not clear whether there is an association between LDA and anemia in the absence of overt bleeding, but there may be an association between LDA and fall in Hb in (a subset of) older patients. The available evidence has significant limitations, which are discussed; studies including more older patients, and publication of individual patient data, would help clarify this important matter.

Optimal management of peptic ulcer disease in the elderly

Recent data report that the incidence of peptic ulcer is decreasing in the general population; conversely, the rates of gastric and duodenal ulcer hospitalization and mortality remain very high in older patients. Two major factors that might explain this epidemiological feature in the elderly population are the high prevalence of Helicobacter pylori infection and the increasing prescriptions of gastroduodenal damaging drugs, including NSAIDs and/or aspirin (acetylsalicylic acid). The main goals for treating peptic ulcer disease in old age are to reduce recurrence of the disease and to prevent complications, especially bleeding and perforation. The available treatments for peptic ulcer are essentially based on gastric acid suppression with antisecretory drugs and the eradication of H. pylori infection. The aim of this article is to report the available data on clinical efficacy and tolerability of peptic ulcer treatments in elderly patients and provide recommendations for their optimal use in this special population. Proton pump inhibitor (PPI)-based triple therapies for 7 days are highly effective for the cure of H. pylori-positive peptic ulcers as well as for reducing ulcer recurrence. Antisecretory drugs are also the treatment of choice for NSAID- or aspirin-related peptic ulcers and are useful as preventive therapy in chronic users of NSAIDs and low-dose aspirin as antiplatelet therapy. Antisecretory PPI therapy has a favourable tolerability profile in geriatric patients; however, monitoring is suggested in older patients with frequent pulmonary infections, gastrointestinal malabsorption, unexplained chronic diarrhoea, osteoporosis or those taking concomitant cytochrome P450 2C19-metabolized medications. The overall approach to the geriatric patient should include a comprehensive geriatric assessment that ensures multidimensional evaluation of the patient in order to better define the clinical risk of adverse outcomes in the older patient with peptic ulcer and its complications.

Investigation of upper gastrointestinal bleeding after implantation of drug-eluting stents; prospective cohort study

OBJECTIVE

After implantation of drug-eluting stents (DES), two or more anti-thrombotic agents are required. The risk of upper gastrointestinal bleeding (UGIB) in cases of DES implantation is thought to be significant. However, the incidence of UGIB has not yet been investigated in DES-implanted patients. This study aimed to investigate the incidence of UGIB after DES implantation and the awareness among cardiologists about this complication.

MATERIAL AND METHODS

Subjects were 397 consecutive patients implanted with DES from August 2004 to September 2007 at two institutions. Endoscopic examinations were performed on DES-implanted patients who presented with hematemesis and/or tarry stools. The concomitant use of acid-suppressing agents was left to the cardiologists. In addition, 37 cardiologists were administered a questionnaire regarding UGIB after DES implantation.

RESULTS

Low-dose aspirin and ticlopidine were prescribed in all patients. Forty-six patients had a past history of peptic ulcer. Acid-suppressing agents were concomitantly prescribed to 224 patients (56%) including 32 patients (70%) with a past history of peptic ulcer. UGIB due to gastric ulcers developed in 5 cases (1.3%). One case had received a half dose of H2-RA. No bleeding occurred in patients who received proton pump inhibitors (PPI). The incidence of UGIB was 4.0 per 1000 patient-years. The cardiologists who were surveyed recognized the risk of UGIB after DES implantation and the necessity for its prevention. However, they indicated that adequate management for preventing this complication has not been established.

CONCLUSIONS

This study reassuringly demonstrated a low incidence of UGIB after DES implantation. Further study regarding the prophylaxis for UGIB after DES implantation is necessary.

Identification of NSAID users at risk for gastrointestinal complications: a systematic review of current guidelines and consensus agreements

NSAIDs are among the most often used drugs worldwide. Numerous NSAID users are at risk for developing gastrointestinal complications. The purpose of this review was to identify and stratify risk factors for gastrointestinal complications in NSAID users documented in guidelines and consensus agreements, and to collect recommendations regarding over-the-counter (OTC) NSAID use. To facilitate this, a PubMed search from 1 January 1999 until 1 March 2009 was performed, resulting in the inclusion of nine English-language guidelines in our analysis. Risk factors were defined as 'definite' if mentioned in all guidelines; otherwise they were defined as 'controversial' risk factors. 'Definite' risk factors were a history of (complicated) peptic ulcer disease, older age (cut-off range 60-75 years), concomitant anticoagulant or corticosteroid use and multiple NSAID use, including low-dose aspirin (acetylsalicylic acid). 'Controversial' risk factors were high-dose NSAID use, concomitant clopidogrel or selective serotonin reuptake inhibitor use, a history of gastrointestinal symptoms, rheumatoid arthritis disability and cardiovascular disease. Infection with Helicobacter pylori was identified as an additive risk factor. Risk factors in OTC NSAID users were difficult to identify in the current literature. Risk factors were not all uniformly present in analysed guidelines and consensus agreements. We identified a history of (complicated) peptic ulcer disease, older age, concomitant anticoagulant or corticosteroid use and multiple NSAID use, including low-dose aspirin, as definite gastrointestinal risk factors in NSAID users.

Nonsteroidal Anti-Inflammatory Drug-Induced Gastroduodenal Bleeding: Risk Factors and Prevention Strategies

Nonsteroidal anti-inflammatory drugs (NSAIDs) are the most widely prescribed medications in the World. A frequent complication of NSAID use is gastroduodenal bleeding. Risk factors for gastroduodenal bleeding while on NSAID therapy are age, prior peptic ulcer and co-medication with anti-platelet agents, anticoagulants, glucocorticosteroids and selective serotonin-reuptake inhibitors (SSRI). Prevention strategies for at-risk patients include the use of the lowest effective dose of NSAIDs, co-therapy with proton-pump inhibitors and/or the use of a COX-2 selective agent. Treatment of Helicobacter pylori infection is beneficial for primary prophylaxis of NSAID-induced gastroduodenal bleeding in NSAID-naive patients. For patients with cardiovascular risk factors requiring NSAIDs, naproxen should be selected. In very high risk patients for both gastrointestinal and cardiovascular complications NSAID therapy should be avoided altogether.

Non-Steroidal Anti-Inflammatory Drugs: An Overview of Cardiovascular Risks

While aspirin may offer protection, other non-aspirin non-steroidal anti-inflammatory drugs (NSAIDs) can cause serious cardiovascular side effects and complications. This has led to a general "black box" warning for cardiovascular adverse events for NSAIDs. This review explores the different mechanisms underlying the protective effects of aspirin, the NSAID associated renovascular effects causing hypertension, edema and heart failure, the cardiovascular effects causing myocardial infarction and stroke, and the possible deleterious interaction between NSAIDs and aspirin.

Critical appraisal of a fixed combination of esomeprazole and low dose aspirin in risk reduction

Low dose aspirin (≤325 mg) is routinely used for primary and secondary prophylaxis of cardiovascular and cerebrovascular events. The use of low dose aspirin is associated with two- to four-fold greater risk of symptomatic or complicated peptic ulcers. Risk factors associated with low dose aspirin induced gastrointestinal toxicity includes prior history of ulcer or upper gastrointestinal (GI) bleeding, concomitant use of other nonsteroidal anti-inflammatory drugs, corticosteroid or warfarin, dual antiplatelet therapy, Helicobacter pylori (H. pylori) infection, and advanced age. Esomeprazole, like other proton pump inhibitors (PPIs) is very effective in decreasing the risk of aspirin induced gastrointestinal toxicity. Although evidence to support esomeprazole or other PPIs for primary prophylaxis in aspirin induced gastrointestinal toxicity is limited, its role in secondary prophylaxis is well established.

Secondary prevention strategies for coronary heart disease

Patients with established coronary heart disease (CHD) have a high risk of subsequent cardiovascular events, including myocardial infarction (MI), stroke, and death from cardiovascular disease. Adherence to evidence-based secondary prevention therapies for CHD has improved in recent years but still remains suboptimal. Mortality from CHD in the United States (US) has decreased substantially in recent decades. The decline in US deaths from CHD from 1980 through 2000 has been attributed to reductions in major risk factors and utilization of evidence-based medical therapies. It has been estimated that optimization of secondary prevention strategies could save as many as 80,000 more lives per year in the US. The American College of Cardiology (ACC) and American Heart Association (AHA) updated its guidelines for secondary prevention for patients with atherosclerotic vascular disease in 2006. The guidelines emphasize evidence-based developments in the field of CHD secondary prevention and also reinforce the need to implement these recommendations in actual clinical practice through programs such as the ACC's Guidelines Applied to Practice and the AHA's Get With The Guidelines. This review will discuss the epidemiology and risk assessment of CHD, current pharmacologic and nonpharmacologic strategies available for the secondary prevention of CHD, and summarize the guidelines and evidence that support these treatment options. There will be an emphasis on antiplatelet therapy given the important role of thrombosis in clinical cardiovascular events.

Management of Antiplatelet Therapy During Acute Percutaneous Coronary Intervention: New Strategies and Therapeutics

Aggressive intravenous and oral dual antiplatelet therapy has established primary percutaneous coronary intervention (PCI) as the standard of care for acute myocardial infarction. Clopidogrel is currently the thienopyridine of choice for dual antiplatelet therapy in patients treated with PCI. The dose regime and duration of therapy of clopidogrel has undergone multiple refinements. Recently, 2 novel third generation oral inhibitors of P2Y12 receptors, prasugrel and ticagrelor, have undergone clinical evaluation with promising results. This article is a non-exhaustive review of the literature, concentrating on the role of current and novel oral antiplatelet agents for acute myocardial infarction particularly highlighting the limitations and issues associated with clopidogrel use. Key words: Acute myocardial infarction, Clopidogrel, Dual antiplatelet therapy, Prasugrel, Ticagrelor

A comparison of aspirin and clopidogrel with or without proton pump inhibitors for the secondary prevention of cardiovascular events in patients at high risk for gastrointestinal bleeding

OBJECTIVE

This study was conducted to compare the risk of recurrent hospitalization for major gastrointestinal (GI) complications (peptic ulcer, bleeding, and perforation) in patients at high GI risk who require ongoing antiplatelet therapy (aspirin [acetylsalicylic acid] or clopidogrel) with or without proton pump inhibitors (PPIs).

METHODS

This population-based, retrospective cohort study employed data from the Taiwanese National Health Insurance database (January 2001 through December 2006) for patients who had a history of hospitalization for GI complications before the initiation of antiplatelet therapy with aspirin or clopidogrel. Recurrent hospitalizations for major GI complications were analyzed using a Cox proportional hazards model, with adjustment for age, sex, ulcer-related medical history, ulcer-related risk factors, and use of ulcer-related medications during follow-up. The propensity score method was applied to adjust for selection bias.

RESULTS

The analysis included data from 14,627 patients (12,001 receiving aspirin, 2626 receiving clopidogrel). The incidence of recurrent hospitalization for major GI complications was 0.125 per person-year in aspirin users, 0.103 per person-year in users of aspirin plus a PPI, 0.128 per person-year in clopidogrel users, and 0.152 per person-year in users of clopidogrel plus a PPI. Among aspirin users, those taking PPIs had a significantly lower adjusted risk of hospitalization for major GI complications than did non-PPI users (hazard ratio [HR] = 0.76; 95% CI, 0.64-0.91). Use of a PPI was not associated with a significant risk reduction among clopidogrel users (HR = 1.08; 95% CI, 0.89-1.33). An adjusted survival curve for the risk of recurrent hospitalization for major GI complications indicated that the risk increased numerically faster in clopidogrel users compared with those using aspirin plus a PPI, although the mean drug cost per person-year was 5.08 times higher in clopidogrel users than in users of aspirin plus a PPI.

CONCLUSIONS

In this analysis in patients at high GI risk who were receiving antiplatelet therapy for the secondary prevention of cardiovascular events, aspirin plus a PPI was associated with a reduced risk of recurrent hospitalization for major GI complications. This was not the case for clopidogrel plus a PPI.

Advances in clinical research on the interaction between proton pump inhibitors and clopidogrel

As a new antiplatelet drug, clopidogrel is the cornerstone of drug treatment for coronary artery disease. However, clinical use of clopidogrel frequently leads to gastrointestinal injury or increases the risk of gastrointestinal bleeding. To prevent clopidogrel-associated gastrointestinal injury, concomitant proton pump inhibitors (PPIs) have been used widely in clinical practice. However, recent studies show that treatment with clopidogrel plus PPIs can increase the incidence of adverse cardiovascular events. Despite being controversial, this finding has attracted wide attention from clinicians. This article will review the recent advances in clinical research on the interaction between proton pump inhibitors and clopidogrel.

A review of international pharmacoeconomic models assessing the use of aspirin in primary prevention

PURPOSE

The aim of this narrative review was to summarise the cost analyses and supporting trial data for aspirin prophylaxis in primary prevention.

METHODS

A PubMed search using the term 'aspirin and cost-effective and primary prevention' was performed. Professional meetings (2009) were also searched for any relevant abstracts contacting the terms 'aspirin' and 'cost effectiveness'. Where possible, outcomes were discussed in terms of cost implications (expressed as quality-adjusted life-year [QALY], disability-adjusted life-year or incremental cost-effectiveness ratio) in relation to the annual risk of cardiovascular disease. Aspirin was included in cost-effectiveness models that determined direct cost savings.

RESULTS

A total of 67 papers were identified using PubMed, and 17 cost-effectiveness studies, which assessed aspirin in primary prevention (largely based on the key primary prevention studies), and two abstracts were included in the review. These analyses showed that low-dose aspirin was cost effective in a variety of scenarios. In the UK, Germany, Spain, Italy and Japan, the mean 10-year direct cost saving (including follow-up costs and aspirin costs) per patient was €201, €281, €797, €427 and €889 with aspirin use in patients with an annual coronary heart disease risk of 1.5%. Cost-effectiveness analyses were affected by age, risk level for stroke and myocardial infarction (MI), risk of bleeds and adherence to aspirin. Underutilisation is a major limiting factor, as the appropriate use of aspirin in an eligible population (n=301,658) based on the NHANES database would prevent 1273 MIs, 2184 angina episodes and 565 ischaemic strokes in patients without previous events; this would result in a direct cost saving of $79.6 million (€54.7 million; 2010 values), which includes aspirin costs.

CONCLUSIONS

Most analyses in primary prevention have shown that low-dose aspirin is a cost-effective option, and is likely to meet the willingness of a healthcare system to pay for any additional QALY gained in the majority of healthcare systems.

Drug-related damage of the ageing gastrointestinal tract

Drug use increases with age and the elderly is at increased risk of adverse drug reactions. Gastrointestinal adverse effects are one of the most often reported. Serious event are mostly caused by NSAIDs and/or aspirin which are the most widely prescribed medications in the world. NSAIDs and/or aspirin use are associated with complications from both the upper and the lower gastrointestinal tract. The risk of these complications depends on presence of risk factors, and age is the most frequent and relevant one. At-risk patients should be on prevention strategies including the use of the lowest effective dose, co-therapy with a gastroprotective agents or use of a COX-2 selective agent. Treatment of Helicobacter pylori infection is beneficial in patients starting therapy with these agents, especially in the presence of ulcer history. The best strategy to prevent lower GI complications has yet to be defined.

Gastroduodenal toxicity of low-dose acetylsalicylic acid: a comparison with non-steroidal anti-inflammatory drugs

BACKGROUND

Low-dose acetylsalicylic acid (ASA; aspirin; 75-325 mg/day) is effective for the prevention of cardiovascular events, and its use in this indication is rapidly increasing. However, the use of ASA and, indeed, other non-steroidal anti-inflammatory drugs (NSAIDs) is limited by the incidence of adverse gastroduodenal events. OBJECTIVES AND SCOPE: To review the clinical evidence for, and the pharmacodynamic basis of, ASA-induced gastroduodenal toxicity in comparison with NSAIDs, and address the question of whether low-dose ASA is 'safe' from a gastroduodenal perspective. This was a narrative, descriptive review, rather than a formal systematic review.

FINDINGS

Adverse gastroduodenal effects, which are well known to occur with NSAIDs, are also prevalent in patients receiving low-dose ASA for cardiovascular protection even at doses as low as 75 mg/day. The risk of gastroduodenal toxicity is particularly high among 'at-risk' low-dose ASA patients (aged >70 years, previous ulcer or upper gastrointestinal bleeding and users of antiplatelets or NSAIDs). There are important differences in the mechanism of ASA-induced gastroduodenal toxicity, relative to NSAIDs. These differences include the effects on the cyclooxygenase (COX)-1 isoenzyme, local effects on the gastroduodenal mucosa specific to ASA and a reduction in platelet aggregation.

CONCLUSION

Data suggest that ASA causes significant gastroduodenal damage even at the low doses used for cardiovascular protection. These effects (both systemic and possibly local) may be pharmacodynamically distinct from the gastroduodenal toxicity seen with NSAIDs. Studies are required to establish strategies for improving the tolerability of low-dose ASA, allowing patients to continue to benefit from the cardiovascular protection associated with such therapy.

Peptic ulcer disease

Peptic ulcer disease had a tremendous effect on morbidity and mortality until the last decades of the 20th century, when epidemiological trends started to point to an impressive fall in its incidence. Two important developments are associated with the decrease in rates of peptic ulcer disease: the discovery of effective and potent acid suppressants, and of Helicobacter pylori. With the discovery of H pylori infection, the causes, pathogenesis, and treatment of peptic ulcer disease have been rewritten. We focus on this revolution of understanding and management of peptic ulcer disease over the past 25 years. Despite substantial advances, this disease remains an important clinical problem, largely because of the increasingly widespread use of non-steroidal anti-inflammatory drugs (NSAIDs) and low-dose aspirin. We discuss the role of these agents in the causes of ulcer disease and therapeutic and preventive strategies for drug-induced ulcers. The rare but increasingly problematic H pylori-negative NSAID-negative ulcer is also examined.