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

Clopidogrel versus aspirin in patients with recent ischemic stroke and established peripheral artery disease: an economic evaluation in a Chinese setting

BACKGROUND AND OBJECTIVES

Clopidogrel or aspirin are indicated for patients with recent ischemic stroke (IS) or established peripheral artery disease (PAD). We compared the cost effectiveness of clopidogrel with that of aspirin in Chinese patients with recent IS or established PAD.

METHODS

A discrete-event simulation was developed to evaluate the economic implications of secondary prevention with clopidogrel versus aspirin. All available evidence was derived from clinical studies. Costs from a Chinese healthcare perspective in 2013 US dollars and quality-adjusted life-years (QALYs) were projected over patients' lifetimes. Uncertainties were addressed using sensitivity analyses.

RESULTS

Compared with aspirin, clopidogrel yielded a marginally increased life expectancy by 0.46 and 0.21 QALYs at an incremental cost-effectiveness ratio of $US5246 and $US9890 per QALY in patients with recent IS and established PAD, respectively. One-way sensitivity analyses showed that the evaluation of patients with PAD and recent IS was robust except for the parameter of patient age. Given a willingness-to-pay of $US19,877 per QALY gained, clopidogrel had a probability of 90 and 68% of being cost effective in the recent IS or established PAD subgroups compared with aspirin, respectively.

CONCLUSIONS

The analysis suggests that clopidogrel for secondary prevention is cost effective for patients with either PAD or recent IS in a Chinese setting in comparison with aspirin.

[Drug-drug interactions in the elderly : Which ones really matter?]

Pharmacotherapy in the elderly is challenging due to age-related physiological changes, high interindividual variability, and increasing frequency of multimorbidity. The resulting polypharmacy increases the risk of drug-drug interactions and requires an individual risk assessment. Some drug-drug interactions are documented to be associated with harm in older adults including intoxication, gastrointestinal bleeding, or falls. Therefore, they are considered to be of special importance in the elderly. Moreover, frequent risk factors and continuous physiological alterations in the elderly should be taken into account during risk assessment. This review exemplifies clinically relevant drug-drug interactions and risk factors in the elderly. In addition, assessment tools as well as prevention and management strategies for clinical practice are presented.

The Role of Aspirin, Vitamin D, Exercise, Diet, Statins, and Metformin in the Prevention and Treatment of Colorectal Cancer

Colorectal cancer (CRC) is a worldwide health problem leading to significant morbidity and mortality. Several strategies based on either lifestyle modifications or pharmacological interventions have been developed in an attempt to reduce the risk of CRC. In this review article, we discuss these interventions including aspirin (and other non-steroidal anti-inflammatory drugs), vitamin D, exercise, diet, statins, and metformin. Depending upon the risk of developing CRC, the current evidence supports the beneficial role of aspirin, vitamin D, diet, and exercise especially in high-risk individuals (advanced adenoma or CRC). However, even with these established interventions, there are significant knowledge gaps such as doses of aspirin and 25-hydroxy vitamin D are not well established. Similarly, there is no convincing data from randomized controlled trials that a high fiber diet or a low animal fat diet reduces the risk of CRC. Some potential interventions, such as statins and metformin, do not have convincing data for clinical use even in high-risk individuals. However, these may have emerging roles in the prevention and treatment of CRC. Greater understanding of molecular mechanisms and the application of genomic tools to risk stratify an individual and tailor the interventions based on that individual's risk will help further advance the field. Some of this work is already underway and is a focus of this article.

The Association of Drugs With Severity and Specific Causes of Acute Lower Gastrointestinal Bleeding: A Prospective Study

OBJECTIVES

Studies on the association of acute lower gastrointestinal bleeding (ALGIB) and drugs are scarce. We aimed to investigate the association of drugs and ALGIB, especially regarding specific causes of ALGIB, and their role in the severity of ALGIB.

MATERIALS AND METHODS

The study was prospective and included all patients undergoing colonoscopy in 2010 and 2013 at the National University Hospital of Iceland. Use of nonsteroidal anti-inflammatory drugs (NSAIDs), low-dose aspirin (LDA), and warfarin before ALGIB was registered. Clinically significant bleeding was defined as: hemoglobin <100 g/L, hemodynamic instability, blood transfusion, surgery, or death.

RESULTS

Overall, 2392 patients underwent 2751 colonoscopies, of those, 325 (14%) had ALGIB, mean age 64 years (±20). The commonest diagnoses were diverticulosis (22%) and ischemic colitis (14%). In multivariate analysis, NSAIDs, LDA, and warfarin use was associated with ALGIB, odds ratio (OR) 3.3 [95% confidence interval (95% CI), 1.99-5.82], OR 1.5 (95% CI, 1.01-2.13), and OR 2.7 (95% CI, 1.61-4.57), respectively. Clinically significant bleeders were more likely than nonclinically significant bleeders to use NSAIDs or LDA+warfarin, OR 2.3 (95% CI, 1.26-3.76) and OR 33.0 (95% CI, 6.74-595), respectively. Patients with diverticular bleeding had greater odds than controls of NSAID, LDA, and warfarin use, OR 8.3 (95% CI, 3.8-18.3), OR 2.1 (95% CI, 1.15-3.67), and OR 2.6 (95% CI, 1.24-5.56), respectively. Patients with ischemic colitis were more likely than controls to use LDA, OR 2.3 (95% CI, 1.14-4.45).

CONCLUSIONS

NSAIDs, LDA, and warfarin were associated with ALGIB and diverticular bleeding. These drugs may have a role in other etiologies of ALGIB and seem to increase the risk of clinically significant bleeding.

Spontaneous subdural hematoma and antiplatelet therapy: Does efficacy of Ticagrelor come with added risk?

Antiplatelet therapy has established clinical benefit on cardiovascular outcome and has reduced the rates of re-infarction/in stent thrombosis following percutaneous coronary intervention in acute coronary syndromes. Major bleeding episodes can occur with antiplatelet therapy and intracranial hemorrhage (ICH) is one of the most feared complications resulting in significant morbidity and mortality. Identification of high risk groups and judicious use of antiplatelet therapy reduces the bleeding risk. Ticagrelor is a newer P2Y12 receptor antagonist with established clinical benefit. However, risks of having an ICH with these newer molecules cannot be ignored. Here, we report a case of spontaneous acute subdural hematoma developing in a patient on antiplatelet therapy with aspirin and ticagrelor. Early recognition, discontinuation of the medication and appropriate management resulted in resolution of hematoma and good clinical outcome. Authors have reviewed the antithrombotic drugs and their tendencies in causing intracranial bleeds from a neurophysicians perspective.

Proton-Pump Inhibitors Reduce Gastrointestinal Events Regardless of Aspirin Dose in Patients Requiring Dual Antiplatelet Therapy

BACKGROUND

The COGENT (Clopidogrel and the Optimization of Gastrointestinal Events Trial) showed that proton-pump inhibitors (PPIs) safely reduced rates of gastrointestinal (GI) events in patients requiring dual antiplatelet therapy (DAPT). However, utilization of appropriate prophylactic PPI therapy remains suboptimal, especially with low-dose aspirin.

OBJECTIVES

The authors investigated the safety and efficacy of PPI therapy in patients receiving DAPT in low- and high-dose aspirin subsets.

METHODS

Randomized patients with available aspirin dosing information in COGENT (N = 3,752) were divided into "low-dose" (≤ 100 mg) and "high-dose" (>100 mg) aspirin groups. The primary GI and cardiovascular endpoints were composite upper GI events and major adverse cardiac events, respectively. All events were adjudicated by independent, blinded gastroenterologists and cardiologists.

RESULTS

Median duration of follow-up was 110 days. Low-dose aspirin users (n = 2,480; 66.1%) were more likely to be older, female, and have higher rates of peripheral artery disease, prior stroke, and hypertension, whereas high-dose aspirin users (n = 1,272; 33.9%) had higher rates of hyperlipidemia, smoking, a history of percutaneous coronary intervention, and were more than twice as likely to be enrolled from sites within the United States (80.4% vs. 39.8%). High-dose aspirin was associated with similar 180-day Kaplan-Meier estimates of adjudicated composite GI events (1.7% vs. 2.1%; adjusted hazard ratio: 0.88; 95% confidence interval: 0.46 to 1.66) and major adverse cardiac events (4.8% vs. 5.5%; adjusted hazard ratio: 0.73; 95% confidence interval: 0.48 to 1.11) compared with low-dose aspirin. Randomization to PPI therapy reduced 180-day Kaplan-Meier estimates of the primary GI endpoint in low-dose (1.2% vs. 3.1%) and high-dose aspirin subsets (0.9% vs. 2.6%; p for interaction = 0.80), and did not adversely affect the primary cardiovascular endpoint in either group.

CONCLUSIONS

Gastroprotection with PPI therapy should be utilized in appropriately selected patients with coronary artery disease requiring DAPT, even if the patients are on low-dose aspirin. (Clopidogrel and the Optimization of Gastrointestinal Events Trial [COGENT]; NCT00557921).

Aspirin and colorectal cancer: the promise of precision chemoprevention

Aspirin (acetylsalicylic acid) has become one of the most commonly used drugs, given its role as an analgesic, antipyretic and agent for cardiovascular prophylaxis. Several decades of research have provided considerable evidence demonstrating its potential for the prevention of cancer, particularly colorectal cancer. Broader clinical recommendations for aspirin-based chemoprevention strategies have recently been established; however, given the known hazards of long-term aspirin use, larger-scale adoption of an aspirin chemoprevention strategy is likely to require improved identification of individuals for whom the protective benefits outweigh the harms. Such a precision medicine approach may emerge through further clarification of aspirin's mechanism of action.

Prediction models for intracranial hemorrhage or major bleeding in patients on antiplatelet therapy: a systematic review and external validation study

ESSENTIALS: Prediction models may help to identify patients at high risk of bleeding on antiplatelet therapy. We identified existing prediction models for bleeding and validated them in patients with cerebral ischemia. Five prediction models were identified, all of which had some methodological shortcomings. Performance in patients with cerebral ischemia was poor.

SUMMARY

Background Antiplatelet therapy is widely used in secondary prevention after a transient ischemic attack (TIA) or ischemic stroke. Bleeding is the main adverse effect of antiplatelet therapy and is potentially life threatening. Identification of patients at increased risk of bleeding may help target antiplatelet therapy.

OBJECTIVE

This study sought to identify existing prediction models for intracranial hemorrhage or major bleeding in patients on antiplatelet therapy and evaluate their performance in patients with cerebral ischemia.

METHODS

We systematically searched PubMed and Embase for existing prediction models up to December 2014. The methodological quality of the included studies was assessed with the CHARMS checklist. Prediction models were externally validated in the European Stroke Prevention Study 2, comprising 6602 patients with a TIA or ischemic stroke. We assessed discrimination and calibration of included prediction models.

RESULTS

Five prediction models were identified, of which two were developed in patients with previous cerebral ischemia. Three studies assessed major bleeding, one studied intracerebral hemorrhage and one gastrointestinal bleeding. None of the studies met all criteria of good quality. External validation showed poor discriminative performance, with c-statistics ranging from 0.53 to 0.64 and poor calibration.

CONCLUSION

A limited number of prediction models is available that predict intracranial hemorrhage or major bleeding in patients on antiplatelet therapy. The methodological quality of the models varied, but was generally low. Predictive performance in patients with cerebral ischemia was poor. In order to reliably predict the risk of bleeding in patients with cerebral ischemia, development of a prediction model according to current methodological standards is needed.

NSAID-induced Gastrointestinal Injury: A Focused Update for Clinicians

Gastroenterologists care for users of nonsteroidal anti-inflammatory drugs (NSAIDs) when the vast population exposed to the medication class experiences a relatively uncommon serious gastrointestinal (GI) side effect. As serious adverse cardiovascular (CV) effects of these drugs have also been recognized, there remains continued confusion about the best treatment for patients who benefit from NSAID therapy and are at risk for GI and CV adverse events. Recognition of those patients at risk and strategies to reduce the adverse side effects of NSAIDs continues to provide an opportunity to improve patient outcomes. This review discusses the injury induced by these agents throughout the GI tract as well as strategies to prevent acute injury and reduce the development of serious adverse events. NSAID medication selection as well as GI cotherapy should balance individual patients' GI and CV risks.

Aspirin in the prevention of cardiovascular events in patients with diabetes

Diabetes imparts a substantial increased risk for cardiovascular disease-related mortality and morbidity. Because of this, current medical guidelines recommend prophylactic treatment with once-daily, low-dose aspirin (acetylsalicylic acid) for primary and secondary prevention of cardiovascular (CV) events in high-risk patients. However, only modest reductions in CV events and mortality have been observed with once-daily aspirin treatment in patients with diabetes, including patients with a previous CV event, perhaps because of disparity between aspirin pharmacokinetics and diabetes-related platelet abnormalities. Once-daily aspirin irreversibly inactivates platelets for only a short duration (acetylsalicylic acid half-life, approximately 15-20 minutes), after which time newly generated, active platelets enter the circulation and weaken aspirin's effect. Platelets from patients with diabetes are more reactive and are turned over more rapidly than platelets from normal individuals; the short inhibitory window provided by once-daily aspirin may therefore be insufficient to provide 24-h protection against CV events. Alternative conventional aspirin regimens (e.g. higher daily dose, twice-daily dosing, combination with clopidogrel) and newer formulations (e.g. 24-h, extended-release) have been proposed to overcome the apparent limited efficacy of conventional aspirin in patients with diabetes; however, tolerability concerns and limited clinical efficacy data need to be taken into account when considering the use of such regimens.

Perioperatively acquired disorders of coagulation

Purpose of review

To provide an overview of acquired coagulopathies that can occur in various perioperative clinical settings. Also described are coagulation disturbances linked to antithrombotic medications and currently available strategies to reverse their antithrombotic effects in situations of severe hemorrhage.

Recent findings

Recent studies highlight the link between low fibrinogen and decreased fibrin polymerization in the development of acquired coagulopathy. Particularly, fibrin(ogen) deficits are observable after cardiopulmonary bypass in cardiac surgery, on arrival at the emergency room in trauma patients, and with ongoing bleeding after child birth. Regarding antithrombotic therapy, although new oral anticoagulants offer the possibility of efficacy and relative safety compared with vitamin K antagonists, reversal of their anticoagulant effect with nonspecific agents, including prothrombin complex concentrate, has provided conflicting results. Specific antidotes, currently being developed, are not yet licensed for clinical use, but initial results are promising.

Summary

Targeted hemostatic therapy aims to correct coagulopathies in specific clinical settings, and reduce the need for allogeneic transfusions, thus preventing massive transfusion and its deleterious outcomes. Although there are specific guidelines for reversing anticoagulation in patients treated with antiplatelet agents or warfarin, there is currently little evidence to advocate comprehensive recommendations to treat drug-induced coagulopathy associated with new oral anticoagulants.

Aspirin for Venous Ulcers: Randomised Trial (AVURT): study protocol for a randomised controlled trial

BACKGROUND

Venous leg ulcers (VLUs) are the commonest cause of leg ulceration, affecting 1 in 100 adults. There is a significant health burden associated with VLUs - it is estimated that the cost of treatment for 1 ulcer is up to £1300 per year in the NHS. The mainstay of treatment is with graduated compression bandaging; however, treatment is often prolonged and up to one quarter of venous leg ulcers do not heal despite standard care. Two previous trials have suggested that low-dose aspirin, as an adjunct to standard care, may hasten healing, but these trials were small and of poor quality. Aspirin is an inexpensive, widely used medication but its safety and efficacy in the treatment of VLUs remains to be established.

METHODS/DESIGN

AVURT is a phase II randomised double blind, parallel-group, placebo-controlled efficacy trial. The primary objective is to examine whether aspirin, in addition to standard care, is effective in patients with chronic VLUs (i.e. over 6 weeks in duration or a history of VLU). Secondary objectives include feasibility and safety of aspirin in this population. A target of 100 participants, identified from community leg ulcer clinics and hospital clinics, will be randomised to receive either 300 mg of aspirin once daily or placebo. All participants will receive standard care with compression therapy. The primary outcome will be time to healing of the reference ulcer. Follow-up will occur for a maximum of 27 weeks. The primary analysis will use a Cox proportional hazards model to compare time to healing using the principles of intention-to-treat. Secondary outcomes will include ulcer size, pain evaluation, compliance and adverse events.

DISCUSSION

The AVURT trial will investigate the efficacy and safety of aspirin as a treatment for VLU and will inform on the feasibility of proceeding to a larger phase III study. This study will address the paucity of information currently available regarding aspirin therapy to treat VLU.

TRIAL REGISTRATION

The study is registered on a public database with clinicaltrials.gov ( NCT02333123 ; registered on 5 November 2014).

Cost-Effectiveness of Proton Pump Inhibitor Co-Therapy in Patients Taking Aspirin for Secondary Prevention of Ischemic Stroke

BACKGROUND

Low-dose aspirin (ASA) is effective for secondary prevention of ischemic stroke but can increase the risks of hemorrhagic stroke, upper gastrointestinal bleeding (UGIB), and dyspepsia. Prophylactic administration of proton pump inhibitors (PPIs) reduces the risks of these digestive symptoms. We investigated the cost effectiveness of adding a PPI to ASA therapy for ischemic stroke patients in Japan.

METHODS

A Markov state-transition model was developed to compare the cost effectiveness of ASA monotherapy with ASA plus PPI co-therapy in patients with histories of upper gastrointestinal ulcers and ischemic stroke. The model takes into account ASA adherence rate and adverse effects due to ASA, including hemorrhagic stroke and UGIB. The analysis was performed from the perspective of healthcare payers in 2013.

RESULTS

In the base case, total life-years by PPI co-therapy and monotherapy were 16.005 and 15.932, respectively. The difference in duration of no therapy (no ASA or PPI) between the therapies was 558.5 days, which would prevent 30.3 recurrences of ischemic stroke per 1000 person-years. The incremental cost-effectiveness ratio of PPI co-therapy relative to monotherapy was ¥1,191,665 (US$11,458) per life-year gained. In a one-way sensitivity analysis, PPI co-therapy was consistently cost effective at a willingness to pay of ¥5,000,000 (US$48,077) per life-year gained. In a probabilistic sensitivity analysis, the probability that PPI co-therapy was cost effective was 89.74% at the willingness to pay.

CONCLUSIONS

Co-therapy with ASA plus PPI appears to be cost-effective compared with ASA monotherapy. The addition of PPI also appeared to prolong the duration of ASA therapy, thereby reducing the risk of ischemic stroke.

Drug delivery and therapeutic impact of extended-release acetylsalicylic acid

Current treatment guidelines recommend once-daily, low-dose acetylsalicylic acid (ASA; aspirin) for secondary prevention of cardiovascular events. However, the anti-thrombotic benefits of traditional ASA formulations may not extend over a 24-h period, especially in patients at high risk for a recurrent cardiovascular event. A next-generation, extended-release ASA formulation (ER-ASA) has been developed to provide 24-h anti-thrombotic coverage with once-daily dosing. The pharmacokinetics of ER-ASA indicates slower absorption and prolonged ASA release versus immediate-release ASA, with a favorable safety profile. ER-ASA minimizes systemic ASA absorption and provides sustained antiplatelet effects over a 24-h period.

Current Strategies to Reduce Gastrointestinal Bleeding Risk Associated with Antiplatelet Agents

Antiplatelet agents remain the cornerstone in the primary and secondary therapeutic intervention for cardiovascular disease. Some patients may be subjected to a year or more of dual antiplatelet therapy to reduce the risk of subsequent cardiovascular events. Patients on antiplatelet therapy have an increased risk of gastrointestinal bleeding; however, not all patients benefit from concomitant acid suppressive therapy. This review will provide an overview of the pharmacology of antiplatelet agents and outline patient risk profiles that ought to be considered when considering prophylactic therapy to reduce gastrointestinal toxicity. In addition, we discuss the current risk-reduction strategies intended to mitigate against the potential for related gastroduodenal injury.

Time-trends in the prescribing of gastroprotective agents to primary care patients initiating low-dose aspirin or non-steroidal anti-inflammatory drugs: a population-based cohort study

AIMS

Low-dose aspirin (LDA) and non-steroidal-anti-inflammatory drugs (NSAIDs) both increase the risk of upper gastrointestinal events (UGIEs). In the Netherlands, recommendations regarding the prescription of gastroprotective agents (GPAs) in LDA users were first issued in 2009 in the HARM-Wrestling consensus. National guidelines on gastroprotective strategies (GPSs) in NSAID users were issued in the first part of the preceding. The aim of the present study was to examine time-trends in GPSs in patients initiating LDA and those initiating NSAIDs between 2000 and 2012.

METHODS

Within a large electronic primary healthcare database, two cohorts were selected: (i) patients newly prescribed LDA and (ii) patients newly prescribed NSAIDs between 2000 and 2012. Patients who had been prescribed a GPA in the previous six months were excluded. For both cohorts, patients' risk of a UGIE was classified as low, moderate or high, based on the HARM-Wrestling consensus, and the presence of an adequate GPSwas determined.

RESULTS

A total of 37 578 patients were included in the LDA cohort and 352 025 patients in the NSAID cohort. In both cohorts, an increase in GPSs was observed over time, but prescription of GPAs was lower in the LDA cohort. By 2012, an adequate GPS was present in 31.8% of high-risk LDA initiators, vs. 48.0% of high-risk NSAID initiators.

CONCLUSIONS

Despite a comparable risk of UGIEs, GPSs are prescribed less in high-risk LDA initiators than in high-risk NSAID initiators. For both groups of patients, there is still room for improvement in guideline adherence.

Platelets in cancer. From basic research to therapeutic implications

Platelets are well-known for their major role in primary hemostasis and thrombosis. Cancer patients frequently manifest thrombotic events and present abnormalities in blood coagulation which appear to be linked to altered platelet function and turnover. Moreover, numerous studies indicate an intimate cross-talk between platelets and tumor growth, angiogenesis and metastatic dissemination. Finally, several experimental data and clinical trials suggest possible benefits of anti-platelet drugs on some cancers. Here, we will review the current state of basic biological research regarding the role of platelets in cancer progression. We also critically review the possible clinical applicability of some anti-platelet therapies to limit tumor growth and prevent metastatic dissemination.

Do the Effects of Secondary Prevention of Cardiovascular Events in PAD Patients Differ from Other Atherosclerotic Disease?

Atherosclerosis is considered a generalized disease. Similar or identical etiopathogenetic mechanisms and risk factors are involved in various atherosclerotic diseases, and the positive effects of preventive measures on atherogenesis in different parts of the arterial system were shown. However, until know, great emphasis has been placed on the aggressive pharmacological management of coronary artery disease (CHD), while less attention has been devoted to the management of peripheral arterial disease (PAD), despite its significant morbidity and mortality. Data on the efficacy of preventive measures in PAD patients have mostly been gained from subgroup analyses from studies devoted primarily to the management of coronary patients. These data have shown that treatment of risk factors for atherosclerosis with drugs can reduce cardiovascular events also in patients with PAD. The effects of some preventive procedures in PAD patients differ from coronary patients. Aspirin as a basic antiplatelet drug has been shown to be less effective in PAD patients than in coronary patients. The latest Antithrombotic Trialists' Collaboration (ATC) meta-analysis demonstrates no benefit of aspirin in reducing cardiovascular events in PAD. Statins reduce cardiovascular events in all three of the most frequently presented cardiovascular diseases, including PAD to a comparable extent. Recent studies indicate that in PAD patients, in addition to a reduction in cardiovascular events, statins may have some hemodynamic effects. They prolong walking distance and improve quality of life. Similarly, angiotensin enzyme inhibitors are also effective in the prevention of cardiovascular events in coronary, cerebrovascular, as well as PAD patients and show positive effects on the walking capacity of patients with intermittent claudication. In PAD patients, the treatment of hypertension and diabetes also effectively prevents cardiovascular morbidity and mortality. As PAD patients are at a highest risk of cardiovascular complications, the risk factors of atherosclerosis should be treated intensively in this group of patients. Most of the preventive measures, including the drugs used for prevention of CHD, are also effective in PAD patients.

Management of low-dose aspirin and clopidogrel in clinical practice: a gastrointestinal perspective

Low-dose aspirin, alone or combined with other antiplatelet agents, is increasingly prescribed for cardiovascular prevention. However, the cardiovascular benefits should be evaluated together with the gastrointestinal risks. Low-dose aspirin is associated with upper and lower gastrointestinal injury, although lower gastrointestinal effects are poorly characterized. This gastrointestinal risk differs among antiplatelets drugs users. The most important risk factors are history of peptic ulcer, older age, and concomitant use of non-steroidal anti-inflammatory drugs or dual antiplatelet therapy. Effective upper gastrointestinal prevention strategies are available and should be used in at-risk patients taking low-dose aspirin or clopidogrel. Proton pump inhibitors seem to be the best gastroprotective agents, whereas the benefits of Helicobacter pylori eradication are still unclear. Low-dose aspirin has additional effects in the gastrointestinal tract. A large body of evidence indicates that it can protect against different cancers, in particular colorectal cancer. This effect could modify the future indications for use of low-dose aspirin and the risk-benefit balance.

Prevention of colorectal cancer and dietary management

OBJECTIVES

This systematic review focuses on dietary and lifestyle risk factors for colorectal cancer (CRC) prevention and chemoprevention among high-risk populations.

METHODS AND MATERIALS

We searched PubMed for English-language articles about dietary components, lifestyle risk factors, and chemoprevention agents in relation to colorectal cancer and their references published from 1980 through 2013. We reviewed articles jointly for the most clinically important information, emphasizing randomized trials and meta-analyses where available.

RESULTS

There is convincing evidence that intake of garlic, vitamin B6 and magnesium, active living, maintaining a healthy weight and waist, avoiding or reducing red meat, alcohol, and smoking, as well as hormone replacement therapy among women may significantly protect against developing colorectal cancer. There is less consistent evidence for fruit and vegetable intake (fiber and folate), fish and Omega-3 fatty acids, selenium, dairy, calcium and vitamin D. For high-risk populations, aspirin have been shown to protect against the development of colonic adenomas and CRC, while a minimal effective dose remains unclear.

CONCLUSIONS

Colorectal cancer can be prevented in general population through dietary and lifestyle interventions, and aspirin may be a good choice of chemoprevention agent among high risk individuals.

Chemopreventive effects of aspirin at a glance

Experimental, epidemiological, and clinical data from the last two decades have each supported the hypothesis that aspirin possesses anticancer properties, and that its use may also reduce the lifetime probability of developing or dying from a number of cancers. Aspirin's ability to act on multiple key metabolic and signaling pathways via inhibition of the cyclooxygenase (COX) enzyme, as well as through COX-independent mechanisms, makes it particularly relevant in the fight against cancer. A growing body of evidence indicates that aspirin may not only reduce cancer risk, but also prevent metastasis and angiogenesis while slowing the rate of mutation-inducing DNA damage. These emerging benefits of aspirin are offset to some extent by the known risks of treatment, such as cardiovascular events and gastrointestinal bleeding. However, it has been shown that pre-treatment risk assessment of individual patients and the use of proton pump inhibitors or Helicobacter pylori eradication therapy concomitantly with aspirin treatment can reduce these potential risks. Thus, the significant benefits of aspirin treatment, coupled with recent data concerning its risks, may prove to tip the balance in favor of aspirin use in cancer prevention.

Antithrombotic drugs, patient characteristics, and gastrointestinal bleeding: Clinical translation and areas of research

Gastrointestinal bleeding (GIB) is a potentially fatal and avoidable medical condition that poses a burden on global health care costs. Current understanding of the roles of platelet activation and thrombin generation/activity in vascular medicine has led to the development of effective antithrombotic treatments. However, in parallel with a sustained coronary and cerebral flow patency, the increasingly intensive treatment with warfarin; direct oral anticoagulant drugs [DOACs], and/or with aspirin ± clopidogrel (or ± prasugrel or ± ticagrelor), has increased the burden of GIBs related to the use of antithrombotic agents. Compelling evidence concerning this issue is accumulating to indicate that: 1) the risk of GIB related to the use of antithrombotic drugs dramatically differs in different clinical settings; and 2) the characteristics of patients (e.g., severity of illness, comorbidities) in whom it is used exert a greater impact on the risk of GIB than the type of antithrombotic agent employed. The latter concept argues for the occurrence of GIB as reflecting the presence of patients at the highest risk for adverse outcomes. The HAS-BLED score identifies subjects at risk of bleeding among those untreated and those treated with warfarin, DOACs and/or low-dose aspirin. Its use within the frame of a severity score (e.g., the CHA2DS2-VASc score in patients with atrial fibrillation) helps balance the benefits and the risks of an antithrombotic treatment and identify those patients in whom the absolute gain (vascular events prevented) outweighs the risk of GIB. Potential implications of the latter information in settings other than atrial fibrillation is thoroughly discussed.

Safe prescribing of non-steroidal anti-inflammatory drugs in patients with osteoarthritis--an expert consensus addressing benefits as well as gastrointestinal and cardiovascular risks

BACKGROUND

There are several guidelines addressing the issues around the use of NSAIDs. However, none has specifically addressed the upper versus lower gastrointestinal (GI) risk of COX-2 selective and non-selective compounds nor the interaction at both the GI and cardiovascular (CV) level of either class of drugs with low-dose aspirin. This Consensus paper aims to develop statements and guidance devoted to these specific issues through a review of current evidence by a multidisciplinary group of experts.

METHODS

A modified Delphi consensus process was adopted to determine the level of agreement with each statement and to determine the level of agreement with the strength of evidence to be assigned to the statement.

RESULTS

For patients with both low GI and CV risks, any non-selective NSAID (ns-NSAID) alone may be acceptable. For those with low GI and high CV risk, naproxen may be preferred because of its potential lower CV risk compared with other ns-NSAIDs or COX-2 selective inhibitors, but celecoxib at the lowest approved dose (200 mg once daily) may be acceptable. In patients with high GI risk, if CV risk is low, a COX-2 selective inhibitor alone or ns-NSAID with a proton pump inhibitor appears to offer similar protection from upper GI events. However, only celecoxib will reduce mucosal harm throughout the entire GI tract. When both GI and CV risks are high, the optimal strategy is to avoid NSAID therapy, if at all possible.

CONCLUSIONS

Time is now ripe for offering patients with osteoarthritis the safest and most cost-effective therapeutic option, thus preventing serious adverse events which could have important quality of life and resource use implications. Please see related article: http://dx.doi.org/10.1186/s12916-015-0291-x.

[Managing antithrombotic therapy in vitreoretinal surgery]

Given the growing number of patients on antithrombotic therapy we are increasingly confronted with the management of this therapy before, during and after vitreoretinal surgery. In the absence of a consensus, the decision to withdraw antithrombotic therapy is based on the cardiovascular thromboembolism risk versus the theoretical risk of bleeding if the antithrombotic treatment is continued. As suggested by the literature, antiplatelet therapy (acetylsalicylic acid or clopidogrel) may be safely continued for vitreoretinal surgery, including retinal detachment repair. However, the risk/benefit ratio for patients being treated with two antiplatelet therapies is unknown. It appears that an International Normalized Ratio (INR) less than 3 for patients treated with anticoagulant therapy does not increase the perioperative risk of ocular bleeding. This risk has not been evaluated in patients treated by new antithrombotic therapies (prasugrel, ticagrelor as antiplatelet medication, or dabigatran, rivaroxaban, apixaban as anticoagulant therapy), and there is a need to study it further.

Prophylactic use of aspirin: systematic review of harms and approaches to mitigation in the general population

A careful assessment of benefits and harms is required to assess suitability of aspirin as a prophylactic public health measure. However, comprehensive population-level data on harms are lacking. We collected and synthesized age and sex-specific data on harms relevant to aspirin use in average-risk individuals aged 50 years or older. We conducted systematic literature searches to identify baseline rates of gastrointestinal (GI) bleeding, peptic ulcer, major extra-cranial bleeding, and case-fatality rates due to GI bleeding or peptic ulcer in general population. The magnitude of aspirin-associated increase, the prevalence and attributable risk of Helicobacter pylori infection on these events in aspirin users was also assessed. Baseline rates of major extracranial bleeding events and GI complications increase with age; an almost threefold to fourfold increase is observed from age 50-54 to 70-74 years. Low or standard-dose aspirin use increases GI bleeding events by 60% leading to an annual excess of 0.45 and 0.79 GI bleeding events per 1,000 women and men aged 50-54 years respectively. 5-10% of major GI complications are fatal; a clear age dependence--higher fatality in older individuals, is seen. Eradication of H. pylori infection before aspirin use could reduce the incidence of upper GI complications by 25-30%. GI complications are increased by about 60% due to aspirin use but are fatal only in a very small proportion of individuals younger than 70 years of age. Major bleeding events that are comparable in severity to cancer or CVD, are infrequent. Screening and eradication of H. pylori infection could substantially lower aspirin-related GI harms.

Epidemiology and diagnosis of acute nonvariceal upper gastrointestinal bleeding

Acute upper gastrointestinal bleeding (UGIB) is a common gastroenterological emergency. A vast majority of these bleeds have nonvariceal causes, in particular gastroduodenal peptic ulcers. Nonsteroidal antiinflammatory drugs, low-dose aspirin use, and Helicobacter pylori infection are the main risk factors for UGIB. Current epidemiologic data suggest that patients most affected are older with medical comorbidit. Widespread use of potentially gastroerosive medications underscores the importance of adopting gastroprotective pharamacologic strategies. Endoscopy is the mainstay for diagnosis and treatment of acute UGIB. It should be performed within 24 hours of presentation by skilled operators in adequately equipped settings, using a multidisciplinary team approach.

Endoscopic management of nonvariceal, nonulcer upper gastrointestinal bleeding

Upper gastrointestinal bleeding (UGIB) is the most common emergency condition in gastroenterology. Although peptic ulcer and esophagogastric varices are the predominant causes, other conditions account for up to 50% of UGIBs. These conditions, among others, include angiodysplasia, Dieulafoy and Mallory-Weiss lesions, gastric antral vascular ectasia, and Cameron lesions. Upper GI cancer as well as lesions of the biliary tract and pancreas may also result in severe UGIB. This article provides an overview of the endoscopic management of these lesions, including the role of novel therapeutic modalities such as hemostatic powder and over-the-scope-clips.

Risk factors for early and delayed post-operative bleeding after endoscopic submucosal dissection of gastric neoplasms, including patients with continued use of antithrombotic agents

BACKGROUND

Endoscopic submucosal dissection (ESD) has become widely accepted as a standard treatment for gastric epithelial neoplasms. Antithrombotic agents are widely used to prevent thromboembolic disease. However, the feasibility of endoscopic procedures for patients using such agents has been rarely investigated. The aim of this study was to identify risk factors for post-operative bleeding after gastric ESD and to evaluate the relationship between the use of antithrombotic agents and post-operative bleeding.

METHODS

From June 2005 to March 2014, 413 patients with 425 gastric neoplasms were treated by ESD. The demographic and clinical parameters associated with post-operative bleeding were investigated. 83 patients receiving antithrombotic agents were separately assessed using various methods of administration during the ESD procedure. Post-operative bleeding that occurred within 5 days of ESD was defined as early post-operative bleeding, whereas subsequent bleeding was defined as delayed bleeding.

RESULTS

The overall post-operative bleeding rate was 4.7%. In patients with continued low-dose aspirin (LDA), heparin replacement (HR), or continued LDA along with HR, post-operative bleeding rates were 9.5%, 23.8%, and 25.0%, respectively. On multivariate analysis, a specimen size of ≥40 mm was a risk factor for early post-operative bleeding [odds ratio (OR) 6.08, 95% CI: 1.74-21.27], and HR and chronic kidney disease (CKD) requiring hemodialysis were risk factors for delayed bleeding (OR 12.23, 95% CI: 2.63-56.77 and OR 28.35, 95% CI: 4.67-172.11, respectively). Continued LDA was not a risk factor for post-operative bleeding.

CONCLUSIONS

Large specimen size is a risk factor for early post-operative bleeding, and HR and CKD requiring hemodialysis are risk factors for delayed bleeding. Patients with risk factors should be carefully watched, allowing for the timing of post-operative bleeding after ESD.

Cost-effectiveness of aspirin adjuvant therapy in early stage colorectal cancer in older patients

BACKGROUND & AIMS

Recent observational studies showed that post-operative aspirin use reduces cancer relapse and death in the earliest stages of colorectal cancer. We sought to evaluate the cost-effectiveness of aspirin as an adjuvant therapy in Stage I and II colorectal cancer patients aged 65 years and older.

METHODS

Two five-state Markov models were constructed separately for Stage I and II colorectal cancer using TreeAge Pro 2014. Two hypothetical cohorts of 10,000 individuals at a starting age of 65 years and with colorectal cancer in remission were put through the models separately. Cost-effectiveness of aspirin was evaluated against no treatment (Stage I and II) and capecitabine (Stage II) over a 20-year period from the United States societal perspective. Extensive one-way sensitivity analyses and multivariable Probabilistic Sensitivity Analyses (PSA) were performed.

RESULTS

In the base case analyses, aspirin was cheaper and more effective compared to other comparators in both stages. Sensitivity analyses showed that no treatment and capecitabine (Stage II only) can be cost-effective alternatives if the utility of taking aspirin is below 0.909, aspirin's annual fatal adverse event probability exceeds 0.57%, aspirin's relative risk of disease progression is 0.997 or more, or when capecitabine's relative risk of disease progression is less than 0.228. Probabilistic Sensitivity Analyses (PSA) further showed that aspirin could be cost-effective 50% to 80% of the time when the willingness-to-pay threshold was varied from USD 20,000 to USD 100,000.

CONCLUSION

Even with a modest treatment benefit, aspirin is likely to be cost-effective in Stage I and II colorectal cancer, thus suggesting a potential unique role in secondary prevention in this group of patients.

Interaction between Helicobacter pylori infection, nonsteroidal anti-inflammatory drugs and/or low-dose aspirin use: Old question new insights

Previous reports clearly demonstrated that Helicobacter pylori (H. pylori) infection, nonsteroidal anti-inflammatory drugs (NSAID) or low dose aspirin (ASA) use significantly and independently increased the risk for the development of peptic ulcer disease. Today, the presence of H. pylori infection associated with low dose ASA and/or NSAID use in the same patient is becoming more frequent and therefore the potential interaction between these factors and the consequences of it has important implications. Whether NSAID intake in the presence of H. pylori infection may further increase the risk of peptic ulcer carried by the presence of only one risk factor is still a matter of debate. Studies on the interaction between the two risk factors yielded conflicting data and no consensus has been reached in the last years. In addition, the interaction between H. pylori infection and low-dose ASA remains even more controversial. In real clinical practice, we can find different clinical scenarios involving these three factors associated with the presence of different gastrointestinal and cardiovascular risk factors. These huge variety of possible combinations greatly hinder the decision making process of physicians.

Personalized approach to primary and secondary prevention of ischemic stroke

Primary and secondary prevention of ischemic stroke represents a significant part of stroke management and health care. Although there are official guidelines concerning stroke management, new knowledge are introduced to them with a slight delay. This article provides an overview of current information on primary and secondary prevention of ischemic stroke. It summarizes information especially in the field of cardioembolic stroke, the use of new anticoagulants and the management of carotid stenosis based on the results of recent clinical studies. The optimal approach in stroke management is to follow these recommendations, to know new strategies and to apply an individual personalized approach in our clinical decisions.

Prevention and treatment of cancer with aspirin: where do we stand?

Aspirin is arguably the synthesized drug that has been used most commonly in human history. Aspirin was originally developed and marketed for the treatment of inflammatory disorders at the end of the 19th century, but its mechanism of action remained unknown until the second half of the 20th century. Since the latter part of the 20th century aspirin also has been used for the primary and secondary prevention of cardiovascular diseases given its anti-thrombotic properties. An association between intake of aspirin and decreased cancer risk was identified in the past decades. Whether aspirin can be used as an anticancer agent in patients with a diagnosis of cancer was unknown until recently. Recent studies suggest that aspirin might provide therapeutic benefit in the adjuvant treatment of certain forms of cancer. This review provides a critical update on this topic, which has potential implications for oncologists and their patients.

The failure of cancer chemoprevention

Chemoprevention is proposed as a clinical analogue of population prevention, aimed at reducing likelihood of disease progression, not across the population, but in identified high-risk individuals and not by behavioral or lifestyle modification, but by the use of pharmaceutical agents. Cardiovascular chemoprevention is successful via control of hyperlipidemias and hypertension. However, chemoprevention of cancer is an almost universal failure: not only are some results null; even more frequently, there is an excess of disease, including disease that the agents were chosen specifically to reduce. A brief introduction is followed by the evidence for a wide variety of agents and their largely deleterious, sometimes null, and in one case, largely beneficial, consequences as possible chemopreventives. The agents include (i) those that are food derived and their synthetic analogues: β-carotene, folic acid, retinol and retinoids, vitamin E, multivitamin supplements, vitamin C, calcium and selenium and (ii) agents targeted at metabolic and hormonal pathways: statins, estrogen and antagonists, 5α-reductase inhibitors. There are two agents for which there is good evidence of benefit when the strategy is focused on those at defined high risk but where wider application is much more problematic: aspirin and tamoxifen. The major problems with cancer chemoprevention are presented. This is followed by a hypothesis to explain the failure of cancer chemoprevention as an enterprise, arguing that the central tenets that underpin it are flawed and showing why, far from doing good, cancer chemoprevention causes harm.

Perioperative management of antiplatelet therapy

Worldwide, cardiovascular events represent the major cause of morbidity and mortality. A key role in the pathogenesis of these events is played by platelets. Interventional procedures, with placement of coronary and vascular stents, often represent the preferred therapeutic strategy. Antiplatelet medications are considered first-line therapy in preventing cardiovascular thrombotic events. A wide array of antiplatelet agents is available, each with different pharmacological properties. When patients on antiplatelet agents present for surgery, the perioperative team must design an optimal strategy to manage antiplatelet medications. Each patient is stratified according to risk of developing a cardiovascular thrombotic event and inherent risk of surgical bleeding. After risk stratification analysis, various therapeutic pathways include continuing or discontinuing all antiplatelet agents or maintaining one antiplatelet agent and discontinuing the other. This review focuses on the pharmacological and pharmacokinetic properties of both older and novel antiplatelet drugs, and reviews current literature and guidelines addressing options for perioperative antiplatelet management.

Role of chemoprophylaxis with either NSAIDs or statins in patients with Barrett's esophagus

The incidence of esophageal adenocarcinoma, a poor prognosis neoplasia, has risen dramatically in recent decades. Barrett's esophagus represents the best-known risk factor for esophageal adenocarcinoma development. Non-steroidal anti-inflammatory drugs through cyclooxygenase-2 inhibition and prostaglandin metabolism regulation could control cell proliferation, increase cell apoptosis and regulate the expression of growth and angiogenic factors. Statins can achieve equivalent effects through prenylation and subsequently control of cellular signaling cascades. At present, epidemiological studies are small and underpowered. Their data could not justify either medication as a chemo-preventive agent. Population based studies have shown a 43% reduction of the odds of developing an esophageal adenocarcinoma, leaving out or stating a 25% reduction in patients consuming non-aspirin nonsteroidal anti-inflammatory drugs and a 50% reduction in those patients consuming aspirin. They have also stated a 19% reduction of esophageal cancer incidence when statins have been used. Observational studies have shown that non-steroidal anti-inflammatory drugs could reduce the adenocarcinoma incidence in patients with Barrett's esophagus by 41%, while statins could reduce the risk by 43%. The cancer preventive effect has been enhanced in those patients taking a combination of non-steroidal anti-inflammatory drugs and statins (a 74% decrease). Observational data are equivocal concerning the efficacy of non-steroidal anti-inflammatory drug subclasses. Non-steroidal anti-inflammatory drugs clearly have substantial potential for toxicity, while statins are rather safe drugs. In conclusion, both non-steroidal anti-inflammatory drugs and statins are promising chemopreventive agents and deserve further exploration with interventional studies. In the meanwhile, their use is justified only in patients with cardiovascular disease.

Gastroprotection in low-dose aspirin users for primary and secondary prevention of ACS: results of a cost-effectiveness analysis including compliance

PURPOSE

Low-dose aspirin (ASA) increases the risk of upper gastrointestinal (GI) complications. Proton pump inhibitors (PPIs) reduce these upper GI side effects, yet patient compliance to PPIs is low. We determined the cost-effectiveness of gastroprotective strategies in low-dose ASA users considering ASA and PPI compliance.

METHODS

Using a Markov model we compared four strategies: no medication, ASA monotherapy, ASA+PPI co-therapy and a fixed combination of ASA and PPI for primary and secondary prevention of ACS. The risk of acute coronary syndrome (ACS), upper GI bleeding and dyspepsia was modeled as a function of compliance and the relative risk of developing these events while using medication. Costs, quality adjusted life years and number of ACS events were evaluated, applying a variable risk of upper GI bleeding. Probabilistic sensitivity analyses were performed.

RESULTS

For our base case patients using ASA for primary prevention of ACS no medication was superior to ASA monotherapy. PPI co-therapy was cost-effective (incremental cost-effectiveness ratio [ICER] €10,314) compared to no medication. In secondary prevention, PPI co-therapy was cost-effective (ICER €563) while the fixed combination yielded an ICER < €20,000 only in a population with elevated risk for upper GI bleeding or moderate PPI compliance. PPI co-therapy had the highest probability to be cost-effective in all scenarios. PPI use lowered the overall number of ACS.

CONCLUSIONS

Considering compliance, PPI co-therapy is likely to be cost-effective in patients taking low dose ASA for primary and secondary prevention of ACS, given low PPI prices. In secondary prevention, a fixed combination seems cost-effective in patients with elevated risk for upper GI bleeding or in those with moderate PPI compliance. Both strategies reduced the number of ACS compared to ASA monotherapy.

Treatment of arterial ischemic stroke in children

Stroke is a rare but increasingly recognized disorder in children. Current therapies for arterial ischemic stroke include thrombolytic, antithrombotic and antiplatelet agents, blood transfusion and surgery. Adult studies, pediatric case studies and expert opinion form the basis for these treatment strategies. Thrombolytic agents are increasingly used but, as in adults, the majority of arterial ischemic strokes in children are treated with antiplatelet and antithrombotic agents. Sickle-cell patients, a distinct subset of the pediatric stroke population, are treated primarily with transfusion therapy. Pediatric arterial ischemic stroke studies are needed to determine the most appropriate course of treatment. An international study is currently in progress to formally study the incidence, risk factors, treatment strategies and outcomes of stroke in children.