Risk of Upper Gastrointestinal Bleeding in a Cohort of New Users of Low-Dose ASA for Secondary Prevention of Cardiovascular Outcomes

Associations between COVID-19 therapies and inpatient gastrointestinal bleeding: A multisite retrospective study

Little data is available regarding the incidence of gastrointestinal bleeding in adults hospitalized with COVID-19 infection and the influence of patient comorbidities and demographics, COVID-19 therapies, and typical medications used. In this retrospective study, we utilized the National COVID Cohort Collaborative to investigate the primary outcome of the development of gastrointestinal bleeding in 512 467 hospitalized US adults (age >18 years) within 14 days of a COVID-19 infection and the influence of demographics, comorbidities, and selected medications. Gastrointestinal bleeding developed in 0.44% of patients hospitalized with COVID-19. Comorbidities associated with gastrointestinal bleeding include peptic ulcer disease (adjusted odds ratio [aOR] 10.2), obesity (aOR 1.27), chronic kidney disease (aOR 1.20), and tobacco use disorder (aOR 1.28). Lower risk of gastrointestinal bleeding was seen among women (aOR 0.76), Latinx (aOR 0.85), and vaccinated patients (aOR 0.74). Dexamethasone alone or with remdesivir was associated with lower risk of gastrointestinal bleeding (aOR 0.69 and aOR 0.83, respectively). Remdesivir monotherapy was associated with upper gastrointestinal bleeding (aOR 1.25). Proton pump inhibitors were more often prescribed in patients with gastrointestinal bleeding, likely representing treatment for gastrointestinal bleeding rather than a risk factor for its development. In adult patients hospitalized with COVID-19, the use of dexamethasone alone or in combination with remdesivir is negatively associated with gastrointestinal bleeding. Remdesivir monotherapy is associated with increased risk of upper gastrointestinal bleeding.

Helicobacter pylori eradication for primary prevention of peptic ulcer bleeding in older patients prescribed aspirin in primary care (HEAT): a randomised, double-blind, placebo-controlled trial

BACKGROUND

Peptic ulcers in patients receiving aspirin are associated with Helicobacter pylori infection. We aimed to investigate whether H pylori eradication would protect against aspirin-associated ulcer bleeding.

METHODS

We conducted a randomised, double-blind, placebo-controlled trial (Helicobacter Eradication Aspirin Trial [HEAT]) at 1208 primary care centres in the UK, using routinely collected clinical data. Eligible patients were aged 60 years or older who were receiving aspirin at a daily dose of 325 mg or less (with four or more 28-day prescriptions in the past year) and had a positive C13 urea breath test for H pylori at screening. Patients receiving ulcerogenic or gastroprotective medication were excluded. Participants were randomly assigned (1:1) to receive either a combination of oral clarithromycin 500 mg, metronidazole 400 mg, and lansoprazole 30 mg (active eradication), or oral placebo (control), twice daily for 1 week. Participants, their general practitioners and health-care providers, and the research nurses, trial team, adjudication committee, and analysis team were all masked to group allocation throughout the trial. Follow-up was by scrutiny of electronic data in primary and secondary care. The primary outcome was time to hospitalisation or death due to definite or probable peptic ulcer bleeding, and was analysed by Cox proportional hazards methods in the intention-to-treat population. This trial is registered with EudraCT, 2011-003425-96.

FINDINGS

Between Sept 14, 2012, and Nov 22, 2017, 30 166 patients had breath testing for H pylori, 5367 had a positive result, and 5352 were randomly assigned to receive active eradication (n=2677) or placebo (n=2675) and were followed up for a median of 5·0 years (IQR 3·9-6·4). Analysis of the primary outcome showed a significant departure from proportional hazards assumptions (p=0·0068), requiring analysis over separate time periods. There was a significant reduction in incidence of the primary outcome in the active eradication group in the first 2·5 years of follow-up compared with the control group (six episodes adjudicated as definite or probable peptic ulcer bleeds, rate 0·92 [95% CI 0·41-2·04] per 1000 person-years vs 17 episodes, rate 2·61 [1·62-4·19] per 1000 person-years; hazard ratio [HR] 0·35 [95% CI 0·14-0·89]; p=0·028). This advantage remained significant after adjusting for the competing risk of death (p=0·028) but was lost with longer follow-up (HR 1·31 [95% CI 0·55-3·11] in the period after the first 2·5 years; p=0·54). Reports of adverse events were actively solicited; taste disturbance was the most common event (787 patients).

INTERPRETATION

H pylori eradication protects against aspirin-associated peptic ulcer bleeding, but this might not be sustained in the long term.

FUNDING

National Institute for Health and Care Research Health Technology Assessment.

Efficacy and Safety of Aspirin for Primary Cardiovascular Risk Prevention in Younger and Older Age: An Updated Systematic Review and Meta-analysis of 178,310 Subjects from 21 Randomized Studies

AIMS

 The efficacy and safety of aspirin for primary cardiovascular disease (CVD) prevention is controversial. The aim of this study was to investigate the efficacy and safety of aspirin in subjects with no overt CVD, with a focus on age as a treatment modifier.

METHODS AND RESULTS

 Randomized trials comparing aspirin use versus no aspirin use or placebo were included. The primary efficacy outcome was all-cause death. The primary safety outcome was major bleeding. Secondary ischemic and bleeding outcomes were explored. Subgroup analyses were conducted to investigate the consistency of the effect sizes in studies including younger and older individuals, using a cut-off of 65 years. A total of 21 randomized trials including 173,810 individuals at a mean follow-up of 5.3 years were included. Compared with control, aspirin did not reduce significantly the risk of all-cause death (risk ratio: 0.96; 95% confidence interval: 0.92-1.00, p = 0.057). Major adverse cardiovascular events were significantly reduced by 11%, paralleled by significant reductions in myocardial infarction and transient ischemic attack. Major bleeding, intracranial hemorrhage, and gastrointestinal bleeding were significantly increased by aspirin. There was a significant age interaction for death (p for interaction = 0.007), with aspirin showing a statistically significant 7% relative benefit on all-cause death in studies including younger patients.

CONCLUSION

 The use of aspirin in subjects with no overt CVD was associated with a neutral effect on all-cause death and a modest lower risk of major cardiovascular events at the price of an increased risk in major bleeding. The benefit of aspirin might be more pronounced in younger individuals.

Effect of Proton Pump Inhibitors on Risks of Upper and Lower Gastrointestinal Bleeding among Users of Low-Dose Aspirin: A Population-Based Observational Study

Estimates of the effect of proton pump inhibitors (PPIs) on risks of upper and lower gastrointestinal bleeding (UGIB and LGIB) among low-dose aspirin users in routine clinical practice are variable (UGIB) or lacking (LGIB). We aimed to establish these risks in the same observational study population. Using UK primary care data, we followed 199,049 new users of low-dose aspirin (75–300 mg/day) and matched non-users at start of follow-up to identify incident UGIB/LGIB cases. In nested case–control analyses, adjusted odds ratios (ORs) were calculated for concomitant PPI use vs. past (discontinued) PPI use among current low-dose aspirin users. For UGIB (n = 987), ORs (95% CIs) were 0.69 (0.54–0.88) for >1 month PPI use and 2.65 (1.62–4.3) for ≤1 month PPI use. Among the latter group, ORs (95% CIs) were 3.05 (1.75–5.33) for PPI initiation after start of aspirin therapy, and 1.66 (0.63–4.36) for PPI initiation on/before start of aspirin therapy. For LGIB (n = 1428), ORs (95% CIs) were 0.98 (0.81–1.17) for >1 month PPI use and 1.12 (0.73–1.71) for ≤1 month PPI use. Among low-dose aspirin users, maintaining PPI use (>1 month) was associated with a significantly reduced UGIB risk. Neither short nor long-term PPI use affected LGIB risk.

Incidence of Upper and Lower Gastrointestinal Bleeding in New Users of Low-Dose Aspirin

BACKGROUND & AIMS

There are few data on the incidence of upper and lower gastrointestinal bleeding (UGIB and LGIB) from observational studies of low-dose aspirin users. We aimed to estimate incidence rates of UGIB and LGIB in a large cohort of new users of low-dose aspirin in the United Kingdom, with subanalyses of hospitalization status and fatalities.

METHODS

We performed a population-based study of 199,079 new users of low-dose aspirin (median age, 64.0 years) identified from the Health Improvement Network primary care database (2000-2012). Individuals were followed for a median 5.4 years (maximum, 14 years) to identify new cases of UGIB and LGIB. Following multistep validation, we calculated overall and age- and sex-specific incidence rates; we performed subanalyses for health care use and death within 30 days of GIB. We also estimated rates within a matched (1:1) cohort of nonusers of low-dose aspirin at the start of the follow-up period.

RESULTS

The low-dose aspirin users had 1115 UGIB events and 1936 LGIB events; most subjects with UGIB events (58.9%) were hospitalized, whereas most subjects with LGIB events were referred to secondary care (72.8%). Crude incidence rates of GIB per 1000 person-years were 0.97 for subjects with UGIB (95% CI, 0.91-1.02) and 1.68 for subjects with LGIB (95% CI, 1.60-1.75). Incidence rates per 1000 person-years for patients hospitalized for GIB were 0.57 for UGIB (95% CI, 0.53-0.61) and 0.45 for LGIB (95% CI, 0.42-0.49); for referred (but not hospitalized) cases, these values were 0.39 for UGIB (95% CI, 0.36-0.43) and 1.22 for LGIB (1.16-1.29). Incidence rates per 1000 person-years were 0.06 for fatal UGIB (95% CI, 0.04-0.07), 0.01 for fatal LGIB (95% CI, 0.01-0.02), 0.91 for nonfatal UGIB (95% CI, 0.86-0.97), and 1.66 for nonfatal LGIB (95% CI, 1.59-1.74). Among nonusers of low-dose aspirin, incidence rates per 1000 person-years were 0.67 (95% CI, 0.63-0.75) for UGIB and 0.76 (95% CI, 0.72-0.82) for LGIB.

CONCLUSION

In a population-based study of low-dose aspirin users, the incidence of LGIB was higher than the incidence of UGIB. However, incidence rates of hospitalized GI bleeds and 30-day mortality rates were lower for LGIB than for UGIB. These estimates are valuable for benefit-risk assessments of low-dose aspirin for cardiovascular and colorectal cancer prevention.

Low-dose aspirin and risk of upper/lower gastrointestinal bleeding by bleed severity: a cohort study with nested case-control analysis using primary care electronic health records from the United Kingdom

Introduction: Risks of low-dose aspirin-associated upper and lower gastrointestinal bleeds (UGIB/LGIB) may vary by severity and presence of cardiovascular disease (CVD). No study has quantified these risks for UGIB and LGIB in the same real-world study population. Patients and methods: Using UK primary care data, 199,049 new users of low-dose aspirin (75-300 mg/day) and 1:1 matched non-users were followed to identify incident UGIB (N = 1843)/LGIB (N = 2763) cases. Nested case-control analyses compared current low-dose aspirin vs. non-use on UGIB/LGIB risk. Results: Adjusted incidence rate ratios (ORs; 95% CIs) were 1.62 (1.42-1.86) for non-fatal UGIB, 1.63 (1.47-1.81) for non-fatal LGIB, 0.77 (0.51-1.16) for fatal UGIB, 1.29 (0.50-3.36) for fatal LGIB. For hospitalizations, adjusted ORs (95% CIs) were 1.55 (1.32-1.81) for UGIB and 1.89 (1.58-2.27) for LGIB; for referred only cases, they were 1.52 (1.26-1.84) for UGIB and 1.54 (1.37-1.73) for LGIB. In primary CVD prevention, adjusted ORs (95% CI) were 1.62 (1.38-1.90) for UGIB and 1.60 (1.42-1.81) for LGIB; in secondary CVD prevention, they were 1.16 (0.89-1.50) for UGIB and 1.67 (1.34-2.09) for LGIB. Conclusion: Low-dose aspirin was associated with increased risks of non-fatal but not fatal UGIB/LGIB. Key message Low-dose aspirin is associated with an increased risks of non-fatal UGIB/LGIB but not fatal UGIB/LGIB.

[Antiplatelet duration in the elderly patients after percutaneous coronary intervention]

Ischemic heart disease is a leading cause of death in Europe. At the same time, older patients are at high risk for coronary heart disease and represent an increasing proportion of patients in the catheterization laboratory in the context of an ageing population. The elderly patients are also at higher bleeding risk, and were poorly represented in major randomized trials. Duration of dual antiplatelet therapy (DAPT), after percutaneous coronary intervention (PCI) should be modulated in a personalized way taking into account hemorrhagic and ischemic risk factors, using risk scores based on the latest recommendations of the European Society of Cardiology. Even if the optimal duration of DAPT after PCI is 6 months in case of stable coronary disease and 12 months in case of an acute coronary syndrome, it can be drastically reduced, up to one month in case of high hemorrhagic risk, or can be prolonged for more than 12 months in case of high ischemic risk. The use of latest generation drug eluting stents associated with a short duration of DAPT has thus demonstrated its safety compared to these durations. In case of triple therapy treatment, associating DAPT and anticoagulation therapy, DAPT is recommended to be as short as possible, potentially reduced to 1 month. Finally, the concomitant prescription of proton pump inhibitor is essential to prevent gastrointestinal bleedings. This literature review will discuss the hemorrhagic risk stratification and choice of DAPT in elderly patients.

The contribution of clinical and pathological predisposing factors to severe gastro-duodenal lesions in patients with long-term low-dose aspirin and proton pump inhibitor therapy

BACKGROUND

Preventive strategies developed to avoid the complications of antiplatelet therapies recommend the evaluation of risk factors for gastrointestinal events and indicated gastroprotective strategies.

AIM

We aimed to assess the impact of predisposing factors - histological findings, concomitant drug consumption, comorbidities, symptoms, social habits, Helicobacter pylori infection - on severe gastro-duodenal lesions in patients with low-dose aspirin and concomitant protective therapy with proton pump inhibitors (PPI).

METHOD

We enrolled 237 patients with LDA and PPI therapy, referred for upper digestive endoscopy, divided into two groups according to the severity of their endoscopic lesions (172 patients with no or mild endoscopic lesions and 65 patients with severe endoscopic lesions).

RESULTS

In the univariate logistic regression model, the factors associated with severe gastro-duodenal lesions were gender (OR=1.87, 95% CI: 1.04-3.41), anticoagulants (OR=2.40, 95% CI: 1.26-4.53), gastric atrophy and/or intestinal metaplasia (OR=1.85, 95% CI: 1.04-3.32), congestive heart failure (OR=2.59, 95% CI: 1.16-6.62), anaemia (OR=3.01, 95% CI: 1.67-5.47) and smoking (OR=4.29, 95% CI: 1.57-12.32). In the final model, anticoagulants (p=0.041<0.05) and anaemia (p=0.019<0.05) were risk factors for severe lesions via multivariate regression analysis, while for active/inactive chronic gastritis and smoking a positive dependency with a tendency towards statistical significance (p<0.10) was noticed for severe gastric lesions.

CONCLUSIONS

In patients treated with low-dose aspirin and gastroprotective therapy with proton pump inhibitors we have enough evidence to consider co-treatment with anticoagulants and anaemia important predictors for severe endoscopic lesions, while other factors such as inflammation in gastric biopsies, congestive heart failure, co-treatment with clopidogrel and smoking tended to have a positive influence on risk for severe gastro-duodenal lesions.

Age-specific risks, severity, time course, and outcome of bleeding on long-term antiplatelet treatment after vascular events: a population-based cohort study

BACKGROUND

Lifelong antiplatelet treatment is recommended after ischaemic vascular events, on the basis of trials done mainly in patients younger than 75 years. Upper gastrointestinal bleeding is a serious complication, but had low case fatality in trials of aspirin and is not generally thought to cause long-term disability. Consequently, although co-prescription of proton-pump inhibitors (PPIs) reduces upper gastrointestinal bleeds by 70-90%, uptake is low and guidelines are conflicting. We aimed to assess the risk, time course, and outcomes of bleeding on antiplatelet treatment for secondary prevention in patients of all ages.

METHODS

We did a prospective population-based cohort study in patients with a first transient ischaemic attack, ischaemic stroke, or myocardial infarction treated with antiplatelet drugs (mainly aspirin based, without routine PPI use) after the event in the Oxford Vascular Study from 2002 to 2012, with follow-up until 2013. We determined type, severity, outcome (disability or death), and time course of bleeding requiring medical attention by face-to-face follow-up for 10 years. We estimated age-specific numbers needed to treat (NNT) to prevent upper gastrointestinal bleeding with routine PPI co-prescription on the basis of Kaplan-Meier risk estimates and relative risk reduction estimates from previous trials.

FINDINGS

3166 patients (1582 [50%] aged ≥75 years) had 405 first bleeding events (n=218 gastrointestinal, n=45 intracranial, and n=142 other) during 13 509 patient-years of follow-up. Of the 314 patients (78%) with bleeds admitted to hospital, 117 (37%) were missed by administrative coding. Risk of non-major bleeding was unrelated to age, but major bleeding increased steeply with age (≥75 years hazard ratio [HR] 3·10, 95% CI 2·27-4·24; p<0·0001), particularly for fatal bleeds (5·53, 2·65-11·54; p<0·0001), and was sustained during long-term follow-up. The same was true of major upper gastrointestinal bleeds (≥75 years HR 4·13, 2·60-6·57; p<0·0001), particularly if disabling or fatal (10·26, 4·37-24·13; p<0·0001). At age 75 years or older, major upper gastrointestinal bleeds were mostly disabling or fatal (45 [62%] of 73 patients vs 101 [47%] of 213 patients with recurrent ischaemic stroke), and outnumbered disabling or fatal intracerebral haemorrhage (n=45 vs n=18), with an absolute risk of 9·15 (95% CI 6·67-12·24) per 1000 patient-years. The estimated NNT for routine PPI use to prevent one disabling or fatal upper gastrointestinal bleed over 5 years fell from 338 for individuals younger than 65 years, to 25 for individuals aged 85 years or older.

INTERPRETATION

In patients receiving aspirin-based antiplatelet treatment without routine PPI use, the long-term risk of major bleeding is higher and more sustained in older patients in practice than in the younger patients in previous trials, with a substantial risk of disabling or fatal upper gastrointestinal bleeding. Given that half of the major bleeds in patients aged 75 years or older were upper gastrointestinal, the estimated NNT for routine PPI use to prevent such bleeds is low, and co-prescription should be encouraged.

FUNDING

Wellcome Trust, Wolfson Foundation, British Heart Foundation, Dunhill Medical Trust, National Institute of Health Research (NIHR), and the NIHR Oxford Biomedical Research Centre.

Low-Dose Aspirin Is Effective Chemoprophylaxis Against Clinically Important Venous Thromboembolism Following Total Joint Arthroplasty: A Preliminary Analysis

BACKGROUND

Aspirin is a safe and effective prophylaxis for the prevention of venous thromboembolism following total joint arthroplasty. The optimal dose of aspirin prophylaxis is unknown. Our hypothesis was that lower-dose aspirin is as effective as higher-dose aspirin for the prevention of venous thromboembolism and is associated with fewer gastrointestinal side effects.

METHODS

In a prospective, crossover study, we analyzed 4,651 primary total joint arthroplasty cases performed from July 2013 to June 2015. For 4 weeks, 3,192 patients received enteric-coated 325-mg aspirin twice daily (the 325-mg aspirin group) and 1,459 patients received 81-mg aspirin twice daily (the 81-mg aspirin group). There were no significant differences (p > 0.05) in sex, body mass index, or Charlson Comorbidity Index between the two patient populations. Recorded complications occurring within 90 days postoperatively included symptomatic venous thromboembolism (deep venous thrombosis and pulmonary embolism), gastrointestinal complications, acute periprosthetic joint infection, and death.

RESULTS

The incidence of venous thromboembolism of 0.1% (95% confidence interval [CI], 0% to 0.3%) in the 81-mg aspirin group (1 with deep venous thrombosis and 1 with pulmonary embolism) was not significantly different (p = 0.345) from 0.3% (95% CI, 0.1% to 0.6%) in the 325-mg aspirin group (7 with deep venous thrombosis and 5 with pulmonary embolism). The incidence of gastrointestinal bleeding or ulceration of 0.3% (95% CI, 0% to 0.5%) in the 81-mg aspirin group was slightly, but not significantly (p = 0.66), lower than the 0.4% (95% CI, 0.2% to 0.6%) in the 325-mg aspirin group. The incidence of acute periprosthetic joint infection was 0.2% (95% CI, 0% to 0.4%) in the 81-mg aspirin group compared with 0.5% (95% CI, 0.2% to 0.7%) in the 325-mg aspirin group (p = 0.28). The 90-day mortality rate was similar in both groups at 0.1% (95% CI, 0% to 0.2%) in the 81-mg aspirin group and 0.1% (95% CI, 0% to 0.2%) in the 325-mg aspirin group (p = 0.78).

CONCLUSIONS

Our study demonstrates that low-dose aspirin is not inferior to high-dose aspirin for venous thromboembolism prophylaxis following total joint arthroplasty. This is not unexpected, as the available literature demonstrates that low-dose aspirin is as effective as higher-dose aspirin in the prevention of acute coronary syndrome and cerebrovascular events.

LEVEL OF EVIDENCE

Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Bleeding Risk with Long-Term Low-Dose Aspirin: A Systematic Review of Observational Studies

BACKGROUND

Low-dose aspirin has proven effectiveness in secondary and primary prevention of cardiovascular events, but is also associated with an increased risk of major bleeding events. For primary prevention, this absolute risk must be carefully weighed against the benefits of aspirin; such assessments are currently limited by a lack of data from general populations.

METHODS

Systematic searches of Medline and Embase were conducted to identify observational studies published between 1946 and 4 March 2015 that reported the risks of gastrointestinal (GI) bleeding or intracranial hemorrhage (ICH) with long-term, low-dose aspirin (75-325 mg/day). Pooled estimates of the relative risk (RR) for bleeding events with aspirin versus non-use were calculated using random-effects models, based on reported estimates of RR (including odds ratios, hazard ratios, incidence rate ratios and standardized incidence ratios) in 39 articles.

FINDINGS

The incidence of GI bleeding with low-dose aspirin was 0.48-3.64 cases per 1000 person-years, and the overall pooled estimate of the RR with low-dose aspirin was 1.4 (95% confidence interval [CI]: 1.2-1.7). For upper and lower GI bleeding, the RRs with low-dose aspirin were 2.3 (2.0-2.6) and 1.8 (1.1-3.0), respectively. Neither aspirin dose nor duration of use had consistent effects on RRs for upper GI bleeding. The estimated RR for ICH with low-dose aspirin was 1.4 (1.2-1.7) overall. Aspirin was associated with increased bleeding risks when combined with non-steroidal anti-inflammatory drugs, clopidogrel and selective serotonin reuptake inhibitors compared with monotherapy. By contrast, concomitant use of proton pump inhibitors decreased upper GI bleeding risks relative to aspirin monotherapy.

CONCLUSIONS

The risks of major bleeding with low-dose aspirin in real-world settings are of a similar magnitude to those reported in randomized trials. These data will help inform clinical judgements regarding the use of low-dose aspirin in prevention of cardiovascular events.

The Protective Effect of Low-Dose Aspirin against Colorectal Cancer Is Unlikely Explained by Selection Bias: Results from Three Different Study Designs in Clinical Practice

BACKGROUND

We conducted three differently designed nested case-control studies to evaluate whether the protective effect of low-dose aspirin against colorectal cancer (CRC) is explained by selection bias.

METHODS

Using a large validated UK primary care database, we followed different cohorts of patients, who varied in their demographic and clinical characteristics, to identify first ever cases of CRC. In Studies 1 and 2, two cohorts were followed, i) new users of low-dose aspirin at start of follow-up (N = 170,336 in Study 1, N = 171,527 in Study 2) and either ii) non-users of low-dose aspirin (Study 1, N = 170,336) or new users of paracetamol (Study 2, N = 149,597) at start of follow-up. In Study 3 a single cohort of individuals näive to low-dose aspirin at the start of observation was followed. Controls were selected using incidence sampling and logistic regression used to obtain an unbiased estimate of the incidence rate ratio (RR) with 95% confidence intervals (CIs). Low-dose aspirin exposure was analyzed 'as-treated' before the index date (CRC date for cases, random date for controls).

RESULTS

In the three studies, median (maximum) follow-up was 5.1 (12), 5.8 (12) and 7.5 (13) years, respectively. 3033 incident CRC cases were identified in Study 1, 3174 in Study 2, and 12,333 in Study 3. Current use of low-dose aspirin was associated with a significantly reduced risk of 34%, 29% and 31% in the three studies, respectively; corresponding RRs (95% CIs) were 0.66 (0.60-0.73), 0.71 (0.63-0.80) and 0.69 (0.64-0.74). In each study, significantly reduced risks of CRC were seen when low-dose aspirin was used for primary or secondary cardiovascular disease prevention, in both sexes, and across all age groups evaluated.

CONCLUSION

Low-dose aspirin is associated with a significantly reduced risk of CRC. The consistency of our findings across different studies makes selection bias an unlikely explanation.

Validation of low-dose aspirin prescription data in The Health Improvement Network: how much misclassification due to over-the-counter use?

Purpose

We aimed to quantify the extent of over‐the‐counter (OTC) low‐dose aspirin use among patients in The Health Improvement Network (THIN) in the UK.

Methods

In September 2013, a random sample of low‐dose aspirin users (75 past users and 75 never users) was identified based on prescriptions recorded in THIN. Primary care practitioners (PCPs) were sent questionnaires to provide information on patients' use of OTC low‐dose aspirin.

Results

One hundred and forty valid questionnaires were received (93.30% [95%CI: 88.16–96.34] response rate). Current use of low‐dose aspirin was reported by PCPs in 4.23% (95%CI: 1.45–11.70) (n = 3) of past users (OTC use in one patient) and in 2.9% (95%CI: 0.78–9.70) (n = 2) of never users (OTC use in one patient). In addition, PCPs reported past use of low‐dose aspirin in 88.70% (95%CI: 79.31–94.18) (n = 63) of past users (all prescribed; none as OTC) and in 2.82% (95%CI: 0.78–9.70) (n = 2) of never users (as OTC). Among past users, PCPs reported the indication for low‐dose aspirin as primary cardiovascular disease (CVD) prevention in 63.16% (95%CI: 50.18–74.48) of patients and secondary CVD prevention in 31.58% (95%CI: 21.00–44.48) of patients. Corresponding percentages based on THIN were 78.95% (95%CI: 66.71–87.53) and 21.1% (95%CI: 12.47–33.29), respectively.

Conclusion

Our findings show the small impact of potential misclassification of low‐dose aspirin use in THIN due to unrecorded OTC use. The small proportion of false negatives confirms the utility of THIN for utilization and outcome studies of low‐dose aspirin. © 2015 The Authors. Pharmacoepidemiology and Drug Safety published by John Wiley & Sons Ltd.

Aspirin resistance and other aspirin-related concerns

Aspirin is a widely used medication and has become a cornerstone for treating cardiovascular disease. Aspirin can significantly reduce the incidence of cardiovascular ischemic events, recurrence and mortality, thereby improving the long-term prognosis of patients. However, there has been a staggering increase in the volume of literature addressing the issue of so-called "aspirin resistance" in recent years, and for some patients, it is difficult to avoid adverse reactions to aspirin. In this review, we present both the historical aspects of aspirin use and contemporary developments in its clinical use.

Gastrointestinal bleeding in patients receiving oral anticoagulation: Current treatment and pharmacological perspectives

Gastrointestinal bleeding (GIB) is a potentially fatal and avoidable medical condition that poses a burden on global health care costs. The rate of major GIB related to the use of some direct acting oral anticoagulant drugs (DOACs), is higher than that detected in warfarin users. Current strategies in the treatment of GIBs in patients receiving warfarin or DOACs (vitamin K, activated charcoal; hemodialysis; recombinant factor VIIa; [activated] prothrombin complex concentrates) including indications for the treatment of bleeding based on different degrees of severity of the episodes, is reported in this article. Potential preventive strategies to mitigate the risk of GIBs (e.g. upper endoscopy/biopsy, colon cancer screening; eradication of Helicobacter pylori prior to starting anticoagulation; use of proton-pump inhibitors, identification of risk factors for bleeding) are also reported as well as the fact that some of them have not been tested so far in patients receiving DOACs. Antidotes that experimentally reverse the anti-coagulant effect of dabigatran (Idarucizumab; BI 655075; Boehringer Ingelheim); of rivaroxaban, apixaban, or edoxaban (Andexanet alfa, r-Antidote, PRT064445; Portola Pharmaceuticals) or of all DOACs (Aripazine, PER-977, ciraparantag; Perosphere Inc.) are discussed. Likewise, population pharmacokinetics modeling related to the rate of major DOACs-related GIBs is presented. It is also emphasized that the occurrence of GIB reflects the presence of patients at the highest risk for adverse outcomes. Finally, the implications of the concept that patient characteristics and the severity of illness (i.e. comorbidities) exert a greater impact on the risk of GIB than the type of antithrombotic agent employed, are analyzed.

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.

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.

Risk of uncomplicated peptic ulcer disease in a cohort of new users of low-dose acetylsalicylic acid for secondary prevention of cardiovascular events

BACKGROUND

The aim of this study was to analyse the risk of uncomplicated peptic ulcer disease (PUD) in a cohort of new users of low-dose acetylsalicylic acid (ASA) for secondary prevention of cardiovascular events in a UK primary care setting.

METHODS

New users of low-dose ASA for secondary prevention of cardiovascular events, aged 50-84 years in 2000-2007, were identified from The Health Improvement Network. Among those 38,975 individuals, 309 patients were considered to be incident cases of uncomplicated PUD. Incidence of uncomplicated PUD was calculated and a nested case-control analysis adjusted for potential confounding factors was performed to calculate the odds ratios (ORs) for the association of potential risk factors with uncomplicated PUD.

RESULTS

The crude incidence of uncomplicated PUD was 1.41 per 1000 person-years (95% confidence interval [CI], 1.26-1.58). Individuals with a history of PUD were more likely to develop uncomplicated PUD than those without such a history (hazard ratio [HR], 2.22, 95% CI, 1.60-3.09). In nested case-control analyses, the risk of uncomplicated PUD was associated with current use of non-steroidal anti-inflammatory drugs, oral steroids or acid suppressants. Other risk factors for developing uncomplicated PUD included smoking, stress, depression, anaemia and social deprivation.

CONCLUSION

Our results indicate that several risk factors significantly increase the risk of development of uncomplicated PUD in new users of low-dose ASA. Therefore, physicians should monitor ASA users for gastrointestinal symptoms and signs of ulcer, particularly if they have additional risk factors.

Use of aspirin for primary and secondary cardiovascular disease prevention in the United States, 2011-2012

BACKGROUND

Aspirin use has been shown to be an effective tool in cardiovascular disease (CVD) prevention among high-risk patients. The patient-reported physician recommendation for aspirin as preventive therapy among high- and low-risk patients is unknown.

METHODS AND RESULTS

We conducted an analysis of the National Health and Nutrition Examination Survey 2011-2012 to examine the use of aspirin for CVD prevention. Patients without previously diagnosed CVD were classified into high and low risk based on their Framingham Risk Score (10-year coronary heart disease risk). Among patients without previously diagnosed CVD, 22.5% were classified as high risk. Of the high-risk individuals, 40.9% reported being told by their physician to take aspirin, with 79.0% complying. Among those who were at low risk, 26.0% were told by their physician to take aspirin, with 76.5% complying. Logistic regression analysis indicated that age, access to a regular source of care, education, and insurance status were significant predictors of patient-reported physician recommendations for aspirin use for primary prevention. Among high-risk patients, age, race, and insurance status were significant predictors of reported recommendations for aspirin use. Among low-risk patients, age, education, obesity, and insurance status were significant predictors of reported recommendations for aspirin use.

CONCLUSIONS

Patient reports indicate nonideal rates of being told to take aspirin, for both high- and low-risk patients for primary prevention. Clinical decision support tools that could assist physicians in identifying patients at risk may increase patient reports of physician recommendations for aspirin use.

Aspirin for cardioprotection and strategies to improve patient adherence

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in North America. Aspirin therapy has proven clinical effectiveness in the prevention and treatment of CVD and is one of the most widely used drugs nationwide. However, despite the medication's popularity and utility, adherence to a proper aspirin regimen is suboptimal, resulting in adverse health outcomes and increased health care costs. Our review outlines current knowledge on aspirin therapy adherence, causes of nonadherence, and strategies available to increase adherence to aspirin and medications in general. We demonstrate that, indeed, aspirin adherence rates are suboptimal, ranging from 72% to 92%, and that a combination of patient- and medication-related factors contribute to nonadherence. A multidimensional approach involving patient education and medication innovations to reduce aspirin side effects is imperative to improving rates of aspirin therapy adherence.

Gastrointestinal ulcers, role of aspirin, and clinical outcomes: pathobiology, diagnosis, and treatment

Peptic ulcer disease is a major cause of morbidity and mortality in the US with more than six million diagnoses annually. Ulcers are reported as the most common cause of hospitalization for upper gastrointestinal (GI) bleeding and are often a clinical concern due to the widespread use of aspirin and nonsteroidal anti-inflammatory drugs, both of which have been shown to induce ulcer formation. The finding that Helicobacter pylori infection (independent of aspirin use) is associated with the development of ulcers led to a more thorough understanding of the causes and pathogenesis of ulcers and an improvement in therapeutic options. However, many patients infected with H. pylori are asymptomatic and remain undiagnosed. Complicating matters is a current lack of understanding of the association between aspirin use and asymptomatic ulcer formation. Low-dose aspirin prescriptions have increased, particularly for cardioprotection. Unfortunately, the GI side effects associated with aspirin therapy continue to be a major complication in both symptomatic and asymptomatic patients. These safety concerns should be important considerations in the decision to use aspirin and warrant further education. The medical community needs to continue to improve awareness of aspirin-induced GI bleeding to better equip physicians and improve care for patients requiring aspirin therapy.

[Antiplatelet therapy with acetylsalicylic acid: approaches to reducing the frequency of gastrointenstinal adverse reactions]

Acetylsalicylic acid (ASA) is highly effective in preventing cardiovascular events, but associated with increased risk for digestive adverse reactions. The paper provides an update on the epidemiology, mechanisms, and risk factors of esophagogastroduodeno- and enteropathies during long-term low-dose ACA therapy. It outlines the key principles of their prevention.

Low-dose acetylsalicylic acid use and the risk of upper gastrointestinal bleeding: a meta-analysis of randomized clinical trials and observational studies

BACKGROUND

Low-dose acetylsalicylic acid (LDA, 75 mg/day to 325 mg/day) is recommended for primary and secondary prevention of cardiovascular events, but has been linked to an increased risk of upper gastrointestinal bleeding (UGIB).

OBJECTIVE

To analyze the magnitude of effect of LDA use on UGIB risk.

METHODS

The PubMed and Embase databases were searched for randomized controlled trials (RCTs) reporting UGIB rates in individuals receiving LDA, and observational studies of LDA use in patients with UGIB. Studies were pooled for analysis of UGIB rates.

RESULTS

Eighteen studies were included. Seven RCTs reported UGIB rates in individuals randomly assigned to receive LDA (n=22,901) or placebo (n=22,923). Ten case-control studies analyzed LDA use in patients with UGIB (n=10,816) and controls without UGIB (n=30,519); one cohort study reported 207 UGIB cases treated with LDA only. All studies found LDA use to be associated with an increased risk of UGIB. The mean number of extra UGIB cases associated with LDA use in the RCTs was 1.2 per 1000 patients per year (95% CI 0.7 to 1.8). The number needed to harm was 816 (95% CI 560 to 1500) for RCTs and 819 (95% CI 617 to 1119) for observational studies. Meta-analysis of RCT data showed that LDA use was associated with a 50% increase in UGIB risk (OR 1.5 [95% CI 1.2 to 1.8]). UGIB risk was most pronounced in observational studies (OR 3.1 [95% CI 2.5 to 3.7]).

CONCLUSIONS

LDA use was associated with an increased risk of UGIB.

Risk factors for gastrointestinal bleeding associated with low-dose aspirin

Low-dose aspirin use is associated with an increased risk for gastrointestinal ulceration and bleeding. At-risk low-dose aspirin users are therefore recommended to take proton-pump inhibitors. However, it is poorly understood which aspirin users are at risk to develop such complications. It is assumed that the known risk factors for NSAID-induced upper gastrointestinal events also apply to low-dose aspirin users. The conventional risk factors for upper gastrointestinal complications associated with aspirin therapy include: (1) a history of peptic ulcer disease or gastrointestinal bleeding, (2) older age, (3) concomitant use of NSAIDs, including coxibs, (4) concomitant use of anticoagulants or other platelet aggregation inhibitors, (5) the presence of severe co-morbidities, and (6) high aspirin dose. In patients with a history of peptic ulcer disease, Helicobacter pylori infection should be assessed and treated. This review focuses on the evidence for upper gastrointestinal risk factors in aspirin users.