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

Transient Expression of Zika NS2B Protein Antigen in Nicotiana benthamiana and Use for Arboviruses Diagnosis

Zika (ZIKV) and Dengue (DENV) viruses are clinically significant due to their severe neurological and hemorrhagic complications. Rapid diagnostics often rely on nonstructural proteins to generate specific antibodies. This study aimed to produce IgG antibodies from the recombinant ZIKV protein and plant-expressed NS2B protein for arbovirus detection in serum and urine samples. The NS2B protein was expressed in Nicotiana benthamiana and purified chromatographically. Validation of recombinant NS2B as an antigen in indirect immunoassays demonstrated 95% sensitivity and 100% specificity in IgM/IgG ELISA tests, enabling effective detection of ZIKV and DENV. Notably, r-ZIKV-NS2B IgG identified positive ZIKV and DENV cases in urine but failed to detect negatives, suggesting limitations in specificity for urine diagnostics. Using urine as a diagnostic medium offers a less invasive and more practical approach, broadening the test applicability. This study utilized patient-derived positive urine samples and healthy samples spiked with an exogenous virus. Findings highlight the potential of the ZIKV-NS2B protein as a robust antigen for arbovirus diagnosis and demonstrate the viability of plant-based systems for antigen production, advancing diagnostics for neglected tropical diseases.

High risks adverse events associated with usage of aspirin in chronic obstructive pulmonary disease

BACKGROUND

Despite potential benefits and widespread prescription of aspirin among chronic obstructive pulmonary disease (COPD) patients, limited research has investigated its adverse effects (AEs) in COPD population.

METHODS

We conducted a retrospective analysis of adverse drug events (ADEs) reported in the US Food and Drug Administration Adverse Event Reporting System (FAERS) between Q1 2013 and Q2 2022. COPD patients were categorized into two groups based on aspirin use. ADEs related to aspirin use were identified using combined reporting odds ratio (ROR), proportional reporting ratio (PRR), information component (IC) methods.

RESULTS

A total of 56,660 ADEs reports associated with COPD patients were included in the study. Among these reports, 144 adverse events were linked to aspirin use in COPD patients, including fatigue (4.12%), diarrhea (3.13%), dyspnea exertional (2.03%), rhinorrhea (1.99%), weight increased (1.89%) and vomiting (1.84%), muscle spasms (1.79%), cardiac disorder (1.74%), heart rate increased (1.69%) and peripheral swelling (1.59%). Subgroup analysis indicates that age and gender might affect the AEs frequency in COPD patients using aspirin.

CONCLUSIONS

Our findings identify 10 most frequently reported ADEs associated with aspirin use in COPD patients, thus offer valuable insights into the AEs of aspirin for safer clinical utilization in COPD management.

Analysis of Adverse Reactions of Aspirin in Prophylaxis Medication Based on FAERS Database

Objective

As the most commonly used drug in the world, aspirin has shown benefits for myocardial infarction, stroke, and vascular death in many secondary prevention trials and their meta-analysis. The purpose of this study was to evaluate the association between aspirin and its adverse reactions as a preventive drug using the FDA adverse event reporting system (FAERS).

Methods

The FAERS database was queried for the adverse drug events (ADE) reported from the first quarter of 2004 to the second quarter of 2021. We counted and trended reports to FAERS in which aspirin was associated with anaphylaxis or anaphylaxis followed by death.

Results

The search retrieved 858 aspirin-associated cases within the reporting period; 108 AE pairs with significant disproportionality were retained. The top 10 AE pairs associated with using aspirin for prophylaxis were melaena, duodenal ulcer, gastritis erosive, gastric ulcer hemorrhage, etc. The top 10 AE pairs for thrombosis prophylaxis were melaena, duodenal ulcer, microcytic anemia, lip erosion, vascular stent thrombosis, etc. The screened adverse event reports are classified and counted according to the system organ class (SOC); it mainly focuses on gastrointestinal disorders, general disorders, and administration site conditions. Among the 858 cases of aspirin used as prophylaxis medication in the FAERS database, the reporting areas were mainly in Europe and the Americas.

Conclusion

Adverse drug reactions may occur in the clinical use of aspirin. It should strengthen patient medication education, pay close attention to adverse reactions, and adjust the administration method in time to ensure the safety of medication.

Low-Dose Aspirin is Safe and Effective for Venous Thromboembolism Prevention in Patients Undergoing Revision Total Knee Arthroplasty: A Retrospective Cohort Study

Venous thromboembolism (VTE) events are rare, but serious complications of total joint replacement affect patients and health care systems due to the morbidity, mortality, and associated cost of its complications. There is currently no established universal standard of care for prophylaxis against VTE in patients undergoing revision total knee arthroplasty (rTKA). The aim of this study was to determine whether a protocol of 81-mg aspirin (ASA) bis in die (BID) is safe and/or sufficient in preventing VTE in patients undergoing rTKAs versus 325-mg ASA BID. In 2017, our institution adopted a new protocol for VTE prophylaxis for arthroplasty patients. Patients initially received 325-mg ASA BID for 1 month and then changed to a lower dose of 81-mg BID. A retrospective review from 2011 to 2019 was conducted identifying 1,438 consecutive rTKA patients and 90-day postoperative outcomes including VTE, gastrointestinal, and wound bleeding complications, acute periprosthetic joint infection, and mortality. In the 74 months prior to protocol implementation, 1,003 rTKAs were performed and nine VTE cases were diagnosed (0.90%). After 26 months of the protocol change, 435 rTKAs were performed with one VTE case identified (0.23%). There was no significant difference in rates or odds in postoperative pulmonary embolism (PE; p = 0.27), DVT (p = 0.35), and total VTE rates (p = 0.16) among patients using either protocol. There were also no differences in bleeding complications (p = 0.15) or infection rate (p = 0.36). No mortalities were observed. In the conclusion, 81-mg ASA BID is noninferior to 325-mg ASA BID in maintaining low rates of VTE and may be safe for use in patients undergoing rTKA.

Digestive system injury induced by drugs for secondary prevention of ischemic stroke

The recurrence of ischemic stroke can be reduced by active secondary prevention, including antithrombotic, lipid-lowering, antihypertensive, and hypoglycemic treatment. However, long-term use of drugs for secondary prevention can cause damage to the digestive system, reduce patient compliance, increase the recurrence of stroke, and even lead to ulcer bleeding and life-threatening events. It is necessary to early identify populations at a high risk for digestive system injury, understand the adverse reactions of various drugs, and standardize the treatment, which can improve the effect of secondary prevention of ischemic stroke.

Major bleeding risk and mortality associated with antiplatelet drugs in real-world clinical practice. A prospective cohort study

Background

Major bleedings other than gastrointestinal (GI) and intracranial (ICH) and mortality rates associated with antiplatelet drugs in real-world clinical practice are unknown. The objective was to estimate major bleeding risk and mortality among new users of antiplatelet drugs in real-world clinical practice.

Methods and findings

A population-based prospective cohort using the French national health data system (SNIIRAM), identified 69,911 adults living within five well-defined geographical areas, who were new users of antiplatelet drugs in 2013–2015 and who had not received any antithrombotics in 2012. Among them, 63,600 started a monotherapy and 6,311 a dual regimen. Clinical data for all adults referred for bleeding was collected from all emergency departments within these areas, and medically validated. Databases were linked using common key variables. The main outcome measure was time to major bleeding (GI, ICH and other bleedings). Secondary outcomes were death, and event-free survival (EFS). Hazard ratios (HR) were derived from adjusted Cox proportional hazard models. We used Inverse Propensity of Treatment Weighting as a stratified sensitivity analysis according to the antiplatelet monotherapy indication: primary prevention without cardiovascular (CV) risk factors, with CV risk factors, and secondary prevention. We observed 250 (0.36%) major haemorrhages, 81 ICH, 106 GI and 63 other types of bleeding. Incidences were twice as high in dual therapy as in monotherapy. Compared to low-dose aspirin (≤ 100 mg daily), high-dose (> 100 up to 325 mg daily) was associated with an increased risk of ICH (HR = 1.80, 95%CI 1.10 to 2.95). EFS was improved by high-dose compared to low-dose aspirin (1.41, 1.04 to 1.90 and 1.32, 1.03 to 1.68) and clopidogrel (1.30, 0.73 to 2.3 and 1.7, 1.24 to 2.34) respectively in primary prevention with and without CV risk factors.

Conclusion

The incidence of major bleeding and mortality was low. In monotherapy, low-dose aspirin was the safest therapeutic option whatever the indication.

Trial registration

NCT02886533.

Low-Dose Aspirin Is Safe and Effective for Venous Thromboembolism Prevention in Patients Undergoing Revision Total Hip Arthroplasty: A Retrospective Cohort Study

BACKGROUND

Currently, there is no established universal standard of care for prophylaxis against venous thromboembolism (VTE) in orthopedic patients undergoing revision total hip arthroplasty (rTHA). The aim of this study is to determine whether a protocol of 81-mg aspirin (ASA) bis in die (BID) is safe and/or effective in preventing VTE in patients undergoing rTHAs vs 325-mg ASA BID.

METHODS

In 2017, a large academic medical center adopted a new protocol for VTE prophylaxis in arthroplasty patients at standard risk. Initially, patients received 325-mg ASA BID but switched to 81-mg ASA BID. A retrospective review (2011-2019) was performed to identify 1361 consecutive rTHA patients and their associated 90-day postoperative complications such as VTE, including pulmonary embolism (PE) and/or deep vein thrombosis (DVT), as the primary outcome; and gastrointestinal and wound bleeding, acute periprosthetic joint infection, and mortality as the secondary outcome.

RESULTS

From 2011 to 2017, 973 rTHAs were performed and 13 total VTE cases were diagnosed (1.34%). From 2017 to 2019, 388 rTHAs were performed with 3 total VTE cases identified (0.77%). Chi-squared analyses and logistic regression models showed no differences in rates or odds in postoperative PE (P = .09), DVT (P = .79), PE and DVT (P = .85), and total VTE (P = .38) using either dose. There were also no differences between bleeding complications (P = .14), infection rate (P = .46), and mortality (P = .53).

CONCLUSION

Using a protocol of 81-mg of ASA BID is noninferior to 325-mg ASA BID and may be safe and effective in maintaining low rates of VTE in patients undergoing rTHA.

Eighteen-Year Trends in the Prevalence of, and Health Care Use for, Noncancer Pain in the United States: Data from the Medical Expenditure Panel Survey

We used data from the nationally representative Medical Expenditure Panel Survey to determine the 18-year trends in the overall rates of noncancer pain prevalence and pain-related interference, as well as in health care use attributable directly to pain management. The proportion of adults reporting painful health condition(s) increased from 32.9% (99.7% confidence interval [CI] = 31.6-34.2%;120 million adults) in 1997/1998 to 41.0% (99.7% CI = 39.2-42.4%; 178 million adults) in 2013/2014 (P_trend < .0001). Among adults with severe pain-related interference associated with their painful health condition(s), the use of strong opioids specifically for pain management more than doubled from 11.5% (99.7% CI = 9.6-13.4%) in 2001/2002 to 24.3% (99.7% CI = 21.3-27.3%) in 2013/2014 (P_trend < .0001). A smaller increase (P_interaction < .0001) in strong opioid use was seen in those with minimal pain-related interference: 1.2% (99.7% CI = 1.0-1.4%) in 2001/2002 to 2.3% (99.7% CI = 1.9-2.7%) in 2013/2014. Small but statistically significant decreases (P_trend < .0001) were seen in 1) the percentage of adults with painful health condition(s) who had ≥1 ambulatory office visit for their pain: 56.1% (99.7% CI = 54.2-58.0%) in 1997/1998 and 53.3% (99.7% CI = 51.4-55.4%) in 2013/2014; 2) the percentage who had ≥1 emergency room visit for their pain; 9.9% (99.7% CI = 8.6-11.2%) to 8.8% (99.7% CI = 7.9-9.7%); and 3) the percentage with ≥1 overnight hospitalization for their pain: 3.2% (99.7% CI = 2.6-4.0%) to 2.3% (99.7% CI = 1.8-2.8%). PERSPECTIVE: Our data illustrate changes in the management of painful health conditions over the last 2 decades in the United States. Strong opioid use remains high, especially in those with severe pain-related interference. Additional education of health care providers and the public concerning the risk/benefit ratio of opioids appears warranted.

Gastrointestinal risk factors and prescribing pattern of antiulcer agents in patients taking low-dose aspirin in Japan

Objectives

To identify prescribing patterns of antiulcer agents in patients on low-dose aspirin (LDA) and to evaluate the number of gastrointestinal (GI) risk factors of the patients.

Methods

A retrospective chart review of patients taking LDA was conducted at the National Cerebral and Cardiovascular Center in Japan. The rate of concomitant use of antiulcer agents and the risk of each patient to develop GI complications were evaluated.

Results

Of the 314 patients, 64 were not on antiulcer agents and 55 of them had &gt;1 risk factor. More patients not on antiulcer agents had started LDA before hospitalization.

Conclusion

The rate of coprescribing antiulcer agents with LDA was high. However, the timing of initiating LDA therapy affected the prescribing pattern of antiulcer agents.

Evidence of Drug-Nutrient Interactions with Chronic Use of Commonly Prescribed Medications: An Update

The long-term use of prescription and over-the-counter drugs can induce subclinical and clinically relevant micronutrient deficiencies, which may develop gradually over months or even years. Given the large number of medications currently available, the number of research studies examining potential drug-nutrient interactions is quite limited. A comprehensive, updated review of the potential drug-nutrient interactions with chronic use of the most often prescribed medications for commonly diagnosed conditions among the general U.S. adult population is presented. For the majority of the interactions described in this paper, more high-quality intervention trials are needed to better understand their clinical importance and potential consequences. A number of these studies have identified potential risk factors that may make certain populations more susceptible, but guidelines on how to best manage and/or prevent drug-induced nutrient inadequacies are lacking. Although widespread supplementation is not currently recommended, it is important to ensure at-risk patients reach their recommended intakes for vitamins and minerals. In conjunction with an overall healthy diet, appropriate dietary supplementation may be a practical and efficacious way to maintain or improve micronutrient status in patients at risk of deficiencies, such as those taking medications known to compromise nutritional status. The summary evidence presented in this review will help inform future research efforts and, ultimately, guide recommendations for patient care.

A Comparison of Two Dosing Regimens of ASA Following Total Hip and Knee Arthroplasties

BACKGROUND

The purpose of this study was to compare short-term side effects of aspirin (ASA) 325 mg vs ASA 81 mg orally twice daily (PO BID) when used as thromboembolic prophylaxis following primary total joint arthroplasty.

METHODS

A 1-year prospective cohort study was performed on 643 primary unilateral total joint arthroplasty patients operated on by a single surgeon. Two hundred eighty-two patients were administered ASA 325 mg PO BID and 361 patients were administered ASA 81 mg PO BID for 1 month. A questionnaire assessing the side effects of ASA intake was administered 1 month postoperatively.

RESULTS

The overall rate of gastrointestinal side effects (GI upset and nausea) was 1.9%, but ASA 325 mg had a higher rate 9/282 (3.2%) than ASA 81 mg 3/361 (0.8%), P = .04. Overall GI bleeding was 0.9%, with 2/282 (0.7%) in the ASA 325 mg group, vs 4/361 (1.1%) in the ASA 81 mg group, P = .70. One patient in the ASA 81 mg group (0.3%) developed a deep vein thrombosis. No patient developed pulmonary embolism, periprosthetic joint infection, tinnitus, wheezing and/or shortness of breath, chest pain, or headaches. In the ASA 325 mg group, 9/282 (3.2%) discontinued ASA and in the ASA 81 mg group, 8/361 (2.2%) discontinued ASA, P = .47. Four patients in the ASA 325 group (1.4%) changed to ASA 81 mg.

CONCLUSION

ASA 81 mg is associated with significantly less GI distress and nausea compared with ASA 325 mg. GI bleeding was equally prevalent between the 2 dosing regimens, so patients need to be informed of this risk regardless of the ASA dose.

The budget impact of using enteric-coated aspirin 325 mg + immediate-release omeprazole 40 mg to prevent recurrent cardiovascular events

OBJECTIVE

Aspirin (acetylsalicylic acid; ASA) is commonly used for secondary prevention of cardiovascular (CV) events, but may be associated with gastrointestinal (GI) adverse events, which can reduce adherence. Use of ASA co-therapy with proton pump inhibitors in patients at risk may be suboptimal. PA32540 (Yosprala™) is a coordinated-delivery tablet combining EC-ASA 325 mg and immediate-release omeprazole 40 mg. The objective of this flexible budget impact model was to project the financial consequences of introducing PA32540 325 mg/40 mg to prevent recurrent CV events, while reducing ASA-associated GI events in US adults.

METHODS

A Markov Model was employed to estimate health state transitions associated with ASA 75-325 mg, ASA 75-325 mg + generic delayed-release omeprazole 40 mg, PA32540, or clopidogrel 75 mg to prevent recurrent CV events. Health states included ulcers, GI bleeding, CV events, and death. Model inputs included demographics, treatment dosages, treatment costs, adverse GI and CV events, and premature death. Data from peer-reviewed literature and censuses enabled appropriate allocation of CV and GI disease prevalence and mortality. The PA32540 non-adherence rate was conservatively set at 20%. PA32540 market share was set to 50%.

RESULTS

The model projected annual savings of $81.0 million to $190.9 million within 1-5 years after PA32540 introduction to the plan, which included 134,558 members at risk for recurrent CV events. These values translate into savings of $602 (year 5) to $1,419 (year 1) per patient per year, and $81 (year 5) to $191 (year 1) per member per year. These values were robust to variations in parameters under a deterministic sensitivity analysis.

CONCLUSION

PA32540 use to prevent recurrent CV events was associated with cost reductions in each year examined with the model. From a health plan perspective, PA32540 is likely to have a net overall effect, resulting in significant cost savings.

Upper Gastrointestinal Toxicity Associated With Long-Term Aspirin Therapy: Consequences and Prevention

Antiplatelet therapy represents a fundamental part of preventive management for patients who are at risk of a secondary cardiovascular disease (CVD) event. In most cases, the antiplatelet regimen is based on low-dose aspirin, a drug that is highly effective in reducing the incidence of CVD events, but is associated with a substantial risk of gastrointestinal (GI) toxicity. The dyspeptic symptoms, which can result from aspirin administration, and which may occur with or without associated ulceration and bleeding, may lead patients to discontinue therapy, thus increasing their CVD risk. For patients in whom aspirin is indicated and who are deemed to be at increased risk of upper GI events, concomitant therapy with a proton pump inhibitor (PPI) is currently recommended. These agents are highly effective in reducing the upper GI lesions associated with aspirin therapy and have been associated with increased aspirin adherence. However, widespread under-prescribing of PPIs and potential noncompliance with their use means that substantial numbers of patients are at unnecessary risk of upper GI toxicity and-if aspirin therapy is discontinued-CVD events. Provision of aspirin and an immediate-release PPI as a coordinated-delivery combination tablet has been shown to both reduce the risk of gastric ulcer formation and improve patient compliance. This strategy, which may ultimately reduce the incidence of CVD outcomes because of the associated reduction in GI symptoms and the potential for greater patient adherence to aspirin, warrants further investigation under both randomized controlled conditions (explanatory trials), and in real-life settings (pragmatic trials).

Long-Term Safety of a Coordinated Delivery Tablet of Enteric-Coated Aspirin 325 mg and Immediate-Release Omeprazole 40 mg for Secondary Cardiovascular Disease Prevention in Patients at GI Risk

Introduction

In two, 6‐month, randomized, double‐blind Phase 3 trials, PA32540 (enteric‐coated aspirin 325 mg and immediate‐release omeprazole 40 mg) compared to aspirin alone was associated with fewer endoscopic gastric and duodenal ulcers in patients requiring aspirin therapy for secondary cardiovascular disease (CVD) prevention who were at risk for upper gastrointestinal (UGI) events.

Aims

In this 12‐month, open‐label, multicenter Phase 3 study, we evaluated the long‐term cardiovascular and gastrointestinal safety of PA32540 in subjects who were taking aspirin 325 mg daily for ≥3 months for secondary CVD prevention and were at risk for aspirin‐associated UGI events. Enrolled subjects received PA32540 once daily for up to 12 months and were assessed at baseline, month 1, month 6, and month 12.

Results

The overall safety population consisted of 379 subjects, and 290 subjects (76%) were on PA32540 for ≥348 days (12‐month completers). Adverse events (AEs) caused study withdrawal in 13.5% of subjects, most commonly gastroesophageal reflux disease (1.1%). Treatment‐emergent AEs occurred in 76% of the safety population (11% treatment‐related) and 73% of 12‐month completers (8% treatment‐related). The most common treatment‐related AE was dyspepsia (2%). One subject had a gastric ulcer observed on for‐cause endoscopy. There were five cases of adjudicated nonfatal myocardial infarction, one nonfatal stroke, and one cardiovascular death, but none considered treatment‐related.

Conclusions

Long‐term treatment with PA32540 once daily for up to 12 months in subjects at risk for aspirin‐associated UGI events is not associated with any new or unexpected safety events.

Risk of bleeding after hospitalization for a serious coronary event: a retrospective cohort study with nested case-control analyses

Background

Bleeding events have been associated with the use of antiplatelet agents. This study estimated the incidence of bleeding events in patients previously hospitalized for a serious coronary event and determined the risks of bleeding associated with the use of acetylsalicylic acid (ASA) and/or clopidogrel.

Methods

A UK primary care database was used to identify 27,707 patients aged 50 to 84 years, hospitalized for a serious coronary event during 2000 to 2007 and who were alive 30 days later (start date). Patients were followed up until they reached an endpoint (hemorrhagic stroke, upper or lower gastrointestinal bleeding [UGIB/LGIB]), death or end of study [June 30, 2011]) or met an exclusion criterion. Risk factors for bleeding were determined in a nested case-control analysis.

Results

Incidences of hemorrhagic stroke, UGIB, and LGIB were 5.0, 11.9, and 25.5 events per 10,000 person-years, respectively, and increased with age. UGIB and LGIB led to hospitalization in 73 and 23 % of patients, respectively. Non-users of ASA, who were mostly discontinuers, and current users of ASA had similar risks of hemorrhagic stroke, UGIB, and LGIB. Users of combined antithrombotic therapy (warfarin and antiplatelets) experienced an increased risk of hemorrhagic stroke (odds ratio [OR], 6.36; 95 % confidence interval [CI], 1.34–30.16), whereas users of combined antiplatelet therapy (clopidogrel and ASA) experienced an increased risk of UGIB (OR, 2.42; 95 % CI, 1.09–5.36). An increased risk of LGIB (OR, 1.86; 95 % CI, 1.34–2.57) was also observed in users of clopidogrel.

Conclusions

In patients previously hospitalized for a serious coronary event, combined antithrombotic therapy was associated with an increased risk of hemorrhagic stroke, whereas combined antiplatelet therapy was associated with an increased risk of UGIB.Non-use of ASA was rare in this population and use of ASA was not associated with a significantly increased risk of hemorrhagic stroke, UGIB, or LGIB.

Electronic supplementary material

The online version of this article (doi:10.1186/s12872-016-0348-6) contains supplementary material, which is available to authorized users.

Ticagrelor versus Aspirin in Acute Stroke or Transient Ischemic Attack

BACKGROUND

Ticagrelor may be a more effective antiplatelet therapy than aspirin for the prevention of recurrent stroke and cardiovascular events in patients with acute cerebral ischemia.

METHODS

We conducted an international double-blind, controlled trial in 674 centers in 33 countries, in which 13,199 patients with a nonsevere ischemic stroke or high-risk transient ischemic attack who had not received intravenous or intraarterial thrombolysis and were not considered to have had a cardioembolic stroke were randomly assigned within 24 hours after symptom onset, in a 1:1 ratio, to receive either ticagrelor (180 mg loading dose on day 1 followed by 90 mg twice daily for days 2 through 90) or aspirin (300 mg on day 1 followed by 100 mg daily for days 2 through 90). The primary end point was the time to the occurrence of stroke, myocardial infarction, or death within 90 days.

RESULTS

During the 90 days of treatment, a primary end-point event occurred in 442 of the 6589 patients (6.7%) treated with ticagrelor, versus 497 of the 6610 patients (7.5%) treated with aspirin (hazard ratio, 0.89; 95% confidence interval [CI], 0.78 to 1.01; P=0.07). Ischemic stroke occurred in 385 patients (5.8%) treated with ticagrelor and in 441 patients (6.7%) treated with aspirin (hazard ratio, 0.87; 95% CI, 0.76 to 1.00). Major bleeding occurred in 0.5% of patients treated with ticagrelor and in 0.6% of patients treated with aspirin, intracranial hemorrhage in 0.2% and 0.3%, respectively, and fatal bleeding in 0.1% and 0.1%.

CONCLUSIONS

In our trial involving patients with acute ischemic stroke or transient ischemic attack, ticagrelor was not found to be superior to aspirin in reducing the rate of stroke, myocardial infarction, or death at 90 days. (Funded by AstraZeneca; ClinicalTrials.gov number, NCT01994720.).

Comparison of Estimates between Cohort and Case-Control Studies in Meta-Analyses of Therapeutic Interventions: A Meta-Epidemiological Study

Background

Observational studies are increasingly being used for assessing therapeutic interventions. Case–control studies are generally considered to have greater risk of bias than cohort studies, but we lack evidence of differences in effect estimates between the 2 study types. We aimed to compare estimates between cohort and case–control studies in meta-analyses of observational studies of therapeutic interventions by using a meta-epidemiological study.

Methods

We used a random sample of meta-analyses of therapeutic interventions published in 2013 that included both cohort and case–control studies assessing a binary outcome. For each meta-analysis, the ratio of estimates (RE) was calculated by comparing the estimate in case–control studies to that in cohort studies. Then, we used random-effects meta-analysis to estimate a combined RE across meta-analyses. An RE < 1 indicated that case–control studies yielded larger estimates than cohort studies.

Results

The final analysis included 23 meta-analyses: 138 cohort and 133 case–control studies. Treatment effect estimates did not significantly differ between case–control and cohort studies (combined RE 0.97 [95% CI 0.86–1.09]). Heterogeneity was low, with between–meta-analysis variance τ² = 0.0049. Estimates did not differ between case–control and prospective or retrospective cohort studies (RE = 1.05 [95% CI 0.96–1.15] and RE = 0.99 [95% CI, 0.83–1.19], respectively). Sensitivity analysis of studies reporting adjusted estimates also revealed no significant difference (RE = 1.03 [95% CI 0.91–1.16]). Heterogeneity was also low for these analyses.

Conclusion

We found no significant difference in treatment effect estimates between case–control and cohort studies assessing therapeutic interventions.

Aspirin in the Treatment of Cancer: Reductions in Metastatic Spread and in Mortality: A Systematic Review and Meta-Analyses of Published Studies

BACKGROUND

Low-dose aspirin has been shown to reduce the incidence of cancer, but its role in the treatment of cancer is uncertain.

OBJECTIVES

We conducted a systematic search of the scientific literature on aspirin taken by patients following a diagnosis of cancer, together with appropriate meta-analyses.

METHODS

Searches were completed in Medline and Embase in December 2015 using a pre-defined search strategy. References and abstracts of all the selected papers were scanned and expert colleagues were contacted for additional studies. Two reviewers applied pre-determined eligibility criteria (cross-sectional, cohort and controlled studies, and aspirin taken after a diagnosis of cancer), assessed study quality and extracted data on cancer cause-specific deaths, overall mortality and incidence of metastases. Random effects meta-analyses and planned sub-group analyses were completed separately for observational and experimental studies. Heterogeneity and publication bias were assessed in sensitivity analyses and appropriate omissions made. Papers were examined for any reference to bleeding and authors of the papers were contacted and questioned.

RESULTS

Five reports of randomised trials were identified, together with forty two observational studies: sixteen on colorectal cancer, ten on breast and ten on prostate cancer mortality. Pooling of eleven observational reports of the effect of aspirin on cause-specific mortality from colon cancer, after the omission of one report identified on the basis of sensitivity analyses, gave a hazard ratio (HR) of 0.76 (95% CI 0.66, 0.88) with reduced heterogeneity (P = 0.04). The cause specific mortality in five reports of patients with breast cancer showed significant heterogeneity (P<0.0005) but the omission of one outlying study reduced heterogeneity (P = 0.19) and led to an HR = 0.87 (95% CI 0.69, 1.09). Heterogeneity between nine studies of prostate cancer was significant, but again, the omission of one study led to acceptable homogeneity (P = 0.26) and an overall HR = 0.89 (95% CI 0.79-0.99). Six single studies of other cancers suggested reductions in cause specific mortality by aspirin, and in five the effect is statistically significant. There were no significant differences between the pooled HRs for the three main cancers and after the omission of three reports already identified in sensitivity analyses heterogeneity was removed and revealed an overall HR of 0.83 (95% CI 0.76-0.90). A mutation of PIK3CA was present in about 20% of patients, and appeared to explain most of the reduction in colon cancer mortality by aspirin. Data were not adequate to examine the importance of this or any other marker in the effect of aspirin in the other cancers. On bleeding attributable to aspirin two reports stated that there had been no side effect or bleeding attributable to aspirin. Authors on the other reports were written to and 21 replied stating that no data on bleeding were available.

CONCLUSIONS AND IMPLICATIONS

The study highlights the need for randomised trials of aspirin treatment in a variety of cancers. While these are awaited there is an urgent need for evidence from observational studies of aspirin and the less common cancers, and for more evidence of the relevance of possible bio-markers of the aspirin effect on a wide variety of cancers. In the meantime it is urged that patients in whom a cancer is diagnosed should be given details of this research, together with its limitations, to enable each to make an informed decision as to whether or not to take low-dose aspirin.

SYSTEMATIC REVIEW PROTOCOL NUMBER

CRD42015014145.

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.

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.

Venous thromboprophylaxis in gastrointestinal bleeding

OBJECTIVE

To study the use of venous thromboembolism (VTE) prophylaxis and the incidence of thrombotic events in patients with acute gastrointestinal (GI) bleeding.

METHODS

Individuals admitted with a primary diagnosis of a GI bleed along with any endoscopically confirmed source (over a two-year period) were included. Patient comorbidity and data regarding anticoagulation or antiplatelet agent use before hospitalization were collected, in addition to type of VTE prophylaxis and duration of treatment. The primary end point was the development of VTE (deep vein thrombosis or pulmonary embolism) within one year of presentation.

RESULTS

Data from 504 patients admitted with GI bleeding were eligible for review. The total number of VTE events was 20 (4%) while the mortality rate during hospitalization was 4.6%; 397 patients were not given VTE prophylaxis during their hospitalization. Of the patients who were given VTE prophylaxis, 68 received prophylactic heparin or heparin derivatives during their admission. One hundred sixty-five patients had at least one other significant risk factor for VTE including recent or subsequent surgery, past thrombotic event or malignancy. The incidence of thrombosis in those with significant risk factors for VTE was significantly higher than those without (8.5% versus 1.8%; P=0.0009). Overall, there was no significant difference in thrombotic events between individuals receiving pharmacological prophylaxis (1.2%) and those who did not (2.8%) (P=0.4).

CONCLUSION

Overall, VTE prophylaxis did not significantly affect thrombotic events in patients admitted for an active GI bleed.