A Thorough Literature Review of the Potential Benefits and Drawbacks of Long-Term Aspirin Use for the Primary Prevention of Cardiovascular Disease

This article examines the role of aspirin in the primary prevention of cardiovascular disease. It highlights findings from major studies such as ASPREE (ASPirin in Reducing Events in the Elderly), ARRIVE (Aspirin to Reduce Risk of Initial Vascular Events), and ASPREE-XT (ASPirin in Reducing Events in the Elderly - eXTension) , among others. The review focuses on aspirin's role in primary prevention for specific populations including older adults, diabetics, hypertension patients, rheumatoid arthritis patients, kidney transplant recipients, and those with specific lipoprotein(a) genotypes, among other groups. We review these studies, noting aspirin's role in reducing events such as myocardial infarctions and its potential for increasing bleeding risks. The review also considers the implications for patients with kidney disease, referencing the Chronic Renal Insufficiency Cohort (CRIC) study and the International Polycap Study-3 (TIPS-3) trial. Additionally, it addresses the shifting paradigms in guidelines from the US Preventive Services Task Force and other entities, underscoring the importance of individualized aspirin use by balancing benefits against bleeding risks. The article further explores the concept of platelet reactivity, discusses strategies for improving adherence to aspirin therapy, and identifies existing research gaps, such as the phenomenon of aspirin resistance. It concludes by suggesting potential areas for future investigation to enhance understanding and application of aspirin in cardiovascular disease prevention.

Aspirin Use to Prevent Cardiovascular Disease and Colorectal Cancer: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Low-dose aspirin is used for primary cardiovascular disease prevention and may have benefits for colorectal cancer prevention.

OBJECTIVE

To review the benefits and harms of aspirin in primary cardiovascular disease prevention and colorectal cancer prevention to inform the US Preventive Services Task Force.

DATA SOURCES

MEDLINE, PubMed, Embase, and the Cochrane Central Register of Controlled Trials through January 2021; literature surveillance through January 21, 2022.

STUDY SELECTION

English-language randomized clinical trials (RCTs) of low-dose aspirin (≤100 mg/d) compared with placebo or no intervention in primary prevention populations.

DATA EXTRACTION AND SYNTHESIS

Single extraction, verified by a second reviewer. Quantitative synthesis using Peto fixed-effects meta-analysis.

MAIN OUTCOMES AND MEASURES

Cardiovascular disease events and mortality, all-cause mortality, colorectal cancer incidence and mortality, major bleeding, and hemorrhagic stroke.

RESULTS

Eleven RCTs (N = 134 470) and 1 pilot trial (N = 400) of low-dose aspirin for primary cardiovascular disease prevention were included. Low-dose aspirin was associated with a significant decrease in major cardiovascular disease events (odds ratio [OR], 0.90 [95% CI, 0.85-0.95]; 11 RCTs [n = 134 470]; I2 = 0%; range in absolute effects, -2.5% to 0.1%). Results for individual cardiovascular disease outcomes were significant, with similar magnitude of benefit. Aspirin was not significantly associated with reductions in cardiovascular disease mortality or all-cause mortality. There was limited trial evidence on benefits for colorectal cancer, with the findings highly variable by length of follow-up and statistically significant only when considering long-term observational follow-up beyond randomized trial periods. Low-dose aspirin was associated with significant increases in total major bleeding (OR, 1.44 [95% CI, 1.32-1.57]; 10 RCTs [n = 133 194]; I2 = 4.7%; range in absolute effects, 0.1% to 1.0%) and in site-specific bleeding, with similar magnitude.

CONCLUSIONS AND RELEVANCE

Low-dose aspirin was associated with small absolute risk reductions in major cardiovascular disease events and small absolute increases in major bleeding. Colorectal cancer results were less robust and highly variable.

Antiplatelet agents for chronic kidney disease

BACKGROUND

Antiplatelet agents are widely used to prevent cardiovascular events. The risks and benefits of antiplatelet agents may be different in people with chronic kidney disease (CKD) for whom occlusive atherosclerotic events are less prevalent, and bleeding hazards might be increased. This is an update of a review first published in 2013.

OBJECTIVES

To evaluate the benefits and harms of antiplatelet agents in people with any form of CKD, including those with CKD not receiving renal replacement therapy, patients receiving any form of dialysis, and kidney transplant recipients.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 13 July 2021 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

We selected randomised controlled trials of any antiplatelet agents versus placebo or no treatment, or direct head-to-head antiplatelet agent studies in people with CKD. Studies were included if they enrolled participants with CKD, or included people in broader at-risk populations in which data for subgroups with CKD could be disaggregated.

DATA COLLECTION AND ANALYSIS

Four authors independently extracted data from primary study reports and any available supplementary information for study population, interventions, outcomes, and risks of bias. Risk ratios (RR) and 95% confidence intervals (CI) were calculated from numbers of events and numbers of participants at risk which were extracted from each included study. The reported RRs were extracted where crude event rates were not provided. Data were pooled using the random-effects model. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

We included 113 studies, enrolling 51,959 participants; 90 studies (40,597 CKD participants) compared an antiplatelet agent with placebo or no treatment, and 29 studies (11,805 CKD participants) directly compared one antiplatelet agent with another. Fifty-six new studies were added to this 2021 update. Seven studies originally excluded from the 2013 review were included, although they had a follow-up lower than two months. Random sequence generation and allocation concealment were at low risk of bias in 16 and 22 studies, respectively. Sixty-four studies reported low-risk methods for blinding of participants and investigators; outcome assessment was blinded in 41 studies. Forty-one studies were at low risk of attrition bias, 50 studies were at low risk of selective reporting bias, and 57 studies were at low risk of other potential sources of bias. Compared to placebo or no treatment, antiplatelet agents probably reduces myocardial infarction (18 studies, 15,289 participants: RR 0.88, 95% CI 0.79 to 0.99, I² = 0%; moderate certainty). Antiplatelet agents has uncertain effects on fatal or nonfatal stroke (12 studies, 10.382 participants: RR 1.01, 95% CI 0.64 to 1.59, I² = 37%; very low certainty) and may have little or no effect on death from any cause (35 studies, 18,241 participants: RR 0.94, 95 % CI 0.84 to 1.06, I² = 14%; low certainty). Antiplatelet therapy probably increases major bleeding in people with CKD and those treated with haemodialysis (HD) (29 studies, 16,194 participants: RR 1.35, 95% CI 1.10 to 1.65, I² = 12%; moderate certainty). In addition, antiplatelet therapy may increase minor bleeding in people with CKD and those treated with HD (21 studies, 13,218 participants: RR 1.55, 95% CI 1.27 to 1.90, I² = 58%; low certainty). Antiplatelet treatment may reduce early dialysis vascular access thrombosis (8 studies, 1525 participants) RR 0.52, 95% CI 0.38 to 0.70; low certainty). Antiplatelet agents may reduce doubling of serum creatinine in CKD (3 studies, 217 participants: RR 0.39, 95% CI 0.17 to 0.86, I² = 8%; low certainty). The treatment effects of antiplatelet agents on stroke, cardiovascular death, kidney failure, kidney transplant graft loss, transplant rejection, creatinine clearance, proteinuria, dialysis access failure, loss of primary unassisted patency, failure to attain suitability for dialysis, need of intervention and cardiovascular hospitalisation were uncertain. Limited data were available for direct head-to-head comparisons of antiplatelet drugs, including prasugrel, ticagrelor, different doses of clopidogrel, abciximab, defibrotide, sarpogrelate and beraprost.

AUTHORS' CONCLUSIONS

Antiplatelet agents probably reduced myocardial infarction and increased major bleeding, but do not appear to reduce all-cause and cardiovascular death among people with CKD and those treated with dialysis. The treatment effects of antiplatelet agents compared with each other are uncertain.

The safety of upper gastrointestinal endoscopic biopsy in patients receiving antithrombic drugs. A single-centre prospective observational study

Introduction

In July 2012, the Japan Gastroenterological Endoscopy Society updated their guidelines on gastroenterological endoscopy in patients undergoing antithrombotic therapy, although the safety of endoscopic procedures in patients receiving antithrombotic drugs has yet to be sufficiently studied.

Aim

This study evaluates the safety of upper gastroenterological endoscopic biopsy in patients receiving antithrombotic drugs. We evaluated the prospective observational safety of endoscopic biopsy performed in the endoscopy unit of our patients using antithrombotic drugs.

Material and methods

Oesophagogastroduodenoscopies (OGD) and biopsies performed at a single endoscopy unit between July 2018 and February 2019 were examined in this prospective observational study. Patients receiving antithrombotic drugs due to cardiovascular and neurological reasons, who underwent an endoscopic mucosal biopsy for diagnostic purposes, were included in the study.

Results

The study was completed with 166 patients who underwent an endoscopic biopsy, from whom a total of 327 biopsies taken. The patients were examined in two groups: those “receiving antithrombotic drugs” and those who had “stopped taking antithrombotic drugs”. There was no statistically significant difference between the two groups with respect to bleeding.

Conclusions

This prospective observational study showed that performing an endoscopic biopsy without the cessation of antithrombotic drugs does not increase bleeding risk. Low-risk procedures, such as endoscopic mucosal biopsies, can be performed confidently by experienced endoscopists.

Bleeding Risk Related to Upper Gastrointestinal Endoscopic Biopsy in Patients Receiving Antithrombotic Therapy: A Multicenter Prospective Observational Study

BACKGROUND

Although antithrombotic agents are widely used for cardiac and cerebrovascular disease prevention, they increase the risk of gastrointestinal (GI) bleeding.

OBJECTIVE

To examine GI bleeding risk in association with an esophagogastroduodenoscopy (EGD) biopsy performed in patients without cessation of antithrombotic therapy.

METHODS

This study was prospectively conducted at 14 centers. EGD biopsies were performed in patients receiving antithrombotic agents without cessation, as well as age- and sex-matched controls not receiving antithrombotic therapy. Patients treated with warfarin before the biopsy had a prothrombin time-international normalized ratio level <3.0. The proportion of GI bleeding events was compared between the groups.

RESULTS

The patient group (n = 277) underwent a total of 560 biopsies while continuing antithrombotic therapy, of whom 24 were receiving multiple antiplatelet drugs, and 9 were receiving both antiplatelet and anticoagulant agents. The control patients (n = 263) underwent 557 biopsies. The upper-GI bleeding rate within 30 days after the EGD biopsy did not increase in patients without cessation of antithrombotic treatment, regardless of receiving single or multiple antithrombotic agents.

CONCLUSIONS

We found no significant increase in upper-GI bleeding risk following an EGD biopsy in patients taking antithrombotic agents, suggesting its safety without the need for antithrombotic treatment interruption.

Silent myocardial ischemia in asymptomatic patients with type 2 diabetes mellitus without previous histories of cardiovascular disease

BACKGROUND

The number of patients with type 2 diabetes mellitus (T2DM) continues to increase all over the world. Cardiovascular disease (CVD), especially coronary artery disease (CAD), is a major cause of the morbidity and mortality in patients with T2DM. The prognosis of patients with silent myocardial ischemia (SMI) is worse than that in those without.

METHODS AND RESULTS

Thus, to assess how many patients with SMI existed among those patients, CVD screening tests were performed in 128 asymptomatic patients with T2DM without previous histories of CVD. SMI could be detected in 24 patients (19%) by exercise stress tests and/or the coronary fractional flow reserve. Their 12-lead electrocardiogram and cardiac ultrasonography were both normal. Compared to those without SMI, those with had a statistically significant longer history of T2DM (17±1 versus 11±1years, p=0.006), and the co-existence of a family history of CVD (42% versus 21%, p=0.037). Furthermore, these factors were demonstrated as independent risk factors of SMI by a multivariate analysis (Odds ratio 1.060 and 4.000, respectively), and in accordance with the disease duration of T2DM, the prevalence of patients with SMI has been increasing (p=0.019).

CONCLUSIONS

Physicians should be aware of these conditions when examining patients with T2DM, especially with a family history of CVD and/or long disease duration (>11years) of T2DM, even though they have no symptoms, previous histories of CVDs, and/or abnormal findings on the 12-lead electrocardiogram and cardiac ultrasonography. This may be an effective, safe, and attractive diagnostic strategy for those asymptomatic patients with T2DM.

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.

Safety of gastrointestinal endoscopic biopsy in patients taking antithrombotics

BACKGROUND AND AIM

Current Japanese gastrointestinal (GI) endoscopic guidelines permit endoscopic biopsy without cessation of antiplatelet agents and warfarin in patients with a therapeutic range of prothrombin time-international normalized ratio (PT-INR) levels, although the evidence levels are low. We evaluated the safety of endoscopic biopsy in patients currently taking antithrombotics.

METHODS

Consecutive patients receiving antithrombotics who underwent GI endoscopy from August 2012 to August 2013 were enrolled. Adverse events and endoscopic hemostasis after biopsy were evaluated. PT-INR level was measured in patients taking warfarin the day before endoscopy.

RESULTS

Among 7939 patients undergoing endoscopy, 1034 patients (13.0%, 706 men and 328 women, average age 72.8 years) were receiving antithrombotics. Antithrombotics included aspirin (44.8%), warfarin (34.7%), thienopyridine (16.1%), cilostazol (10.3%), dabigatran (4.8%) etc. PT-INR levels in patients taking warfarin were >3.0 in 13 patients (4.3%), between 2.5 and 3.0 in 18 patients (6.0%), <2.5 in 269 patients (89.7%). Two hundred and six patients received endoscopic biopsy while taking aspirin (51.2%), warfarin (22.8%), and thienopyridine (13.6%). Endoscopic hemostasis was required in three patients after endoscopic biopsy (spraying thrombin in two patients, spraying thrombin and clipping in one patient). There were no major complications. The incidence of endoscopic hemostasis after biopsy in patients without antithrombotic cessation was not significantly different than in the controls not taking antithrombotics (1.5% vs 0.98%, P = 0.51).

CONCLUSION

Endoscopic biopsy did not increase the bleeding risk despite not stopping antithrombotics prior to biopsy even among patients taking warfarin whose PT-INR was within the therapeutic range.