Competition between low-dose aspirin and other NSAIDs for COX-1 binding and its clinical consequences for the drugs’ antiplatelet effects

Association of Prediagnosis Obesity and Postdiagnosis Aspirin With Survival From Stage IV Colorectal Cancer

IMPORTANCE

The potential relationship between obesity and colorectal cancer (CRC) outcome is poorly understood in patients with late-stage disease. Increased body mass index may negate aspirin use for cancer prevention, but its role as a factor on the effectiveness of postdiagnosis aspirin use is unclear.

OBJECTIVE

To evaluate how prediagnosis obesity and postdiagnosis aspirin use may be associated with overall survival in patients with late-stage colorectal cancer.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study used self-reported data from patients with metastatic or treatment-refractory disease who consented to a clinical protocol at MD Anderson Cancer Center, a large US cancer treatment center. Patients were enrolled between 2010 and 2018 and followed up for mortality through July 2020. Analyses were conducted through March 2022.

EXPOSURES

Body mass index in the decade prior to initial diagnosis and regular aspirin use at survey completion.

MAIN OUTCOMES AND MEASURES

Overall survival was measured from stage IV diagnosis until death or last follow-up. Cox proportional hazards models were constructed to estimate associations of prediagnosis obesity and postdiagnosis aspirin use with overall survival.

RESULTS

Of 656 patients included in this analysis, 280 (42.7%) were women, 135 (20.6%) were diagnosed with CRC before age 45 years, 414 (63.1%) were diagnosed between ages 45 and 65 years, and 107 (16.3%) were diagnosed at 65 years or older; 105 patients (16.0%) were Black or Hispanic, and 501 (76.4%) were non-Hispanic White. Controlling for age, sex, race, stage at initial diagnosis, and weight change between prediagnosis and survey date, patients with obesity in the decade prior to CRC diagnosis had significantly higher likelihood of death (hazard ratio, 1.45; 95% CI, 1.11-1.91) compared with those with normal prediagnosis body mass index. Furthermore, only patients with normal prediagnosis body mass index experienced significant survival benefit with postdiagnosis aspirin use (hazard ratio, 0.59; 95% CI, 0.39-0.90).

CONCLUSIONS AND RELEVANCE

In this cross-sectional study, our findings suggest potentially differential tumor development in the long-term physiologic host environment of obesity. Confirmation and further evaluation are needed to determine whether prediagnosis body mass index may be used to estimate the benefit from postdiagnosis aspirin use.

The Protective Effect of Aspirin against Myocardial Hypertrophy in Rats

The protective effect of aspirin against myocardial hypertrophy (MH) was studied. Model rats of pressure overload MH were prepared by abdominal aortic coarctation. Rats were randomly divided into the sham group (n = 9), MH model group (n = 9), and MH+aspirin group (n = 9), which was, respectively, divided into the 4-week group and 8-week group according to the time of intragastric administration. Arterial blood pressure and left ventricular mass index (LVMI) were measured. Changes in myocardial tissue structure were observed by HE staining, Masson staining, and reticular fiber staining. Cardiomyocyte apoptosis was detected by TUNEL assay. The levels of TNF-α, IL-10, TXA2, and PGI2 in myocardium and plasma were detected by ELISA. The arterial blood pressure in the MH model group was significantly higher than that in the 4- and 8-week sham groups, but that in the MH+aspirin group was significantly lower than that in the MH model group. At 4 and 8 weeks, the LVWI in the MH model group was significantly higher than that in the sham group, but it was significantly reduced after aspirin treatment. The myocardial cell hypertrophy was obvious, collagen fibers were proliferated, and reticular fibers were reduced in the 4- and 8-week MH model groups. Compared with the MH model groups, myocardial cells in the MH+aspirin groups were significantly reduced, the collagen fiber content was significantly reduced, and the reticular fiber content was increased. The apoptotic cardiomyocytes in the 4- and 8-week MH model groups were obviously increased. The apoptosis of myocardial cells in the MH+aspirin groups was obviously decreased. The TNF-α levels in the myocardial tissue of the 4- and 8-week MH model groups were significantly increased, while those of the MH+aspirin groups were significantly decreased. There was no significant change in the IL-10 level or PGI2 level at 4 weeks. At 8 weeks, the PGI2 level was significantly decreased in the MH model group while significantly increased in the MH+aspirin group. The TXA2 levels were significantly increased in the 4- and 8-week MH model groups and those in the 4- and 8-week MH+aspirin groups were significantly lower. Aspirin has an anti-inflammatory effect, can effectively reduce the expression of inflammatory factors, inhibit myocardial apoptosis, and has a certain protective effect against MH.

Studying additive interaction in a healthcare database: Case study of NSAIDs, cardiovascular profiles, and acute myocardial infarction

Purpose

There are clinical trial data on risk of acute myocardial infarction (MI) with nonsteroidal anti-inflammatory drugs (NSAIDs) in patients at increased cardiovascular (CV) risk requiring chronic daily treatment. This study investigated whether risks of acute MI with real-world prescription NSAIDs, such as low-dose or intermittent use, vary according to an individual’s CV profile.

Methods

Nested case-control analyses were carried out on an administrative health cohort from Quebec, Canada by randomly selecting 10 controls per case matched on age ± 1 year, sex, and month and year of cohort entry. We measured the additive joint effects on acute MI of current NSAID use and presence of hypertension, coronary heart disease (CHD), history of previous MI, or concomitant use of cardioprotective aspirin. The endpoint was the relative excess risk due to interaction (RERI). To verify the robustness of interaction findings, we performed sensitivity analyses with varying specifications of NSAID exposure-related variables.

Results

The cohort consisted of 233 816 elderly individuals, including 21 256 acute MI cases. For hypertension, CHD, and previous MI, we identified additive interactions on MI risk with some but not all NSAIDs, which also depended on the definition of NSAID exposure. Hypertension was sub-additive with naproxen but not with the other NSAIDs. Celecoxib and CHD were sub-additive in the primary analysis only (modelling NSAID dose on index date or up to 7 days before–best-fitting base model) whereas celecoxib and rofecoxib were super-additive with a history of previous MI in the secondary analysis only (modelling NSAID use on index date). For cardioprotective aspirin we found no evidence for an additive interaction with any of the NSAIDs.

Conclusions

Alternative specifications of NSAID exposure concurred in finding that concomitant use of cardioprotective aspirin does not attenuate the risks of acute MI with NSAIDs. However we were unable to demonstrate consistent interactions between an individual’s cardiovascular comorbidities and NSAID-associated acute MI. Our study highlights challenges of studying additive interactions in a healthcare database and underscores the need for sensitivity analyses.

Aspirin resistance may be identified by miR-92a in plasma combined with platelet distribution width

OBJECTIVE

Aspirin is a widely used drug for prevention of thrombotic events in cardiovascular patients, but approximately 25% of patients experience insufficient platelet inhibition due to aspirin, and remain in risk of cardiovascular events. This study aimed to investigate the value of circulating miR-92a and platelet size as biomarkers of the individual response to aspirin therapy.

METHODS

Blood samples were collected from 50 healthy blood donors without antithrombotic medication and 50 patients with intermittent claudication on daily aspirin therapy. Based on results from the arachidonic acid stimulated aggregation test on Multiplate®analyzer (ASPItest), patients were defined as aspirin resistant (n=10) or aspirin responders (n=40). Plasma levels of miR-92a were evaluated by RT-qPCR analysis and platelet distribution width (PDW) was used to assess platelet size variability. Receiver operating characteristic curves for miR-92a levels and PDW were used to set cut-off values for discrimination between aspirin responding and aspirin resistant patients.

RESULTS

When defining aspirin resistance as an ASPItest ≥30U, the optimal cut-off values for discrimination of aspirin responders and aspirin resistant patients were found to be PDW>11.8fL and a relative expression level of miR-92a>4.5. Using these cut-off values we could define a PDW/miR-92a-score with a specificity of 97.5% and a sensitivity of 80.0% in relation to detect aspirin resistance. The corresponding positive and negative predictive values were found to be 88.9% and 95.1%, respectively.

CONCLUSION

Aspirin resistance can potentially be identified by miR-92a levels in plasma combined with PDW.

Celecoxib interferes to a limited extent with aspirin-mediated inhibition of platelets aggregation

AIMS

The aim of the study was to analyze the interaction between celecoxib and low dose aspirin for COX-1 binding and its consequences on the aspirin-mediated antiplatelet effects.

METHODS

We investigated ex vivo the interaction between celecoxib and aspirin for COX-1 binding and measured the resulting antiplatelet effects. We applied mechanism-based pharmacokinetic-pharmacodynamic (PKPD) modelling to analyze these data and to predict in vivo platelet aggregation for different doses and administration schedules of aspirin and celecoxib.

RESULTS

The predictions of the PK-PD model were consistent with results from previous studies that investigated interaction between aspirin and celecoxib. The modelling results indicate that celecoxib can attenuate to a limited extent the in vivo antiplatelet effects of low dose aspirin. The extent of this interaction can be substantial (up to 15% increase in platelet aggregation by 200 mg day(-1) celecoxib when combined with low dose aspirin) during the first days of aspirin administration in patients who are already treated with celecoxib, and it cannot be prevented by separate administration of the interacting drugs.

CONCLUSIONS

At the recommended therapeutic doses, celecoxib can attenuate to a limited extent the in vivo antiplatelet effects of low dose aspirin. Patients receiving a combination of low dose aspirin and the recommended doses of celecoxib were not identified to have increased risk of cardiovascular and cerebrovascular events due to competition between these drugs for COX-1 binding. Interaction between low dose aspirin and other COX-2 inhibitors and its clinical consequences requires further investigation.