Aspirin's Role in Blood Clots Following COVID-19 in Veterans

As of mid-June 2023, it is estimated that nearly 880,000 Veterans in the United States were infected with COVID-19, leading to nearly 25,000 deaths. Many Veterans are also facing long-term issues related to the virus. Initially, the focus was on severe lung problems caused by the virus. However, research has shown that COVID-19 can lead to other serious issues, such as Blood Clots and inflammation throughout the body. Studies indicate that around 25-30% of patients infected with the virus, especially those who were very ill, experienced blood-related issues.

Researchers have been looking into whether taking Aspirin could help prevent blood clots following a COVID-19 infection, but the results have been mixed. Current medical guidelines suggest that people diagnosed with COVID-19 should not start taking low doses of aspirin for this purpose without more evidence.

The Veterans Health Administration (VHA) is the largest healthcare system in the U.S., serving more than 9 million Veterans. Many Veterans are older and have multiple health issues, putting them at higher risk for complications from COVID-19 compared to the general population. This study aims to examine how often blood clot issues occur due to COVID-19 in Veterans, identify risk factors for these issues, and see if pre-existing aspirin use had any effect.

#Study Overview

The research involved looking back at medical records from Veterans diagnosed with COVID-19 between March 2020 and June 2022. The study included Veterans over 18 years old who had confirmed COVID-19 through a lab test. The researchers excluded those with negative test results or incomplete health assessments. They followed the patients for 12 months after their first positive COVID-19 test to see if they developed blood clot issues.

The index date of the study was the first positive COVID-19 test for each Veteran. For example, if a Veteran tested positive in March 2020 and again in August 2021, the August test would be the focus of the study. Researchers used health records to check if patients had been prescribed aspirin at the time of their COVID-19 diagnosis. Those who had an active prescription for aspirin, as well as those who had filled prescriptions in the prior month, were included in the aspirin group.

Blood clot issues were identified using specific health codes in the patients' records. These included conditions like deep vein thrombosis (DVT) and ischemic stroke, among others. Other factors considered in the analysis included age, sex, race, body mass index (BMI), existing Health Problems, and vaccination status.

#Results

The study found that out of over 334,000 Veterans diagnosed with COVID-19, about 25% were taking aspirin before their diagnosis. Before matching the groups for comparison, 10.1% of Veterans developed blood clot issues after their COVID-19 diagnosis. After matching the groups based on similar characteristics, this number rose to 14.4%. Among the most common conditions were ischemic strokes and ischemic heart disease.

When comparing aspirin users to non-users, the results showed that those taking aspirin had a lower chance of developing certain types of blood clots, like pulmonary embolism and DVT. However, there was an increased risk of arterial blood clots, like strokes and heart-related issues, among those taking aspirin.

Interestingly, the study revealed that older Veterans, males, and those with existing health conditions like heart failure and high blood pressure were at a higher risk for developing blood clot issues after COVID-19.

#Aspirin Use and Blood Clots

In the analysis, those who were already using aspirin before getting COVID-19 had a decreased risk of developing venous blood clots but an increased risk of arterial blood clots during the follow-up period. This may be because those taking aspirin were already identified as being at higher risk for heart-related issues, and COVID-19 may have added to that risk.

The study utilized a large data set of Veterans’ medical records, which provided valuable insights into the effects of aspirin and the incidence of blood clots. The Veterans Health Administration is uniquely positioned to track both prescription and over-the-counter medication use, which allowed for a thorough assessment of aspirin use among Veterans.

#Limitations

The results of this study may not apply to all populations, as the Veterans involved may face specific health challenges related to their military service. While efforts were made to balance the groups being compared, it is acknowledged that the association of aspirin use with increased risk for arterial disease could reflect pre-existing conditions that led to the prescription of aspirin in the first place.

Because this study is observational, it cannot definitively establish cause and effect. More research, particularly randomized control trials, is necessary to further investigate the potential for aspirin to prevent blood clot issues following COVID-19.

#Conclusions

Patients who were taking aspirin before getting COVID-19 were found to have a lower risk of developing venous blood clots but a higher risk of arterial blood clots. This suggests that pre-existing health issues may influence these outcomes. Further studies are necessary to explore the role of aspirin in preventing blood clots following COVID-19.

As COVID-19 continues to affect many, understanding its long-term impacts, especially among vulnerable populations like Veterans, remains crucial for improving patient care and treatment options. Effective measures need to be explored to address the potential risks and benefits of medications like aspirin in the context of COVID-19 and its complications.