Aspirin use may be associated with improved outcomes in hospitalised COVID-19 patients, a new study shows. Clinical researchers at the University of Maryland School of Medicine (UMSOM) conducted the study on 412 adult patients admitted with COVID-19 to numerous hospitals in the US. The primary outcome was the need for mechanical ventilation. Secondary outcomes were ICU admission and in-hospital mortality.
The "retrospective, observational cohort" study was conducted on adult patients admitted with COVID-19 to multiple hospitals in the US between March 2020 and July 2020. It was published as a pre-print in Anesthesia and Analgenia medical journal on October 21, 2020.
The study's conclusion: Hospitalised COVID-19 patients who were taking a daily low-dose aspirin to protect against cardiovascular disease had a significantly lower risk of complications and death compared to those who were not taking aspirin.
Aspirin takers were less likely to be placed in the intensive care unit (ICU) or hooked up to a mechanical ventilator. Moreover, they were more likely to survive the infection compared to hospitalised patients who were not taking aspirin. The study provides "cautious optimism," the researchers say, for an inexpensive, accessible medication with a well-known safety profile that could help prevent severe complications.
Widely available medication
"This is a critical finding that needs to be confirmed through a randomized clinical trial. If our finding is confirmed, it would make aspirin the first widely available, over-the-counter medication to reduce mortality in COVID-19 patients," said study leader Jonathan Chow, MD, Assistant Professor of Anesthesiology at UMSOM.
To conduct the study, Dr Chow and his colleagues culled through the medical records of 412 COVID-19 patients, age of 55 on average, who were hospitalized over the past few months due to complications of their infection. They were treated at the University of Maryland Medical Center in Baltimore and three other hospitals along the East Coast. About a quarter of the patients were taking a daily low-dose aspirin (usually 81 milligrams) before they were admitted or right after admission to manage their cardiovascular disease.
47%reduction in the risk of dying in the hospital among COVID-19 patients taking aspirin
The researchers found aspirin use was associated with a 44 per cent reduction in the risk of being put on a mechanical ventilator, a 43 per cent decrease in the risk of ICU admission, and — most importantly — a 47 per cent decrease in the risk of dying in the hospital compared to those who were not taking aspirin. The patients in the aspirin group did not experience a significant increase in adverse events such as major bleeding while hospitalised.
Aspirin use had a crude association with less mechanical ventilation (35.7% aspirin vs. 48.4% non-aspirin, p=0.03) and ICU admission (38.8% aspirin vs. 51.0% non-aspirin, p=0.04), but no crude association with in-hospital mortality (26.5% aspirin vs. 23.2% non-aspirin, p=0.51).
After adjusting for 8 confounding variables, aspirin use was independently associated with decreased risk of mechanical ventilation (adjusted HR 0.56, 95% CI 0.37-0.85, p=0.007), ICU admission (adjusted HR 0.57, 95% CI 0.38-0.85, p=0.005), and in-hospital mortality (adjusted HR 0.53, 95% CI 0.31-0.90, p=0.02). There were no differences in major bleeding (p=0.69) or overt thrombosis (p=0.82) between aspirin users and non-aspirin users. [Source: Anesthesia and Analgesia]
The team of researchers, including 38 medical doctors, controlled for several factors that may have played a role in a patient's prognosis including age, gender, body mass index, race, hypertension, and diabetes. They also accounted for heart disease, kidney disease, liver disease, and the use of beta blockers to control blood pressure.
COVID-19 infections increase the risk of dangerous blood clots that can form in the heart, lungs, blood vessels, and other organs. Complications from blood clots can, in rare cases, cause heart attacks, strokes, and multiple organ failure as well as death.
Doctors often recommend daily low-dose aspirin for patients who have previously had a heart attack or stroke caused by a blood clot to prevent future blood clots. Daily use, however, can increase the risk of major bleeding or peptic ulcer disease.
'Blood-thinning effects prevents microclot formation'
"We believe that the blood-thinning effects of aspirin provides benefits for COVID-19 patients by preventing microclot formation," said study co-author Michael A. Mazzeffi, MD, Associate Professor of Anesthesiology at UMSOM. "Patients diagnosed with COVID-19 may want to consider taking a daily aspirin as long as they check with their doctor first," added Mazzeffi.
Those at increased bleeding risk due to chronic kidney disease, for example, or because they regularly use certain medications, like steroids or blood thinners, may not be able to safely take aspirin, he added.
Researchers from Wake Forest School of Medicine, George Washington University School of Medicine, Northeast Georgia Health System, and Walter Reed National Military Medical Center also participated in this study.
"This study adds to the tremendous work our researchers are doing in the School of Medicine to help find new treatments against COVID-19 and save patients' lives," said E. Albert Reece, MD, PhD, MBA, Executive Vice President for Medical Affairs, UM Baltimore, and the John Z. and Akiko K. Bowers Distinguished Professor and Dean, University of Maryland School of Medicine.
"While confirmatory studies are needed to prove that aspirin use leads to better outcomes in COVID-19, the evidence thus far suggests that patients may want to discuss with their doctor whether it is safe for them to take aspirin to manage potentially prevent serious complications," added Reece.
Researchers recommended that sufficiently-powered randomised controlled trial is needed to assess whether a causal relationship exists between aspirin use and reduced lung injury and mortality in COVID-19 patients.