Aspirin a potential addition in arsenal against COVID-19

Aspirin appears to exert protective effects in patients with the novel coronavirus disease (COVID-19) by reducing the risk of death and the need for intensive care or mechanical ventilation, according to a recent study.

“Aspirin is inexpensive, widely available, and has a well described risk profile. These attributes, in conjunction with our pilot data, support aspirin’s role as a potential adjunctive therapeutic in COVID-19,” the researchers said, though cautioning that further trials are needed for validation. Until then, the practice should balance the potential benefits with known risks.

Of the 412 COVID-19 patients (median age, 55 years; 59.2 percent male) enrolled, 98 (23.7 percent) were on aspirin medication. These patients were on significantly less oxygen support admission (p=0.005) and were more likely to be admitted on room air or standard nasal cannula oxygen. [Anesth Analg 2020;doi:10.1213/ANE.0000000000005292]

Baseline vital signs and laboratory findings did not differ according to aspirin use, but those who were on the medication saw significantly lower rates of mechanical ventilation during their hospital stay, according to unadjusted analysis.

The same was true for admission into the intensive care. On the other hand, aspirin appeared to exert no such effect on major bleeding, overt thrombosis, or in-hospital mortality.

However, upon multivariate adjustments to the Cox proportional hazards model, aspirin demonstrated a significantly protective effect against in-hospital mortality, almost halving its risk (adjusted hazard ratio [HR], 0.53, 95 percent confidence interval [CI], 0.31–0.90; p=0.02).

The risk of needing mechanical ventilation (adjusted HR, 0.56, 95 percent CI, 0.37–0.85; p=0.007) and intensive care (adjusted HR, 0.57, 95 percent CI, 0.38–0.85; p=0.005) remained significantly suppressed after controlling for confounders.

Notably, these findings were robust to subgroup and sensitivity analyses. Aspirin remained significantly beneficial for patients who did not require mechanical ventilation at admission.

In addition, an unexplained and strong confounder—interacting with both aspirin use and mechanical ventilation at a risk ratio of 2.35—would be needed to completely negate the principal findings.  

“Mechanistically, these findings are plausible given aspirin’s irreversible antiplatelet effect and the frequent hypercoagulability observed in COVID-19 patients,” the researchers said. “The results of our study are intriguing, especially because aspirin has been thoroughly studied in chronic cardiovascular disease, has a well-described safety profile, and is readily available throughout the world.”

“The preliminary, hypothesis-generating nature of our study provides the basis for a larger study, which will be needed to confirm our findings and assess the extent to which the relationships observed in our study are causal,” they added.