Rising reports of thromboembolic cases among COVID-19 patients have prompted physicians and also several trials to evaluate higher doses of heparin than are typically used as an anticoagulant strategy, but experts noted there is still a lack of clarity on the optimal regimen. Additionally, they said, while all hospitalized patients stand to benefit from a prophylactic dose, whether to use the higher therapeutic dose in those patients is an open question.
Several trials are evaluating higher doses of anticoagulants like heparin or enoxaparin—a low molecular weight heparin—in COVID-19 patients who are mechanically ventilated or hospitalized but not ventilated. While the latter population is an important group to study, as they could benefit from early intervention, there is more experience and the risk-benefit profile is more established in the former group from non-COVID-19 settings.
Several anticoagulants are being evaluated, including a nebulized form of heparin, which the trial investigator said could target clots in the air sacs outside blood vessels inaccessible to intravenous heparin. Tissue plasminogen activator (tPA) also got attention as a possible intervention against blood clots after positive reports of five patients treated at Mount Sinai. Experts said due to the associated bleeding risks, it will likely be relegated to salvage therapy only.