COVID-19 flu guidance, data on convalescent plasma, cardiac effects, and clot risk

The NIH recently updated its COVID-19 guidelines to address influenza season. Where both influenza and SARS-CoV-2 are circulating, testing for both viruses is recommended for all hospitalized patients with acute respiratory illness. For outpatients, influenza testing is recommended if it will change clinical management. Treatment of flu remains the same regardless of whether patients are co-infected with SARS-CoV-2; empiric treatment with oseltamivir is recommended for hospitalized patients without waiting for influenza test results, the guidelines said. The Oct. 22 update also advised that patients with COVID-19 should receive an inactivated flu vaccine if they are being vaccinated.

Convalescent plasma did not improve outcomes in a randomized, open-label trial published by The BMJ on Oct. 22. It included 464 hospitalized patients with moderate COVID-19 (e.g., PaO₂/FiO₂ ratio of 200 to 300 mm Hg). Those who received two doses of 200 mL of convalescent plasma, transfused 24 hours apart, were more likely to show conversion of SARS-CoV-2 RNA on day 7 but had similar rates of progression to severe disease and 28-day mortality. The study authors said that “a priori measurement of neutralising antibody titres in donors and participants might further clarify the role of convalescent plasma,” but an accompanying editorial, titled “Convalescent Plasma Is Ineffective for Covid-19,” urged greater caution about the use of plasma even in clinical trials.

The incidence of thromboembolic complications in COVID-19 was described by a study in the Oct. 26 Journal of the American College of Cardiology. It included 170 ICU patients, 229 hospitalized but not in the ICU, and 715 outpatients. Rates of major arterial or venous thromboembolism (VTE), major cardiovascular adverse events, and symptomatic VTE were highest in the ICU cohort (35.3%, 45.9%, and 27.0%, respectively), followed by the medical floor patients (2.6%, 6.1%, and 2.2%, respectively) and the outpatient cohort (0% for all). The authors concluded that the results show a high frequency of these events with COVID-19, especially in the ICU, despite high use of thromboprophylaxis (89.4% in the ICU cohort, 84.7% on the ward). However, an accompanying editorial noted that the 76.9% of the VTEs in the ICU were attributable to central venous lines and that apart from that category, the event rates “do not appear inflated relative to prior published incidence rates from the pre-COVID-19 era.” The editorialists added that clinicians should “resist the urge to overprevent or overtreat patients” and follow the evidence-based guidelines for clot prophylaxis and treatment. “Adding major hemorrhage to the condition of a patient already severely compromised from the viral infection will undoubtedly increase the mortality risk,” they wrote.

Researchers in the United Kingdom developed and validated a score for predicting risk of death or hospitalization from COVID-19, called QCOVID. According to results published by The BMJ on Oct. 20, predictors included age, ethnicity, socioeconomic deprivation, body mass index, and a range of comorbidities. The results would need to be confirmed in other countries but have numerous applications, including trial enrollment, vaccination prioritization, and “discussions between patients and clinicians on workplace or health risk mitigation—for example, through weight reduction,” the authors said.

Many studies of tocilizumab were released in the past week, with very mixed results, including a negative randomized trial in the New England Journal of Medicine on Oct. 21 and positive, mixed, and negative results in JAMA Internal Medicine on Oct. 22, accompanied by an editorial offering the advice to “wait out the torrent of positive observational studies” for more randomized, controlled data. An additional retrospective analysis with positive results was published by CHEST on Oct. 16.

On Oct. 22, remdesivir was approved by the FDA for the treatment of COVID-19 requiring hospitalization in adult and pediatric patients 12 years of age and older and weighing at least 40 kilograms. The agency's press release noted that the emergency use authorization for the drug, issued in May, includes more pediatric patients than the current approval.