Latest research on COVID-19 antibodies, cardiac and stroke risks, mortality rates

Antibodies to SARS-CoV-2 were a focus of much research last week. A monoclonal antibody treatment appeared to accelerate natural decline in viral load among outpatients with recently diagnosed mild or moderate COVID-19, according to an interim analysis of an industry-funded randomized trial published by the New England Journal of Medicine (NEJM) on Oct. 28. The treatment also appeared safe, and if the results are confirmed, it “could become a useful treatment for emergency use in patients with recently diagnosed Covid-19,” the authors said. Also from NEJM, on Oct. 29, an analysis of more than 1,000 Icelanders who had COVID-19 found that their antibodies against SARS-CoV-2 did not decline within four months after diagnosis. Similarly, an analysis of 121 donors of convalescent plasma, published by Science on Oct. 28, found relatively stable antibody titers over approximately five months. However, a study of 65 symptomatic patients and 31 health care workers, published by Nature on Oct. 26, found declining antibody titers within three months.

Other recent studies looked at cardiac and cerebrovascular effects of COVID-19. An international registry of 110 hospitalized patients found QTC interval prolongation in 14%, according to results published by Clinical Infectious Diseases on Oct. 24. Another analysis of 43 ICU patients, published by CHEST on Oct. 27, found cardiac injury in 49% at ICU admission and 70% within 14 days, most frequently left ventricular abnormalities, followed by right ventricular systolic dysfunction and pericardial effusion. COVID-19 does not appear to carry increased risk of ischemic stroke, according to a study published by Stroke on Oct. 27. Of more than 24,000 discharges from one health care system, the 2,513 with COVID-19 were significantly less likely to present with ischemic stroke than non-COVID-19 patients (odds ratio [OR], 0.25; 95% CI, 0.16 to 0.40). However, concurrent infection was associated with significantly higher mortality after stroke (OR, 10.50; 95% CI, 3.54 to 31.18).

In patients with uncertain viral status who have an ischemic stroke, CT angiogram can identify COVID-19, according to a study published by Stroke on Oct. 29. A review of apical lung assessments of 57 patients found that combined with self-reported cough or shortness of breath, these had a sensitivity of 0.83 for diagnosing COVID-19, leading study authors to conclude that apical lung assessment on CT is “an accurate screening tool for COVID-19 and can serve as part of a combined screening approach.”

Several studies looked at mortality from COVID-19. An analysis of 5,121 hospitalizations from three New York hospitals, published by the Journal of Hospital Medicine on Oct. 23, found that risk-adjusted mortality dropped from 25.6% in March to 7.6% in August. “Incremental improvements in outcomes are likely a combination of increasing clinical experience, decreasing hospital volume, growing use of new pharmacologic treatments (such as systemic corticosteroids, remdesivir, and anticytokine treatments), nonpharmacologic treatments (such as placing the patient in the prone position, or proning, rather than on their back), earlier intervention, community awareness, and, potentially, lower viral load exposure from increased mask wearing and social distancing,” the authors said. A meta-analysis of 69 studies with 57,420 patients who received mechanical ventilation also noted higher mortality in early COVID-19 epicenters. Overall, it found high heterogeneity in case-fatality rates across studies and pooled fatality estimates ranging from 47.9% in patients ages 40 years or younger to 84.4% in patients over age 80 years, according to results published by the American Journal of Respiratory and Critical Care on Oct. 29. A retrospective study developed a model, largely based on laboratory values at admission (particularly hematologic abnormalities and renal function), to predict risk of severe illness and mortality. It was published by JAMA Network Open on Oct. 30.

Another study, published by the Annals of the American Thoracic Society on Oct. 29, found that higher SARS-CoV-2 viral load at hospital admission predicted worse outcomes.

Finally, as ACP celebrated National Internal Medicine Day on Oct. 28, ACP's Vice President of Membership and Global Engagement, Philip A. Masters, MD, FACP, shared his insights on internal medicine, the pandemic, and William Osler in his latest KevinMD column. Dr. Masters writes: “Recognizing internal medicine and the work of internists is particularly pertinent in the midst of an ongoing pandemic in which the specialty occupies such a central role. Internists across the spectrum of practice have both stepped-up and stepped-in to manage the novel coronavirus crisis around the world.” His column looks at the origin of the specialty to “gain a historical perspective around how we approach the work we do and to better understand how the core tenets of the discipline established many years ago prepare us well for the current challenges we are facing.”