Which Treatments Improve Long-term Outcomes of Critical COVID Illness?

Carolyn Crist

January 11, 2023

Editor's note: Find the latest COVID-19 news and guidance in Medscape's Coronavirus Resource Center.

Treatment with interleukin 6 (IL-6) receptor antagonists or antiplatelet agents improves survival and outcomes at 6 months for critically ill patients with COVID-19, according to new data.

However, survival wasn't improved with therapeutic anticoagulation, convalescent plasma, or lopinavir-ritonavir, and survival was worsened with hydroxychloroquine.

Dr Patrick Lawler

"After critically ill patients leave the hospital, there's a high risk of readmission, death after discharge, or exacerbations of chronic illness," study author Patrick Lawler, MD, a clinician-scientist at the Peter Munk Cardiac Centre at University Health Network and an assistant professor of medicine at the University of Toronto, told Medscape Medical News.

"When looking at the impact of treatment, we don't want to improve short-term outcomes yet worsen long-term disability," he said. "That long-term, 6-month horizon is what matters most to patients."

The study was published online on December 16 in JAMA.

Investigating Treatments

The investigators analyzed data from an ongoing platform trial called Randomized Embedded Multifactorial Adaptive Platform for Community Acquired Pneumonia (REMAP-CAP). The trial is evaluating treatments for patients with severe pneumonia in pandemic and nonpandemic settings.

In the trial, patients are randomly assigned to receive one or more interventions within the following six treatment domains: immune modulators, convalescent plasma, antiplatelet therapy, anticoagulation, antivirals, and corticosteroids. The trial's primary outcome for patients with COVID-19 is hospital survival and organ support–free days up to 21 days. Researchers previously observed improvement after treatment with IL-6 receptor antagonists (which are immune modulators).

For this study, the research team analyzed data for 4869 critically ill adult patients with COVID-19 who were enrolled between March 2020 and June 2021 at 197 sites in 14 countries. A 180-day follow-up was completed in March 2022. The critically ill patients had been admitted to an intensive care unit and had received respiratory or cardiovascular organ support.

The researchers examined survival through day 180. A hazard ratio (HR) <1 represented improved survival, and an HR >1 represented harm. Futility was represented by a relative improvement in outcome of <20%, which was shown by an HR >0.83.

Among the 4869 patients, 4107 patients had a known mortality status, and 2590 were alive at day 180. Among the 1517 patients who died by day 180, 91 deaths (6%) occurred between hospital discharge and day 180.

Overall, use of IL-6 receptor antagonists (either tocilizumab or sarilumab) had a greater than 99.9% probability of improving 6-month survival, and use of antiplatelet agents (aspirin or a P2Y12 inhibitor such as clopidogrel, prasugrel, or ticagrelor) had a 95% probability of improving 6-month survival, compared with control therapies.

In contrast, long-term survival wasn't improved with therapeutic anticoagulation (11.5%), convalescent plasma (54.7%), or lopinavir-ritonavir (31.9%). The probability of trial-defined statistical futility was high for anticoagulation (99.9%), convalescent plasma (99.2%), and lopinavir-ritonavir (96.6%).

Long-term survival was worsened with hydroxychloroquine, with a posterior probability of harm of 96.9%. In addition, the combination of lopinavir-ritonavir and hydroxychloroquine had a 96.8% probability of harm.

Corticosteroids didn't improve long-term outcomes, although enrollment in the treatment domain was terminated early in response to external evidence. The probability of improving 6-month survival ranged from 57.1% to 61.6% for various hydrocortisone dosing strategies.

Consistent Treatment Effects

When considered along with previously reported short-term results from the REMAP-CAP trial, the findings indicate that initial in-hospital treatment effects were consistent for most therapies through 6 months.

"We were very relieved to see that treatments with a favorable benefit for patients in the short term also appeared to be beneficial through 180 days," said Lawler. "This supports the current clinical practice strategy in providing treatment to critically ill patients with COVID-19."

In a subgroup analysis of 989 patients, health-related quality of life at day 180 was higher among those treated with IL-6 receptor antagonists and antiplatelet agents. The average quality-of-life score for the lopinavir-ritonavir group was lower than for control patients.

Among 720 survivors, 273 patients (37.9%) had moderate, severe, or complete disability at day 180. IL-6 receptor antagonists had a 92.6% probability of reducing disability, and anakinra (an IL-1 receptor antagonist) had a 90.8% probability of reducing disability. However, lopinavir-ritonavir had a 91.7% probability of worsening disability.

The REMAP-CAP trial investigators will continue to assess treatment domains and long-term outcomes among COVID-19 patients. They will evaluate additional data regarding disability, quality of life, and long-COVID outcomes.

"Reassuring" Results

Commenting on the study for Medscape, Angela Cheung, MD, PhD, a professor of medicine at the University of Toronto and senior scientist at the Toronto General Research Institute, said, "It is important to look at the longer-term effects of these therapies, as sometimes we may improve things in the short term, but that may not translate to longer-term gains. Historically, most trials conducted in this patient population assess only short outcomes, such as organ failure or 28-day mortality."

Dr Angela Cheung

Cheung, who wasn't involved with this study, serves as the co-lead for the Canadian COVID-19 Prospective Cohort Study (CANCOV) and the Recovering From COVID-19 Lingering Symptoms Adaptive Integrative Medicine Trial (RECLAIM). These studies are also analyzing long-term outcomes among COVID-19 patients.

"It is reassuring to see that the 6-month outcomes are consistent with the short-term outcomes," she said. "This study will help guide critical care medicine physicians in their treatment of critically ill patients with COVID-19."

The study was supported by numerous grants and funds, including the Canadian Institute of Health Research COVID-19 Rapid Research Funding. Amgen and Eisai also provided funding. Lawler received grants from Canadian Institutes for Health Research and the Heart and Stroke Foundation of Canada during the conduct of the study and personal fees from Novartis, CorEvitas, Partners Healthcare, and the American College of Cardiology outside the submitted work. Cheung has disclosed no relevant financial relationships.

JAMA. 2022;329:39-51. Full text

Carolyn Crist is a health and medical journalist who reports on the latest studies for Medscape, MDedge, and WebMD.

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