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ACE inhibitors and severe COVID-19: Protective in older patients?


 

A new nationwide U.S. observational study suggests that ACE inhibitors may protect against severe illness in older people with COVID-19, prompting the start of a randomized clinical trial to test the strategy.

In addition, a new meta-analysis of all the available data on the use of ACE inhibitors and angiotensin-receptor blockers (ARBs) in COVID-19–infected patients has concluded that these drugs are not associated with more severe disease and do not increase susceptibility to infection.

The observational study, which was published on the MedRxiv preprint server on May 19 and has not yet been peer reviewed, was conducted by the health insurance company United Heath Group and by Yale University, New Haven, Conn.

The investigators analyzed data from 10,000 patients from across the United States who had tested positive for COVID-19, who were enrolled in Medicare Advantage insurance plans or were commercially insured, and who had received a prescription for one or more antihypertensive medications.

Results showed that the use of ACE inhibitors was associated with an almost 40% lower risk for COVID-19 hospitalization for older people enrolled in Medicare Advantage plans. No such benefit was seen in the younger commercially insured patients or in either group with ARBs.

Dr. Harlan M. Krumholz, Yale cardiologist and professor of medicine Courtesy Yale University

Dr. Harlan M. Krumholz

At a telephone media briefing on the study, senior investigator Harlan M. Krumholz, MD, said: “We don’t believe this is enough info to change practice, but we do think this is an interesting and intriguing result.

“These findings merit a clinical trial to formally test whether ACE inhibitors – which are cheap, widely available, and well-tolerated drugs – can reduce hospitalization of patients infected with COVID-19,” added Dr. Krumholz, professor of medicine at Yale and director of the Yale New Haven Hospital Center for Outcomes Research.

A pragmatic clinical trial is now being planned. In this trial, 10,000 older people who test positive for COVID-19 will be randomly assigned to receive either a low dose of an ACE inhibitor or placebo. It is hoped that recruitment for the trial will begin in June of 2020. It is open to all eligible Americans who are older than 50 years, who test negative for COVID-19, and who are not taking medications for hypertension. Prospective patients can sign up at a dedicated website.

The randomized trial, also conducted by United Health Group and Yale, is said to be “one of the first virtual COVID-19 clinical trials to be launched at scale.”

For the observational study, the researchers identified 2,263 people who were receiving medication for hypertension and who tested positive for COVID-19. Of these, approximately two-thirds were older, Medicare Advantage enrollees; one-third were younger, commercially insured individuals.

In a propensity score–matched analysis, the investigators matched 441 patients who were taking ACE inhibitors to 441 patients who were taking other antihypertensive agents; and 412 patients who were receiving an ARB to 412 patients who were receiving other antihypertensive agents.

Results showed that during a median of 30 days after testing positive, 12.7% of the cohort were hospitalized for COVID-19. In propensity score–matched analyses, neither ACE inhibitors (hazard ratio [HR], 0.77; P = .18) nor ARBs (HR, 0.88; P =.48) were significantly associated with risk for hospitalization.

However, in analyses stratified by the insurance group, ACE inhibitors (but not ARBs) were associated with a significant lower risk for hospitalization among the Medicare group (HR, 0.61; P = .02) but not among the commercially insured group (HR, 2.14; P = .12).

A second study examined outcomes of 7,933 individuals with hypertension who were hospitalized with COVID-19 (92% of these patients were Medicare Advantage enrollees). Of these, 14.2% died, 59.5% survived to discharge, and 26.3% underwent ongoing hospitalization. In propensity score–matched analyses, use of neither an ACE inhibitor (HR, 0.97; P = .74) nor an ARB (HR, 1.15; P = .15) was associated with risk of in-hospital mortality.

The researchers said their findings are consistent with prior evidence from randomized clinical trials suggesting a reduced risk for pneumonia with ACE inhibitors that is not observed with ARBs.

They also cited some preclinical evidence that they said suggests a possible protective role for ACE inhibitors in COVID-19: that ACE inhibitors, but not ARBs, are associated with the upregulation of ACE2 receptors, which modulate the local interactions of the renin-angiotensin-aldosterone system in the lung tissue.

“The presence of ACE2 receptors, therefore, exerts a protective effect against the development of acute lung injury in infections with SARS coronaviruses, which lead to dysregulation of these mechanisms and endothelial damage,” they added. “Further, our observations do not support theoretical concerns of adverse outcomes due to enhanced virulence of SARS coronaviruses due to overexpression of ACE2 receptors in cell cultures – an indirect binding site for these viruses.”

The authors also noted that their findings have “important implications” for four ongoing randomized trials of ACE inhibitors/ARBs in COVID-19, “as none of them align with the observations of our study.”

They pointed out that of the four ongoing trials, three are testing the use of ACE inhibitors or ARBs in the treatment of hospitalized COVID-19 patients, and one is testing the use of a 10-day course of ARBs after a positive SARS-CoV-2 test to prevent hospitalization.

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