A new study, published on the MedRxiv, has suggested that ACE inhibitors, which are often prescribed to people with hypertension, may offer protection against severe illness in older people with COVID-19.

The study findings have prompted experts to start a randomized clinical trial to determine the efficacy of the drug while treating COVID-19.

The study, which has not yet been peer-reviewed, was conducted by the researchers of Yale University School of Medicine and the health insurance company United Health Group.

The researchers looked at 10,000 patients across the United States who had tested positive for COVID-19 and who had received a prescription for one or more high blood pressure medications.

They found that the use of ACE inhibitors reduced the risk of COVID-19 hospitalization in older people by 40 percent.

Senior researcher Dr. Harlan Krumholz from Yale 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,” he added.

Now, the researchers will conduct a randomized trial in which participants will receive either a low-dose ACE inhibitor or a placebo. The trial is expected to begin within the next 3 to 4 weeks.

The researchers said their findings are consistent with prior evidence suggesting a reduced risk of pneumonia with ACE inhibitors, which is not observed with angiotensin II receptor blockers (ARBs).

However, some experts were not overly optimistic about the findings.

Dr. Michael Weber from the State University of New York said, “This report adds to the growing number of observational studies that show varying effects of ACE inhibitors and ARBs in increasing or decreasing hospitalizations for COVID-19 and the likelihood of in-hospital mortality.”

“Overall, this new report differs from others in the remarkable effects of insurance coverage: in particular, for ACE inhibitors, there was a 40% reduction in fatal events in Medicare patients but a twofold increase in patients using commercial insurance ― albeit the test for heterogeneity when comparing the two groups did not quite reach statistical significance,” he added.

“In essence, these authors are saying that ACE inhibitors are highly protective in patients aged 65 or older but bordering on harmful in patients aged below 65. I agree that it’s worthwhile to check this finding in a prospective trial…but this hypothesis does seem to be a reach.”

Dr. John McMurray from the University of Glasgow said, “This looks like a subgroup of a subgroup type analysis based on small numbers of events ― I think there were only 77 hospitalizations among the 722 patients treated with an ACE inhibitor, and the Medicare Advantage subgroup was only 581 of those 722 patients.” “The hazard ratio had wide 95% CI [confidence interval] and a modest P value,” he added. “So yes, interesting and hypothesis-generating, but not definitive.”