In a small preliminary study, an experimental gene-editing treatment dramatically reduced cholesterol levels, perhaps permanently, after a single infusion, scientists reported Monday.

If confirmed in larger studies, researchers hope these findings could lead to a definitive solution for preventing heart disease in large numbers of people. Most gene therapies focus on rare diseases, but cardiovascular diseases kill nearly 800,000 Americans a year.

“We have these debates and new guidelines that suggest we should treat people earlier,” said Dr. John HP Alexander, a cardiologist at Duke University who was not involved in the study. “A curative therapy would change everything.”

The study, published in The New England Journal of Medicine, was an interim analysis of 35 patients in a trial that will include up to 85 participants. They all have genetically high levels of LDL cholesterol – the bad cholesterol – or suffer from heart disease.

In all 35 patients, a single infusion of the highest dose of the treatment reduced LDL cholesterol levels by up to 62 percent. This change has been maintained in a subgroup whose members were treated 18 months ago.

Next, a larger study will be carried out with 200 patients.

It is unusual for The New England Journal of Medicine to publish such a preliminary result. However, “it seems to work pretty well,” said Dr. Eric Rubin, editor-in-chief. Additionally, he noted that the trial represents an ambitious attempt to apply cutting-edge gene therapy to the leading cause of death in the United States.

However, “we need a lot more safety data,” said Dr. J. Michael Gaziano, director of preventive cardiology at the Boston Veterans Health System, who was not involved in the new study. The Food and Drug Administration (FDA) requires that all patients participating in gene therapy studies be monitored for 15 years.

Patients in the trial received an infusion containing a gene-editing “machine,” a tiny molecular factory coated in fat. These fat-coated particles travel through the blood directly to the liver, where they are absorbed by cells that eliminate the fatty layer.

The editing machine runs through the DNA of the liver cell until it finds its target, a gene called PCSK9. There it stops and deletes one DNA base from the gene, replacing it with another.

That simple change turns off the PCSK9 gene and prevents cells from producing the PCSK9 protein. Without it, the liver removes more LDL cholesterol from the bloodstream, thus keeping levels lower.

The study was led by Dr. Sekar Kathiresan, CEO of Verve Therapeutics, now a subsidiary of Eli Lilly. Dr Kathiresan, a cardiologist by profession, said his motivation came from his personal experience.

His grandmother, his father, his uncle and his brother all suffered heart attacks. His brother died of cardiac arrest at age 42, just after returning from a run.

Gene therapies for rare diseases have a multimillion-dollar cost. But Dr. Daniel Skovronsky, chief scientist at Eli Lilly, said that would not be the case if this treatment were to be approved.

“That’s not what we’re looking for here,” he said. “We are looking for a medicine that one day can be part of primary care.”

High LDL levels are perfectly treatable with a variety of medications, including classic ones such as daily statins. Among the most recent advances are injectable drugs that block the protein produced by the PCSK9 gene, achieving the same effect as gene editing.

But too many people can’t or won’t take the medications. Between one-third and one-half of patients stop taking cholesterol-lowering medications within a year of starting them, even people who have had heart attacks.

Kristy Faulkner, 45, of Guilford, Connecticut, is one of the people who need treatment but are reluctant to take a powerful medication. Heart disease runs in her family, and she suffered a heart attack at age 42.

“There’s a kind of internal denial, like I can’t take these medications every day of my life,” he said.

“I understand the importance,” she added, “and I feel ashamed.”

Her cardiologist, Dr. Erica Spatz of Yale University, hopes that Ms. Faulkner’s insurance will cover the cost of a PCSK9 inhibitor that only needs to be given every six months. Her medical history means “there is no margin for error,” Dr. Spatz said.

But a one-time gene editing treatment?

“This kind of therapeutic breakthrough could change everything for people like her,” Dr. Spatz said.

Alice Thomas, 64, of Lexington, North Carolina, wishes she could take cholesterol-lowering medications, but she can’t get them. His only income comes from Social Security, and although statins are inexpensive, he cannot tolerate them.

Her insurance did not approve injectable medications that could have helped her. He has suffered two strokes and, a few months ago, his LDL cholesterol level was dangerously high, reaching 190.

“I had nothing,” Ms. Thomas said. “Then I found out about this study.”

He received the infusion in Dr. Kathiresan’s trial on March 30. Two weeks later, his cholesterol level was 50.

“This is great,” he said. “Once and it’s over.”