“Fantastic,” said Dr. Sekar Kathiresan of the Broad Institute and Massachusetts General Hospital who studies the genetics of heart disease but had no part in the study. “A truly spectacular result for patients.”

Dr. Harlan M. Krumholz, a Yale cardiologist not associated with the study, said he wished there was a peer-reviewed journal article instead of a presentation of the results at a meeting — the data analysis was completed just last week — but, assuming the result holds up, “this is the result we were hoping for.”

At the same time, and by sheer coincidence, two other groups of researchers reported genetic studies that supported the trial’s conclusions. One, led by Dr. Brian A. Ference of Wayne State University School of Medicine found that gene mutations mimicking the effect of ezetimibe and ones mimicking the effect of statins had the same effect on heart disease risk for a given reduction in cholesterol. The implication, he said, is that “lowering cholesterol with ezetimibe, or a statin, or both, should each lower the risk of heart disease by about the same amount.”

The other, led by Dr. Kathiresan, examined mutations that disabled one copy of the cholesterol absorption gene, producing the same effect as ezetimibe. The result was a 50 percent reduction in cholesterol absorption — the same as produced by ezetimibe — and an LDL reduction of 12 milligrams per deciliter of blood, also the same amount as produced by ezetimibe. The mutation, which gave people the equivalent of a lifelong exposure to ezetimibe, reduced the heart attack rate by 50 percent.

The study’s results are making many wonder about the latest cholesterol guidelines, which did not mention any drug other than a statin. And instead of providing goals for cholesterol levels, they simply advised those at high risk to take a statin.

“The guidelines didn’t say they didn’t believe in cholesterol, but they made it clear that the evidence is for a statin, not for any agent that lowers cholesterol,” said Dr. Eugene Braunwald, a study chairman who is a cardiologist at Brigham and Women’s and a longtime leader in the field.

Dr. Neil Stone, the head of the guidelines committee and a cardiologist at Northwestern University, has a more nuanced view of what the guidelines say, but adds that the study result “gives doctors another option if they have a patient who can’t tolerate a high-intensity statin.”