Despite the high hopes for the new tests, there are many questions.

Some critics say that a focus on treating younger people is misplaced because they may not comply with taking a statin or another drug for the rest of their lives. It can be difficult for young people to focus on possible threats to their health decades in the future, and some of Dr. Rader’s patients have put off even getting polygenic risk tests after he recommends them.

The real need, these critics say, is with the huge group of older people who need cholesterol-lowering treatment but are not getting it, or who are abandoning their prescriptions. In one study, about 40 percent of people 65 and older who had a heart attack and need lipid-lowering medications for the rest of their lives stop taking statins within two years.

Others, like Dr. Rita F. Redberg, a cardiologist at the University of California, San Francisco, the editor at JAMA Internal Medicine and a critic of the overuse of statins, is concerned that polygenic risk scores could introduce new problems.

“There is a lot of downside to labeling people with a disease,” she said.

The label, she added, “inexorably leads to tests and a search for treatments.” And, she said, “because the person, who now has become a ‘patient,’ is asymptomatic, more tests and possible treatments in most cases will not make the person feel any better.”

People can go from thinking of themselves as healthy to thinking of themselves as someone with a disease. “Now, whenever they experience the common aches, pains and twinges of life, they wonder if it is because they have this ‘disease,’” Dr. Redberg said. “And they may then go to the doctor or even emergency room for things they would not have previously. And that also will lead to more tests and procedures, with their attendant risk of harms.”