The popular cholesterol-reducing drug Lipitor made by Pfizer does not prevent obstruction of the heart valve that leads to the aorta, the body’s largest artery, according to study findings published in The New England Journal of Medicine.

In a study conducted to determine whether the drug, also known by its generic name atorvastatin, did more than just reduce cholesterol, doctors found that Lipitor failed to prevent obstructions that can keep the heart from pumping blood adequately.

The condition, known as calcified aortic stenosis, occurs when a key heart valve narrows or becomes blocked, preventing the heart from pumping blood properly and can manifest itself in spite of reductions of cholesterol levels, according to the study.

Surgery is usually required to fix it.

Aortic stenosis affects 3 percent of adults over 75, making it the most common valve defect in North America and Europe and occurs gradually over several decades. By the time symptoms appear, surgery is typically needed to repair or replace the valve.

As part of the study, 155 volunteers with signs of calcified aortic stenosis were given a placebo or Lipitor, which like other drugs known as statins slow the narrowing of small heart arteries caused by heart disease.

After a little more than two years, the team led by Joanna Cowell of Royal Infirmary in Edinburgh found that the drug brought cholesterol levels down as expected but produced no real improvement as far as obstructions are concerned.

“Aortic stenosis progresses despite intensive reductions in serum cholesterol concentrations,” the Cowell team concluded.

The study was funded in part by an educational award from Pfizer, a grant from the British Heart Foundation and the Welcome Trust Clinical Resource Facility in Scotland.

In journal editorial, Raphael Rosenhek of the Vienna General Hospital in Austria agreed, saying that prescribing statins “is not justified” unless a patient has another, more established, reason for taking the medicine.