It may seem obvious that lowering LDL cholesterol would inevitably reduce the risk of heart disease. But drugs can be unpredictable. They tend to have many effects. A drug that ameliorates one risk factor might have other effects that offset the benefit.
On Friday, investigators reported the results of a highly anticipated trial of a PCSK9 inhibitor called evolocumab (brand name Repatha). This medication reduced LDL levels to an almost unfathomable 30 mg/dl from about 90 mg/dl on average, which is typically considered low.
Over about two years of study, the researchers found that the new drug, when added to statin therapy, further reduced the risk of heart attack or stroke by about 15 percent. For about every 70 people treated with the drug, one person benefited in this way. This is not far off the size of the benefit that statins provide.
So the drug works, which is good news for patients. And no safety concerns emerged. But the applause from heart experts has been muted, because expectations were so much higher. Their hope had been that drastically low LDL cholesterol levels would make it difficult — or even impossible — to have a heart attack.
Where does that leave someone contemplating whether they should add this drug to an existing regimen?
For people with a high risk of heart attack or stroke, there is now…