MONDAY, Nov. 17, 2014 (HealthDay News) -- Driving "bad" LDL cholesterol down to extremely low levels with a combination drug appears to significantly reduce heart attacks and strokes in high-risk patients with clogged arteries, a new study found.
Patients experienced fewer heart attacks and strokes when taking Vytorin, a drug that combines a cholesterol-lowering statin called simvastatin with a non-statin medication called ezetimibe, said principal investigator Dr. Christopher Cannon, a cardiologist at Brigham and Women's Hospital in Boston and a professor at Harvard Medical School.
Vytorin reduced LDL cholesterol levels in patients to just under 54 milligrams per deciliter (mg/dL) of blood. That's far below where cholesterol levels ended up with statin therapy alone -- 69 mg/dL, according to the researchers.
This is the first study to show that reducing bad cholesterol by combining statins with non-statin cholesterol-lowering drugs can better prevent heart attacks and strokes than treatment with a statin alone, according to Cannon.
"There is a lot of evidence that demonstrates that low cholesterol is better, and our findings suggest that even lower is even better," Cannon said.
Findings from the study were presented Monday at the American Heart Association annual meeting in Chicago. Study results presented at meetings are generally considered preliminary until they've been published in a peer-reviewed journal.
The U.S. Food and Drug Administration approved Vytorin in 2004, but up to now studies have failed to prove that either the combination drug or its non-statin component, ezetimibe, help prevent heart attacks and strokes.
Despite this, doctors regularly prescribe ezetimibe (Zetia) or Vyortin, particularly for patients who suffer side effects from high doses of statins, said Dr. Lori Mosca, a professor at Columbia University Medical Center and director of Preventive Cardiology at New York-Presbyterian Hospital.
"Our hand was forced," said Mosca, who has been prescribing ezetimibe for more than a decade. "When you don't have other options, you have to use your own judgment in high-risk patients. We see a lot of patients who are intolerant of statins, and if they can't take statins, I have this option."
Based on the study, Vyortin's maker, Merck & Co., announced plans to submit the data to the FDA in mid-2015 to support a new indication for use of the drug in reducing the risk of heart attack and stroke.
Statins like simvastatin (brand name: Zocor) block cholesterol production in the liver. Ezetimibe works in a different way, by reducing the body's absorption of cholesterol in the intestines from food sources. It was expected that combining the two would lower bad cholesterol levels even more than statins alone.
The study, called IMPROVE-IT, took place at nearly 1,200 centers in 39 countries. It enrolled more than 18,000 patients with clogged arteries who were 50 or older, according to the study. The researchers recruited the study volunteers within 10 days of hospitalization for a heart attack or unstable angina. They were followed for an average of about six years, according to the study.
The researchers compared how well some did with Vytorin versus others taking just Zocor.
Researchers found that people taking the combination drug had a 6.4 percent lower combined risk of subsequent heart attack, stroke, heart-related death and hospitalization for heart problems.
Both heart attacks and nonfatal strokes were reduced by 14 percent, according to the study. Researchers reported that approximately two cardiovascular events were prevented in the trial for every 100 patients treated, with the difference driven by reductions in heart attack or stroke.
However, deaths from heart disease overall were about the same in both groups.
"Our findings suggest that, among this population of patients, we may want to consider changes to our clinical guidelines, which might include an LDL cholesterol target of closer to 55, or lower," Dr. Eugene Braunwald, co-study chair and founding chairman of the TIMI Study Group at Brigham and Women's Hospital, said in a hospital news release.
Vytorin also proved to be safe, producing about the same amount of side effects as Zocor alone.
"That's what I'm most impressed with," said Dr. Neil Stone, a professor of cardiology at Northwestern University School of Medicine.
Mosca said the trial's results are "very exciting news for the field of preventive cardiology. This has really confirmed the central importance of lowering LDL in preventing heart disease."
Both Stone and Mosca said that in day-to-day practice, they likely would start a person on low-cost statins and then move to the combination therapy if the person developed side effects or did not respond to even high doses of statins.
For more information on cholesterol levels, visit the American Heart Association.