NEW ORLEANS -- How low should cholesterol go? For victims of recent heart attacks, the answer appears to be rock bottom.
A major study released Monday found that especially aggressive treatment with statin drugs, intended to drive cholesterol far below current standards, prevents new heart problems and saves lives.
These drugs are already a cornerstone of cardiac care, routinely prescribed for heart attack victims. However, the new results suggest doctors should opt for high doses of the most powerful brands to give recently discharged heart patients the best chance of survival.
"It's a lifesaving strategy and will become a huge paradigm shift in the treatment of patients with high cholesterol," predicted Dr. Steven Nissen of the Cleveland Clinic.
For several years, federal guidelines have recommended bringing down heart attack patients' levels of LDL, the bad cholesterol, below 100. To test whether this is far enough, doctors compared two strategies -- moderate doses of an older statin versus high doses of a more powerful newer one.
The older drug, Pravachol, dropped patients' LDL by almost one-quarter to 95. But the newer one, Lipitor, cut it in half to just 62.
The lower cholesterol made a difference. After two years of follow-up, 26 percent of those getting Pravachol had died or experienced a variety of other ill events, including new heart attacks, bypass surgery, rehospitalization for chest pain or strokes. The same happened in 22 percent on Lipitor.
The benefits appeared especially important for women. Their risk of these bad outcomes fell by seven percentage points.
"We have very big news in the treatment of cholesterol," said the study's director, Dr. Christopher Cannon of Boston's Brigham and Women's Hospital. Heart attack "patients going home from the hospital beginning today need to be treated with more intensive cholesterol-lowering."
Doctors caution that it is still too soon to say whether the same is true for heart patients who have not had recent heart attacks. Several studies are underway to see if they, too, benefit from getting their LDL far below 100.
Nevertheless, Cannon and others said the LDL goal for recent heart attack patients should be lowered, and soon. Dr. Thomas Pearson of the University of Rochester, who helped draw up the federal guidelines several years ago, said the 100 target was a guess based on very early research data.
"It may need some improvement," Pearson said. "Now we are getting the science, and that's really exciting."
Cannon's study is the second in recent months to show the importance of no-holds-barred cholesterol-lowering. An almost identical comparison, directed by Nissen, found that those getting Lipitor also had less clogging in their heart arteries.
The latest study involved 4,162 people who were randomly assigned to statin treatment within 10 days of heart attacks or severe chest pain episodes. They got either 40 milligrams a day of Pravachol or 80 milligrams of Lipitor, the highest approved doses of both drugs when the research started.
Nissen's study, released in November, was sponsored by Lipitor's maker, Pfizer, while the latest was underwritten by Bristol-Myers Squibb, which makes Pravachol.
Cannon released the results at a meeting in New Orleans of the American College of Cardiology. It will be published in the April 8 issue of the New England Journal of Medicine.
In a journal editorial, Dr. Eric Topol of the Cleveland Clinic called the latest finding "a major surprise," in part because the superiority of the stronger statin became obvious within a month of the start of treatment.
Topol said 36 million Americans should be on statins, though only a third that many actually are. Nevertheless, statins are the biggest-selling category of prescription drugs at $12.5 billion in the United States each year.
The more powerful statins carry a slightly higher risk of side effects and are more expensive. Topol noted the Pravachol dose used in the study costs about $900 a year, while Lipitor costs $1,400.
Dr. Andrew Bodnar, head of medical affairs at Bristol-Myers Squibb, said until more studies are done, "doctors should reserve judgment about the general coronary disease population." He noted abnormal liver enzymes were more common in patients on Lipitor in the latest study and said Pravachol "has an unsurpassed safety record."
Another study at the conference tested whether more victims of congestive heart failure should get implanted defibrillators. Earlier studies showed a benefit in the severest cases, but the new one extended that to more moderate disease, a category that includes between 1 million and 2 million Americans.
After almost four years of follow-up, there was a 23 percent reduction in death in those getting defibrillators. The study, conducted on 2,521 patients, was directed by Dr. Gust Bardy of the University of Washington and financed by the National Institutes of Health.