Research sponsored by

Pfizer

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says patients taking high doses of Lipitor not only reduced so-called bad cholesterol below recommended levels but also had "significantly fewer" heart attacks and strokes vs. people taking low doses of Lipitor who cut their bad cholesterol to recommended levels.

The research, presented Tuesday at the American Conference of Cardiology conference in Orlando, Fla., showed the high-dose group had fewer heart attacks, strokes and hospitalizations for congestive heart failure.

But the study didn't answer all questions about the most effective heart care. For example, it revealed no statistically significant difference in heart-related deaths -- or in total deaths -- between the low-dose group and the high-dose group. In fact, there were slightly more nonheart-related deaths among the high-dose group.

In addition, the high-dose group had a significantly higher incidence (1.2% vs. 0.2%) of certain elevated liver enzymes, a signal for potential liver problems that doctors must monitor in people taking Lipitor and other cholesterol drugs known as statins. There was no significant difference among the test groups in cases of rhabdomyolysis, a rare and dangerous muscle-wasting disease.

Lipitor is the best-selling drug in the world; last year sales hit $10.9 billion.

The test of 10,000 patients known as Treating to New Targets, or TNT, was published concurrently online in the

New England Journal of Medicine.

The research ran five years and was conducted at medical centers in 14 countries. It compared people who took 80 milligrams of Lipitor daily vs. people who took 10 milligrams.

"Previous clinical trials ... have shown the outstanding ability of Lipitor at 10 milligrams to safely get patients to their goal levels and reduce the risk of cardiovascular events," said Dr. Joseph Feczko, Pfizer's chief medical officer, in a prepared statement. "TNT is the very first study to demonstrate even greater benefits lowering LDL (bad cholesterol) beyond recommended guidelines with Lipitor at 80 milligrams."

LDL, or low-density lipoprotein, is bad cholesterol. The recommended level is a score of 100 or lower. The high-dose group had an average score of 77; the low-dose group had an average score of 101.

Eighty milligrams of Lipitor daily for patients with stable heart disease "provides significant clinical benefit beyond that afforded by treatment with 10 milligrams," said the

Journal

article, whose lead author, and the TNT lead investigator, is Dr. John C. LaRosa, of the State University of New York Health Science Center. "The data confirm and extend the growing body of evidence indicating that lowering LDL cholesterol levels well below currently recommended levels can have clinical benefit."

In an accompanying editorial in the

Journal,

Dr. Bertram Pitt of the University of Michigan School of Medicine, said "clinicians will need to ask themselves how compelling the new information ... is for clinical practice and whether it is sufficient to change our current goals for LDL cholesterol levels in patients with stable coronary heart disease."

Pitt noted that although the number of heart disease-related deaths was reduced by 26 among high-dose Lipitor patients, the number of deaths from non-cardiovascular causes increased by 31. Although this finding "could be due to chance, it is a matter of concern," he said. Cancer was the leading cause of non-cardiovascular deaths in both groups. (Pitt has been a consultant for Pfizer,

AstraZeneca

and

Novartis

.)

"Until the safety and effectiveness of an 80-milligram daily dose

of Lipitor have been established, patients and their physicians will need to carefully weigh" the benefits of reducing cardiovascular risks "against the uncertainty of an increase in death from non-cardiovascular events," Pitt added. Doctors "need further reassurance as to the safety of this approach" before advocating a "major shift" in achieving lower bad cholesterol levels.

Shares of Pfizer slipped 19 cents, or 0.7%, to $26.99.