Researchers analyzed a data from the Myocardial Ischemia Reduction with Aggressive Cholesterol Lowering (MIRACL) trial. That study examined the effect of an early, rapid and profound reduction in cholesterol on further cardiovascular problems after a heart attack or chest pain, says lead author David D. Waters, M.D., chief of the division of cardiology at San Francisco General Hospital and professor of medicine at the University of California, San Francisco School of Medicine.
Between May 1997 and September 1999, 3,086 patients were randomly assigned to receive the cholesterol-lowering drug atorvastatin or a placebo within four days of hospitalization. Currently, most patients start cholesterol-lowering therapy several weeks after an acute coronary event. Previous research indicated other important treatments should be begun first in the hospital and that changes in diet be made to lower cholesterol before drugs, says Waters.
Stroke is a rare, but devastating complication of an acute coronary event. In this four-month study, less that two percent of patients had a stroke. Thirty-six patients had 38 strokes – 12 in statin-users, 24 in placebo-users. Three in the statin group and two in the placebo group had fatal strokes. There were three instances of hemorrhagic stroke, which is caused by bleeding into the brain rather than by a blocked blood vessel. All three hemorrhagic strokes were in the placebo group, helping to dispel a concern that statin treatment could increase the risk of hemorrhagic stroke, Waters says. Although statins have never been associated with increased hemorrhagic stroke risk, there has been concern about a possible link because several studies found an increased risk of bleeding stroke in one group of men with naturally low cholesterol levels, Waters says.
"An estimated 1 million to 2 million people a year suffer from acute coronary syndromes each year in the United States alone. So if these results are confirmed in future studies, an absolute reduction of stroke of this order means that many strokes would be prevented," he says.
An accompanying editorial agrees that lowering cholesterol immediately after a heart attack appears to reduce the risk for later stroke. However, the small number of patients who experienced a stroke in the MIRACL trial means that these results must be confirmed in larger studies, say the editorial authors Antonio M. Gotto, Jr., M.D., D. Phil., dean and professor of medicine at Weill Medical College of Cornell University in New York and John A. Farmer, M.D., chief of cardiology at Ben Taub General Hospital and associate professor of medicine at Baylor College of Medicine in Houston.
Waters' co-authors were Gregory G. Schwartz, M.D., Ph.D.; Anders G. Olsson, M.D., Ph.D.; Andreas Zeiher, M.D.; Michael F. Oliver, M.D.; Peter Ganz, M.D.; Michael Ezekowitz, M.B., Ch.B.; Bernard R. Chaitman, M.D.; Sally J. Leslie, Ph.D.; and Theresa Stern, Ph.D. MIRACL was supported by a grant from Pfizer, Inc.
CONTACT: For journal copies only,
please call: (214) 706-1396
For other information, call:
Carole Bullock: (214) 706-1279
Bridgette McNeill: (214) 706-1135