Newswise — Treating heart-attack patients earlier with a more aggressive regimen of cholesterol-lowering medicines may help diminish their chances of sustaining more complications later or dying after their heart attack, researchers at UT Southwestern Medical Center at Dallas have found.
The findings, published online today by The Journal of the American Medical Association, show benefits of treating patients who have recently suffered acute coronary syndromes with higher doses of the cholesterol-lowering drugs called statins soon after they experience heart-attack symptoms.
Dr. James de Lemos, assistant professor of internal medicine at UT Southwestern, is lead author of the second of a two-part, collaborative international study called the Aggrastat to Zocor study, or A to Z study. Dr. Michael Blazing of the Duke Clinical Research Institute presented the study Aug. 30 at the European Society of Cardiology meeting in Munich, Germany.
The primary objective of the first phase or the "A" phase was to assess the safety and effectiveness of two different forms of clot-preventing drugs " enoxaparin and unfractionated heparin " in treatment following heart attacks.
The second, or "Z" phase, evaluated two different strategies of treating patients with cholesterol-lowering medicines.
In the past, Dr. de Lemos said, heart-attack patients were stabilized for several weeks or months and placed on low-cholesterol diets before physicians intervened with statin drugs.
"Earlier medical protocols called for patients to receive lower dosages of statins later following a heart attack," said Dr. de Lemos, an investigator in the Donald W. Reynolds Cardiovascular Clinical Research Center at UT Southwestern. "We observed trends that suggested an earlier, more intensive cholesterol-lowering regimen was better than a delayed, less-aggressive regimen."
The trial " which enrolled patients between December 1999 and January 2003 " followed 4,500 patients at 322 medical facilities spanning 41 different countries. Half of the trial participants received higher dosages of statin drugs soon after a heart attack. The second group was given lower dosages of the same medicines after a longer recovery time following a heart attack.
Patients given statin drugs earlier showed modest improvement in the rate of subsequent death, congestive heart failure, heart attack and stroke compared with patients who received a later start of a lower-dose statin regimen.
According to the study, 14.4 percent of patients in the group that got higher dosages of statins soon after a heart attack suffered other cardiac events such as heart attacks and strokes compared to 16.7 percent of patients receiving later intervention with lower dosages of the cholesterol-lowering drugs.
"Until recently, little information was available about the timing of initiating statin drugs after a heart attack," Dr. de Lemos said. "The findings from the A to Z trial suggest that statins can be initiated earlier and in dosages well above the typical starting dose."
Dr. de Lemos also warned that statin drugs must be closely monitored and the dose decreased or discontinued if side effects such as muscle weakness occur. Muscle pain and weakness (myopathy) is an important side effect of statin drugs and was observed in 0.4 percent of patients receiving the highest dose of simvastatin.
Other investigators included Dr. Eugene Braunwald of Brigham and Women's Hospital in Boston, the paper's senior author; researchers from Duke Clinical Research Institute; the University of Edinburgh in Scotland; Green Lane Hospital in Aukland, New Zealand; the University of Montreal and Aker Hospital in Oslo, Norway.
The study was supported by a grant from Merck & Co.