"If you are at low risk or intermediate risk for death with ACS, it doesn't matter whether you have your angiogram early or late, but if you are at high risk the early intervention strategy is far better," said Shamir R. Mehta, M.D., M.Sc., study author, director of interventional cardiology at Hamilton Health Sciences Corp. and associate professor of medicine at McMaster University, Hamilton, Canada.
About two-thirds of the patients in the study were in the low or intermediate risk groups. The study of 3,031 patients treated at 100 medical centers in 17 countries was a prospective comparison of the relative usefulness, safety and cost effectiveness of intervention as soon as possible (and within 24 hours) versus a delay of more than 36 hours after unstable angina (chest pain) or non-ST segment elevation acute coronary syndrome (ACS), a common type of heart attack.
For the primary endpoint, a composite of death, recurrent heart attack or stroke within six months, the researchers found no significant risk reduction (p value 0.15) in favor of early intervention. However, striking results emerged when the researchers compared patients based on their Grace Risk Score, a way of predicting the risk of dying within the next six months based on factors like age, other medical conditions, kidney function and a history of heart failure.
Among the 961 patients who measured >140 on the Grace Risk Score, the primary endpoint was seen in 21.6 percent of the late intervention group versus 14.1 percent of the high-risk patients, a 35 percent reduction in relative risk that was of high statistical significance (p value = 0.005), indicating a clear benefit for early coronary angiography and treatment, he said.
"This is by far, the largest study of ACS
|SOURCE American Heart Association|
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