Aggrenox® treatment does not affect non-infarct artery disease progression

January 2007

In patients after ST-elevation myocardial infarction (STEMI), antiplatelet therapy reduces subsequent cardiac events, which are often attributed to recurrent thrombosis with (sub) total occlusion in the infarct-related artery. Whether antiplatelet therapy influences the often subclinical process of coronary disease progression in noninfarct arteries has not been reported.

Dr. Dieker and his collegagues from the Department of Cardiology, Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands, focused the concern that antiplatelet therapy could be related to the progression of coronary artery diseases.

The authors performed quantitative coronary angiography of noninfarct arteries on paired cine-angiograms of 149 patients from fibrinolytic trials who had a patent infarct-related artery 3 to 4 weeks following STEMI and who were randomized to either continue the daily combination of 50-mg aspirin and 400-mg dipyridamole or to take a matching placebo. Follow-up angiography was scheduled at 1 year.

On a per-patient basis, the investigators detected a change in minimal luminal diameter (MLD) of 0.00 mm in the aspirin/dipyridamole group (n = 76) and of 0.01 mm in the placebo group (n = 73). There was no difference between these groups in the changes in MLD, nor were there significant differences in either the mean luminal diameter or in the diameter stenosis. Progression was seen in two thirds of patients and did not independently predict long-term death and/or reinfarction.

The authors concluded that in this placebo-controlled trial after STEMI, the combination of aspirin and dipyridamole did not affect noninfarct artery disease progression. They pointed out that progression did not predict a long-term clinical outcome.