Antiplatelet therapy and progression of coronary artery disease: a placebo-controlled trial with angiographic and clinical follow-up after myocardial infarction.

ABSTRACT

INTRODUCTION: 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. METHODS: Quantitative coronary angiography of noninfarct arteries was performed 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 matching placebo. Follow-up angiography was scheduled at 1 year. RESULTS: On a per-patient basis, the change in minimal luminal diameter (MLD) was 0.00 mm in the aspirin/dipyridamole group (n = 76) and was 0.01 mm in the placebo group (n = 73). There was no difference between these groups in the changes in MLD (-0.02 mm; 95% CI -0.09 to 0.05), neither were there significant differences in mean luminal diameter and diameter stenosis. Progression (1 segment/patient with > or = 0.40 mm decrease in MLD) was seen in two thirds of patients and did not independently predict long-term death and/or reinfarction. CONCLUSION: In this placebo-controlled trial after STEMI, the combination of aspirin and dipyridamole did not affect noninfarct artery disease progression. Progression did not predict long-term clinical outcome.