Prevention of restenosis after coronary angioplasty: a pharmacological approach

Evaluations of drugs for the prevention of restenosis after human coronary angioplasty have been disappointing. Heparin failed to reduce restenosis in a randomized study in Atlanta, Georgia, in patients maintained on heparin for 24 h. A randomized study in the same centre compared acetylsalicylic acid to anticoagulation with coumadin. Restenosis was slightly but not significantly less frequent in patients on acetylsalicylic acid. An American multicentre randomized study comparing a combination of acetylsalicylic acid and dipyridamole to ticlopidine and to placebo revealed no difference in terms of incidence of restenosis. Dipyridamole alone shows no effect against acute or late coronary artery restenosis. Two calcium antagonists (diltiazem and nifedipine) did not significantly diminish restenosis in randomized trials. Neither did a thromboxane A2 inhibitor. Only eicosapentaenoic acid (EPA), an n-3 fatty acid, significantly reduced restenosis in a randomized study using a high dose. But the same compound proved ineffective in a similar study using a somewhat lower dose. Despite scientific evidence for the inefficacy of virtually all tested compounds, I do not know of a single institution that does not continue to discharge its patients after coronary angioplasty on one or several of them.