SPONTANEOUS REGRESSION OF RESTENOSIS - AN ANGIOGRAPHIC STUDY

Objectives. This study was designed to examine the possibility that sp ontaneous regression in stenosis severity occurs over time in patients with restenosis after percutaneous transluminal coronary angioplasty. Background. The underlying mechanisms of restenosis are intimal hyper plasia and smooth muscle cell proliferation in response to vascular in jury, We hypothesized that the initial hyperplastic response is follow ed by dynamic remodeling and eventual spontaneous regression, leading to stabilization or a reduction in stenosis severity. Methods. A total of 136 patients participated in a trial to evaluate the efficacy of f ish oil versus placebo in preventing restenosis after angioplasty. One hundred thirteen patients completed this study with angiographic foll ow-up, of whom 56 had restenosis. Of these, 19 were asymptomatic and d id not undergo repeat revascularization; 15 consented in a separate st udy to undergo repeat angiography, which was performed 6 to 25 months later to assess the possibility of regression. Results. There was a si gnificant mean (+/-SD) decrease in lesion severity from 66.9 +/- 8.7% to 47.5 +/- 9.0% (p < 0.0001) and a significant mean increase in minim al lumen diameter from 0.91 +/- 0.31 mm to 1.44 +/- 0.35 mm (p < 0.000 1). No patient shelved progression of stenosis, but regression of rest enosis, defined as a decrease in minimal lumen diameter greater than o r equal to 0.2 mm, was noted in 12 of the patients. Conclusions. Altho ugh all 15 study patients were asymptomatic, similar changes may occur in symptomatic patients. A trial of medical therapy may be appropriat e in asymptomatic or mildly symptomatic patients before further interv entions. This strategy would avoid unnecessary invasive procedures, pr event a ''restenosis cycle'' and result in significant cost savings.