HYPERSENSITIVITY OF HUMAN CORONARY SEGMENTS TO ERGONOVINE 6 MONTHS AFTER INJURY BY CORONARY ANGIOPLASTY - A QUANTITATIVE ANGIOGRAPHIC STUDYIN CONSECUTIVE PATIENTS UNDERGOING SINGLE-VESSEL ANGIOPLASTY

Objective Multiple studies have been designed to analyse restenosis an giographically but few have studied the aso-reactivity of coronary seg ments subjected to angioplasty a few months before. In the present stu dy we analysed, with use of a quantitative angiography, the vasoreacti vity of previously dilated segments to graded doses of ergonovine and of isosorbide dinitrate. Patients Fifty consecutive patients undergoin g follow-up angiography 6 months after a single coronary angioplasty p rocedure were studied. Results The vasoconstrictor response at dilated segments (-19.3 +/- 3.0%) was significantly greater than at control p roximal and distal sites in dilated (-7.3 +/- 1.1%, -11.0 +/- 2.9%) an d non-dilated (-9.1 +/- 1.3%, -8.3 +/- 2.2%) vessels for the lowest do se of ergonovine (100 mu g). The constrictor response to 100 mu g ergo novine (-20.2 +/- 5.3%) at restenosed segments ( > 50% stenosis, n = 1 8) was similar to that (-18.8 +/- 3.8%) at non-restenosed sites (n = 3 2). In contrast, the degree of constrictor response was similar in all segment including dilated segments for the highest dose of ergonovine used. All segments dilated significantly after intracoronary injectio n of isosorbide dinitrate. Conclusion Our results demonstrate hypersen sitivity of the dilated site to ergonovine 6 months after angioplasty at both restenosed and non-restenosed sites. This response may reflect partial dysfunction of endothelium that has regenerated after injury or hypersensitivity of vascular smooth muscle cells at the site of art erial injury.