Percutaneous transluminal coronary angioplasty in patients with silent myocardial ischemia during exercise testing.

Silent myocardial ischemia was present in 50 of 507 patients undergoing PTCA. Of these patients, five had type 1 (asymptomatic with no previous myocardial infarction), 27 had type 2 (asymptomatic after myocardial infarction) and 18 had type 3 silent myocardial ischemia (angina present in addition to silent episodes). Ischemia was documented in all patients in the exercise ECG, in 18 patients with thallium scintigraphy and in four with radionuclide ventriculography. The indication for PTCA was considered established in patients with type 1 silent ischemia based on ECG changes in the presence of high grade stenosis of the left anterior descending artery under the assumption of improved prognosis. The fact that patients with myocardial infarction have a poorer prognosis in the presence of ST-segment depression served as the basis for the indication for PTCA in type 2 patients. In type 3 patients, PTCA was carried out to ameliorate the symptomatic as well as asymptomatic episodes of ischemia. The follow-up period averaged 12 +/- 6 months. The primary rate of success was 92% with no differences between the groups. There were no complications in type 1 and type 2 patients; in two patients with type 3 silent ischemia, immediate bypass surgery was carried out due to acute occlusion of the dilated vessel. One patient in the latter group had myocardial infarction in the region perfused by the dilated vessel four months after the procedure. The angiographically-documented rate of restenosis was 33% in type 1 patients, 26% in type 2 and 40% in type 3 patients.(ABSTRACT TRUNCATED AT 250 WORDS)