Role of exercise testing in relationship to coronary artery bypass surgery and percutaneous transluminal coronary angioplasty.

Most patients who are considered candidates for coronary angioplasty should have objective evidence of myocardial ischemia confirmed before the procedure, if clinically possible. In patients with progressive unstable angina, for whom exercise testing is inappropriate, the location of transient resting ECG changes should be looked for on the 12-lead ECG. In clinically stable patients with 1-vessel coronary disease, a pre-PTCA exercise test without radionuclides would suffice for most patients. In the initial months after PTCA, persistence or the return of an ischemic response similar to that observed before the procedure would indicate restenosis. Disease progression in other vessels during the year after the PTCA procedure would be uncommon compared to the incidence of restenosis. In all other stable patients, exercise ECG should be combined with thallium-201 scintigraphy to provide a more useful evaluation of angioplasty results. If only a single vessel is dilated, the importance of the remaining coronary disease may be demonstrated and may influence the clinical decision as to whether further intervention is needed. Dilatation of occluded vessels is occasionally attempted in patients with multivessel coronary disease. The incidence of restenosis is slightly greater (40%) in the months after PTCA than in a stenotic nonoccluded vessel. Multilesion dilatation can also be associated with restenosis at more than one site, and the use of thallium scintigraphy may be helpful in assessing which region of the myocardium is ischemic. As dilatation is performed more frequently in patients with multivessel disease, coronary angiography will remain the 'gold standard' to answer questions about recurrence or progression of the disease, and against which to compare results of noninvasive tests. All exercise tests should be performed without cardioactive medication if possible, and the test should be a sign- or symptom-limited test. The elective exercise test in an asymptomatic individual after PTCA should be performed between 1 and 2 weeks to serve as a baseline for future follow-up. In patients who develop restenosis, symptomatic status will often suggest a PTCA failure. In asymptomatic patients or those with atypical symptoms, the exercise thallium study will often be useful.