In 507 out of a series of 972 patients referred consecutively to coronary angiography (CA) for stable angina pectoris, preceding "blinded" myocardial perfusion scintigraphy (MPS) demonstrated normal perfusion in 51%, reversible defects in 40%, and fixed defects in 9% of patients. CA showed insignificant findings in 49% and in 41% of the entire series. Of 168 revascularised patients, no more than 74% had reversible perfusion defects with MPS. On this basis it could be estimated that almost half of catheterizations and nearly one fifth of revascularisations were "superfluous".