Clinicopathologic study of persistently positive technetium-99m stannous pyrophosphate myocardial scintigrams and myocytolytic degeneration after myocardial infarction.

Abstract

In a select series of 46 patients studied by serial myocardial scintigraphy, 19 (41%) retained persistent, usually low grade (2+) positive 99mTc stannous pyrophosphate (99mTc-PYP) myocardial scintigrams for at least 3 mo. after acute myocardial infarction. The 1 major difference between patients with positive and negative postinfarct 99mTc-PYP myocardial scintigrams was a more symptomatic postinfarct course in the former group, characterized by severe angina pectoris in 16 of 19 patients and by severe congestive heart failure with angina in 3 patients. In a separate clinicopathologic series of 7 patients persistently positive 99mTc-PYP myocardial activity was associated with prominent myocytolytic degeneration involving muscle cells which had survived initial episodes of infarction in 5 patients (3 with ventricular aneurysms) and with extensive myocardial fibrosis in 1 patient with recurrent angina pectoris. One patient with a negative post-infarct 99mTc-PYP myocardial scintigram had transmural fibrosis without residual myocardium in a resected ventricular aneurysm. A persistently positive 99mTc-PYP myocardial scintigram frequently correlates with progressive myocardial damage and muscle loss, and this scintigraphic finding may be an important prognostic indicator of a complicated and symptomatic postinfarct clinical course.