Clinical significance of persistently positive technetium-99m pyrophosphate myocardial scintigrams in patients with acute myocardial infarction

To evaluate the clinical significance of persistently positive technetium-99m pyrophosphate (sup(99m)Tc-PYP) myocardial scintigrams, sup(99m)Tc-PYP myocardial scintigrams were obtazined in 73 patients with acute myocardial infarction (AMI) during acute phase and chronic phase (37 days later in an average). Sixty-three of 70 patients (90%) had a positive scintigram in acute phase. At follow-up scintigraphy, 33% of patients had a persistently positive scintigram and the degree of sup(99m)Tc-PYP myocardial uptake was changed from localized pattern with marked intensity to diffuse pattern with faint intensity. Patients with persistently positive scintigrams were demonstrated to have severe myocardial damages as evidenced by large infarct size (max. LDH 3053 +- 958 IU/l, large size defect with thallium-201 myocardial scintigraphy) and marked left ventricular dysfunction (PADP 18 +- 7 mmHg, RIEF 28 +- 11%). Two patients with persistently positive scintigrams were expired. It is, thus, concluded that a persistently positive sup(99m)Tc-PYP myocardial scintigrams indicates the existence of progressive myocardial damage and accordingly this finding is of great use for assessing the prognosis of AMI. (author)