Comparison in acute myocardial infarction of anisoylated plasminogen streptokinase activator complex versus heparin evaluated by simultaneous thallium-201/technetium-99m pyrophosphate tomography

Abstract

In a subgroup of 45 patients with acute myocardial infarction (AMI) from the German multicenter trial of anisoylated plasminogen streptokinase activator complex (APSAC) (n = 20) versus heparin (n = 25), simultaneous thallium (Tl)-201 technetium (Tc)-99m pyrophosphate (PYP) tomography was initiated to elucidate a possible benefit of APSAC over heparin. Findings in the 2 treatment groups were similar with respect to Tl-201 defect score, relative scintigraphic infarct size, and in keeping with the main group coronary artery patency, global ejection fraction and maximal creatine kinase level. However, 2 different Tl-201/ Tc-99m PYP accumulation patterns within the area of infarction (homogeneous, group A; inhomogeneous, group B) were identified. Both treatment groups were similar with regard to the frequency of the homogeneous and inhomogeneous pattern. In comparing the 2 accumulation patterns, creatine kinase peaked earlier in group A than in group B, and global left ventricular ejection fraction was significantly higher in group A than in group B. In Group A, 30 of 31 patients and in group B 7 of 11 patients had a patent infarct-related vessel (p < 0.025). Tl-201 defect score was lower in group A than in group B. Likewise, relative size of the infarction as determined from Tc-99m PYP images was significantly lower in group A than in group B. Fifteen patients experienced candiogenic shock or severe heart failure. Patients in group B had a higher incidence of these in-hospital complications than patients in group A (92 vs 12%, p < 0.0005). Scintigraphic infarct size and Tl-201 defect score were greater in patients with the aforementioned clinical events. In addition to scintigraphic infarct size and coronary patency, the Tl-201/Tc-99m PYP accumulation pattern was useful in differentiating patients with from those without an adverse clinical course. It is concluded that Tl-201/Tc-99m PYP tomography is a promising tool for evaluating AMI and predicting the clinical course of patients.