Scintigraphic quantification of myocardial necrosis in patients after intravenous injection of myosin-specific antibody.

Abstract

The Fab fragments of antimyosin antibodies, labeled with 9mTc, were used in the scintigraphic examination of 30 patients with myocardial infarction. The ability to detect necrosis and determine its extent from the antimyosin scan were compared with the results of quantitative regional wall motion analysis by contrast ventriculography at 10 to 14 days and 99mTc-pyrophosphate imaging. Antimyosin images recorded by planar and single photon-emission computed tomography (SPECT) delineated areas of myocardial necrosis in 27 of 30 patients (90%) compared with a 91% sensitivity of pyrophosphate in 21 of 23 patients. Infarct size was determined by both antimyosin and pyrophosphate SPECT images. Results by both techniques showed a significant correlation with computer-derived hypokinetic segment length (r = .79 for both, p = .002) and peak creatine kinase (r = .9 for both, p < .01). Although sensitivity for and correlations with markers of necrosis were similar with both techniques, infarct size by pyrophosphate SPECT was 1.7 times larger than infarct size by antimyosin SPECT (p < .01). Certain zones in the infarct area were differentially labeled; the nature and irreversibility of injury within these zones remains to be clarified. Circulation 74, No. 3, 501-508, 1986. WE PREVIOUSLY described a method for localizing and quantifying regions of myocardial necrosis based on the binding of radiolabeled myosin-specific antibodies to cells that have lost the integrity of their plasma membranes.",2 Unlike other methods that are dependent on blood flow, concentration of antibody in the center of an infarct is greater than that at the periphery, with antibody concentration inversely proportional to blood flow.

Targeted In Vivo Labeling of Receptors for Vascular Endothelial Growth Factor

“…One approach has been to radiolabel antibodies directed against diseasespecific epitopes. Radiolabeled monoclonal antibodies against myosin and major histocompatibility complex class II antigens have been used to detect myocardial infarction 15 and acute cardiac transplant rejection, 16 respectively. Atherosclerotic lesions in rabbits have been identified with radiolabeled antibodies or their Fab' fragments that bind to oxidized LDL 17 or proliferating smooth muscle.…”

Early postoperative reduction of monoclonal antimyosin antibody uptake is associated with absent rejection-related complications after heart transplantation.

“…Studies performed at 1-3 (n=97), [4][5][6][7][8][9][10][11] (n=39), [12][13][14][15][16][17][18][19][20][21][22][23] (n=46), and more than 24 months (n=65) showed a prevalence of abnormal antimyosin studies in each of the four periods of 95%, 77%, 65%, and 46%, respectively (p<0.0001) (Figure 2). In these periods, mean visual estimations were 1.95±0.7, 1.33±0.7, 1.15±0.7, and 0.9±0.7, and mean heart-tolung ratios were 1.93 +0.30, 1 In the 33 patients who were prospectively studied since transplantation, 170 antimyosin scans were sequentially performed (mean, 4.8±+ 1.9 scans per patient; range, 1-10 scans), and follow-up extended from 5 to 37 months (mean, 6 months).…”

“…In these periods, mean visual estimations were 1.95±0.7, 1.33±0.7, 1.15±0.7, and 0.9±0.7, and mean heart-tolung ratios were 1.93 +0.30, 1 In the 33 patients who were prospectively studied since transplantation, 170 antimyosin scans were sequentially performed (mean, 4.8±+ 1.9 scans per patient; range, 1-10 scans), and follow-up extended from 5 to 37 months (mean, 6 months). At 1-3 (n=96), [4][5][6][7][8][9][10][11] (n=38), [12][13][14][15][16][17][18][19][20][21][22][23] (n=24), and more than 24 months (n=12), prevalence of abnormal scans in each of the intervals was 95%, 76%, 58%, and 58%, respectively (p<0.0001). Mean values for visual estimation and heart-to-lung ratios in each of the intervals also decreased, to 1.95+0.7, 1.31+0.7, 1.08+0.8, and 0.9±0.9 and to 1.92+0.3, 1.72+0.23, 1.63+0.25, and 1.64+0.3, respectively (p<0.001).…”

Evaluating Microvascular Obstruction After Acute Myocardial Infarction Using Cardiac Magnetic Resonance Imaging and 201-Thallium and 99m-Technetium Pyrophosphate Scintigraphy

“…Previous reports suggested that 99m-Tc localizes in severely injured but still viable myocardium early after reperfusion. 24 Therefore, we assume that 99m-Tc PYP uptake represents calcium overload within severely ischemic cardiomyocytes after reperfusion therapy. We also found that a better WM status or an improvement of MO segments at follow-up is accompanied by a decrease in the DE extent.…”