Correlation between enzymatic estimation of myocardial infarct size and myocardial perfusion defect using SPECT

ABSTRACT

In patients with acute MI correlation between quantitative estimation of infarct size from the marker enzymes and non enzymatic proteins with perfusion defect using thallium 201 can help in the early choice of management strategy. Concentrations of six-marker enzymes and non-enzymatic protein [CPK, CKMB, LDH, SGOT, alpha HBDH and HFABP] were assayed in serial samples from 12 patients with AMI. Quantitative assessment of infarct size was done by a model developed by Witteveen et al in 1975, a modification was done on the model for estimation of infarct size using HFABP as it overestimates the infarct size using the standard model. Myocardial perfusion defect study using SPECT was done within one week of onset of AMI. Correlation between the infarct size using these enzymes and HFABP with perfusion defect was significant for all except infarct size using peak SGOT. A nearly equal estimate in absolute terms was obtained on using all of total [CPK, LDH, alpha HBDH and HFABP applying the modified model]. Infarct size using CKMB and SGOT underestimates the infarct size, on the other hand infarct size using HFABP is overestimated on applying the standard model. Using peak value of HFABP and applying the modified model can give an early reliable estimate of infarct size within 2 hours of admission or 6 hours of onset of symptoms. Conclusions: Using a single peak value of HFABP at 2 hours from admission or 6 hours from the onset of symptoms and applying the modified model can give an early nearly reliable estimate of infarct size. This can be used for early risk stratification and for the early choice of management strategy