Evaluation of value of early and late intravenous thrombolytic therapy in acute myocardial infarction with rest Gated myocardial perfusion imaging

Objectives To evaluate the effects of early(within 6h after onset) and late(6-12h) intravenous thrombolytic therapy(TT) in acute myocardial infarction(AMI) with ^99mTc-MIBI rest Gated myocardial perfusion imaging(GMPI).

Methods 35 pts with AMI,30 males and 5 females, mean age 59.20±11.82 years. According to the starting time of the onset to ITT were divided into two groups: early TT group(ETTG) and late TT group(LTTG). Time from onset to thrombolysis of ETTG is 4.5±1.0 hours, the time of LTTG is 12.0±4.0 hours. Once the diagnosis of AMI is injected ^99mTc-MIBI 925MBq, then began to TT with intravenous drip urokinase 150U within 30min. We have the first rest GMPI after TT for 2 hours, the second rest GMPI after 1 week, nearly half of them for the third imaging after 2 weeks. The QGS calculated perfusion score with it 20-segment demarcation outling.

Results Based on ECG, clinical symptoms and signs, the 15 pts of ETTG in whom reperfusion was achieved, mean scores between the first and the second rest GMPI decreased from 24.57±11.34 before TT to 13.70±8.56 (P<0. 01), also 3 pts with not reperfusion, mean scores from 24.98±10.91 to 23.50±10.02 was statistically insignificant in 1 week(P>0. 05). The 11 pts of LTTG achieved reperfusion, mean scores decreased from 27.65±10.86 before TT to 16.76±9.67 (P<0. 01), 6 pts with not reperfusion, mean scores was statistically insignificant (P>0. 05). After TT for 2 weeks, the 14 pts whom reperfusion, EDV value obviously decline from 100.75±31.05ml to 93.69±30.76ml (P<0. 05), the 5 pts whom not reperfusion, EDV value remains high, and has a rising trend.

Conclusions The potential advantages of rest GMPI in AMI before and after thrombolytic therapy, which provide information for assessing the extent of improvement of myocardial ischemia, and an imaging basis for determining coronary artery reperfusion and evaluating left ventricular remodeling following AMI.