Abstract 14998: Thromboaspiration in Acute Myocardial Infarction. Is it Always Necessary ?
Background: Thromboaspiration (TA) is recommended for all Pts undergoing primary PCI for acute myocardial infarction (AMI) with improvement in reperfusion and clinical outcomes. We hypothesized that there may be some Pts with low thrombus burden who do not require TA.
Methods: We compared myocardial reperfusion using post-PCI cardiac MRI and ST segment resolution in consecutive Pts presenting with AMI within 12 hours of symptom onset. Pts were randomized to either systematic or angiography guided TA prior to coronary stenting. Angiography guided TA was performed if TIMI flow was 0 or 1 and/or a moderate or large thrombus was evident. ST segment resolution>50%, TIMI flow, myocardial blush grade and gadolinium enhanced cardiac MRI were used to assess myocardial reperfusion.
Results: 156 Pts presenting with AMI between September 2008 and April 2010 underwent systematic (n=66) or angio-guided (n=90) TA. There were no significant differences in age (6215 years), diabetes (17%), previous PCI (7%), anterior MI (44%), shock (9%) or time to presentation (90 vs. 87 mins, p=0.89). TA was performed in 47/90 (52%) Pts in the angio-guided group. The magnitude of ST segment resolution >50% was similar between the two groups (80 vs.87% for systematic and angio-guided respectively, p= 0.27) as was final TIMI 3 grade (87 vs. 79% respectively, p=0.23) and myocardial blush grade 2–3 (76 vs. 66% respectively, p=0.17). Cardiac MRI was performed 2 to 4 days after PCI (median 3 days). The % of microvascular obstruction was higher in the systematic TA group compared with the angiography guided group (6.6 vs. 3.2%, p=0.03). There were no differences in LV function or volumes.
Conclusions: Angiography guided TA produced similar angiographic and ECG endpoints to systematic TA suggesting that in selected Pts with TIMI 2–3 flow and a small thrombus burden, it may be possible to avoid TA. Despite systematic TA in Pts with high thrombus burden, there is a significantly higher level of subsequent microvascular obstruction which may reflect higher distal micro-embolization during the procedure.
- © 2010 by American Heart Association, Inc.