A study testing the use of AngioJet rheolytic thrombectomy prior to direct stenting of the infarct-related artery in patients with acute MI has shown that mechanical thrombectomy was associated with more frequent ST-segment resolution， but there was no improvement in scintigraphic infarct size and other surrogate markers of myocardial reperfusion.
　　There are several randomized trials assessing the efficacy of embolic protection or thrombectomy devices in improving myocardial reperfusion and metanalyses derived from them have conflicting results， however only two studies used the rheolytic thrombectomy (RT) device with contradictory outcomes. One of these trails was JETSTENT， a randomized， multicenter， international， two-arm， prospective study， in which 501 patients were randomly assigned to RT before direct stenting or to direct stenting alone， from December 2005 to September 2009. Results of this trial were presented in the Late Breaking Trials Session of CIT 2011 by Dr Alfredo Rodriguez， Buenos Aires.
　　Patients were eligible if they presented with STEMI within 12 hours of symptom onset and had a thrombus grade 3 to 5 detected by angiography. The co-primary end points of the study were early ST-segment resolution， defined as >50% ST-segment-elevation reduction at 30 minutes and infarct size at one month. Secondary end points included major adverse cardiovascular and cerebrovascular events (MACCE) at one， six and twelve months.
　　ST segment resolution was more frequent in the RT arm as compared with the DS alone arm (85.8% vs 78.8%， P=0.043) while no differences were shown in the other surrogate end points (infarct size， for example， was not different between the two treatment arms). Although the ST-segment resolution end point achieved statistical significance by conventional measures (P＜0.043)， it did not meet the predefined value of 0.025， which is the standard value for a study including two co-primary end points. No major procedural complications occurred in the RT arm， whereas one patient in the DS alone arm had a coronary perforation. One month MACE rate was 3.1% in RT arm vs. 6.9% in DS arm (P=0.05) and this difference between groups increases at 6 months (11.2% vs. 19.4%， P=0.01) and maintained at 12 months (14.9% vs 22.7%， P=0.03). One year Kaplan Meier analysis for freedom from MACE were 85.2 ± 2.3% for the RT arm， and 75 ± 3.1% for the DS alone arm (P=0.009).
　　Multivariable analysis showed randomization to rheolytic thrombectomy to be an independent predictor of ST-segment resolution and MACE， with ST-segment resolution also strongly associated with the occurrence of death and MACE.
　　Although the primary efficacy end points were not met， the results of this study support the use of RT before infarct artery stenting in patients with AMI and evidence of coronary thrombus， however the routine use in AMI should be confirmed by larger trials. The conclusions drawn by the study authors were that AngioJet rheolytic thrombectomy before direct IRA stenting as compared to direct stenting alone is associated with better myocardial reperfusion (higher rate of early STR) and improved 6-month clinical outcome (lower MACE rate)， and that the results of the JETSTENT trial support the routine use of AngioJet rheolytic thrombectomy in AMI patients with evidence of thrombus.
　　The panel discussion after the presentation acknowledged the usefulness of this procedure and recognized that the JETSTENT results were more encouraging than a previous study， but remained limited by small size and questioned the conclusion that routine usage of rheolytic thromboectomy was indicated. The quality of published results could be put down to better operator skill and/or a better trial protocol.