Efficacy of rheolytic thrombectomy in early versus late myocardial infarction.

Background: Rheolytic thrombectomy has been used successfully to treat acutely occluded lower-limb vessels, dialysis grafts, intrahepatic portosystemic shunts, and diseased native coronary vessels and saphenous vein grafts. Few studies, however, have examined the efficacy of rheolytic thrombectomy in the acute myocardial infarction (AMI) setting. We sought to determine the efficacy of the AngioJet Rheolytic thrombectomy catheter (Possis Medical, Minneapolis, MN, USA) in patients presenting with AMI either before or after 12 hours of onset of symptoms.

Methods: Procedural and angiographic data on 61 consecutive patients (January 2003-December 2003) who presented with an AMI and had rheolytic thrombectomy with the AngioJet catheter performed were reviewed. Coronary flow was assessed with thrombolysis in myocardial infarction (TIMI) frame counts (TFCs). Of the 61 patients studied, 40 had AngioJet performed within 12 hours and 21 had it done after 12 hours from the onset of symptoms. Procedural success was measured by TFCs measured before and after the procedure and was defined as a change in the TFC of >or=50%. Statistical significance was considered at a P value of <0.05.

Results: Procedural success was achieved in 75% of the patients in the early presentation group (within 12 hours) and 0% of the patients in the late presentation group (after 12 hours). TFC values were statistically different (P<0.001) in the early group, but not significant (P>0.1) in the late thrombectomy group.

Conclusion: Rheolytic thrombectomy with the AngioJet catheter is more effective in terms of improvement in coronary blood flow as assessed by TFCs when used less than 12 hours after the onset of clinical symptoms suggestive of AMI.