1. ‘SMASH IT!’ Mark Mason Interventional Cardiologist Harefield Hospital
Royal Brompton and Harefield NHS Trust

2. Background
Coronary occlusion in AMI comprises a variable amount of thrombus
Evidence suggests that the degree of thrombus burden has an influence on prognosis (JACC 2007;50:573-83)
Simply balloon dilating and stenting seems counter-intuitive in this context
Do mechanical devices offer any greater thombus clearance than simple aspiration devices, and do they confer any clinical benefit?

3. ThromCat ‘Smash and suck’ type device
High pressure jets ‘smash’ and internal ‘Archimedes screw’ draws in the debris
Doesn’t require large permanent console- pack contains all that’s needed (other than some saline)

4. ThromCat
Safety study presented at EuroPCR demonstrating safety and efficacy
No randomised controlled trials
Relatively easy to use (I said relatively!)
Good anecdotal results

5. X-Sizer ‘Suck and smash’ type device
Helical cutter in tip generates a vacuum and then acts as an ‘Archimedes screw’ to break up the thrombus and draw it in
Again, no large console- all required equipment contained in disposable pack

6. X-Sizer Randomised controlled data available-
X AMINE ST trial (JACC 2005;46(2):246-52):
201 pts with AMI randomised to X-Sizer vs. conventional PCI
Significantly higher overall ST resolution and >50% ST resolution
Significant reduction in distal embolisation
No difference in TIMI score, myocardial blush, or 6 month event rates

7. Angiojet ‘Smash and suck’ type device
Requires large permanent console with additional disposable catheters

8. AngioJet Catheter- Mechanism of Action
Saline jets travel backwards at half the speed of sound to create a low pressure zone.
Thrombus is drawn into the catheter where it is fragmented by the jets and evacuated from the body.

9. Angiojet Data variable- In the Angiojet group! WHY?
AiMI trial (JACC 2006;48(2):244-52)
Angiojet vs. conventional PCI:
Higher final infarct size
Lower TIMI 3 rate
Higher MACE
Higher 30-day mortality
In the Angiojet group!
WHY?
Patients enrolled post-angio and did not require angiographic evidence of thrombus!
Clearly cannot support routine use in AMI patients

10. So what are we supposed to do?
De Luca et al- meta-analysis of 21 studies involving ‘rheolytic thrombectomy’ devices, simple aspiration devices, and distal protection devices (Am Heart J 2007;153(3):343-53)
Improved TIMI grade, better myocardial blush grade, reduced distal embolisation, no difference in mortality
No evidence that use of these devices confers a survival benefit (?TAPAS)

11. Should we bother at all then?
Mortality is obviously important, but
it is also commonly measured because it is an easy ‘hard’ endpoint to assess
The long term impact of significant infarcts is clear to us as clinicians, but
few have the will, nor the resources, to assess the morbidity associated with such scenarios

12. Do we use them or not? All three devices appear to be safe
Routine use in AMI/rescue cannot be justified
IMHO, they remain a useful adjunct to conventional modalities in highly selected cases and may make a difference
No evidence exists to guide the choice of device