Distal protection devices Dr Donald Baim Director, Center for Innovative Minimally Invasive Therapy Brigham & Women’s Hospital Boston, MA

Origins Distal protection devices Original PCI studies did not show any significant embolic debris, resulting in a mindset against the idea of distal embolization. But results in saphenous vein grafts where perfect anatomic results still resulted in slowed antegrade flow.

Competing explanations Distal protection devices 1) Platelets releasing serotonin, provoking microvascular spasm and causing slow flow. 2) Platelet aggregates causing blockage. 3) Distal embolization of plaque debris. (now the leading explanation)

Devices Distal protection devices Balloon – PercuSurge® GuardWire™ (A low-pressure elastic balloon put distal to the lesion and then inflated to seal the vessel. After PCI, debris is aspirated.) Filter – Cordis Angioguard™, MedNova Filter, Microvena TrapVFS, etc… (Filter is deployed distally. Liberated debris is captured, the filter is then collapsed and withdrawn from the body.)

Debris capture Distal protection devices

Clinical use Distal protection devices Many devices are already CE marked for Europe. PercuSurge® GuardWire™ registries: SAFE (Saphenous Vein Graft Angioplasty Free of Emboli) CAFE (Carotid Angioplasty Free of Emboli)

Clinical trials Distal protection devices Only one randomized trial has been completed. SAFER (Saphenous Vein Graft Angioplasty Free of Emboli Randomized) 750 patients randomized to PCI treatment either with or without the PercuSurge® GuardWire™.

With GuardWire Without GuardWire MACE*8.4%17.3% Q-wave MI1.1%2.2% Non-Q-wave MI7.3%14.4% 3 of 4 *p-value = Distal protection devices SAFER: Primary endpoints Baim DS, et.al., Transcatheter Cardiovascular Therapeutics 2000

Canadian registry Distal protection devices Set the stage for the randomized trials. Showed that using the capture devices, embolic debris was found with every SVG, and that the rate of MACE in the registry was lower than the historical norm. Showed the material can be recovered and that recovery seemed to lower the number of clinical events.

Events at 30 days Minor stroke3 (2.4%) Major stroke2 (1.6%) Stroke-related death1 (0.8%) 3 of 4 Distal protection devices CAFE registry Mehran R, et.al., American Heart Association Scientific Sessions patients receiving carotid stenting and protected by PercuSurge® GuardWire™

What is being captured? Shattered version of the plaques that one sees in cross section of the arteries before treatment. The plaques that liberate the most debris seem to have the biggest pools of lipids, the “unstable plaques”. 2 of 4 The embolic material Distal protection devices

Perception is that there is less embolization than in SVG. Analyses from Europe suggests that distal embolization may prevent people with acute infarction from restablishing normal myocardial perfusion post PCI. 2 of 4 Native coronaries Distal protection devices

The two devices have advantages and disadvantages. Either has the potential to injure the distal vessel. Balloon is a complete barrier, but interrupts flow for a few minutes. Filter leaves flow, but could allow the smaller particles through. 2 of 4 Restenosis risk Distal protection devices

“Because this no-reflow event is so unpredictable and because it has such devastating consequences, … people are not going to want to play Russian roulette, and use of a distal protection device will become the standard of care for all saphenous vein graft interventions.” Dr Donald Baim Director, Center for Innovative Minimally Invasive Therapy Brigham & Women’s Hospital Boston, MA 2 of 4 When will you use it? Distal protection devices

GPIIb/IIIa receptor inhibitors were used in 60% of patients in both arms of the SAFER trial, mostly started before intervention, chosen non-randomly by the operators. SAFER found that use GP IIb/IIIa made no appreciable difference in the significant reduction of events with distal protection. 2 of 4 GP IIb/IIA interaction Distal protection devices

Successful use of device requires close coordination of the stent operator and the distal capture device operator. The average operator did 5-7 cases with the device before beginning the randomized trial. 2 of 4 Learning curve Distal protection devices

No-reflow SVG patients have a very high in- hospital mortality when no-reflow. Probably is cost-effective there. Cost-efficacy data is being collected. 2 of 4 Cost Distal protection devices

First device of its type. The trial was stopped early because of apparent efficacy and safety. Company has asked for expedited review. Perhaps sometime in January of 4 FDA approval Distal protection devices