The DIRECT trial results

The randomized DIRECT Trial1 demonstrated that lesions treated with the HawkOne™ directional atherectomy system had greater plaque volume reduction and luminal gain — with similar safety profiles — than those treated with the CSI Diamondback 360™* peripheral orbital atherectomy system. Results confirmed through IVUS and angiography.

This is an image of the HawkOne™ directional atherectomy system.

HawkOne™ directional atherectomy system


24-month follow-up in all patients2

There was a non-significant numerical trend in restenosis and revascularization rates in the directional atherectomy (DA) arm compared to the orbital (OA) arm.


Restenosis

(p = 0.29)​

24-month follow-up in all patients-restenosis

Revascularization

(p = 0.47)

24-month follow-up in all patients-revascularization

† ABI drop of ≥0.15 from immediate post-procedure baseline and/or if the patient became symptomatic with claudication or limb ischemia and these findings led to further confirmatory testing using noninvasive imaging (arterial duplex – PSV ratio > 2.5; CTA or MRA – stenosis of > 60%​.


Percent stenosis by angiography

There was a greater reduction in stenosis following directional atherectomy (DA) compared to orbital atherectomy (OA).


Pretreatment

(p = 0.48)

View this chart of the DIRECT trial stenosis pretreatment rate, which includes the HawkOne™ directional atherectomy rate.

Post-atherectomy

(p < 0.001)

View this chart of the DIRECT trial stenosis post-atherectomy rate, which includes the HawkOne™ directional atherectomy rate.

Post-DCB

(p < 0.001)

View this chart of the DIRECT trial stenosis post-drug-coated balloon rate, which includes the HawkOne™ directional atherectomy rate.

Representative case examples


Directional atherectomy — IVUS area stenosis


Pretreatment

69.2%

This is an image of the DIRECT trial pretreatment angiogram using directional atherectomy.

Post-atherectomy

54.1%

This is an image of the DIRECT trial post-atherectomy angiogram using directional atherectomy.

Post-DCB

5.6%

This is an image of the DIRECT trial post-DCB angiogram using directional atherectomy.

Mechanism of lumen enlargement: plaque reduction and vessel stretch

This is an image of the directional atherectomy mechanism of lumen enlargement shown in intravascular ultrasound (IVUS) imagery.

Orbital atherectomy — IVUS area stenosis


Pretreatment

84.2%

This is an image of the pretreatment angiogram using orbital atherectomy.

Post-atherectomy

74.8%

This is an image of the DIRECT trial post-atherectomy angiogram using orbital atherectomy.

Post-DCB

59.8%

This is an image of the DIRECT trial post-DCB angiogram using orbital atherectomy.

Mechanism of lumen enlargement: medical dissection and vessel stretch

This is an image of the orbital atherectomy mechanism of lumen enlargement shown in intravascular ultrasound (IVUS) imagery.

Plaque volume

Greater plaque volume reduction was achieved with directional atherectomy group compared to orbital atherectomy group. This difference in plaque volume reduction persisted following drug-coated balloon (DCB) utilization.


Plaque volume (worst 10 mm segment)

Pretreatment

(p = 0.8)

View this chart of the DIRECT trial plaque pretreatment rate, which includes the HawkOne™ directional atherectomy rate.

Post-atherectomy

(p = 0.0002)

View this chart of the DIRECT trial plaque post-atherectomy rate, which includes the HawkOne™ directional atherectomy rate.

Post-DCB

(p = 0.003)

View this chart of the DIRECT trial plaque post-drug-coated balloon rate, which includes the HawkOne™ directional atherectomy rate.

Plaque volume (entire lesion)

Pretreatment

(p = 0.43)

View this chart of the DIRECT trial plaque volume plaque pretreatment rate, which includes the HawkOne™ directional atherectomy rate.

Post-atherectomy

(p = 0.06)

View this chart of the DIRECT trial plaque volume plaque post-atherectomy rate, which includes the HawkOne™ directional atherectomy rate.

Post-DCB

(p = 0.01)

View this chart of the DIRECT trial plaque volume plaque post-drug-coated balloon rate, which includes the HawkOne™ directional atherectomy rate.

Stent placement rate

  • HawkOne™ directional atherectomy (DA): 7% (2/30)
  • Diamondback 360™* orbital atherectomy (OA): 33% (10/30)

(p = 0.02)

View this chart of the DIRECT trial stent placement rate, including the HawkOne directional atherectomy rate.

Safety events and complications

Overall directional and orbital atherectomy were found to be safe with minimal complications.

Directional atherectomy (n = 30)

  • Perforations: 1 (3%)
  • Distal embolic protection device used: 29 (97%)
  • Distal embolization post-atherectomy: 0 (0%)

Orbital atherectomy (n = 30)

  • Perforations: 0 (0%)
  • Distal embolic protection device used: 28 (93%)
  • Distal embolization post-atherectomy: 1 (3%)

Results may not be indicative of clinical performance, and are dependent on experience and training. The DIRECT study was an investigator-initiated study supported by an institutional grant from Medtronic. Three-year follow-up is ongoing to determine whether these acute performance measures are associated with improved clinical outcomes.

Risks may include but are not limited to: arterial perforation, embolism or arterial thrombosis, arterial dissection, arterial spasm, and vascular complications that could require surgical repair.


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