CrossBoss Catheter Fails to Trim CTO Crossing Times

Patrice Wendling

November 01, 2017

DENVER, CO — Up-front use of the CrossBoss catheter (Boston Scientific) did not shorten chronic total occlusion (CTO) crossing times during PCI compared with a guidewire-escalation strategy in the CrossBoss First trial[1].

Median CTO crossing time, the study's primary efficacy end point, was 56 minutes with CrossBoss and 66 minutes with antegrade guidewire escalation (P=0.323).

In a post hoc subgroup analysis, however, the CrossBoss shaved 15 minutes off crossing times for in-stent-restenosis cases (41 vs 66 minutes; P=0.046), without increasing rates of procedural major adverse cardiovascular events (MACE) (0% vs 4.17%; P=0.302), Dr Emmanouil Brilakis (North Texas Veterans Healthcare System, Dallas) reported at TCT 2017.

"To my mind, this is the first-line device for the stent-restenosis lesions," he said during a press briefing at the meeting.

Commenting for | Medscape Cardiology, Dr Duane Pinto (Beth Israel Deaconess Medical Center, Boston, MA) said the device likely offers no advantage in all-comer CTOs, but for in-stent restenosis cases, "You're certainly not paying a penalty, and it may be faster, so from that perspective it probably should be tried first in many cases or very rapidly moved to a CrossBoss strategy."

He also noted that in about 20% to 25% of antegrade escalation cases, CTO operators had to try other techniques. "So you still have to be facile in the utilization of this device and the Stingray [reentry system]."

CrossBoss is the first randomized controlled trial to compare the two crossing techniques as initial CTO crossing strategy. The results were simultaneously published in JACC Cardiovascular Interventions.

Investigators at 11 US centers randomized 246 patients scheduled for CTO PCI to a planned antegrade crossing approach using either the CrossBoss catheter or guidewire escalation. The choice of guidewires, microcatheters, subsequent CTO crossing equipment/techniques, and the decision to abort the procedure was at the operator's discretion.

About two-thirds of target CTOs were located in the right coronary artery, 44% were moderately or severely calcified, and 24% had moderate or severe vessel tortuosity.

The initial crossing strategy in the CrossBoss and guidewire-escalation groups was antegrade wire escalation in 22% vs 98%, respectively; antegrade dissection and reentry in 77% vs 1%, respectively, and retrograde in 1% each.

The CrossBoss and guidewire-escalation strategies resulted in similar rates of technical success, defined as <30% residual stenosis in the treated segment and restoration of TIMI-3 antegrade flow (88.5% vs 87.1%; P=0.846).

Rates of procedural MACE—defined as death, MI, urgent repeat target vessel revascularization with PCI or coronary artery bypass graft surgery, tamponade requiring pericardiocentesis or surgery, and stroke—were also similar (3.28% vs 4.03%; P=1.0).

In addition, there were no significant differences between the two groups in procedural success (defined as technical success with no procedural MACE), total procedural time, total fluoroscopy time, air kerma (AK) radiation dose, or contrast volume.

Dr Kambis Mashayekhi (University Heartcenter, Bad Krozingen, Germany), who was not involved in the study, said in an interview that "what we saw today is that very experienced operators can use the device with a relatively low complication rate, but I'm a little bit surprised that it's lower than wire escalation, because when it succeeds, it's a weapon."

Mashayekhi said the CrossBoss is a niche product in his lab at less than 1% of the 300 cases he performs yearly, 45% of which are done retrograde. That's unlikely to change even with the restenosis-subgroup finding because these cases can be managed well with wire.

"There is also an economic aspect because it costs nearly a third of what we get in Germany back from insurance and the wire is 10-fold cheaper," he added.

Brilakis reported that the cost of the CrossBoss/Stingray was higher than the guidewire but that overall cost in US dollars was not significantly different between the two strategies.

The trial was funded by Boston Scientific. Brilakis reported receiving consulting/speaker honoraria from Abbott Vascular, Amgen, Asahi, CSI, Elsevier, GE Healthcare, and Medicure; grants from Boston Scientific and Osprety; and spouse employment with Medtronic. Disclosures for the coauthors are listed in the paper.

Follow Patrice Wendling on Twitter: @pwendl. For more from | Medscape Cardiology, follow us on Twitter and Facebook.


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