Antegrade Approach for Coronary CTO: Tapered-Tip, Low-Force Guidewires Deliver Good Results

An initial antegrade wiring escalation approach for crossing coronary chronic total occlusion (CTO) lesions using a new guidewire technology facilitates efficiency and success with excellent safety. So concludes a study recently published in the Journal of Invasive Cardiology (2020;32[5]:161-168) involving use of the guidewires for 164 consecutive CTO lesions treated at Cleveland Clinic.

The study assessed a guidewire type novel to the United States — polymer-jacketed, tapered-tip, low-force guidewires with composite-core, dual-coil design. The research was investigator-initiated and involved no formal industry funding.

“This study details our initial experience using these guidewires as part of an antegrade-first wiring approach in unselected patients,” says lead author Jeffrey Rossi, MD, a fellow in the Department of Cardiovascular Medicine at Cleveland Clinic. “Their performance may lead to extending the spectrum of lesions recommended for this percutaneous coronary intervention strategy.”

Revisiting antegrade wire escalation with new technology

For coronary CTOs, advanced crossing strategies associated with a higher risk of complication are often selected as alternatives to an antegrade strategy because of inadequate wire technology. But with the availability of new guidewires with technological advances (composite-core, dual-coil design with polymer-jacketed and tapered tips), both the Euro and Asia-Pacific CTO Clubs favor an antegrade-first strategy.

“In recent years, Cleveland Clinic started an institutional practice to begin all CTO cases with antegrade wire escalation using the novel guidewires regardless of lesion characteristics,” explains the study’s senior author, Jaikirshan Khatri, MD, an interventional cardiologist who specializes in CTO interventions.

Study design and population

The investigation analyzed outcomes from 164 consecutive CTO lesions (from 155 patients) treated at Cleveland Clinic from March 2017 to December 2018, when a primary antegrade wire escalation strategy with the novel guidewires was used for all CTO cases regardless of angiographic lesion characteristics.

Among the 155 patients, mean age was 64 ± 9.6 years and 83.5% were male; 37.2% had prior coronary artery bypass grafting and 45.7% had diabetes. Most procedures (69.5%) were performed for symptom relief.

Among the lesions, 31.1% were prior failures, 15.9% were in-stent restenoses and 29.3% were previously bypassed. Mean CTO length was 25.0 ± 14.0 mm.

Outcomes

The overall technical success rate was 84.1%, with 67.7% of lesions crossed antegrade, 12.8% crossed retrograde and 3.7% crossed using antegrade dissection and re-entry. Antegrade success rates were evaluated according to procedural complexity as measured by Japanese CTO (J-CTO) score, as follows:

• 79% for J-CTO scores 0-1 (easy to intermediate)
• 60% for J-CTO scores 2-3 (difficult)
• 17% for J-CTO scores 4-5 (very difficult)

Among lesions in which the novel guidewires were able to cross antegrade, the following median wiring times were observed, presented by level of complexity:

• 5 minutes (interquartile range [IQR], 5.0-11.0) for J-CTO scores 0-1
• 0 minutes (IQR, 4.2-14.0) for J-CTO scores 2-3
• 0 minutes (IQR, 9.0-15.0 min) for J-CTO scores 4-5

The differences in wiring times did not reach statistical significance (P = 0.20).

In-hospital major adverse cardiac events occurred in 1.3% of patients. Four wire perforations occurred, with none directly related to the novel wires. There were no in-hospital deaths.

Support for an antegrade-first strategy

Success rates and wiring times in this study compare favorably with those of other published research, although exact comparisons are hampered by most studies not specifying which wire crossed the lesions, the researchers note. This study, they add, is the first to specifically comment on the performance of these wires.

The researchers emphasize the following major findings:

• The new guidewires can achieve high rates of antegrade success in low-complexity lesions. The J-CTO score was a good predictor of procedural success, with high success rates achieved in lesions that had a score of 3 or less without need for an additional wire.
• When able to cross antegrade, wiring times were low regardless of lesion complexity. This finding surprised the research team, according to Dr. Khatri. “When the wire could cross antegrade, wiring times were low and not significantly associated with lesion severity,” he observes.
• The new wires do not perform as well in lesions known to be challenging for an antegrade approach. Results were less successful in bypassed vessels, in lesions with moderate-to-severe calcification or tortuosity, and in lesions at least 20 mm long or having a nontapered stump or ambiguous cap.
• The new guidewire technology demonstrates good safety as part of an antegrade approach. “Overall, our experience with these new wires was excellent in expert hands with an initial antegrade approach,” says co-author Samir Kapadia, MD, Chair of Cardiovascular Medicine at Cleveland Clinic. “Keep in mind, however, that CTO intervention is a very subspecialized branch and success depends on the experience of the operators.”