Fancy Coronary Access Technique Disappoints in Preventing Radial Artery Occlusions

PARIS -- For coronary procedures, conventional radial access held up against a newer technique developed to reduce radial artery occlusion (RAO), according to the DISCO RADIAL investigators.

They found that people undergoing diagnostic coronary angiography and/or percutaneous coronary intervention were left with similarly low rates of forearm RAO at discharge whether they had been randomized to the radial approach or the distal radial approach (0.91% vs 0.31%, P=0.29).

Adel Aminian, MD, of Centre Hospitalier Universitaire de Charleroi in Belgium, presented the DISCO RADIAL randomized trial of more than 1,200 patients at the EuroPCR meeting here. The full manuscript was simultaneously published in JACC: Cardiovascular Interventions.

Aminian said that if operators can produce the same RAO results between both approaches, the real benefit of distal radial access may be easier hemostasis -- albeit at the cost of a more technically challenging procedure compared with conventional radial access. He reported several significant procedural differences between the approaches:

• Hemostasis time: 153 min vs 180 min (P<0.0001)

• Requirement of dedicated compression device: 88.0% vs 99.2% (P<0.001)

• Crossovers: 7.4% vs 3.5% (P=0.002)

"I salute your enthusiasm for a negative trial," said session panelist Hany Eteiba, MD, of the University of Glasgow and Golden Jubilee National Hospital, who nonetheless acknowledged the "potential advantage" of distal radial access. He posed the question of whether shorter hemostasis times may translate into higher turnover for angioplasty for hospitals.

A radial-first strategy is currently recommended by interventional cardiology guidelines because of its relative safety. Nevertheless, RAO is the most frequent complication of radial access coronary interventions, and its occurrence may restrict future percutaneous operations and its use as a conduit for coronary artery bypass grafting surgery.

Established RAO prevention strategies include special steps using a dedicated compression device in the catheterization lab, later in the waiting room, and in the ward. Aminian described wide variability in the uptake of these strategies, however.

Under DISCO RADIAL's rigorous hemostasis protocol, hemostasis was achieved in 94.4% of the trial's radial access arm. "These results establish compliance to best practice recommendations for RAO avoidance as a mandatory new reference in TR [transradial] practice," Aminian told the EuroPCR audience.

"People still using TR -- they have to do a better job," he urged, citing estimates of RAO of 10% or more in some centers.

Participating operators in the study were regular users of the transradial approach who were also proficient at distal radial access, defined as having at least 100 procedures of the latter type under their belt.

Discussion panelist Jorge Belardi, MD, of Instituto Cardiovascular de Buenos Aires in Argentina, suggested that distal radial access is so challenging that it might have a learning curve of more than 100 cases.

DISCO RADIAL was conducted in 15 sites in Europe and one in Japan. It was designed as a superiority trial with the authors assuming RAO rates of 3.5% and 1.0%, respectively, for radial and distal radial access based on previous studies.

Included in DISCO RADIAL were patients randomized to radial (n=657) or distal radial access (n=650) who had been suitable candidates for either approach. Aminian and colleagues excluded people on chronic hemodialysis, those with ST-segment elevation myocardial infarction, and chronic total occlusion recanalization cases.

The two randomized groups were fairly well balanced. Baseline age was 68 years on average, with men representing over 70% of both groups. There were somewhat more aspirin users in the conventional radial access group (69.3% vs 63.7%, P=0.033).

Most patients presented with chronic coronary syndrome (84.9%), the rest having non ST-segment elevation myocardial infarction (7.1%) and unstable angina (8.0%).

Distal radial procedures were associated with more radial artery spasm (2.7% vs 5.4%, P=0.015) but not more pain.

Overall bleeding events and vascular complications did not differ between groups.

The study protocol did not mandate a specific hemostatic protocol for distal radial access because there is no test for persistent flow in this setting.

Another limitation of the trial was that operators used the same model of 6-F access sheath in both approaches.

"Use of the lowest diameter access sheath necessary to perform the procedure is recommended to reduce the RAO rates, and using a 5-F sheath could have been a logical choice. Yet the study protocol mandated using [the] same thin-walled 6-F sheath to avoid heterogeneity among patients and achieve the best balance between sheath thickness and convenience for everyday interventional practice," Aminian's group acknowledged.

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