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Use of radial access for percutaneous coronary intervention (PCI) in patients with ST-segment elevation myocardial infarction (STEMI) more than doubled in New York State between 2009 and 2011, according to a registry study published online February 12, 2014, ahead of print in JACC: Cardiovascular Interventions. Despite the increase, however, radial procedures still accounted for only about 12% of all primary PCI cases.

Investigators led by Edward L. Hannan, PhD, of the University at Albany, State University of New York (Albany, NY), analyzed data from a New York State registry of 11,057 STEMI patients with an onset-to-door time of less than 24 hours who underwent primary or rescue PCI at 58 hospitals from 2009 through 2010. Of these, 7.6% (n = 840) received radial access, including 7 who crossed ove to femoral access after radial attempts.

Radial Rates Vary Widely

The percentage of STEMI patients who received transradial PCI rose steadily over the study period, from 4.9% in first quarter of 2009 to 11.9% in the last quarter of 2010.The percentage of STEMI patients who underwent PCI via radial access varied widely amongst hospitals:

• 12 centers: none
• 44 centers: <5%
• 10 centers: 5%-30%
• 4 centers: >30%

The length of hospital stay with radial access was shorter than with femoral access (3.6 days vs 4.6 days; P < 0.0001).

In a logistic regression analysis, independent predictors of the use of radial access for STEMI were:

• Higher body surface area: OR 2.393; P < 0.0001
• Non-Hispanic ethnicity: OR 2.595; P = 0.0012
• Caucasian race: OR 2.244; P < 0.0001
• Stable hemodynamic state: OR 3.154; P = 0.0011
• EF <30%: OR 1.721; P = 0.0008
• EF ≥50%: OR 1.728; P = 0.0026
• Onset 12-23 hours before index procedure: OR 1.709; P = 0.0003
• Peripheral vascular disease: OR 2.145; P = 0.0016

Hint of a Mortality Benefit

Short-term mortality (including in-hospital and 30-day rates) was lower with radial than femoral access (2.7% vs 3.6%), although the advantage did not reach statistical significance (P = 0.21). After controlling for demographic and clinical risk factors, there was no mortality difference by access site (adjusted OR 0.86; 95% CI 0.59-1.25, for radial vs femoral access). However, when analysis was restricted to hospitals that used transradial PCI for at least 10% of STEMI patients, mortality trended lower with radial access (adjusted OR 0.61; 95% CI 0.36-1.02).

Overall, patients receiving transradial PCI were less likely than those undergoing transfemoral PCI to have door-to-balloon times (D2B) of less than 90 minutes (72% vs 77%; P = 0.0006).

In an email with TCTMD, Sunil V. Rao, MD, of the Duke Clinical Research Institute (Durham, NC), observed that radial use varies according to geographic region, and the New York State figures are “a little bit higher than for the country overall.”

However, the conversion to radial access is “still quite modest,” the authors say, suggesting that the disadvantages associated with transradial PCI, such as a longer learning curve and being more technically demanding, are “still important considerations.”

In a telephone interview with TCTMD, R. Lee Jobe, MD, of Wake Heart and Vascular (Raleigh, NC), said he was both surprised and disappointed to see that within New York State about 76% of hospitals used radial access less than 5% of the time.

Dr. Jobe suggested that the main obstacles to broader adoption of transradial PCI are the paucity of young fellows trained in the technique and the resistance of older, established practitioners who are comfortable with transfemoral PCI and feel no need to switch. 

Early Adopters Can Sway a Cath Lab

On the positive side, he and Dr. Rao agreed that when a hospital has an early adopter ready to help and reassure those less familiar with the approach, the entire cath lab tends to move in the radial direction. Moreover, said Dr. Rao, “the number of training programs that are now teaching fellows the radial approach has significantly increased. I think that’s what is going to lead to greater adoption in the future.”

Although some interventionalists worry that using radial access for STEMI patients may jeopardize D2B times, observational data tend to show no difference compared with femoral access among experienced operators, Dr. Jobe said. However, the question has not been specifically addressed in randomized trials, Dr. Rao added, and it remains a legitimate concern for operators and hospitals.

As in the study, radial access tends to be preferentially used in lower-risk patients because such cases tend to be more straightforward, Dr. Rao observed. However, high-risk patients are more likely to benefit from a radial approach, he said, adding, “This is the classic risk-treatment paradox.”

A bias toward performing transradial PCI in lower-risk patients may also explain why the study showed only a trend toward a mortality difference, Dr. Jobe said. In addition, he cautioned, outcomes in observational studies carry little weight because of the potential influence of unrecognized confounders.

Outcomes Will Turn the Tide

Drs. Jobe and Rao agreed that outcomes data will ultimately drive changes in practice.

Dr. Jobe recommends that interventionalists have at least 40 to 50 elective radial procedures under their belt before attempting transradial PCI in STEMI patients. He added, however, among experienced radialists the paradigm should be radial-first for all patients with suitable radial arteries, reserving femoral access for bailout.

The current observational study serves as a kind of benchmark of the penetration of radial use in 1 state, Dr. Jobe commented. “Of course, it dates back 3 to 4 years, and a contemporary study may show better numbers,” he added. “But continuing to have snapshots of where we are helps us recognize where we need to improve.”

Source:

Hannan EL, Farrell LS, Walford G, et al. Utilization of radial artery access for percutaneous coronary intervention for ST-segment elevation myocardial infarction in New York. J Am Coll Cardiol Intv. 2014;Epub ahead of print.

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