NCDR Study Finds US Operators Take to Radial Procedures Without Ill Consequences

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Despite a learning curve, operators in the United States who are new to radial interventions are able to take on increasingly difficult cases fairly soon after mastering the approach, while maintaining safety, according to registry findings published April 22, 2014, ahead of print in Circulation. Approximately 30 to 50 cases are required to overcome the initial learning curve, the researchers say.

Connie N. Hess, MD, MHS, of Duke University Medical Center (Durham, NC), and colleagues identified 54,561 transradial PCI cases performed by 942 new radial operators at 704 sites in the CathPCI Registry of the National Cardiovascular Data Registry (NCDR) between July 2009 and December 2012. Interventionalists were classified as ‘new,’ if they had performed at least 15 radial cases after a 6-month blanking period during which they performed only femoral cases. Data from these physicians were used to calculate outcomes during the earliest part of the learning curve.

Fluoroscopy Time, Contrast Volume Decrease with More Cases

Approximately half of radial cases were in complex lesions (52.2%), with 7.9% performed for emergency indications and 11.3% in multiple vessels. As the volume of radial procedures per operator increased, so did the relative challenge of the procedures; radial cases became significantly more likely to be performed in women, patients with NYHA class IV heart failure, STEMI patients, and those with higher bleeding risk. Procedures also were more likely to be emergent, technically complex, and involve multiple vessels.

Yet procedural outcomes according to transradial case volume held steady or even improved (table 1).

Table 1. Procedural Outcomes by Number of Radial Cases per Operator

^aMedian.

To pinpoint a threshold of sufficient experience, the relationships between the number of cases and contrast volume and fluoroscopy time were evaluated. There were “greater and faster reductions in fluoroscopy time and contrast volume use associated with increasing… volume along the earlier learning curve for inexperienced operators (< 30-50 [radial] cases) compared with the ongoing learning curve for more experienced operators (> 50 [radial] cases),” the paper explains.

Cutoff for Experience Not Set

“These findings,” the researchers say, “suggest that the learning curve for [transradial interventions] is relatively shallow with the availability of modern interventional equipment and should inform [radial] training guidelines in the [United States].” Operators can use these data as a benchmark when evaluating their own performance, they suggest.

Importantly, the threshold of 30 to 50 cases represents a range not a requirement, Dr. Hess and colleagues note, advising that “decisions regarding an operator’s level of proficiency and comfort with [radial] and, consequently, selection of patients for [radial] during the learning phase, should be made on an individual basis.” Other factors including the expertise of cath lab and ward staff as well as the availability of mentors should also be considered, they add.

J. Dawn Abbott, MD, of Rhode Island Hospital (Providence, RI), points out in an accompanying editorial, however, that the NCDR findings may not capture the entire picture. The exclusion of operators with volumes of less than 15 cases resulted in the omission of 1,862 physicians. The study also excluded any case volumes beyond 200 in the more experienced ‘new’ operators, and overall PCI volumes or crossover rate from radial to femoral were not assessed, she adds.

Even so, Dr. Abbott concludes, “[t]he present study suggests that interventional cardiologists can rapidly incorporate new skills into their armamentarium. Widespread adoption of techniques that improve patient outcomes, including [radial access], therefore are inevitable, and as a profession, we should set standards for training and maintaining competency.”

Current ACC/AHA/SCAI guidelines recommend “a minimum of 50 PCI procedures per year to maintain competency but do not specifically address vascular access,” she reports, while a European consensus document “recommends 80 transradial procedures annually, diagnostic and interventional, to maintain proficiency.”

 

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Sources:
1. Hess CN, Peterson ED, Neely ML, et al. The learning curve for transradial percutaneous coronary intervention among operators in the United States: a study from the National Cardiovascular Data Registry. Circulation. 2014;Epub ahead of print.

2. Abbott JD. The pace of transradial procedural learning [editorial]. Circulation. 2014;Epub ahead of print.

 

 

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