The Learning Curve for Transradial Percutaneous Coronary Intervention Among Operators in the United States: A Study From the National Cardiovascular Data Registry®

Study Questions:

What is the learning curve for transradial percutaneous coronary intervention (TRI)?


The study used CathPCI Registry® data from July 2009 to December 2012, to identify new radial operators. New radial operators were defined by a femoral-only PCI approach for 6 months after their first PCI in the database and ≥15 total TRIs thereafter. Primary outcomes for this study were fluoroscopy time, contrast volume, and procedure success. Secondary outcomes included in-hospital mortality, bleeding, and vascular complications. Adjusted outcomes were analyzed using operator TRI experience as a continuous variable with generalized linear mixed models.


This study included 54,561 TRI procedures performed at 704 sites. Of the entire cohort, 942 operators performed 1-10 cases; 942 operators performed 11-50 cases; 375 operators performed 51-100 cases; and 148 operators performed 101-200 cases. While initially the procedure was used in lower-risk patients, as radial caseload increased, more TRIs were performed in women, and in ST-segment elevation myocardial infarction patients. There was a decrease in fluoroscopy time and contrast use with greater operator TRI experience. Procedure success was high, and mortality, bleeding, and vascular complications remained low across TRI volumes.


As operator TRI volume increases, higher-risk patients are chosen for TRI. There is an increase in operator proficiency, with the threshold to overcome the learning curve being approximately 30-50 cases.


This study confirms prior data that there is a learning curve for TRI, with a threshold of around 50 cases. There has been a significant increase in the use of the radial approach nationally, and many training institutions have switched to a radial first approach. The learning curve in this study reflects the experience of operators who are switching from a nearly 100% femoral approach, and suggests that this switch can be safely accomplished.

Clinical Topics: Invasive Cardiovascular Angiography and Intervention

Keywords: Myocardial Infarction, Learning Curve, United States, Percutaneous Coronary Intervention

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