[Percentage of transradial approach for interventional cardiology in the world and learning the technique].

The transradial approach has been used for the first non selective coronary angiographies but was quickly replaced by the femoral approach until a new birth in 1989 for coronary angiography in 1989 and coronary angioplasty in 1992. Transradial approach use is extremely heterogeneous in the world, dominated by some countries in Europe, Canada, and eastern Asia (India, Taiwan, China, Japan). Risk factors of failure have been well described, allowing two kinds of learning: systematic attempt in all kind of patients when working with a proctor; patient selection when beginning the technique alone in order to get a high and stable success rate from the beginning. Systematic radial approach for coronary angiography is a must to learn the technique.