The MATRIX Score was developed to predict the risk of crossover from radial access to femoral access among patients with acute coronary syndromes undergoing invasive management. The Risk Score is meant to assist operators in anticipating and potentially addressing difficulties in performing trans-radial procedures. The generation dataset consisted of 4197 patients assigned to radial access from the largest randomized trial comparing radial vs femoral access, the MATRIX trial. The Score was externally validated in 3451 and 491 patients assigned to radial access from the second-largest trial with randomized vascular access (RIVAL trial) and one of the largest randomized datasets focusing on STEMI (RIFLE-STEACS trial), respectively. Overall, 8139 patients from the derivation and validation cohorts were enrolled in 240 clinical sites from 33 countries worldwide.
Data analysis, derivation, and validation of the MATRIX Score were performed at the CTU Bern, the Clinical Trials Unit of the Faculty of Medicine of the University of Bern and the Inselspital, Bern University Hospital.
No external funding was used for this analysis.

Executive Committee: Marco Valgimigli, Switzerland – Felice Gragnano, Italy – Paolo Calabrò, Italy.

Scientific Advisory Committee: Mattia Branca, Switzerland – Dik Heg, Switzerland – David Van Klaveren, Netherlands.

Co-authors: Sanjit Singh Jolly, Canada – Shamir Mehta, Canada – Enrico Frigoli, Switzerland – Giuseppe Gargiulo, Italy – Sergio Leonardi, Italy – Pascal Vranckx, Belgium – Dario Di Maio, Italy – Emanuele Monda, Italy – Luigi Fimiani, Italy – Vincenzo Fioretti, Italy – Salvatore Chianese, Italy – Giuseppe Andò, Italy – Giovanni Esposito, Italy – Giuseppe Massimo Sangiorgi, Italy – Giuseppe Biondi-Zoccai, Italy – Stephan Windecker, Switzerland – Enrico Romagnoli, Italy.