Diagnostic Yield and Safety of Invasive Coronary Function Testing After Radial Versus Femoral Access

BACKGROUND: Coronary vasomotor dysfunction is diagnosed by a coronary function testing (CFT). However, protocols vary, and the influence of access site and concomitant vasodilator medication on the diagnostic yield and safety of CFT is unclear. This study assessed the diagnostic yield and safety of CFT by radial access with intraarterial calcium channel blockers compared with CFT by femoral access. METHODS: Data were obtained from the Netherlands Registry of Invasive Coronary Vasomotor Function Testing, a Dutch multicenter collaboration on coronary function testing. Patients who underwent CFT between December 2020 and July 2025 were included. RESULTS: A total of 1885 patients were included, 1436 (76.2%) with primary radial access and 380 (20.2%) with primary femoral access. In 69 (3.7%) patients conversion from radial to femoral access was necessary. The conversion group was analyzed separately. The total diagnostic yield of coronary vasomotor dysfunction was 78.5%. There was no significant difference in the prevalence of coronary vasomotor dysfunction between patients with primary radial versus femoral access (79.2% versus 75.3%; P =0.1). There was also no difference in total diagnostic yield between the group without conversion and the conversion group (78.4% versus 82.6%; P =0.4); however, spasm was more prevalent in the conversion group (67.7% versus 79.4%; P =0.04). There were no differences in CFT complication rates between groups. CONCLUSIONS: Primary radial access with routine administration of calcium channel blockers was not associated with a lower diagnostic yield in CFT than primary femoral access. Procedural safety was comparable.