Acute Kidney Injury After Radial or Femoral Access for Invasive Acute Coronary Syndrome Management: AKI-MATRIX. 
It remains unclear whether radial access (RA), compared with femoral access (FA), mitigates the risk of acute kidney injury (AKI).  The authors assessed the incidence of AKI in patients with acute coronary syndrome (ACS) enrolled in the MATRIX-Access (Minimizing Adverse Haemorrhagic Events by Transradial Access Site and Systemic Implementation of Angiox) trial.  Among 8,404 patients, 194 (2.3%) were excluded due to missing creatinine values, no or an incomplete coronary angiogram, or previous dialysis.  The primary AKI-MATRIX endpoint was AKI, defined as an absolute (>0.5 mg/dl) or a relative (>25%) increase in serum creatinine (sCr).  AKI occurred in 634 patients (15.4%) with RA and 712 patients (17.4%) with FA (odds ratio [OR]: 0.87; 95% confidence interval [CI]: 0.77 to 0.98; p = 0.0181).  A >25% sCr increase was noted in 633 patients (15.4%) with RA and 710 patients (17.3%) with FA (OR: 0.87; 95% CI: 0.77 to 0.98; p = 0.0195), whereas a >0.5 mg/dl absolute sCr increase occurred in 175 patients (4.3%) with RA versus 223 patients (5.4%) with FA (OR: 0.77; 95% CI: 0.63 to 0.95; p = 0.0131).  By implementing the Kidney Disease Improving Global Outcomes criteria, AKI was 3-fold less prevalent and trended lower with RA (OR: 0.85; 95% CI: 0.70 to 1.03; p = 0.090), with stage 3 AKI occurring in 28 patients (0.68%) with RA versus 46 patients (1.12%) with FA (p = 0.0367).  Post-intervention dialysis was needed in 6 patients (0.15%) with RA and 14 patients (0.34%) with FA (p = 0.0814).  Stratified analyses suggested greater benefit with RA than FA in patients at greater risk for AKI.  In ACS patients who underwent invasive management, RA was associated with a reduced risk of AKI compared with FA. ( Minimizing Adverse Haemorrhagic Events by TRansradial Access Site and Systemic Implementation of angioX [MATRIX]; NCT01433627).