Acute kidney injury after percutaneous coronary intervention: Rationale of the AKI-MATRIX (acute kidney injury-minimizing adverse hemorrhagic events by TRansradial access site and systemic implementation of angioX) sub-study

Acute kidney injury (AKI) is an important complication of both diagnostic cardiac cath- eterization and percutaneous coronary intervention (PCI). A large body of evidence supports that AKI is related to volume of contrast used. Despite several measures are available to reduce the impact of contrast media on AKI, its incidence remains signifi- cant as other mechanisms of renal damage are involved. A new paradigm is estab- lished according to which bleeding prevention is at least as important as preventing recurrent ischemic events in the management of patients with acute coronary syn- dromes (ACS) undergoing an invasive approach. Periprocedural bleeding, which is con- sistently reduced by radial approach, is emerging as a risk factor for the development of AKI. Therefore, the role of vascular access as a measure to prevent AKI needs to be systematically assessed in randomized studies. To date, no prospective comparison on renal outcomes has been carried out in randomized trials between radial and femo- ral approach. The Minimizing Adverse hemorrhagic events by TRansradial access site and systemic Implementation of AngioX (MATRIX) trial (ClinicalTrials.gov identifier: NCT01433627) has been designed to test whether to minimize bleeding events by using radial access and bivalirudin, across the whole spectrum of patients with ACS under- going PCI, will result in improved outcomes with respect to both ischemic and bleed- ing complications. The AKI-MATRIX sub-study will provide a unique opportunity to assess whether the advantages of radial approach may even contribute to the reduction of the risk of AKI in patients with ACS.