The MATRIX Trial: AKI After Radial or Femoral Access for Invasive ACS Management
- In a group of patients undergoing radial access, 15.4% developed acute kidney injury (AKI) after percutaneous coronary intervention (PCI) compared with 17.4% in the femoral access group.
Randomized clinical trials demonstrating the effectiveness of radial access (RA) on improved outcomes following percutaneous coronary intervention (PCI) have increased interventionalists’ utilization of RA.1,2 Despite the available evidence which supports the efficacy of RA, whether or not this approach influences the risk of acute kidney injury (AKI) is uncertain.
The Impact of Radial vs Femoral Access on AKI
In approximately 7% of cases, AKI occurs following a PCI and is associated with high mortality.3 There is speculation as to whether AKI and subsequent mortality represent a causal relationship, or if AKI is merely an indicator of an underlying issue.
The amount of contrast media used during a procedure predicts risk; however, there are numerous factors associated with AKI’s pathogenesis. Debate exists as to whether RA or femoral arterial access catheterization should be performed in patients at risk for AKI.
The Minimizing Adverse Haemorrhagic Events by Transradial Access Site and Systemic Implementation of Angiox (MATRIX) trial was a randomized clinical trial comparing femoral and radial access for PCI and coronary angiography in patients with acute coronary syndrome (n = 8404).1 The risk for all-cause mortality was significantly lower in the radial access group (relative risk [RR]: 0.72; 95% confidence interval [CI]: 0.53 to 0.99; P =.045).
A subanalysis of the MATRIX trial, AKI-MATRIX, was designed to evaluate the effect of radial access vs femoral access on post-PCI AKI.4 In the group undergoing radial access, 15.4% developed AKI compared with 17.4% in the femoral access group (odds ratio [OR]: 0.87; 95% CI: 0.77 to 0.98; P =.018).
The lower incidence of bleeding events in the RA group may partly explain the mechanism behind the protective benefit of RA against AKI. Also, the operators in the MATRIX trial had greater RA expertise, which may have played a role. In addition, the analysis showed significant differences between patients referred to trans-radial PCI and trans-femoral PCI in baseline characteristics. Patients receiving trans-femoral PCI were older and had a higher number of comorbidities, and these patients also had a longer hospital stay. Research comparing a balanced patient demographic may provide more revealing answers to the radial vs femoral debate.
In contrast, a single-center, retrospective study by Flaherty et al suggested a protective benefit with Impella® device use in patients undergoing trans-femoral high-risk PCI.5 Patients in this study had an average left ventricular ejection fraction (LVEF) of ≤35%. Due to their low LVEF values, these patients were considered to be at high risk for AKI incidence. In addition to low LVEF, supported patients also had greater comorbidities at baseline than unsupported patients. Despite the greater baseline hazard, there was an observed, notable protective benefit associated with the Impella device.
In summary, the subanalysis of the MATRIX trial by Andò et al shows the radial approach to correlate with a lower risk for AKI compared with femoral, whereas Flaherty et al show that support with the Impella device during trans-femoral PCI procedures may be an effective strategy for reducing AKI incidence and providing a greater absolute risk reduction. Whether there is an additive benefit for radial PCI and Impella support in patients at risk for AKI is not yet known.
- Valgimigli M, Gagnor A, Calabró P, et al. Radial versus femoral access in patients with acute coronary syndromes undergoing invasive management: a randomised multicentre trial. Lancet. 2015;385(9986):2465-2476.
- Jolly SS, Yusuf S, Cairns J, et al. Radial versus femoral access for coronary angiography and intervention in patients with acute coronary syndromes (RIVAL): a randomised, parallel group, multicentre trial. Lancet. 2011;377(9775):1409-1420.
- Tsai TT, Patel UD, Chang TI, et al. Contemporary incidence, predictors, and outcomes of acute kidney injury in patients undergoing percutaneous coronary interventions: insights from the NCDR Cath-PCI registry. JACC Cardiovasc Interv. 2014;7(1):1-9.
- Andò G, Cortese B, Russo F, et al. Acute Kidney Injury After Radial or Femoral Access for Invasive Acute Coronary Syndrome Management: AKI-MATRIX. J Am Coll Cardiol [published online May 11, 2017]. doi: 10.1016/j.jacc.2017.02.070.
- Flaherty MP, Pant S, Patel SV, et al. Hemodynamic Support With a Microaxial Percutaneous Left Ventricular Assist Device (Impella) Protects Against Acute Kidney Injury in Patients Undergoing High-Risk Percutaneous Coronary Intervention. Circ Res. 2017;120(4):692-700.
To learn more about the Impella® platform of heart pumps, including important risk and safety information associated with the use of the devices, please visit: www.protectedpci.com/indications-use-safety-information/