Minimizing Adverse Haemorrhagic Events by Transradial Access Site and Systemic Implementation of AngioX: Radial vs. Femoral - MATRIX: Radial vs. Femoral

Contribution To Literature:

The MATRIX: Radial vs. Femoral trial showed that radial access for acute coronary syndromes was associated with reduced net adverse events compared with femoral access.


The goal of the trial was to evaluate radial access compared with femoral access among subjects undergoing cardiac catheterization for acute coronary syndromes.

Study Design

  • Randomized
  • Parallel
  • Blinded
  • Stratified

Patients with acute coronary syndromes (ST-segment elevation myocardial infarction [STEMI] and non-STEMI [NSTEMI]) were randomized to radial access (n = 4,197) versus femoral access (n = 4,207). By factorial design, patients were also randomized to bivalirudin versus heparin (reported separately).

Patient population:

  • Total number of enrollees: 8,404 subjects
  • Duration of follow-up: 30 days
  • Mean patient age: 66 years
  • Percentage female: 25%
  • Percentage diabetics: 23%

Other salient features/characteristics:

  • Presentation: STEMI (48%), NSTEMI (52%)
  • Percutaneous coronary intervention (PCI) attempted: 80%
  • Anticoagulation in the cath lab: unfractionated heparin (50%), bivalirudin (40%)
  • Access attempted, but unsuccessful: 5.8% of the radial group vs. 2.3% of the femoral group

Inclusion criteria:

  • Patients with acute coronary syndromes undergoing cardiac catheterization
  • Willingness of the interventionalist to perform either radial or femoral catheterization
  • Interventionalist with at least 75 radial procedures in previous year (≥50% during acute coronary syndromes)

Exclusion criteria:

  • Low molecular weight heparin in the previous 6 hours
  • Glycoprotein IIb/IIIa inhibitor in the previous 3 days
  • PCI in the previous 30 days

Principal Findings:

The primary outcome of death, MI, or stroke occurred in 8.8% of the radial group versus 10.3% of the femoral group (p = 0.031; this exceeded the prespecified α level of 2.5%). The only subgroup in which there was evidence of treatment interaction was the hospital’s radial PCI volume; hospitals that performed >80% radial PCIs had better outcomes with radial procedures versus femoral procedures (p for interaction = 0.0048). Hospitals with a low and intermediate proportion of radial PCIs had similar outcomes with either radial or femoral procedures.

The co-primary composite outcome of all-cause death, MI, or stroke: 6.1% among radial/STEMI vs. 6.3% among femoral/STEMI (relative risk [RR] 0.96, 95% confidence interval [CI] 0.75-1.24) and 11.3% among radial/NSTEMI vs. 13.9% among femoral/NSTEMI (RR 0.80, 95% CI 0.67-0.96); p for interaction = 0.25.

The co-primary composite outcome of all-cause death, MI, stroke, or BARC 3 or 5 bleeding: 7.2% among radial/STEMI vs. 8.3% among femoral/STEMI (RR 0.86, 95% CI 0.68-1.08) and 12.2% among radial/NSTEMI vs. 14.7% among femoral/NSTEMI (RR 0.82, 95% CI 0.69-0.97); p for interaction = 0.76.

Secondary outcomes:

  • Death, MI, stroke, or BARC (type 3 or 5) major bleeding: 9.8% vs. 11.7% (p = 0.0092), respectively, for radial vs. femoral
  • All-cause mortality: 1.6% vs. 2.2% (p = 0.045), respectively, for radial vs. femoral
  • Stroke: 0.4% vs. 0.4% (p = 0.99), respectively, for radial vs. femoral
  • BARC (type 3 or 5) major bleeding: 1.6% vs. 2.3% (p = 0.0128), respectively, for radial vs. femoral

A subset of patients was enrolled in the RAD-MATRIX study (n = 7,570). The mean thorax radiation dose to the operator was 77 µSv for radial procedures versus 41 µSv for femoral procedures (p = 0.019). The effective dose delivered to the patient was 13 µSv for radial procedures versus 12 µSv for femoral procedures (p < 0.0001).


Among patients with acute coronary syndromes, radial access for cardiac catheterization was associated with a reduction in net adverse cardiovascular events compared with femoral access. Although there was a favorable trend toward reduction in major adverse cardiovascular events, this co-primary endpoint did not reach formal statistical significance. Benefit was the same across the spectrum of acute coronary syndromes.

Radial access was associated with greater radiation to the operator and the patient. Benefit was most pronounced among the highest volume radial PCI centers (i.e., >80% PCIs by radial access). This suggests that for catheterization laboratories that are facile with femoral access with low bleeding rates, benefit from radial access may be marginal. For catheterization laboratories that have high rates of bleeding with femoral access, conversion to default radial access would be an appropriate mechanism to reduce bleeding and net adverse events. Operators who perform radial procedures need to remain vigil about reducing radiation exposure to patients.


Presented by Dr. Alessandro Sciahbasi at the American College of Cardiology Annual Scientific Session (ACC 2017), Washington, DC, March 18, 2017.

Vranckx P, Frigoli E, Rothenbühler M, et al. Radial versus femoral access in patients with acute coronary syndromes with or without ST-segment elevation: A pre-specified analysis from the randomized minimizing adverse haemorrhagic events by transradial access site and systemic implementation of angioX (MATRIX access). Eur Heart J 2017;Feb 28:[Epub ahead of print].

Valgimigli M, Gagnor A, Calabró P, et al., on behalf of the MATRIX Trial Investigators. Radial versus femoral access in patients with acute coronary syndromes undergoing invasive management: a randomised multicentre trial. Lancet 2015;385:2465-76

Presented by Dr. Marco Valgimigli at ACC.15, San Diego, CA, March 16, 2015.

Clinical Topics: Acute Coronary Syndromes, Invasive Cardiovascular Angiography and Intervention, Interventions and ACS

Keywords: ACC17, ACC Annual Scientific Session, Acute Coronary Syndrome, Hemorrhage, Cardiac Catheterization, Myocardial Infarction, Stroke, Stents, Thrombosis, Femoral Artery, Radial Artery

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