Effects of radial versus femoral artery access in patients with acute coronary syndromes with or without ST-segment elevation

Objectives: The purpose of this study was to determine the consistency of the effects of radial artery access in patients with ST-segment elevation myocardial infarction (STEMI) and in those with non-ST-segment elevation acute coronary syndrome (NSTEACS).

Background: The safety associated with radial access may translate into mortality benefit in higher-risk patients, such as those with STEMI.

Methods: We compared efficacy and bleeding outcomes in patients randomized to radial versus femoral access in RIVAL (RadIal Vs femorAL access for coronary intervention trial) (N = 7,021) separately in those with STEMI (n = 1,958) and NSTEACS (n = 5,063). Interaction tests between access site and acute coronary syndrome type were performed.

Results: Baseline characteristics were well matched between radial and femoral groups. There were significant interactions for the primary outcome of death/myocardial infarction/stroke/non-coronary artery bypass graft-related major bleeding (p = 0.025), the secondary outcome of death/myocardial infarction/stroke (p = 0.011) and mortality (p = 0.001). In STEMI patients, radial access reduced the primary outcome compared with femoral access (3.1% vs. 5.2%; hazard ratio [HR]: 0.60; p = 0.026). For NSTEACS, the rates were 3.8% and 3.5%, respectively (p = 0.49). In STEMI patients, death/myocardial infarction/stroke were also reduced with radial access (2.7% vs. 4.6%; HR 0.59; p = 0.031), as was all-cause mortality (1.3% vs. 3.2%; HR: 0.39; p = 0.006), with no difference in NSTEACS patients. Operator radial experience was greater in STEMI versus NSTEACS patients (400 vs. 326 cases/year, p < 0.0001). In primary PCI, mortality was reduced with radial access (1.4% vs. 3.1%; HR: 0.46; p = 0.041).

Conclusions: In patients with STEMI, radial artery access reduced the primary outcome and mortality. No such benefit was observed in patients with NSTEACS. The radial approach may be preferred in STEMI patients when the operator has considerable radial experience. (A Trial of Trans-radial Versus Trans-femoral Percutaneous Coronary Intervention (PCI) Access Site Approach in Patients With Unstable Angina or Myocardial Infarction Managed With an Invasive Strategy [RIVAL]; NCT01014273).