RadIal Vs femorAL access for coronary intervention - RIVAL

Description:

There has been a lot of interest in the past few years for the use of radial access over femoral access for percutaneous coronary intervention (PCI), given advantages such as reduced bleeding, patient comfort, etc. However, studies indicate that radial access is associated with longer procedure times, increased fluoroscopic times, and typically a steep learning curve. In addition, certain complex PCIs are easier to do transfemoral rather than transradial.

The current study is the first trial to systematically compare outcomes between radial and femoral access in patients undergoing cardiac catheterization for acute coronary syndrome (ACS).

Hypothesis:

Radial access would be associated with a reduction in the composite endpoint of death, myocardial infarction (MI), stroke, or non-coronary artery bypass grafting (CABG) major bleeding at 30 days in ACS patients undergoing cardiac catheterization, as compared with femoral access.

Study Design

  • Parallel
  • Randomized

Patient Populations:

  • Intact dual circulation of hand (normal Allen’s test)
  • Interventionalist experienced with both (minimum 50 radial procedures in last year)

    Number of enrollees: 7,021
    Duration of follow-up: 30 days
    Mean patient age: 62 years
    Percentage female: 27%

Exclusions:

  • Age <18 years
  • Active bleeding or significant increased risk of bleeding (severe hepatic insufficiency, current peptic ulceration, proliferative diabetic retinopathy)
  • Uncontrolled hypertension
  • Cardiogenic shock
  • Prior CABG surgery with use of N1 internal mammary artery
  • Documented severe peripheral vascular disease precluding a femoral approach
  • Previously entered in the study
  • Investigational treatment (drug or device) within the previous 30 days
  • Medical, geographic, or social factors making study participation impractical or inability to provide written informed consent and to understand the full meaning of the informed consent

Primary Endpoints:

  • Death, MI, stroke, or non-CABG-related major bleeding (CURRENT-OASIS 7 definition) at 30 days

Secondary Endpoints:

  • Death, MI, or stroke at 30 days
  • Non-CABG major bleeding at 30 days

Drug/Procedures Used:

Patients presenting with non-ST-elevation ACS and ST-elevation MI (STEMI) were randomized to either radial access or femoral access. Interventionalists had to be facile with both access routes, and have performed at least 50 radial PCIs in the preceding year.

Concomitant Medications:

Aspirin (99.3%), clopidogrel (96%), unfractionated heparin (33%), bivalirudin (3%), glycoprotein (GP) IIb/IIIa inhibitors (25%), and fondaparinux (10.9%)

Principal Findings:

A total of 7,021 patients were enrolled, 3,507 to radial access and 3,514 to femoral access. Baseline characteristics were fairly similar between the two arms. About 28% presented with STEMI, 22% had diabetes, and 67% underwent PCI, while 8% underwent CABG. PCI success rates were similar between radial and femoral access arms (95.3%). The median operator annual volume of PCIs was 300, of which a median of 40% were done radially. Access site cross-over was greater in the radial access arm compared with femoral access (7.6% vs. 2.0%, p < 0.0001).

The primary outcome of death, MI, stroke, and non-CABG bleeding was similar between radial and femoral access arms (3.7% vs. 4.0%, hazard ratio 0.92, 95% confidence interval 0.72-1.17, p = 0.5). Secondary outcomes, including death, MI, or stroke (3.2% vs. 3.2%, p = 0.9) and non-CABG major bleeding (0.7% vs. 0.9%, p = 0.23) were similar. However, major vascular access site complications (1.4% vs. 3.7%, p < 0.0001), and ACUITY non-CABG major bleeding (1.9% vs. 4.5%, p < 0.0001) were significantly lower in the radial access arm.

Other clinical outcomes at 30 days, including death (1.3% vs. 1.5%), MI (1.7% vs. 1.9%), stroke (0.6% vs. 0.4%), and stent thrombosis (0.7% vs. 1.2%) were similar between the two arms (p > 0.05 for all). Although PCI procedure times were similar (35 vs. 34 minutes, p = 0.62), fluoroscopy times were higher with radial access (9.3 vs. 8.0 minutes, p < 0.0001). Patient preferred access site for next procedure was almost twice as high with radial access (90% vs. 49%, p < 0.0001).

On subgroup analysis, centers that were in the highest tertile for volume for radial PCIs and STEMI patients seemed to do significantly better with radial access, as compared with femoral access.

Interpretation:

The results of the RIVAL trial on the hotly debated topic of radial versus femoral access confirm a lot of the current thinking on this topic. Radial access, as compared with femoral access, is associated with a decreased incidence of major vascular access site complications and possibly bleeding, but associated with increased fluoroscopy times. Clinical outcomes at 30 days are similar between the two access strategies. Patient comfort with the procedure is very high. On subgroup analyses, centers in the highest volume for radial PCI and patients presenting with STEMI seemed to do better with radial rather than femoral access.

Several caveats exist. For one, the use of bivalirudin in this trial was only about 2-3%, while the use of GP IIb/IIIa inhibitors was about 25%. Bivalirudin has been shown to significantly decrease the risk of bleeding compared with GP IIb/IIIa inhibitors, and is commonly used in patients undergoing PCI for ACS, based on data from the HORIZONS-AMI and ACUITY trials. It is thus unclear if a higher use of bivalirudin would negate some of the reduction in bleeding noted with radial access over femoral access.

Further, the learning curve associated with radial access must be emphasized. The maximum benefit was noted in laboratories with the highest volume for radial access, and thus in centers that do not utilize radial access routinely or preferentially, procedure times may increase substantially, and again negate some of the other advantages of radial access. The increased fluoroscopic times noted in this trial are similar to those noted by other nonrandomized studies, and are potentially a cause of concern, since the long-term impact, especially to operators, is unclear.

Finally, the door-to-balloon times associated with radial access in STEMI patients in this trial are unknown. These are likely to be higher in centers/operators not extremely facile with radial access, and could potentially be associated with worse outcomes in real life.

References:

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;377:1409-20.

Presented by Dr. Sanjit Jolly at at the ACC.11/i2 Summit, New Orleans, LA, April 4, 2011.

Keywords: Polysaccharides, Myocardial Infarction, Stroke, Fluoroscopy, Acute Coronary Syndrome, Pyridinolcarbamate, Cardiac Catheterization, Heparin, Learning Curve, Ticlopidine, Hirudins, Platelet Membrane Glycoprotein IIb, Stents, Percutaneous Coronary Intervention, Thrombosis, Peptide Fragments, Confidence Intervals, Coronary Artery Bypass, Diabetes Mellitus, Platelet Glycoprotein GPIIb-IIIa Complex


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