Meta-Analysis of Radial Versus Femoral Access for Percutaneous Coronary Interventions in Non-ST-Segment Elevation Acute Coronary Syndrome

Selected in The American Journal of Cardiology by D. Milasinovic

References

Authors

Bavishi C, Panwar SR, Dangas GD, Barman N, Hasan CM, Baber U, Kini AS, Sharma SK

Reference

Am J Cardiol. 2016 Jan 15;117(2):172-8

Published

15 January 2016

Link

Read the abstract

My Comment

What is known

Radial artery access has been repeatedly associated with reduced rates of bleeding and vascular complications compared to femoral access for percutaneous coronary intervention (PCI). In addition, several randomised studies showed mortality benefit of radial over femoral access, albeit preferentially in a mixed acute coronary syndrome (ACS) population or in patients with ST-segment elevation myocardial infarction (STEMI) only. The here presented meta-analysis aimed at investigating  effects of radial access on bleeding and mortality specifically in patients with non-ST segment elevation acute coronary syndrome (NSTE-ACS).

Methodology

  • 220,126 patients (94,663 with radial and 125,463 patients with femoral access) from 2 randomised controlled trials (RCT), 3 secondary analyses of RCTs and 4 retrospective cohort studies, were included.
  • Bleeding definition was study specific, but in case of multiple reported bleeding scales, Thrombolysis in Myocardial Infarction (TIMI) major bleeding was used.
  • Random-effects model was used to compare pooled rates of major bleeding and mortality in radial versus femoral group, while accounting for heterogeneity among studies.

Major findings

  • Radial access was associated with a tendency toward lower 30-day mortality rate (1.2% vs. 2.0%, p=0.12) and a significant reduction in one-year mortality (4% vs. 5%, p=0.02).
  • Patients with radial access had lower rates of major bleeding (0.2% vs. 0.9%, p<0.001) and access site-related bleeding (0.4% vs. 4.0%, p=0.007).
  • Lower incidence of major bleeding was reflected by the reduction in blood transfusion in radial access patients (3.5% vs. 4.6%, p=0.02).

My comment

Although this meta-analysis showed the potential of transradial intervention to reduce bleeding and all-cause mortality in the setting of NSTE-ACS, the significant between-study heterogeneity for all assessed outcomes warrants caution and appears to reflect several inconsistencies in the hypothesis linking radial access and less bleeding with the reduced mortality risk.

First, while previous comparative analyses attributed greater prognostic significance to non-access than access site bleeding, only the latter is expected to be reduced by radial approach. Secondly, the definition of major bleeding has not been uniform across the trials, which appears to have obscured the mechanisms linking non-fatal bleeding events with increased mortality risk. Thirdly, radial access could be associated with differential clinical impact in NSTE-ACS patients undergoing early versus delayed invasive intervention.

Thus, although the presented meta-analysis indicates potential benefit of radial over femoral access, future studies with standardized protocols in respect to bleeding classification and timing of intervention seem to be warranted, in order to assess the true impact of transradial intervention in patients with NSTE-ACS.

2 comments

  • luis delgado 04 Mar 2016

    I think, we are overestimate the radial Acces. the mortality can not be atributed only to bleeding. That will be very simple. we are oblígate to continúe Investing Luis Delgado

  • Dejan Milasinovic 13 Mar 2016

    Thank you very much for your comment. Both bleeding and ischemic complications have been associated with increased mortality risk, and in case of their concurrence the negative effect on survival was shown to be synergistic in the ACUITY study population. Therefore, it seems that taking bleeding out of the equation could decrease the risk of mortality, both directly and perhaps indirectly due to minimization of disruption of dual antiplatelet therapy. However, the exact mechanisms between transradial intervention and decreased mortality risk do seem to remain incompletely elucidated, which is reflected by differing results of the hitherto conducted clinical trials. A possible source of heterogeneity could be the non-uniformity in the definition of major bleeding, as well as insufficient understanding of the differential impact of access site versus non-access site bleeding on the mortality risk. Given the need for future prospective studies to provide a more comprehensible account of mortality reduction by radial approach, the question still may be asked what the downsides of transradial intervention are. In other words, if there is a chance of reducing mortality by performing PCI via radial approach, what would the community consider to be the main practical limitations that could hamper its widespread use?