Meta-Analysis Boosts Case for Increased Use of Radial Access

Take Home: Meta-Analysis Boosts Case for Increased Use of Radial AccessA meta-analysis of recent randomized trials comparing femoral- and radial- access PCI in ACS patients points to significant reductions in deaths, major adverse cardiac events (MACE), and major bleeding with the radial approach. The study, led by Giuseppe Andò, MD, PhD, of the University of Messina (Messina, Italy), was published online November 10, 2015 ahead of print in the Annals of Internal Medicine.  

“These findings apply to patients across the broad spectrum of ACS undergoing invasive management and consolidate the role of transradial intervention as a life-saving procedure, warranting an upgrade of current guidelines recommendations,” write the authors.   

Of 17 trials identified in the literature, the researchers included 4 in their analysis—a total of 17,133 patients—that were considered to be of adequately high quality: RIVAL (2011), RIFLE-STEACS (2012), STEMI-RADIAL (2014), and MATRIX (2015). Individually, these trials included different proportions of STEMI patients and yielded different results with regards to mortality. Both STEMI-RADIAL and RIVAL showed no differences in mortality by access route while MATRIX showed a reduction in all-cause mortality and RIFLE-STEACS showed a reduction in cardiac mortality, both with the radial approach.  

By pooling the data, Andò et al showed that radial access was associated with reductions in death, MACE, and major bleeding at 30 days, although procedures performed using the radial approach were slightly longer and had a higher cross over rate (6.3% vs. 1.7%). 

 The Take Home: Meta-Analysis Boosts Case for Increased Use of Radial Access

Bleeding Linked With Survival

While the authors acknowledge that their findings are limited by different outcomes and “treatment modifiers” across studies, including operator experience in radial procedures and use of concurrent anticoagulants, they note that improvements in all-cause mortality with the radial approach were seen in patients both with and without STEMI, even after taking trial heterogeneity into account.  

“The observed reduction in mortality with radial access was achieved in parallel with reductions in MACE and bleeding, both access-site–related and major according to the trials definitions,” continue the authors. “A link between bleeding and ischemic events, including mortality, has increasingly emerged in interventional studies over time, supported by the notion that strategies aimed at reducing bleeding are also associated with improved survival in patients with ACS.” 

The authors say these findings warrant inclusion in PCI guidelines and indeed, European guidance was updated in August 2015 to support a radial approach over femoral in ACS patients in order to reduce both bleeding and all-cause mortality. The 2011 ACCF/AHA/SCAI guidelines for PCI, however, have not yet updated their radial recommendations. These gave the choice of radial access over femoral a Class IIa recommendation, specifically with the aim of reducing access site complications — no mention of mortality.

Call to Arms in Favor of a Radial Approach

In an accompanying editorial, Michael P. Savage, MD of Thomas Jefferson University Hospital (Philadelphia, PA), and colleagues refer to these findings as a “call to arms” for US cardiologists.  

“This is not to say that the radial artery must be viewed as the exclusive or default route for cardiac procedures,” they write. “Like fine wine, the best medical care should have balance. The message to interventional cardiologists, both domestic and abroad, is that we best serve patients by having operators who are facile from both the arm and leg.” 

Also commenting on the study for TCTMD, Binita Shah, MD, of New York University School of Medicine (New York NY), agreed with the authors’ and editorialists’ stated benefits of radial access, but she pointed out that the technical demands of the procedure, as well as its steep learning curve, cannot be understated.  

 “There may be significant subclavian artery tortuosity and variation with respiration that may make it more difficult to cannulate the coronary artery of interest and provide good guide support during a PCI,” she observed in an email. “Additionally, the radial artery is more prone to vasospasm that can limit torque ability. Finally, the caliber of a patient’s radial artery may limit the use of larger devices.” 

These kind of limitations are becoming more infrequent as the technology advances and outcomes improve, Shah added. “The use of appropriate vasodilator agents, hydrophilic wires with a tight and smaller caliber J tip, universal catheters and guides, smaller sheath sizes, and the availability of long hydrophilic sheaths have allowed transradial operators to increase their PCI success rates in the most difficult of anatomy.” 

Overall, the data in favor of radial access are “compelling, and patient preference also leans towards a transradial approach,” she added. That’s led to an increase in the number of PCIs performed via the radial artery approach. “Our numbers in the United States, however, lag behind those in Europe and Canada, likely due to the need for an investment in time to gain the appropriate experience. This is difficult to do in our current system where time is associated with workload and the predominate systems are [relative value unit] (RVU)-based. “ 

1. Andò G, Capodanno D. Radial versus femoral access in invasively managed patients with acute coronary syndrome: systematic review and meta-analysis. Ann Intern Med. 2015;Epub ahead of print. 

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Meta-Analysis Boosts Case for Increased Use of Radial Access

  • Drs. Andò and Shah report no relevant conflicts of interest