January 25, 2019
6 min read

Transradial Access Emerging, but Questions Remain

Evidence for the transradial approach in PCI is mostly encouraging, but the transfemoral approach may be better for some patients.

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Transradial access is the most common approach for PCI in much of the world, though in the United States, despite an uptick in adoption, it still lags behind transfemoral access. The evidence suggests that the transradial approach is associated with better outcomes, particularly access-site bleeding, but questions remain about the validity of some of the head-to-head studies and the appropriate patient population.

Cardiology Today’s Intervention spoke with Cindy L. Grines, MD, FSCAI, FACC, Michael S. Lee, MD, FACC, FSCAI, and Jordan Safirstein, MD, FACC, FSCAI, about to what extent enthusiasm over the transradial approach is warranted.

Should transradial access be used in all PCI cases?

Cindy L. Grines, MD, FSCAI, FACC

The short answer is no. Even though I try to perform transradial access in most patients and it is my default strategy, there are several situations where transradial access is difficult and may result in substantial discomfort to the patient and prolonged procedural times. These may include patients in whom deeper sedation may be dangerous (more spasm if not adequately sedated), very short patients (difficult to engage due to short aortic root), small radial arteries often seen in patients with small wrists, elderly women with hypertension (small radial, tortuous subclavian), need for larger catheters for complex PCI, etc.

Cindy L. Grines

The available data indicate that transradial access is superior to femoral with regard to bleeding and vascular complications, and in patients with STEMI there appears to be a mortality advantage. How these data should be applied to U.S. practice is unclear given the following:

  • There was only one randomized trial conducted in the U.S. (SAFE-PCI), and it did not show any difference in bleeding.
  • The trials that showed benefit of transradial approach were all performed outside the U.S. and required that operators were very experienced with transradial PCI. Unfortunately, this meant that they were not very proficient with femoral access. In fact, the rate of bleeding and complications were much higher than expected in femoral patients, likely due to inexperience with the femoral approach. This paradox was nicely summarized in an editorial in Circulation: Cardiovascular Interventions.
  • The largest randomized trial (MATRIX) showed no reduction in bleeding with transradial PCI unless the center performed more than 65% of the cases by the transradial approach, and no reduction in net adverse clinical events (NACE) unless the center performed more than 80% of cases via the transradial approach. This was not due to improved outcomes in high-volume radial centers, rather it was due to a doubling of NACE, suggesting harm when the transfemoral approach is performed by physicians inexperienced in transfemoral technique.
  • Many of these trials did not use contemporary transfemoral tech-niques. Use of ultrasound-guided, micro-puncture techniques and vascular closure devices as well as no longer using glycoprotein IIb/IIIa agents have reduced the rate of femoral access-site bleeds.
  • U.S. physicians typically perform diagnostic catheterization with ad hoc PCI, and only one-third of diagnostic cases go on to receive PCI. Transradial catheterization requires higher-dose heparin (5,000 units recommended) than the transfemoral approach. Since the access site accounts for less than 50% of bleeding complications, there is some concern that “overall” bleeding could be increased in these diagnostic cath patients treated with high-dose heparin.

In summary, although transradial access is my default strategy and I strongly encourage operators to become proficient, I do not think it is mandatory. As with most invasive procedures, the outcomes are usually best when the operator chooses the technique with which they have the most experience.


Michael S. Lee, MD, FACC, FSCAI

Michael S. Lee

Despite various clinical trials reporting improved clinical outcomes with transradial intervention compared with transfemoral intervention, the majority of cases in the U.S. are still performed with transfemoral intervention. One important aspect of these trials is that they were designed and conducted predominantly by operators who perform the vast majority of their cases with transradial intervention. One could make the analogy that this is about as unfair as a football team making its own rules and hiring its own referees to officiate a football game.

The clinical trials that compared transradial intervention and transfemoral intervention did not mandate bleeding performance strategies like fluoroscopy to identify the femoral head, femoral angiography, ultrasound guidance for vascular access, optimal pharmacotherapy and vascular closure devices. In the ACUITY trial, the rate of 30-day major access-site bleeding was lower in patients who were treated with bivalirudin and a vascular closure device compared with patients treated with heparin plus glycoprotein IIb/IIIa inhibitor and no vascular closure device. In the RIVAL trial, the transfemoral intervention group included 24% who received a glycoprotein IIb/IIIa inhibitor, 11% who received thrombolytic therapy and 52% who received low-molecular-weight heparin. Although the mortality rate in the STEMI population was lower in the transradial intervention group (1.3% vs. 3.2%), it was not explained by lower non-CABG major bleeding (0.8% vs. 0.9%). Interestingly, in the non-STEMI population, the transradial intervention group had a trend toward higher mortality (1.2% vs. 0.8%) and the composite of death, MI or stroke (3.4% vs. 2.7%).

Other factors to consider are that radiation exposure for the operator and patient is higher with transradial intervention. Upper extremity dysfunction, including decreased fingertip sensation, wrist weakness and increased volumetry of the hand, was observed in 75% of patients who underwent transradial intervention.

One wonders if transfemoral intervention performed by experienced transfemoral intervention operators who used bleeding avoidance strategies would level the playing field and provide similar clinical outcomes compared with transradial intervention. As an interventional cardiologist who also performs peripheral interventions, it will always be an essential skill to obtain transfemoral access and minimize vascular access-site complications and bleeding with optimal technique.


Jordan Safirstein, MD, FACC, FSCAI

In my opinion, transradial access should always merit first consideration. Across all age groups, clinical scenarios (ACS, non-STEMI, STEMI), and the spectrum of complexity, the transradial approach to cardiac catheterization has maintained fewer vascular access complications, less bleeding, earlier ambulation and patient preference/comfort compared with the femoral approach. There is now more than 2 decades’ worth of evidence since Lucien Campeau, MD, first utilized the radial artery for diagnostic cardiac catheterization in 100 patients.

Jordan Safirstein

As the prevalence of the radial approach has increased, it has been expanded to higher-risk patient populations where it has demonstrated even greater benefit, achieving a significant mortality benefit in patients with STEMI and earning a class I indication for non-ST segment elevation ACS in the European Society of Cardiology guidelines. While the U.S. has lagged slightly behind, there has been consistent growth in its use each and every year, besting the 50% at our own institution and approaching that number nationwide.

There are very few “all” or “nevers” in medicine and the above question is no exception. For patients with diminished radial pulses, those on hemodialysis with an arteriovenous fistula or patients with certain vasculitides, the radial approach may be less desirable. There are other potential limitations, but the transradial approach should always be a consideration, and discussion of these risks and benefits should be undertaken with the patient prior to the procedure.

Earlier ambulation, fewer vascular access complications and greater patient comfort have been replicated in multiple studies and will be increasingly important as elective cardiac catheterization procedures have become classified as “outpatient,” essentially encouraging interventional cardiologists and their institutions to discharge stable patients on the same day. Additional studies have illustrated the significant cost benefit to transitioning from transfemoral overnight stays to same-day PCI programs, saving nearly $3,000 per patient with such changes.

The femoral technique will always have a place in the cardiac catheterization spectrum — especially with more refined techniques and the use of U.S. guidance and best practices to minimize complications — but given the excellent success rates of transradial intervention across all type of cases, decreased bleeding and vascular complications, faster ambulatory times and patient preference, all patients should be considered for #RadialFirst.

Disclosures: Grines, Lee and Safirstein report no relevant financial disclosures.