Radial-First STEMI Approach Need Not Compromise Door-to-Balloon Time

Transradial primary percutaneous coronary intervention (TR-PPCI) for ST-elevation myocardial infarction (STEMI) can be successfully adopted by a hospital system without harming door-to-balloon time performance.

That’s the conclusion from an analysis of more than 1,200 patients treated at Cleveland Clinic over a six-year period during which door-to-balloon times significantly improved despite a more than 25-fold increase in the use of TR-PPCI. The study was published in Catheterization & Cardiovascular Interventions (2020 Feb 27 [Epub ahead of print]).

“Concerns about a radial-first STEMI approach potentially lengthening door-to-balloon times have contributed to slow adoption of this approach in the United States,” says the study’s corresponding author, Umesh Khot, MD, Head of Regional Cardiovascular Medicine at Cleveland Clinic. “Our findings indicate that a high use rate of this procedure can be achieved without compromising the critical gains in treatment time that have been made over the past 20 years.”

Lagging adoption of the transradial approach

TR-PPCI remains underutilized in the U.S., with an overall use rate estimated at less than 25%. This is despite the fact that TR-PPCI offers a mortality benefit relative to transfemoral (TF) PPCI and has a class 1A indication in the 2017 European STEMI guidelines. A major contributor to its lagging adoption is likely the assumption that it lengthens door-to-balloon time, a key hospital-level STEMI quality metric that is closely associated with risk of early death.

Prior investigations comparing TR and TF approaches to PPCI have used various study designs and resulted in conflicting findings. “Our analysis was prompted by the need for more evidence on this question based on experience from hospitals that have adopted TR-PPCI,” explains lead author Chetan Huded, MD, MSc, an interventional cardiology fellow at Cleveland Clinic.

Study design and population

Data were analyzed from 1,272 consecutive patients from a Cleveland Clinic observational registry who were treated for STEMI with PPCI from January 2011 through December 2016. During that time, the annual rate of TR-PPCI attempts rose from 2.6% in 2011 to 79.4% in 2016.

Of the total study sample, 551 patients were initially treated with attempted TR-PPCI, with the following results:

• 494 attempts (89.7%) were successful
• 57 cases (10.3%) required crossover to TF-PPCI

The remaining 721 patients were treated with attempted TF-PPCI, with the following results:

• 719 attempts (99.7%) were successful
• 2 cases (0.3%) required crossover to TR-PPCI

Propensity score matching was performed to enable comparison of similar-risk patients treated with each procedure, yielding 273 well-matched pairs.

Results: Times improved, with no between-group differences

The analysis yielded two broad findings, detailed below.

1)Door-to-balloon performance improved over time. Overall, door-to-balloon time decreased from a median of 102 minutes (interquartile range, 81-142) in 2011 to 84 minutes (60-105) in 2016 (P < 0.001 for trend).

In the TR-PPCI group specifically, median time decreased from 102 minutes (80-129) in 2011 to 85 minutes (60-104) in 2016 (P < 0.001 for trend).

2) Median door-to-balloon times were similar between the two approaches.No significant differences were found in any year between the transradial and transfemoral approaches.

Additionally, no significant difference was found between patients with successful TR-PPCI (91 minutes [72-112]) and those who required crossover to TF-PPCI to complete the procedure (99 minutes [70-115]) (P = 0.432). Moreover, no significant difference was found between patients with initial TR-PPCI who required crossover to TF-PPCI (99 min) and those undergoing initial TF-PPCI (103 min) (P = 0.139).

Propensity matching analysis found no significant difference between the initial TR-PPCI group (98 minutes [78-117]) and the initial TF-PPCI group (101 minutes [76-132]) (P = 0.304).

Becoming a radial-first hospital

According to Dr. Khot, the Cleveland Clinic experience demonstrates that a significant ramp-up in use of a radial-first approach to STEMI can be successfully implemented in a large hospital. He and his co-authors recommend several key strategies to optimize the transition:

• Adopt radial access as the default approach for STEMI patients. To accomplish this, “additional training is likely needed to get the entire healthcare team up to speed,” advises Dr. Khot. “We invited outside experts to teach our physicians and nurses tricks of the trade and ways to improve workflow.”
• Train current operators, not just the next generation. Studies have shown that physicians who have been in practice since before 2012 are less likely to use a transradial approach. But since this demographic performs the vast majority of PCIs for STEMI, it is critical to increase utilization of radial access among these veteran physicians as well as among those more recently trained.
• Don’t be intimidated. The authors acknowledge the technical challenges inherent in the transradial approach, which can be heightened under time pressure. But they note that research has demonstrated that the mortality benefit of adopting the transradial strategy is high enough to offset an additional 21 minutes of door-to-balloon time. Operators should also accept the fact that crossover to TF-PPCI will be needed at times, and that this can occur without causing major delay.

“We expect that our experience would be applicable to other large centers with a high caseload,” observes study co-author Samir Kapadia, MD, Chair of Cardiovascular Medicine at Cleveland Clinic. “STEMI outcomes can be improved nationwide if the transradial approach is widely adopted.”