Operators more often chose transfemoral over transradial PCI in a patients with higher predicted bleeding risks, despite evidence of fewer bleeding complications with the latter approach. Transfemoral PCI patients also tended to be sicker, according to this observational study.

Michael J. Howe, MD, of the Frankel Cardiovascular Center at the University of Michigan in Ann Arbor, and colleagues evaluated trends in the use of radial PCI in Michigan with data from the Blue Cross Blue Shield of Michigan Cardiovascular Consortium database. They identified 122,728 procedures done in 47 hospitals between 2010 and 2013 that met their inclusion criteria.

Of the nearly 120,000 patients in the study, 14.8 percent underwent transfemoral PCI. When the diagnosis was STEMI, 8.3 percent of cases used radial access and when the diagnosis was non-STEMI, unstable angina or nonacute coronary syndrome, 15.6 percent of cases were radial.  

The median predicted bleeding risk for STEMI cases was higher in transfemoral cases than transradial cases, at 2.3 percent vs. 2.1 percent. For the other indications, the rates were 1.1 percent with transfemoral and 1 percent with transradial. At baseline, patients with STEMI on average were older with lower ejection fractions and were more likely to have renal dysfunction and a lower body mass index.

“Although we excluded those patients in shock or after cardiac arrest, it seems clear from our data that sicker patients are, in general, still preferentially being selected for [transfemoral access],” Howe et al wrote.

Adoption of the transradial approach increased over time for PCI patients with STEMI and other indications but was much slower with STEMI patients. The rate of increase was about 1.2 percent per quarter in STEMI cases vs. about 2 percent per quarter with other indications. But throughout the study period, the use of a transradial approach decreased with increasing bleeding risk for all indications.

In adjusted and propensity-matched analyses, they found no differences in mortality between the two access approaches but compared with transfemoral access, transradial PCI had lower incidence of bleeding, transfusions and vascular complications with similar rates of postprocedural contrast-induced nephropathy and stroke.

Howe and colleagues called these finding a paradox, “given the widely reported benefits of [transradial access] for bleeding complications and our own data.” They suggested that some operators may be selecting lower-risk patients for transradial PCI as they develop their skills and gain experience. As their radial-access case volume grows, so might their confidence with radial PCI in the STEMI setting.

The results suggest transradial PCI is underused in situations where it might offer the greatest benefit, though, they wrote. They published their study in the May issue of Circulation: Cardiovascular Interventions.