A registry analysis of PCI procedures found patient factors accounted for 20 percent of the overall hospital-level variation in bleeding.

The researchers added that bleeding avoidance strategies led to reduced levels of bleeding, although the use of those strategies accounted for less than 10 percent of the hospital-level variation in bleeding during PCIs.

Lead researcher Amit N. Vora, MD, PhD, of the Duke Clinical Research Institute, and colleagues published their results in the Journal of the American College of Cardiology: Cardiovascular Interventions on April 25.

“This study urges caution in the use of post-PCI bleeding as a performance measure, as a significant proportion of the hospital-level variation in bleeding remains unexplained,” they wrote. “More granular data collection and further analyses are necessary to explain this variation in bleeding rates to develop best practices to mitigate bleeding following PCI.”

The researchers noted that bleeding was common following PCI and was associated with an increased risk for mortality and stroke, an increased length of hospital stay and higher healthcare costs. They also mentioned hospitals often employ bleeding avoidance strategies such as transradial access, targeted periprocedutal anticoagulation with bivalirudin and the use of vascular closure devices.

For this analysis, the researchers evaluated data from the National Cardiovascular Data Registry’s CathPCI registry, the world’s largest quality improvement program for PCI. The American College of Cardiology and Society for Cardiovascular Angiography and Interventions co-sponsor the CathPCI registry, which capture data from more than 1,500 U.S. sites.

They identified 2,516,937 patients who underwent PCI at 1,453 hospitals between July 2009 and June 2013. They considered a patient as having received a bleeding avoidance strategy if the patient underwent PCI via radial artery access, received bivalirudin for periprocedural anticoagulation or received a vascular closure device to assist with hemostasis following the procedure.

Of the procedures, 5.1 percent had bleeding events. Patients with bleeding events had significantly lower rates of radial access (5.0 percent vs. 11.2 percent), bivalirudin therapy (43.8 percent vs. 59.4 percent) and vascular closure device use (32.9 percent vs. 42.4 percent) compared with patients who did not bleed.

The median hospital rate of bleeding was 5.0 percent. However, the researchers noted there was a wide variation in hospital bleeding rates from 2.12 percent in the 5^th percentile to 9.84 percent in the 95^th percentile.

After adjusting for bleeding risk and in-hospital clustering, the median hospital rate of bleeding was 5.14 percent. The range was similar to the unadjusted rates, too: 2.65 percent in the 5^th percentile and 9.36 percent in the 95^th percentile.

The median hospital rate of a bleeding avoidance strategy was 86.6 percent. Hospitals that used bleeding avoidance strategies at a higher rate also had a decreased probability of having their patients experience a bleeding event.

The researchers mentioned a few limitations of the study, including that sites may report bleeding events differently and that the CathPCI registry only captures in-hospital outcomes. The observational design also did not allow the researchers to exclude the potential of unmeasured confounders.

Patient factors accounted for 20 percent of the hospital-level variation, while radial access plus bivalirudin use accounted for an additional 7.8 percent of the hospital-level variation. Therefore, more than 70 percent of the variation in bleeding was unexplained.

“This analysis highlights the need for more investigation of the causes of site-to-site variability in PCI-related bleeding following PCI,” the researchers wrote.