Radial PCI Plus Bivalirudin Effective in Lowering Bleeding Risk

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The combination of bivalirudin and transradial access results in less bleeding after percutaneous coronary intervention (PCI) than either radial access alone or the combination of femoral access, bivalirudin, and vascular closure devices, according to registry data published online August 6, 2013, ahead of print in Circulation: Cardiovascular Interventions.

Investigators led by Sunil V. Rao, MD, of Duke University Medical Center (Durham, NC), looked at the association between arterial access site, bivalirudin, and periprocedural bleeding in 501,017 patients from the CathPCI Registry who underwent PCI between July 2009 and March 2012. Radial access patients receiving heparin (radial group; n = 63,037) were compared with those receiving bivalirudin (radial combination group; n = 55,188). Femoral access patients who had bivalirudin and a vascular closure device served as a reference group (femoral group; n = 382,792).

Radial Combination Better Than Radial Alone

The overall bleeding rate was 2.59%: 2.71% in the femoral group vs. 2.5% in the radial group and 1.82% in the radial combination group (P < 0.0001). There were no differences among the groups for in-hospital death, stroke, or periprocedural infarction (P = NS for all).

Inverse probability weighting analysis incorporating propensity scores found the risk of bleeding to be lower for patients in the radial combination group, but not those in the radial group compared with the femoral group (table 1).

Table 1. Risk of Bleeding Events

The association between the radial combination and reduced bleeding was seen across the spectrum of bleeding risk, with a number needed to treat (NNT) of 561 in low-risk patients, 253 in medium-risk, and 68 in high-risk patients. The overall NNT to prevent 1 bleeding event with the radial combination strategy was 138.

Radial Does Not Guarantee No Bleeding

According to Dr. Rao and colleagues, the use of glycoprotein IIb/IIIa inhibitors and unfractionated heparin among patients undergoing transradial PCI may reflect “a sense of false security that the radial approach affords a reduction in total bleeding.” In fact, they note, radial access has not been shown to reduce nonaccess-site bleeding.

Additionally, they say the inclusion of patients with femoral access, bivalirudin, and a closure device was an attempt to compare radial access with the default state of the art bleeding avoidance strategy currently used in the United States. Unfortunately they add, prior studies have shown a risk-treatment paradox in the use of this strategy in that while it is associated with lower bleeding rates, particularly among patients at greatest risk for bleeding, it is used less often in higher-risk patients (Marso SP, et al. JAMA. 2010;21:2156-2164).

Similarly, a risk-treatment paradox exists within the radial-bivalirudin combination strategy, the authors write. This may be due to the substantial learning curve with radial access and “reluctance to switch from heparin to bivalirudin for ad hoc PCI because of concerns over increasing bleeding risk, incurring higher costs, or insufficiently developed clinical protocols.”

Additive Effect of Bivalirudin Sends Strong Message

Ian C. Gilchrist, MD, of Hershey Medical Center (Hershey, PA), told TCTMD in a telephone interview that he performs 90% of PCIs radially with bivalirudin, and thus was not surprised by the risk-treatment paradox.

“If you have an intervention that is supposed to reduce the risk of something, you’d expect to get the biggest bang for your buck if you use it on those at the highest risk of having that problem, but time and again we see those at highest risk of bleeding being more likely to get a femoral procedure when we know radial reduces bleeding risk more,” he said.

It is an interesting conundrum, Dr. Gilchrist added, especially with the high cost of bivalirudin. “So you would think the most rational approach would be to reserve bivalirudin for those at highest risk of bleeding in the radial population and treat the lowest risk patients with radial and heparin.”

Dr. Gilchrist said while the overall risk of bleeding was low in all groups, the additional reduction with the combination of bivalirudin and radial access sends a strong message to operators—regardless of their feelings on access site choice—that there is always room for improvement.

“Many people feel strongly that by using bivalirudin and a closure device they’ve solved the bleeding problem,” he said. “These data clearly show that [by doing that] you still are not getting bleeding rates to the point where it’s just like a radial procedure. And this also provides a carrot to radial operators that they can improve on bleeding outcomes by looking to the pharmacology side of things.”

Dr. Gilchrist said while randomized trials are still needed for confirmation, the large number of patients in the registry and the careful analysis suggest the findings are “pretty close to the truth.”

Source:

Baklanov DV, Kim S, Marso SP, et al. Comparison of bivalirudin and radial access across a spectrum of preprocedural risk of bleeding in percutaneous coronary intervention: Analysis from the National Cardiovascular Data Registry. Circ Cardiovasc Interv. 2013;Epub ahead of print.

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