Ongoing Trials Explore Potential Benefits of Transradial PCI

SAN FRANCISCO, CALIF.—Although several studies suggest lower rates of bleeding and access site complications with a transradial approach to PCI, large, multicenter, randomized trials are lacking. However, new data from one study shows an actual mortality benefit from transradial PCI, while several currently enrolling studies presented at TCT 2011 may shed light on the prospective benefits of such an approach compared with transfemoral access in the near future.

REAL Registry, MATRIX trial

Marco Valgimigli, MD, PhD, of the University of Ferrara, Italy, also described two ongoing studies comparing transradial PCI with femoral PCI.

The REAL Registry evaluated more than 11,000 STEMI patients undergoing primary PCI. Approximately 8,000 were transfemoral and more than 3,000 were transradial procedures. According to results currently in press, the transradial approach was associated with a 33% relative risk reduction in mortality. Excluding patients with shock, a 30% relative risk reduction was noted with transradial intervention. The researchers also observed a 27% relative risk reduction in death, MI and cerebrovascular accidents in this intervention group at 2 years. The gain occurred early and persisted unchanged over time, Valgimigli said.

In the MATRIX trial, Valgimigli and colleagues plan to randomly assign approximately 6,800 patients to transradial or transfemoral PCI followed by treatment with heparin or bivalirudin (Angiomax, The Medicines Company). The aim is to demonstrate that, compared with a femoral approach, transradial intervention is associated with a lower rate of the composite endpoint of death, MI or stroke within the first 30 days after randomization in ACS patients undergoing early invasive management.

The reference rate assumption is 6% in the transfemoral group and 4% in the transradial group, with 88% power and an alpha level of 0.01. According to Valgimigli, with a cohort of approximately 7,000 patients, the sample size will be increased 70% by the crossover rate.

Another primary endpoint is death, MI or stroke, and stent thrombosis after 30 days of treatment with heparin or bivalirudin.

STEMI-RADIAL

Currently enrolling, the STEMI-RADIAL study, designed by Ivo Bernat, MD, of the University Hospital Pilsen, Czech Republic, and colleagues aims to randomly assign 700 patients with STEMI to PCI via transradial or transfemoral access. Follow-up occurs 48 hours after the procedure and again at 30 days. Primary endpoints are incidence of major bleeding, per criteria outlined in HORIZONS-AMI, and access site complications. Secondary endpoints include MACE; access site failure; procedural success; contrast media consumption; procedural and fluoroscopic times; duration of hospital or ICU stays; target vessel or target lesion revascularizations; and new hospitalizations.

“We calculated that a sample size of 700 patients would provide 80% power to detect a 70% relative reduction in major bleeding and access site complications with radial approach compared with femoral approach with an alpha level of 0.05, assuming a reference rate of 6.5%,” Bernat said.

Currently, 590 patients have been enrolled in the study.

SAFE-PCI for women

Sunil V. Rao, MD, of Duke Clinical Research Institute, Durham, N.C., noted that a transradial approach may not be appropriate for all patients, particularly women. Compared with men, completing transradial procedures in women is more difficult, he noted, adding that women also have a higher risk for vascular complications, and a higher risk for bleeding after transradial PCI.

In response, Rao and colleagues designed SAFE-PCI for Women to determine the efficacy and feasibility of using transradial PCI in females. “This is the first large multicenter collaborative trial comparing radial and femoral approaches in the modern, post-RIVAL era. Moreover, it is one of only two interventional randomized trials in women,” Rao said. “It offers opportunities and challenges to answering important questions related to access site approaches and bleeding risks and will hopefully develop a template for future interventional trials.”

The researchers randomly assigned 1,800 women at 30 sites undergoing urgent or elective PCI to treatment with a transradial or a femoral approach. The primary efficacy endpoint was defined as bleeding or vascular complications requiring surgical intervention; the primary feasibility endpoint was procedural failure.

Assuming a rate of 8% for the primary composite endpoint in the femoral arm and a 50% reduction with the radial approach, the sample size of 1,800 patients provided more than 90% power at a two-sided alpha level of 0.05, Rao said.

EASY B2B

Olivier F. Bertrand, MD, PhD, of Laval University, Quebec, Canada, discussed the design and objectives of the EASY B2B trial comparing the use of bivalirudin with heparin in patients undergoing transradial PCI who are at high risk for bleeding.

“Residual bleeding risk remains a serious issue, and bleeding risks not associated with PCI procedures are frequent,” Bertrand said. “Strategies to reduce residual bleeding risk have yet to be defined, and the benefit of bivalirudin monotherapy compared with heparin monotherapy in patients at high risk for residual bleeding has yet to be demonstrated.”

Bertrand and colleagues intend to randomly assign approximately 2,500 patients to receive bivalirudin or heparin after transradial PCI. Primary endpoints are death, MI, urgent revascularization and BARC-defined types 2, 3 or 5 bleeding after 30 days of follow-up.

To date, approximately 432 patients have been recruited. They are on average aged 77 years, and most presented with ACS, unstable angina, STEMI and were already receiving some type of anticoagulant treatment prior to the procedure.

Disclosures
  • Dr. Bernat reports no relevant conflicts of interest.
  • Dr. Bertrand, Rao and Valgimigli report financial relationships with various companies.

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