Marco Valgimigli, MD, PhD, of the University of Ferrara, Italy, described two ongoing studies (REAL Registry, MATRIX trial) comparing transradial PCI with femoral PCI at TCT 2011 on November 9th.
Large multicenter, randomized trials are lacking although several studies suggest lower rates of bleeding and access site complications with a transradial approach to PCI. More than 11,000 STEMI patients undergoing primary PCI were evaluated in the REAL Registry.
Approximately transfemoral and transradial procedures were 8,000 and more than 3,000 respectively. The transradial approach was associated with a 33% relative risk reduction in mortality. A 30% relative risk reduction (Excluding patients with shock) was noted with transradial intervention.
A 27% relative risk reduction in death, MI and cerebrovascular accidents were also observed in this intervention group at 2 years. Valgimigli said, the gain occurred early and persisted unchanged over time.
Valgimigli and colleagues in the MATRIX trial 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 objective of this trail is to demonstrate that, transradial intervention compared with a femoral approach 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 in the transfemoral group is 6% and 4% in the transradial group, with 88% power and an alpha level of 0.01.
With a cohort of approximately 7,000 patients, According to Valgimigli, the sample size will be increased 70% by the crossover rate. Death, MI or stroke, and stent thrombosis after 30 days of treatment with heparin or bivalirudin is another primary endpoint.
Another study, led by Ivo Bernat, MD, of the University Hospital Pilsen, Czech Republic, and colleagues, designed the STEMI-RADIAL study is currently enrolling and aims to randomly assign 700 patients with STEMI to PCI via transradial or transfemoral access.
Patients were followed up 48 hours after the procedure and again at 30 days. Incidence of major bleeding, per criteria outlined in HORIZONS-AMI, and access site complications were the primary endpoints.
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 were included as the secondary endpoints.
Bernat said “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%”. 590 patients currently have been enrolled in the study.
A second study led by 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.
He noted completing transradial procedures in women is more difficult as compared with men, adding that a higher risk for vascular complications and a higher risk for bleeding after transradial PCI are reported in women.
Rao and colleagues designed SAFE-PCI in response, for Women to determine the efficacy and feasibility of using transradial PCI in females. Rao said, “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”. “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.”
1,800 women were randomly assigned by the researchers at 30 sites undergoing urgent or elective PCI to treatment with a transradial or a femoral approach. Bleeding or vascular complications requiring surgical intervention was defined as the primary efficacy endpoint; procedural failure was the primary feasibility endpoint.
The sample size of 1,800 patients provided more than 90% power at a two-sided alpha level of 0.05 assuming a rate of 8% for the primary composite endpoint in the femoral arm and a 50% reduction with the radial approach, Rao said.
Apart from the studies mentioned above, the design and objectives of the EASY B2B trial were discussed by Olivier F. Bertrand, MD, PhD, of Laval University, Quebec, Canada, that compared the use of bivalirudin with heparin in patients undergoing transradial PCI who are at high risk for bleeding.
Bertrand said, “Residual bleeding risk remains a serious issue, and bleeding risks not associated with PCI procedures are frequent. 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.” Approximately 2,500 patients are intended to be randomly assigned to receive bivalirudin or heparin after transradial PCI.
Death, MI, urgent revascularization and BARC-defined types 2, 3 or 5 bleeding after 30 days of follow-up were the primary endpoints. Approximately 432 patients to date have been recruited who are of average age of 77 years, and most presented with ACS, unstable angina, STEMI and were already receiving some type of anticoagulant treatment prior to the procedure.