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Transradial percutaneous coronary intervention (PCI) is not associated with reduced bleeding in patients with non-ST-segment elevation acute coronary syndromes (NSTE ACS), according to an analysis from a large trial. The reason, according to the study, published online February 25, 2013, ahead of print in the American Heart Journal, is that the technique may be preferentially used in lower-risk patients.
Researchers led by Sunil V. Rao, MD, of the Duke Clinical Research Institute (Durham, NC), examined post-procedural bleeding and ischemic endpoints in 9,126 NSTE ACS patients enrolled in the multicenter, multinational EARLY-ACS trial of early vs. delayed provisional eptifibatide in ACS. Of these, 86.5% underwent intervention via the femoral approach and 13.5% via the radial approach.
Similar Bleeding Rates
Rates of TIMI major bleeding within 120 hours of randomization were similar between radial and femoral patients (1.6% vs. 2.2%; P = 0.204). Among TIMI major bleeding events, more were access site bleeds in the femoral group compared with the radial group (30.1% vs. 15.05%; P = 0.152).
GUSTO moderate or severe bleeding was more frequent in the femoral group, but the difference was not significant after multivariable adjustment (P = 0.105). GUSTO moderate/severe bleeding also was similar when the analysis was restricted to patients who did not undergo CABG, and the proportion of all access-site bleeds tended to be higher in the femoral group (P = 0.261).
Rates of death/MI/recurrent ischemia requiring urgent revascularization/thrombotic bailout at 96 hours or death/MI at 30 days were not different between the study groups, even after multivariable adjustment. However, radial access was less likely to be associated with 1-year mortality compared with femoral access (adjusted HR 0.57; 95% CI 0.39-0.85; P = 0.006).
Transfusion rates were lower in the radial group, but this difference did not persist after multivariable adjustment (P = 0.483). Stroke occurred in 0.2% of the study cohort regardless of access site.
The authors also found substantial regional variations in the rate of use of radial access with the highest rates in Norway and lowest in Turkey. Overall, radial use was higher in non-US countries compared with the United States (17.0% vs. 2.2%; P < 0.001).
Preference, Nonaccess Site Bleeding Implicated
“The preferential use of radial access in lower-risk patients likely accounts for our inability to show a relationship between radial access and lower bleeding complications,” Dr. Rao and colleagues write. They add that the findings are consistent with those from RIVAL, the largest randomized trial to date comparing radial vs. femoral access (Jolly SS, et al. Lancet. 2011;377:1409-1420). RIVAL showed no difference in the incidence of death, MI, stroke, or non-CABG-related major bleeding between the radial and femoral arms at 30 days, although there was a reduction in major vascular access site complications among patients assigned to radial access.
The study authors also point out that in EARLY-ACS, the use of antithrombin agents (unfractionated or low molecular weight heparins) was similar between the randomized arms and “unlikely to explain the lack of difference in bleeding rates between radial and femoral access.” There also were no interactions between randomized treatment (early eptifibatide vs. early placebo with delayed, provisional eptifibatide use) and GUSTO moderate/severe or TIMI major bleeding or transfusion.
“The most likely explanation is that non-access bleeding, which is more common in ACS patients, overwhelmed the access-site bleeding, thus diluting any effect of access site choice,” Dr. Rao and colleagues write. “Another possibility is that the TIMI and GUSTO definitions of bleeding may not be sensitive enough to detect differences in bleeding between radial and femoral access.”
Furthermore, the study authors say the mortality difference cannot be ascribed solely to the radial approach given the lack of differences in explanatory events such as MI or bleeding and suggest that “whether wider adoption of radial access to higher bleeding risk patients, such as the elderly or women, will also result in better outcomes is unclear, and should be the subject of future investigations.”
Benefits of Radial Extend Beyond Endpoints
In a telephone interview with TCTMD, Philippe Généreux, MD, of Columbia University Medical Center (New York, NY), agreed with this conclusion.
“We need a prospective, randomized trial of comparable-risk patients using contemporary antithrombotic regimens to really judge the impact of radial compared with femoral. That being said, even if the results showed no big difference in terms of bleeding or ischemic endpoints, there are multiple other advantages of radial that should be emphasized including cost reduction, early ambulation and patient comfort and preference,” he said. “These are important factors in the equation because we know that patients would like to be able to get up sooner and go home earlier after their procedure.”
Dr. Généreux added that the findings represent an important snapshot of how operators around the world are practicing and said the study suggests a level of discomfort with radial in many patient subsets, “which may be okay, but we don’t know enough [about patient selection] from a study like this.”
In addition, he said the mortality difference at 1 year most likely reflects the fact that patients chosen for radial were healthier and therefore had better prognoses from the start.
Ongoing trials looking at comparisons of radial vs. femoral access in higher risk subgroups will likely provide more information on this topic. One such trial noted by the study authors is SAFE-PCI for Women, a prospective trial of 3,000 women. Two others, according to Dr. Généreux, are SAFARI-STEMI and MATRIX, both of which involve the use of bivalirudin and are expected to be complete in 2014 and 2015, respectively.
Patients undergoing radial procedures were younger, male, and were less likely to have a history of diabetes, dyslipidemia, hypertension, or prior CABG. Radial patients also had lower TIMI risk score and Killip class at presentation, but more often had ST-segment changes on ECG.
Klutstein MW, Westerhout CM, Armstrong PW, et al. Radial versus femoral access, bleeding and ischemic events in patients with non–ST-segment elevation acute coronary syndrome managed with an invasive strategy. Am Heart J. 2013;Epub ahead of print.