Radial versus Femoral Access for Invasive Coronary Procedures

New Orleans—A large randomized study has concluded that radial access is no less effective than femoral access for patients with acute coronary syndromes (ACS) who are undergoing procedures requiring vascular access, such as coronary angiography and percutaneous coronary intervention (PCI). The RIVAL (Radial vs Femoral Access for Coronary Intervention) trial also reported similar 30-day rates of adverse events with both approaches, with the exception of major vascular complications at the access site, which were significantly less likely to occur with radial access. Sanjit Jolly, MD, an interventional cardiologist at Hamilton Health Sciences and assistant professor at McMaster University in Hamilton, Canada, who presented findings from RIVAL at the ACC meeting, said most study participants repeating coronary angiography or PCI preferred vascular access via the radial artery, and these data support its use. Although femoral and radial arteries are used to secure vascular access at cardiology practices worldwide, it is more common in the United States to enter through the femoral artery. In published findings from the RIVAL study appearing in The Lancet [2011;377(9775):1409-1420], investigators said because the radial artery is a “superficial and readily compressible site,” they had anticipated fewer bleeding events with radial access than with femoral access. Noting that observational studies have linked major bleeding to increased mortality and morbidity from ischemic events, the researchers had predicted radial access would reduce the combined risk of death, major bleeding unrelated to non–coronary artery bypass graft (non-CABG), myocardial infarction (MI), and stroke, a hypothesis supported by their updated meta-analysis of 28 small, randomized, controlled trials (n=8404) comparing femoral and radial access. RIVAL, a multinational, randomized trial, enrolled 7021 patients (median age, 62 years) with ACS; ~half had ST-segment elevation myocardial infarction (STEMI) and half had non–ST-segment elevation myocardial infarction. Patients were included if they had an invasive vascular procedure planned with an interventional cardiologist who was experienced in radial and femoral access, having performed ≥50 radial procedures for coronary angiography or PCI. Nearly three quarters of patients were men, approximately one third were smokers, and all had intact circulation in both hands. RIVAL’s primary end point was the combined rate of death, MI, stroke, and non-CABG bleeding in the 30 days postprocedure. Secondary end points included assessments of each of the primary end point’s event type and a composite end point of death, MI, and stroke at 48 hours and 30 days. Other end points were rates of PCI success, major vascular complications, and minor bleeding events. Patients were randomized to radial (n=3507) or femoral access (n=3514). Baseline characteristics were balanced between the groups, with similar proportions of patients presenting with hypertension, diabetes, MI, and peripheral vascular disease. After randomization, 99.8% of patients in each arm underwent coronary angiography. In the radial access group, 65.9% of patients had PCI and 94.6% received stents versus rates of 66.8% for PCI and 95.1% for stents in the femoral access group. Treating physicians selected the antithrombotic regimen and, for femoral access patients, any vascular closure device. At 30 days postprocedure, 3.7% (128) of radial access group patients had experienced MI, stroke, or non–CABG-related bleeding or had died compared with 4.0% (139) of patients in the femoral access arm (hazard ratio [HR], 0.92; 95% confidence interval [CI], 0.72-1.17; P=.50), a nonsignificant difference. Analysis of each event category found no significant differences between the study arms. A non-CABG bleeding event was considered major if it met one of several prespecified criteria, such as causing death or severe disability or requiring surgery. The 30-day rate of non-CABG major bleeding was relatively low: 0.7% (24) in the radial arm compared with 0.9% (33) in the femoral group (HR, 0.73; 95% CI, 0.43-1.23; P=.23). Most non-CABG major bleeding (68%) originated distant to the access site, with 37% in the gastrointestinal tract; smaller proportions originated intracranially or pericardially. RIVAL investigators said the access site used is probably unrelated to distant bleeding episodes. A post hoc analysis assessing major bleeding according to parameters outlined in the ACUITY (Acute Catheterization and Urgent Intervention Strategy) trial found a significantly lower rate with radial access than with femoral access (1.9% vs 4.5%, respectively; HR, 0.43; 95% CI, 0.32-0.57; P<.0001). The authors said this corresponded with updated findings from the meta-analysis, which associated radial access with a significant reduction in the rate of non-CABG major bleeding (P=.0003). Radial access patients in RIVAL had a significantly lower rate of major vascular complications, which encompassed pseudoaneurysms requiring closure,large hematomas, arteriovenous fistulas, and ischemic limbs needing surgical repair. Only 1.4%(49) of patients given radial access experienced a major vascular complication compared with 3.7% (131) with femoral access (HR, 0.3 7; 95% CI, 0.27-0.52; P<.0001). Large hematomas were the most frequent complication, developing in 1.2% (42) of patients with radial access and 3.0% (106) of patients with femoral access (P<.0001). Subanalyses demonstrated no significant relationship between age, sex, and body mass index and the trial’s primary end point. Stratifying primary end point data according to ST-segment elevation showed that patients with STEMI benefited more from radial access than did patients with non–ST segment elevation (2.7% vs 3.4%, respectively; P=.18). In patients with STEMI, the mortality rate was lower with radial access than with femoral access (1.3% vs 3.2%, respectively; P=.006) as was the combined rate of death, MI, and stroke(2.7% vs 4.6%, respectively; P=.031). Nearly all PCI procedures were successful, with a 95.4% radial access success rate and a 95.2% femoral access success rate. The time it took to perform the procedure was similar with radial and femoral access as was the duration of hospitalization. Small percentages of patients in the radial and femoral arms reported persistent pain at the access site, lasting >2 weeks (2.6% vs 3.1%, respectively; P=.22). Interventional cardiologists who treated patients enrolled in RIVAL were very experienced, executing a median of 300 PCI procedures annually. The authors pointed out that this exceeds the median rate of PCI procedures performed at US centers each year and suggests RIVAL’s surgeons were highly adept at femoral access procedures, likely accounting for the unexpectedly low rate of major bleeding (0.1%) in the femoral access group. In Dr. Jolly’s ACC presentation, he proposed that as cardiologists gain experience in performing radial procedures, outcomes with radial access would improve. RIVAL was not sufficiently powered to offer a conclusive assessment of relative risk reduction on the composite primary outcome. However, Dr. Jolly and associates said the study did demonstrate that both approaches to providing vascular access are safe and effective when performed by an experienced interventional cardiologist.