Should physicians introduce the catheter (a long, thin tube) through the femoral artery (transfemoral access via the groin) or the radial artery (transradial access via the wrist) to reach the coronary arteries (blood vessels supplying the heart) for the diagnosis or treatment of coronary artery disease?
Coronary artery disease contributes to half of deaths caused by cardiovascular (heart and blood vessels) disease. Restoration of adequate blood flow through the coronary arteries can be achieved by introducing a catheter through a peripheral artery. This allows the introduction of balloons through the aorta (major artery of the heart) to dilate coronary artery narrowing or place arterial scaffolds (tubes called stents) to keep the coronary arteries open. Two main peripheral arteries can provide access; traditionally, the femoral (groin) artery, and more recently, the radial artery (one of two major arteries in the forearm). While gaining popularity, the transradial approach can be more challenging than the transfemoral approach, which may translate to longer procedural durations and technical failures. In addition, this raises concerns regarding radiation exposure to patients and physicians being higher with the transradial approach. We sought to compare the advantages and disadvantages of both approaches to help inform healthcare decisions.
Our search yielded 31 eligible studies comparing the transradial approach to the transfemoral approach in people undergoing diagnostic or therapeutic (or both) coronary catheterisation procedures in different settings, whether urgent (during heart attacks (myocardial infarctions)) or elective (planned procedure). The trials were carried out in many countries and regions, including Canada, China, Europe, Japan, and USA. We also identified two ongoing studies. The evidence was current to October 2017.
Transradial access was associated with a reduction in the composite outcome (comprising two or more combined outcomes) of net adverse clinical events (NACE), including death from cardiac causes, myocardial infarction (injury of the heart muscle), stroke (insult to the brain), need to reintervene on the same site of coronary artery stenosis (narrowing), and bleeding during the first 30 days following intervention. When assessing individual outcomes, the risk of myocardial infarction and stroke was similar between groups. Transradial access reduced death from cardiac causes, death from all causes during the first 30 days following intervention, bleeding, and local complications at the access site. The transradial approach shortened the length of stay in hospital, but was associated with a higher radiation exposure and more technical failures requiring an alternate vascular access route.
Quality of the evidence
We rated the quality of the evidence for short-term myocardial infarction and all-cause death as high. We rated short-term NACE, cardiac death, and success of the procedure as moderate quality evidence. Evidence for bleeding and access site complications was low quality.
Transradial approach for diagnostic CA or PCI (or both) in CAD may reduce short-term NACE, cardiac death, all-cause mortality, bleeding, and access site complications. There is insufficient evidence regarding the long-term clinical outcomes (i.e. beyond 30 days of follow-up).
Cardiovascular disease (CVD) is the major cause of mortality worldwide. Coronary artery disease (CAD) contributes to half of mortalities caused by CVD. The mainstay of management of CAD is medical therapy and revascularisation. Revascularisation can be achieved via coronary artery bypass grafting (CABG) or percutaneous coronary intervention (PCI). Peripheral arteries, such as the femoral or radial artery, provide the access to the coronary arteries to perform diagnostic or therapeutic (or both) procedures.
To assess the benefits and harms of the transradial compared to the transfemoral approach in people with CAD undergoing diagnostic coronary angiography (CA) or PCI (or both).
We searched the following databases for randomised controlled trials on 10 October 2017: Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, and Web of Science Core Collection. We also searched ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform in August 2017. There were no language restrictions. Reference lists were also checked and we contacted authors of included studies for further information.
We included randomised controlled trials that compared transradial and transfemoral approaches in adults (18 years of age or older) undergoing diagnostic CA or PCI (or both) for CAD.
We used the standard methodological procedures expected by Cochrane. At least two authors independently screened trials, extracted data, and assessed the risk of bias in the included studies. We contacted trial authors for missing information. We used risk ratio (RR) for dichotomous outcomes and mean difference (MD) or standardised mean difference (SMD) for continuous data, with their 95% confidence intervals (CIs). All analyses were checked by another author.
We identified 31 studies (44 reports) including 27,071 participants and two ongoing studies. The risk of bias in the studies was low or unclear for several domains. Compared to the transfemoral approach, the transradial approach reduced short-term net adverse clinical events (NACE) (i.e. assessed during hospitalisation and up to 30 days of follow-up) (RR 0.76, 95% CI 0.61 to 0.94; 17,133 participants; 4 studies; moderate quality evidence), cardiac death (RR 0.69, 95% CI 0.54 to 0.88; 11,170 participants; 11 studies; moderate quality evidence). However, short-term myocardial infarction was similar between both groups (RR 0.91, 95% CI 0.81 to 1.02; 19,430 participants; 11 studies; high quality evidence). The transradial approach had a lower procedural success rate (RR 0.97, 95% CI 0.96 to 0.98; 25,920 participants; 28 studies; moderate quality evidence), but was associated with a lower risk of all-cause mortality (RR 0.77, 95% CI 0.62 to 0.95; 18,955 participants; 10 studies; high quality evidence), bleeding (RR 0.54, 95% CI 0.40 to 0.74; 23,043 participants; 20 studies; low quality evidence), and access site complications (RR 0.36, 95% CI 0.22 to 0.59; 16,112 participants; 24 studies; low quality evidence).