Percutaneous coronary angiography is used for the diagnosis and treatment of coronary artery disease. This procedure allows interventionalists to view the coronary arteries and identify blockages that may be reducing blood flow to the heart muscle. Percutaneous coronary interventions (PCI) involve the insertion of a stent in a blocked coronary artery, to revascularise the heart muscle. Advances in PCI techniques have resulted in the increasing use of this treatment modality, thereby reducing the need for coronary artery bypass surgery[1]. This results in significant improvements in patient outcomes and a reduction in health and personal costs[1].
Historically, the femoral artery was the main access site for angiography[2]. However, with improved technologies, other access points have become feasible options, including the radial, distal radial and ulnar arteries[3]. Evidence from a systematic review of randomised control trials found that the transradial approach (TRA) was associated with a decrease in short-term net adverse clinical events, reduction in cardiac death[4, 5], lengths of stay, access site complications[6], bleeding, short term mortality and increased patient satisfaction[7]. Given the benefits, the European Society of Cardiology guidelines for the management of ACS now indicates that TRA should be used for most patients under most circumstances (Class 1 recommendation) as the preferred route of access[8].
Despite the benefits associated with TRA, international rates of uptake of the approach have varied and range from 16.1% in the United States[9] to 73% in Italy[10]. The variable uptake in rates has been associated with risks and complications associated with TRA, limited learning opportunities and a prolonged learning curve for the interventionalists[8]. The risks and complications associated with TRA are multifactorial. Firstly, patients can be exposed to a significantly increased fluoroscopy time and so receive a larger radiation dose when compared to transfemoral procedures, the radiation dose received can also be significantly increased depending on the complexity of the procedure [7, 11]. The main complication associated with TRA is radial artery spasm (RAS)[12], which has been reported to occur in some 30% of TRA procedures[13–15]. This is the sudden constriction and narrowing of the radial artery leading to difficulty in the advancement of the catheter and can result in procedural failure[16]. Procedural failure requires a cross-over to an alternate access site resulting in longer procedural time and increased risk of complications associated with the alternate access site[7, 15].
Various factors including patient demographics, presence of cardiovascular risk factors, anatomy of the radial arteries and procedural factors have been reported to increase the risk of RAS[12, 17–20]. Patient demographics linked to higher rates of RAS include female gender, increased age, smaller height, and lower weight[12, 17, 18]. Cardiovascular risk factors identified to increase the occurrence of RAS include hypertension, smoking, and anxiety[17, 19, 20]. Additionally, procedural factors, such as more than one radial puncture attempt or insertion of a ≥ 7F sheath have also been reported to predict RAS[18]. Based on the various factors that increase the risk of RAS, a predictive score for RAS has been developed, that includes body mass index (BMI), height, hypertension, current smoking status, and peripheral artery disease[17, 18, 21]. The predictive scores enable the implementation of strategies to prevent the occurrence of RAS. Much of these data have been drawn from international research and little research has been undertaken in the Australian context to understand the predictors of RAS and variations between countries.
Various prevention strategies including medications and specialised procedural equipment have been reported in an attempt to reduce RAS. Medications used include vasodilators, calcium channel blockers, sedation and analgesia, or a cocktail of these medications[22–24]. A systematic review found that vasodilatory medications demonstrated a reduction in the occurrence of RAS; however, there is insufficient evidence to identify a superior medication, dose or combination[25]. Prevention strategies related to specialised equipment include the use of hydrophilic equipment, special 6-in-5F sheaths, keeping catheter exchanges to a minimum and avoiding cold intra-arterial injections[26]. These strategies are designed to reduce friction and stimulation of the arterial wall subsequently reducing the occurrence of spasm. To date there has been limited exploration of the practices around RAS prophylaxis in the Australian setting or predictors of RAS for the Australian population.
Once RAS has occurred, it can result in the inability to complete the procedure or in severe cases, may require surgery. Management options to relieve RAS include vasodilators such as nitrates administered via the radial sheath or the intravenous catheter. Other approaches recommended include warm compresses on the external aspect of the affected area[13]. Although this may provide some comfort to the patient the effectiveness of this method requires further research as there is minimal evidence to support this approach.
Given the limited evidence in the Australian context about RAS this study sought to identify predictors, prevention and management of RAS and explore practices concerning TRA for coronary artery catheterisation in Australia. This study is part of a larger study, AnxieTy, health Literacy and radial Artery Spasm (ATLAS) study, which aimed to identify the association of anxiety and health literacy in relation to radial artery spasm during coronary angiography.