The left distal radial approach (DRA) has been introduced as a feasible and safe alternative route of the radial artery. However, there is still lack of evidence for DRA regarding the feasibility, safety, effective time for hemostasis and hemostasis method. This prospective multicenter registry aimed to investigate the safety and efficacy of DRA for CAG and PCI.

Based on the results that radial approach (RA) reduced mortality and bleeding complications compared with femoral approach (FA), RA has become the standard of care for coronary angiography (CAG) and percutaneous coronary intervention (PCI). RA provides better comfortability for the patients and immediate mobilization after CAG or PCI. Therefore, 2018 ESC/EACTS guidelines recommend RA as the standard approach, unless there are overriding procedural considerations.

Operators usually prefer right RA because most of the operators are right-handed and right hand of the patient is closer to the operator. In contrast, longer distance to the left radial artery cause neck or back sprain of the operators, especially when the height of the operator is short, or the patient is obese. Nevertheless, left RA might be easier to manipulate catheter because of less tortuosity compared to the right RA and similar approach curvature with FA. Left RA also gives a chance to the right-handed patients to use their right hand freely.

Recently, the left distal radial approach (DRA) has been introduced as a feasible and safe alternative route of the radial artery. The left hand in the prone position is placed either on the left groin or beside the left hip according to operator preference. The operator punctures the distal radial artery around the anatomical snuffbox. After the first report for the feasibility and safety of left DRA in 70 patients, Lee et al. demonstrated that the success rates of arterial puncture, CAG and PCI were 95.5% (191/200), 100% (187/187), and 98.9% (86/87), respectively. The complication rates were only 7.9% including 14 (7.4%) minor hematomas and one (0.5%) arterial dissection. No serious complications were occurred such as distal radial artery occlusion, perforation, pseudoaneurysm, or arteriovenous fistula. Several studies for DRA also showed similar favorable results regarding procedural success and bleeding complications.

Radial arterial occlusion after RA remains an unsolved problem. According to the Leipzig prospective vascular ultrasound registry, the occlusion rate of radial artery was 14.4% in case of 5Fr sheath and 33.1% in 6Fr sheath, respectively. In this point of view, DRA could be a promising solution to lower the incidence rate of arterial occlusion. Moreover, DRA can have a potential benefit in patients requiring arteriovenous fistula and in patients who need the radial artery as a conduit for coronary artery bypass graft because of the absence of radial injury.

There is still lack of evidence for DRA regarding the feasibility, safety, effective time for hemostasis and hemostasis method. Unknown complications related to DRA also should be addressed. Therefore, this prospective multicenter registry aimed to investigate the safety and efficacy of DRA for CAG and PCI.

Inclusion Criteria:

• Patients aged ≥ 20 years who planned coronary angiography
• Patients with palpable distal radial artery
• Patients who give informed consent

Exclusion Criteria:

• Patients with small or non-palpable distal radial artery
• Positive result in modified Allen test (suspicious of single blood supply)
• Pregnant women, possible candidate for pregnancy, or breastfeeding women
• Patients who are deemed unsuitable by the investigator

Patients who need coronary angiography will be enrolled.