Randomized controlled trial of adaptive design for the safety and efficacy of coronary angiography and percutaneous coronary intervention via distal transradial access using a 6-French Glidesheath Slender in patients with small vessels.

The safety and efficacy of coronary angiography and percutaneous coronary intervention via distal transradial access (dTRA) have been confirmed by a large number of studies, but there are still few studies on its safety and efficacy in patients with small vessels (distal radial artery diameter < 2.0mm). The 6-French Glidesheath Slender, with its smaller outer diameter, should be more suitable for patients with small vessels. To this end, we plan to conduct a single-center, adaptive, randomized controlled trial enrolling 594 patients aged 18-85 years old with distal radial artery diameters <2.0 mm and ≥1.0 mm who are scheduled to undergo coronary angiography and percutaneous coronary intervention via the distal radial artery approach in our center. The study employed a stratification-block randomized design. Stratification was performed based on patient gender, with a block size of 4 within each stratum. Eligible patients were randomly assigned in a 1:1 ratio to either the 6-French Glidesheath Slender group or the 6-French conventional sheath group.

The primary endpoint of the study was distal radial artery occlusion assessed by vascular ultrasound 24 hours postoperatively. Secondary endpoints included puncture success rate, procedure success rate, number of punctures, puncture time, total procedural time, visual analogue scale pain scores during sheath placement, bleeding, hematoma, arteriovenous fistula, finger numbness, and conventional radial artery occlusion at 24 hours postoperatively.

An interim analysis will be conducted when 50% of the total sample size (297 patients) is enrolled, with subsequent sample size adjustments based on preliminary study results.

The results of this study will provide evidence for the safety and efficacy of 6-French Glidesheath Slender for coronary angiography and percutaneous coronary intervention in patients with small vessels via distal transradial access, and provide information for the selection of the best sheath equipment for patients with small vessels.

Inclusion Criteria:

• Age between 18 and 85 years
• Palpable pulses in both the distal radial artery and conventional radial artery
• All patients signed informed consent forms prior to procedure

Exclusion Criteria:

• Ultrasound assessment of the distal radial artery diameter ≥2.0mm or <1.0mm
• Height ≥185.0cm
• Patients with acute ST-segment elevation myocardial infarction, cardiogenic shock, or hemodynamic instability
• Contraindications for puncture of the distal radial artery
• Patients with Raynaud's syndrome
• Patients with coagulation disorders or hematologic diseases
• Patients currently enrolled in other clinical studies

Because cardiac interventionalists need to know which arterial sheaths to use during the procedure, therefore it is not possible to blind them to this information. But, the investigators responsible for outcome assessment and the personnel responsible for preoperative and postoperative radial artery ultrasound evaluations will be blind of this.