Use of subcutaneous nitroglycerin to facilitate transradial access in coronary procedures (NiSAR Study)

Abstract

Introduction and objectives: We assessed whether the routine use of subcutaneous nitroglycerin prior to a cannulation attempt improves transradial access significantly (the NiSAR study [subcutaneous nitroglycerin in radial access]). Methods: Patients undergoing a coronary angiography were enrolled in a prospective, double-blind, multicenter, randomized trial in 2 groups (nitroglycerin group vs control group). The primary endpoints were the overall number of puncture attempts, access and procedural time, switch to transfemoral access, and local perceived discomfort score. The secondary endpoints were the pre- and post-anesthetic pulse score. A subgroup of patients underwent ultrasound scans performed through the radial artery. Results: 736 patients were enrolled in the trial: 379 in the nitroglycerin group and 357 in control group. The average number of puncture attempts was similar (1.70 vs 1.76; P = .42). Access and procedural time did not change significantly (61.1 s and 33.3 s vs 63 s and 33.4 s; P = .66 and P = .64, respectively). No significant differences were found either between the 2 groups in the number of switches to transfemoral access (7.1% vs 8.4%; P = .52). However, the average local perceived discomfort score and post-anesthetic pulse score were significantly better in the nitroglycerin group (2.34 vs 2.76; P < .001 and 2.47 vs 2.22; P < .001). The ultrasound scan performed through the radial artery showed post-anesthetic radial artery lumen diameters that were significantly higher in the nitroglycerin group in both the longitudinal (3.11 mm vs 2.43 mm; P = .002) and cross-sectional planes (2.83 mm vs 2.41 mm; P = .002). A trend towards fewer local hematomas in the nitroglycerin group was seen (6.1% vs 9.8%; P = .059). Headaches were more common in the nitroglycerin group (3.2% vs 0.6%; P = .021). Conclusions: The routine use of subcutaneous nitroglycerin prior to radial puncture was not associated with fewer punctures or shorter access times. However, the lower local perceived discomfort and enlargement of the radial artery size would justify its daily use in the routine clinical practice to enhance the transradial experience for both patients and operators.