Abstract Body (Do not enter title and authors here): Background: Radial artery access is the preferred approach for coronary procedures, however, radial artery spasm (RAS) and radial artery occlusion (RAO) remain frequent complications, and no standardized prevention strategy has been universally adopted.

Research Question: Among patients undergoing transradial percutaneous coronary procedures, how do different intra-arterial vasodilator agents compare in preventing radial artery spasm and occlusion?

Methods: A systematic search of PubMed, Embase, Scopus, and Cochrane databases was conducted to identify randomized controlled trials comparing vasodilator therapies used during trans-radial coronary procedures and reported the outcome of RAS. Heterogeneity was examined with I2 statistics. A random-effects model was used for outcomes with high heterogeneity.

Results: In the network meta-analysis, 21 clinical trials with 11010 patients comparing 10 treatments for the prevention of spasm (Placebo, Verapamil, Diltiazem, Molsidomine, Nitroglycerin, Nicorandil, ISDN, Labetalol, Magnesium, and Phentolamine) were included, forming a network centered on Verapamil and Placebo with multiple direct connections. Using a random-effects model to combine comparisons against placebo, Verapamil demonstrated a significant risk reduction (OR = 0.34; 95% CI 0.21–0.54), followed by Molsidomine (OR = 0.54; 95% CI 0.32–0.91). In contrast, Nitroglycerin (OR = 0.78; 95% CI 0.60–1.02), Diltiazem (OR = 0.27; 95% CI 0.01–7.03), and Nicorandil (OR = 0.95; 95% CI 0.50–1.80) showed no significant difference relative to placebo.

Conclusion: Patients undergoing radial artery catheterization for coronary interventions, verapamil and molsidomine significantly reduced the risk of RAS relative to placebo.