How to limit radial artery spasm during percutaneous coronary interventions: The spasmolytic agents to avoid spasm during transradial percutaneous coronary interventions (SPASM3) study

AIMS: To compare the efficacy of three vasodilators in preventing radial artery spasm (RAS) in patients undergoing transradial percutaneous coronary interventions (PCI). METHODS AND RESULTS: 731 patients were randomized to receive diltiazem 5 mg, verapamil 2.5 mg, or isosorbide dinitrate (ISDN) 1 mg before coronary intervention. RAS occurred in 20.1% in the whole population and was significantly reduced by verapamil and ISDN compared to diltiazem (16.2, 17.2, and 26.6%, respectively; P < 0.006). There was also a trend towards less severe pain (more than 8 on a numerical scale from 0 [no pain] to 10 [maximal pain]), and less severe RAS (complete catheter blockage or severe pain), among patients treated by verapamil compared to ISDN and diltiazem (1.3% vs. 2.8% vs. 2.9%, P = 0.43 and 5.1% vs. 6.2% vs. 9.5%, respectively, P = 0.13). No difference was found between the three vasodilators in terms of crossover or safety events. Female gender, failure at first attempt to access the radial artery, emergency procedures, and the use of diltiazem were independent predictors of RAS. CONCLUSION: Verapamil and ISDN considerably reduce the incidence of RAS compared to diltiazem during transradial PCI.