Effect of randomized prophylactic nitroglycerin on radial artery spasm during transradial catheterization: an analysis based on operator experience

One limitation to transradial access (TRA) is the occurrence of spasms (RAS), for which the use of prophylactic medications is recommended. Improvement in TRA material combined with the increase in operators' expertise, might mitigate this benefit. We assess the effect of preventive nitroglycerin on RAS during TRA, evaluating the role of the operator's experience. Patients received 500 µg nitroglycerin or placebo. The operator's expertise was classified as: inexperienced (I), intermediate (M), and experienced (E). 2040 patients were included. Prophylactic use of nitroglycerin did not reduce RAS (10.8% vs. 13.4% (placebo), p = 0.07). RAS incidence was 14.5% in I, 12.5% in M, and 9.7% in E (p = 0.01). In group I, nitroglycerin reduced RAS (17.4% vs. 11.1%, p = 0.04), which was not observed in other groups. Overall, nitroglycerin does not prevent RAS, which is more common among inexperienced operators. More experienced operators could abolish preventive nitroglycerin use.

Randomized clinical trial on prevention of radial occlusion after transradial access using Nitroglycerin: PATENS trial

OBJECTIVES: The aim of this study was to evaluate whether administration of nitroglycerin at the beginning or end of a transradial approach (TRA) procedure would preserve radial patency. BACKGROUND: The TRA is becoming the preferred vascular access route in coronary interventions. Radial artery occlusion (RAO) is the most frequent complication. Routine vasodilator treatment aims to reduce spasm and possibly prevent RAO. METHODS: The authors designed a prospective, multicenter, randomized, double-blind, 2-by-2 factorial, placebo-controlled trial encompassing patients undergoing the TRA. Patients were randomized to either 500 µg nitroglycerin or placebo; each arm was also subrandomized to early (upon sheath insertion) or late (right before sheath removal) nitroglycerin administration to evaluate the superiority of nitroglycerin in the prevention of RAO with 24 hours on Doppler ultrasound. RESULTS: A total of 2,040 patients were enrolled. RAO occurred in 49 patients (2.4%). Fifteen of these patients (30.6%) showed reestablishment of flow at 30 days. Nitroglycerin, compared with placebo, did not reduce the risk for RAO at either of the 2 time points (early, 2.5% vs 2.3% [P = 0.66]; late, 2.3% vs 2.5% [P = 0.66]). By multivariable analysis, the presence of spasm (OR: 3.53; 95% CI: 1.87-6.65; P < 0.001) and access achieved with more than 1 puncture attempt (OR: 2.58; 95% CI: 1.43-4.66; P = 0.002) were independent predictors of RAO. Conclusions: The routine use of nitroglycerin was not associated with a reduction in the rate of RAO, regardless of the time of administration (at the beginning or end of the TRA procedure).