Differential Predictors of Severe Versus Milder Radial Artery Spasm: Insights From a Large Contemporary Distal Radial Access Cohort

BACKGROUND: Radial artery spasm remains a frequent procedural challenge in transradial intervention; however, its predictors may differ for severe and milder forms of spasm. This distinction is poorly characterized, particularly in contemporary distal radial access (dRA) populations. AIMS: Hereby we intend to approach the predictors of these two types of radial artery spasm. METHODS: This prospective single-center study enrolled 291 consecutive patients planned to undergo dRA (successful in 282 [96.9%] and converted to conventional access [cRA] in nine [3.1%] patients). Spasm was systematically graded via completion angiography using a 4-point scale (0: < 30%, 1: 30%-50%, 2: 50%-70%, 3: > 70% narrowing). Multivariable logistic regression was used to identify the independent predictors of severe spasm (> 70%) and any spasm (≥ 30%). RESULTS: Severe spasms occurred in 91 patients (31.3%), and spasms in 226 patients (77.7%). The predictor profiles differed substantially according to severity. For severe spasms, the independent predictors were younger age (OR: 0.949 per year; 95% CI: 0.926-0.973; p < 0.001), lower body mass index (BMI (OR: 0.915 per kg/m², 95% CI: 0.863-0.970; p = 0.003), and absence of diabetes (OR: 0.495, 95% CI: 0.253-0.970; p = 0.040). For any spasm, the predictors were: female sex (OR: 2.34, 95% CI: 1.15-4.761.15-4.76; p = 0.019), younger age (OR: 0.973, 95% CI: 0.947-0.999; p = 0.043), and interventional procedures (OR: 2.55, 95% CI: 1.11-5.87; p = 0.028). The study was not designed or powered to compare access sites (dRA vs. cRA) because of the extreme cohort imbalance (n = 9 cRA). These findings may enable operators to tailor prophylactic measures based on patient-specific risk profiles. No vascular rupture or radial artery occlusion was observed. CONCLUSIONS: In a contemporary dRA cohort, the predictors of radial artery spasm differed according to severity. While younger age is a universal risk factor, severe spasm is uniquely associated with lower BMI and non-diabetic status, whereas milder spasms are linked to female sex and procedural complexity. These findings may enable operators to tailor prophylactic measures based on patient-specific risk profiles.