Sheath‐to‐Artery Diameter Ratio: A Robust Predictor of Early Access‐Site Adverse Events in Percutaneous Procedures

ABSTRACT Background Vascular access site complications (VASCs) remain an important source of morbidity following percutaneous interventions. Although the sheath‐to‐femoral artery ratio is a recognized risk factor in transcatheter aortic valve implantation (TAVI), its role across a broader range of femoral procedures is less well defined. Objective To evaluate the association between the sheath‑to‑artery diameter (SHAD) ratio and early VASCs in patients undergoing femoral percutaneous interventions with sheaths > 6 Fr. Methods A nested case–control study was performed within a retrospective cohort of 2660 consecutive patients. A total of 177 patients who developed VASCs within 7 days were identified and compared with 353 propensity score–matched controls without complications. The propensity score included age, sex, body mass index, hypertension, diabetes mellitus, peripheral artery disease, and prior femoral access. The SHAD ratio was calculated using pre‑procedural computed tomography angiography (CTA). Inter‑observer agreement for arterial diameter was excellent (intraclass correlation coefficient 0.94). Receiver operating characteristic analysis identified the optimal cutoff (Youden index), and multivariable logistic regression with backward stepwise selection was internally validated by bootstrap. Anatomical factors (calcification, tortuosity) were examined as potential confounders. Results After matching, all baseline characteristics were well balanced (standardized differences < 0.10). The SHAD ratio was significantly higher in patients with VASCs than in controls (1.26 vs. 0.75; p < 0.001). A SHAD ratio ≥ 1.07 optimally predicted complications (AUC 0.83, 95% CI 0.80–0.87; sensitivity 82%; specificity 78%). In the final multivariable model, SHAD ≥ 1.07 remained the strongest independent predictor (OR 6.71, 95% CI 3.87–11.64; p < 0.001). Dual femoral access (OR 2.95, 95% CI 1.65–5.28) and procedural urgency (OR 1.98, 95% CI 1.18–3.32) also increased risk. Ultrasound‑guided puncture (OR 0.15, 95% CI 0.08–0.28) and fluoroscopy‑guided access (OR 0.14, 95% CI 0.07–0.26) were strongly protective. Anterior wall calcification was associated with a higher complication risk in univariable analysis but did not remain significant after adjustment for SHAD. Bootstrap internal validation yielded an optimism‑corrected AUC of 0.91 (95% CI 0.89–0.93), indicating good discrimination. Conclusions A SHAD ratio ≥ 1.07 is a robust predictor of early VASCs across multiple large‑bore femoral interventions. Maintaining a sheath‑to‑artery relationship ≤ 1.0, together with image‑guided access, may substantially reduce complications. The incorporation of SHAD assessment into pre‑procedural planning is supported, pending external validation.