Use of the ductal curvature index to assess the risk of ductal stenting in patients with duct-dependent pulmonary circulation

BACKGROUND: To evaluate whether a quantitative curvature threshold can contribute to risk stratification of ductal stenting in patients with a duct-dependent pulmonary circulation (DDPC). METHODS: A single-center retrospective analysis was performed. The ductal curvature index (DCI) was calculated in 71 patients with DDPC. The ducts were divided into four classes based on quartile thresholds of DCI: class I (≤0.12), class II (0.13–0.33), class III (0.34–0.44), and class IV (≥0.45). The primary outcome of this study was defined as free from all of the following: (I) intervention related death, (II) need of unplanned surgery (III) need of unplanned pulmonary valve (PV) perforation with stent in right ventricular outflow tract (RVOT), and (IV) intervention related permanent complications. RESULTS: Eighty percent of patients in class IV (DCI ≥0.45) failed to achieve the primary outcome; odds ratio (OR) 9 and 95% confidence interval (CI): 3.7–21.4 compared to 26.6% in all classes with DCI <0.45. 66.7% of these patients needed unplanned surgery or PVP with RVOT stent; OR 12.4 (95% CI: 4–39). 80% of major complications were observed in class IV (P<0.01). Need of pulmonary arterioplasty was in class IV 53.3%; OR 3.3 (95% CI: 1.5–7.1). CONCLUSIONS: DCI can be useful to guide the clinical decision-making in patients with torqued ducts. Patients with a DCI ≥0.45 belong to a high-risk group, in which ductal stenting is associated with an elevated risk for early surgery or unplanned re-intervention.