NT-proBNP as Marker of Ventricular Dilatation and Pulmonary Regurgitation After Surgical Correction of Tetralogy of Fallot: A MRI Validation Study.

The goal of this study is to evaluate whether NT-proBNP plasma levels may help as a screening biomarker for monitoring right ventricular dilatation, pulmonary regurgitation and the onset of heart failure in patients with repaired Tetralogy of Fallot. Our single-centre observational prospective study involved 43 patients (15.1 years, SD = 8) with corrected Tetralogy of Fallot. Data collection included: clinical parameters (electrocardiogram, chest X-ray, NYHA scale, time since last surgery), biochemistry (NT-proBNP levels) and MRI values (ventricular volumetry, pulmonary flow assessment). Mean time since last surgery was 13.5 years (SD = 7.8). There was a statistically significant correlation between the NT-proBNP levels (187.4 pg/ml, SD = 154.9) and right ventricular dilatation for both the right ventricular end-diastolic volume (124.9 ml/m2, SD = 31.2) (Pearson = 0.19, p < 0.01) and end-systolic volume (56.1 ml/m2, SD = 18.8) (Pearson = 0.21, p < 0.01) and also with the pulmonary regurgitation fraction (36.5%, SD = 16, Pearson = 0.12, p < 0.01). No significant correlation was found between NT-proBNP and right ventricular ejection fraction (54.6%, SD = 10.6, Pearson = -0.07), left ventricular ejection fraction (59.9%, SD = 7.1, Pearson = -0.18) or any clinical parameters. The receiver operating curve analysis evidenced that a NT-proBNP cut-off value above 133.2 pg/ml predicted the presence of dilated right ventricular end-diastolic and end-systolic volumes over centile 95 (sensitivity 82 and 83% and specificity 93 and 79%, respectively). In conclusion, in patients with surgically corrected Tetralogy of Fallot, NT-proBNP levels correlate with right ventricular dilatation and the degree of pulmonary regurgitation. Ambulatory determination of NT-proBNP might be an easy, readily available and cost-effective alternative for MRI follow-up evaluation of these patients.

3D printed models for planning endovascular stenting in transverse aortic arch hypoplasia.

OBJECTIVES: To evaluate whether three-dimensional (3D) printed models can be used to improve interventional simulation and planning in patients with aortic arch hypoplasia. BACKGROUND: Stenting of a hypoplastic transverse arch is technically challenging, and complications such as stent migration and partial obstruction of the origin of the head and neck vessels are highly dependent on operator skills and expertise. METHODS: Using magnetic resonance imaging (MRI) data, a 3D model of a repaired aortic coarctation of a 15-year-old boy with hypoplastic aortic arch was printed. Simulation of the endovascular stenting of the hypoplastic arch was carried out under fluoroscopic guidance in the 3D printed model, and subsequently in the patient. A Bland-Altman analysis was used to evaluate the agreement between measurements of aortic diameter in the 3D printed model and the patient's MRI and X-ray angiography. RESULTS: The 3D printed model proved to be radio-opaque and allowed simulation of the stenting intervention. The assessment of optimal stent position, size, and length was found to be useful for the actual intervention in the patient. There was excellent agreement between the 3D printed model and both MRI and X-ray angiographic images (mean bias and standard deviation of 0.36 ± 0.45 mm). CONCLUSIONS: 3D printed models accurately replicate patients' anatomy and are helpful in planning endovascular stenting in transverse arch hypoplasia. This opens a door for potential simulation applications of 3D models in the field of catheterization and cardiovascular interventions.