Online Quantitative Aortographic Assessment of Aortic Regurgitation After TAVR: Results of the OVAL Study.

OBJECTIVES: The aim of this study was to investigate the online assessment feasibility of aortography using videodensitometry in the catheterization laboratory during transcatheter aortic valve replacement (TAVR). BACKGROUND: Quantitative assessment of regurgitation after TAVR through aortography using videodensitometry is simple, reproducible, and validated in vitro, in vivo, in clinical trials, and in "real-world" patients. However, thus far the assessment has been done offline. METHODS: This was a single center, prospective, proof-of-principle, feasibility study. One hundred consecutive patients with aortic stenosis and indications to undergo TAVR were enrolled. All final aortograms were analyzed immediately after acquisition in the catheterization laboratory and were also sent to an independent core laboratory for blinded offline assessment. The primary endpoint of the study was the feasibility of the online assessment of regurgitation (percentage of analyzable cases). The secondary endpoint was the reproducibility of results between the online assessment and the offline analysis by the core laboratory. RESULTS: Patients' mean age was 81 ± 7 years, and 56% were men. The implanted valves were either SAPIEN 3 (97%) or SAPIEN 3 Ultra (3%). The primary endpoint of online feasibility of analysis was 92% (95% confidence interval [CI]: 86% to 97%) which was the same feasibility encountered by the core laboratory (92%; 95% CI: 86% to 97%). Reproducibility assessment showed a high correlation between online and core laboratory evaluations (R2 = 0.87, p < 0.001), with an intraclass correlation coefficient of 0.962 (95% CI: 0.942 to 0.975; p < 0.001). CONCLUSIONS: This study showed high feasibility of online quantitative assessment of regurgitation and high agreement between the online examiner and core laboratory. These results may pave the way for the application of videodensitometry in the catheterization laboratory after TAVR. (Online Videodensitometric Assessment of Aortic Regurgitation in the Cath-Lab [OVAL]; NCT04047082).

Validation of a Novel System for Co-Registration of Coronary Angiographic and Intravascular Ultrasound Imaging.

INTRODUCTION: Intravascular ultrasound (IVUS) is a useful adjunct to guide percutaneous coronary intervention (PCI). Correlating IVUS images with angiographic findings can be challenging. We evaluated the utility of a novel co-registration system for IVUS and coronary angiography. METHODS AND RESULTS: A 3-D virtual catheter trajectory was constructed from separate angiographic imaging runs using bespoke software. Intravascular ultrasound images were obtained using a commercially available mechanical rotational transducer with motorized pullback. Co-registration of ultrasound and angiographic images was then performed retrospectively based on the length of pullback, the 3-D trajectory and the start position of the catheter. Validation was performed in a spherical phantom model and in vivo in the coronary circulation of patients undergoing coronary angiography and intravascular imaging for clinical purposes. 111 paired angiographic and IVUS runs were performed in 3 phantom models. The differences between the reference length and the length measured on the 3D reconstructed path was -0.01 ±â€¯0.40 mm. Intra-observer variability was 0.4%. We enrolled 25 patients in 3 European hospitals and performed 35 co-registration attempts with an 86% success rate. 71 landmarks were selected by the first operator, 68 by the second. Differences between angiographic and IVUS landmarks were -0.22 ±â€¯0.72 mm and 0.05 ±â€¯1.01 mm, respectively. Inter-observer variability was 0.23 ±â€¯0.63 mm. CONCLUSION: We present a novel method for the co-registration of IVUS and coronary angiographic images. This system performed well in a phantom model and using images obtained from the human coronary circulation. CLASSIFICATIONS: Innovation, intravascular ultrasound, other technique.

The interaction of de novo and pre-existing aortic regurgitation after TAVI: insights from a new quantitative aortographic technique.

AIMS: The aim of this study was to evaluate the intermediate-term clinical impact of aortic regurgitation (AR) after transcatheter aortic valve implantation (TAVI) using a novel quantitative angiographic method taking into account the influence of pre-existing AR. METHODS AND RESULTS: AR after TAVI was quantified in 338 patients (age 82 [78-86] years; 55% male) and the influence on intermediate-term all-cause mortality was evaluated. In 228 aortograms, AR was quantitated using a dedicated videodensitometric method focused in the left ventricular outflow tract (LVOT-AR). Patients with LVOT-AR >0.17 had a significantly increased all-cause mortality at three years, compared with patients who had LVOT-AR ≤0.17 (adjusted hazard ratio [HR]: 1.73, 95% confidence interval [CI]: 1.05-2.86, p=0.032). Taking the influence of pre-existing AR into account, patients with post-procedural LVOT-AR >0.17 and ≤mild pre-existing AR had a significantly increased mortality at two years, compared to patients with LVOT-AR >0.17 and >mild pre-existing AR (HR: 2.55, 95% CI: 1.16-5.58, p=0.029). In those with >mild pre-existing AR (n=70), post-TAVI LVOT-AR >0.17 was not associated with increased mortality (HR: 0.77, 95% CI: 0.31-1.91, p=0.578). CONCLUSIONS: AR after TAVI could be quantitated utilising LVOT-AR. The cut-point of >0.17 indicates a significant AR pertaining to increased intermediate-term mortality, especially in those with no significant pre-existing AR.

The interaction of de novo and pre-existing aortic regurgitation after TAVI: insights from a new quantitative aortographic technique

AIMS: The aim of this study was to evaluate the intermediate-term clinical impact of aortic regurgitation (AR) after transcatheter aortic valve implantation (TAVI) using a novel quantitative angiographic method taking into account the influence of pre-existing AR.METHODS AND RESULTS:AR after TAVI was quantified in 338 patients (age 82 [78-86] years; 55% male) and the influence on intermediate-term all-cause mortality was evaluated. In 228 aortograms, AR was quantitated using a dedicated videodensitometric method focused in the left ventricular outflow tract (LVOT-AR). Patients with LVOT-AR >0.17 had a significantly increased all-cause mortality at three years, compared with patients who had LVOT-AR ≤0.17 (adjusted hazard ratio [HR]: 1.73, 95% confidence interval [CI]: 1.05-2.86, p=0.032). Taking the influence of pre-existing AR into account, patients with post-procedural LVOT-AR >0.17 and ≤mild pre-existing AR had a significantly increased mortality at two years, compared to patients with LVOT-AR >0.17 and >mild pre-existing AR (HR: 2.55, 95% CI: 1.16-5.58, p=0.029). In those with >mild pre-existing AR (n=70), post-TAVI LVOT-AR >0.17 was not associated with increased mortality (HR: 0.77, 95% CI: 0.31-1.91, p=0.578).CONCLUSIONS:AR after TAVI could be quantitated utilising LVOT-AR. The cut-point of >0.17 indicates a significant AR pertaining to increased intermediate-term mortality, especially in those with no significant pre-existing AR...

Clinical validation of a novel software for quantitative analysis of coronary intravascular ultrasound.

PURPOSE: CAAS IntraVascular (CAAS-IV) is a recently released software that provides options for sophisticated quantitative coronary ultrasound (QCU) analysis. The aim of this study was to validate CAAS-IV for QCU in diseased human coronaries. METHODS: Ten preprocedural and 5 postprocedural IVUS studies were derived from daily practice. Intraobserver, interobserver, intersoftware (CAAS-IV vs. Curad) and interplatform (CAAS-IV vs. Volcano console) variability were assessed for cross-sectional area (CSA) measurements. Interobserver and intersoftware comparisons were made for volume measurements. RESULTS: Measurements of lumen, EEM, plaque and stent CSA demonstrated small differences in the intraobserver (0.0±3.7%, -0.7±2.8%, -0.5±7.0% and -0.9±3.4%), interobserver (0.1±4.4%, 0.1±3.4%, -0.5±8.2% and -0.8±4.3%), intersoftware (-0.3±4.5%, 0.2±2.4%, 0.4±6.8% and -0.5±3.2%) and interplatform (0.7±7.9%, 0.9±4.0%, -1.1±12%, -1.8±3.6%) comparisons. For lumen, EEM, plaque and stent volume, the interobserver (-2.1±9.3%, 0.9±5.6%, 3.4±7.2% and -0.2±3.6%) and intersoftware (-2.2±6.2%, -2.6±6.1%, -2.7±12% and -4.1±3.2%) differences were substantially larger. Excluding large side-branches and calcifications, post-hoc measurements of lumen, EEM, plaque and stent volume showed small differences in the interobserver (-0.3±3.2%, 0.9±2.4%, 2.9±4.4% and -1.3±1.8%) and intersoftware (0.5±2.5%, -1.2±1.7%, -3.4±5.1% and -1.5±2.2%) comparisons. Analysis time for entire pullbacks was reduced by 19.2 [14.9-30.0]% using CAAS-IV (p<0.01). CONCLUSIONS: CAAS-IV demonstrated reliable QCU with excellent agreement with previously validated software and the IVUS imaging console. Precision and reproducibility of measurements were high, proving CAAS-IV to be a valid option for QCU analysis in clinical practice and research. Interactive contour editing reduced analysis time by 20%.

An objective and reproducible method for quantification of aortic regurgitation after TAVI.

AIMS: We describe a new semi-automated method that measures aortic regurgitation (AR) on contrast aortography with the objectives of reducing the inter-observer variability and standardising image acquisition. METHODS AND RESULTS: Aortograms from three participating centres were reviewed to generate the following quality criteria: entire left ventricle and aortic root in view, descending aorta or TOE probe not over-projected, breath hold, no table motion, and adequate contrast opacification of the aortic root. AR was visually graded (Sellers) and was quantified by measuring the area under time-contrast density curves in the aortic root (reference) and the left ventricle. Quality criteria were met in 44 retrospectively identified aortograms and in 22 (69%) of 32 prospectively collected aortograms. The visual AR grade (Sellers) was highly correlated with time-density measurements including relative area under the curve (RAUC) and qRA index (r=0.81 and 0.83, respectively, p<0.001). Inter-observer reproducibility of visual grading was moderate (kappa 0.47-0.60, p<0.001). Inter-observer measurement of RAUC and qRA index were highly correlated (r=0.98, p<0.001) and showed a high level of agreement. CONCLUSIONS: Quantification of aortic regurgitation by measurement of time-density changes on contrast aortography may improve the reproducibility of AR assessment in the catheter laboratory. Steps for standardised aortography acquisition are proposed.

A new method for real-time co-registration of 3D coronary angiography and intravascular ultrasound or optical coherence tomography.

We present a new clinically practical method for online co-registration of 3D quantitative coronary angiography (QCA) and intravascular ultrasound (IVUS) or optical coherence tomography (OCT). The workflow is based on two modified commercially available software packages. Reconstruction steps are explained and compared to previously available methods. The feasibility for different clinical scenarios is illustrated. The co-registration appears accurate, robust and induced a minimal delay on the normal cath lab activities. This new method is based on the 3D angiographic reconstruction of the catheter path and does not require operator's identification of landmarks to establish the image synchronization.

Evaluation of a highly-radiopaque iodine-containing acrylic bone cement for use in augmentation of vertebral compression fractures.

Vertebroplasty and balloon kyphoplasty are widely used for the augmentation of osteoporosis-induced vertebral compression fractures. Almost invariably, an injectable poly(methyl methacrylate) (PMMA) bone cement that contains a large amount of BaSO(4) particles is used in these procedures. The deleterious effects of this radiopacifier on various properties of PMMA cement have been detailed in the literature. The objective of the present study was therefore to avoid such high levels of inorganic contrast agent and thus to develop an all-polymeric bone cement, for which radiopacity was provided by 60 wt % of an iodine-containing methacrylic copolymer, incorporated into the powder (IO cement), ultimately leading to 6.6 wt % of iodine in the cement. A large array of properties of this cement were determined, ranging from setting time and injectability to fatigue life under fully-reversed tension-compression loading and cytotoxicity, and a comprehensive comparison with a cement containing 30 wt % BaSO(4) in the powder component (BA cement) has been made (11 wt % of Ba in the cement). Statistical analyses of the results showed that, for the majority of the properties, the difference between the means for the two cements was not significant. It is therefore suggested that the IO cement is a suitable alternative to the BA cement for use in the aforementioned procedures.

Synthesis and characterization of radiopaque iodine-containing degradable PVA hydrogels.

Poly (vinyl alcohol) (PVA) hydrogels are highly attractive for biomedical applications, especially for controlled release of drugs and proteins. Recently, degradable PVA hydrogels have been described, having the advantage that the material disappears over time from the implantation site. Herein, we report the synthesis of radiopaque degradable PVA, which gives a further advantage that the position of the hydrogel can precisely be determined by X-ray fluoroscopy. Radiopacity has been introduced by replacing 0.5% of the pendent alcohol groups on the PVA with 4-iodobenzoylchloride. This level of substitution rendered the polymer adequately radiopaque. The subsequent modification of 0.8% of the pendent hydroxyl groups with an ester acrylate functional group allowed for cross-linking of the macromers. The radiopaque hydrogels degraded over a time span of 140 days. Rheology data suggested that the macromer solutions were appropriate for injection.