Impact of Different Iterations of Devices and Degree of Aortic Valve Calcium on Paravalvular Regurgitation After Transcatheter Aortic Valve Implantation

Quantification of Aortic Valve Calcification in Contrast-Enhanced Computed Tomography

Background: The goal of our study is to evaluate a method to quantify aortic valve calcification (AVC) in contrast-enhanced computed tomography for patients with suspected severe aortic stenosis pre-interventionally. Methods: A total of sixty-five patients with aortic stenosis underwent both a native and a contrast-enhanced computed tomography (CECT) scan of the aortic valve (45 in the training cohort and 20 in the validation cohort) using a standardized protocol. Aortic valve calcification was semi-automatically quantified via the Agatston score method for the native scans and was used as a reference. For contrast-enhanced computed tomography, a calcium threshold of the Hounsfield units of the aorta plus four times the standard deviation was used. Results: For the quantification of aortic valve calcification in contrast-enhanced computed tomography, a conversion formula (691 + 1.83 x AVCCECT) was derived via a linear regression model in the training cohort. The validation in the second cohort showed high agreement for this conversion formula with no significant proportional bias (Bland-Altman, p = 0.055) and with an intraclass correlation coefficient in the validation cohort of 0.915 (confidence interval 95% 0.786-0.966) p < 0.001. Conclusions: Calcium scoring in patients with aortic valve stenosis can be performed using contrast-enhanced computed tomography with high validity. Using a conversion factor led to an excellent agreement, thereby obviating an additional native computed tomography scan. This might contribute to a decrease in radiation exposure.

A systematic review of contrast-enhanced computed tomography calcium scoring methodologies and impact of aortic valve calcium burden on TAVI clinical outcomes

Different methodologies have been used to assess the role of AV calcification (AVC) on TAVI outcomes. This systematic review aims to describe the burden of AVC, synthesize the different methods of calcium score quantification, and evaluate the impact of AVC on outcomes after TAVI. We included studies of TAVI patients who had reported AV calcium scoring by contrast-enhanced multidetector CT and the Agatston method. The impact of calcification on TAVI outcomes without restrictions on follow-up time or outcome type was evaluated. Results were reported descriptively, and a meta-analysis was conducted when feasible. Sixty-eight articles were included, with sample sizes ranging from 23 to 1425 patients. Contrast-enhanced calcium scoring was reported in 30 studies, calcium volume score in 28 studies, and unique scoring methods in two. All studies with calcium volume scores had variable protocols, but most utilized a modified Agatston method with variable attenuation threshold values of 300-850 HU. Eight studies used the Agatston method, with the overall mean AV calcium score in studies published from 2010 to 2012 of 3342.9 AU [95%CI: 3150.4; 3535.4, I2 ​= ​0%]. The overall mean score was lower and heterogenous in studies published from 2014 to 2020 (2658.9 AU [95% CI: 2517.3; 2800.5, I2 ​= ​79%]. Most studies reported a positive association between calcium burden and increased risk of adverse outcomes, including implantation of permanent pacemaker (7/8 studies), paravalvular leak (13/13 studies), and risk of aortic rupture (2/2 studies). AVC quantification methodology with contrast-enhanced CT is still variable. AVC negatively impacts TAVI outcomes independently of the quantification method.

Fractal dimension of the aortic annulus: a novel predictor of paravalvular leak after transcatheter aortic valve implantation

To evaluate the prognostic relevance of aortic annulus (AA) and left ventricular outflow tract (LVOT) Fractal dimension (FD). FD is a mathematical concept that describes geometric complexity of a structure and has been shown to predict adverse outcomes in several contexts. Computed tomography (CT) scans from the SOLVE-TAVI trial, which, in a 2 × 2 factorial design, randomized 447 patients to TAVI with the balloon-expandable Edwards Sapien 3 or the self-expanding Medtronic Evolut R, and conscious sedation or general anesthesia, were analyzed semi-automatically with a custom-built software to determine border of AA and LVOT. FD was measured by box counting using grid calibers between 0.8 and 6.75 mm and was compared between patients with none/trivial and mild/moderate paravalvular regurgitation (PVR). Overall, 122 patients had CT scans sufficient for semi-automatic PVR in 30-day echocardiography. PVR was none in 65(53.3%) patients, trace in 9(7.4%), mild in 46(37.7%), moderate in 2(1.6%) and severe in 0 patients. FD determined in diastolic images was significantly higher in patients with mild/moderate PVR (1.0558 ± 0.0289 vs. 1.0401 ± 0.0284, p = 0.017). Annulus eccentricity was the only conventional measure of AA and LVOT geometry significantly correlated to FD (R = 0.337, p < 0.01). Area under the curve (AUC) of diastolic annular FD for prediction of mild/moderate PVR in ROC analysis was 0.661 (0.542-0.779, p = 0.014). FD shows promise in prediction of PVR after TAVI. Further evaluation using larger patient numbers and refined algorithms to better understand its predictive performance is warranted.Trial Registration: www.clinicaltrials.gov , identifier: NCT02737150, date of registration: 13.04.2016.

Predictors and impact of low diastolic blood pressure and widened pulse pressure following transcatheter aortic valve replacement

BACKGROUND

The association between post-operative diastolic blood pressure (DBP) and pulse pressure (PP) with outcomes following transcatheter aortic valve replacement (TAVR) remains unclear. We sought to assess the prevalence, predictors, and impact of post-operative DBP and PP on presence of post-procedural aortic insufficiency (AI) and mortality in adults undergoing TAVR.

METHODS

The study population included 194 patients who underwent TAVR from 2016 to 2017 at an academic tertiary medical center, of which 176 had invasive arterial pressures available postoperatively. Low DBP and widened PP were defined as ≤40 mmHg and ≥80 mmHg respectively on invasive arterial line on post-operative day 1. Clinical outcomes of interest included post-procedural AI and 1-year all-cause mortality.

RESULTS

Post-operative low DBP and widened PP were noted in 32.4% and 58.5% of the study population. No significant association between post-operative AI and low DBP (p = 0.82) or widened PP (p = 0.32) was noted. There was a trend toward higher rates of mortality in patients with low DBP (19.3% vs 9.2%, p = 0.06) but no difference in mortality in patients with widened PP (10.7% vs 15.1%, p = 0.39) or those with ≥1+ post-procedural AI (16.7% vs 10.7%, p = 0.32). In multivariable analysis, low DBP was associated with a trend toward higher rates of 1-year mortality [odds ratio (OR) 2.43, 95% confidence interval (CI) 0.97-6.11, p = 0.06]. When excluding patients with a post-operative invasive systolic blood pressure < 80 mmHg, low DBP was associated with significantly higher risk-adjusted mortality at 1 year [OR 2.75, 95% CI (1.07-7.07), p = 0.04].

CONCLUSIONS

In this contemporary study of adults undergoing TAVR, low DBP and widened PP were widely prevalent post TAVR. Low DBP was associated with a trend toward higher rates of 1-year mortality but not with post-procedural AI.

Threshold for calcium volume evaluation in patients with aortic valve stenosis: correlation with Agatston score

BACKGROUND

The evaluation of aortic valve calcium burden is important when planning for transcatheter aortic valve implantation (TAVI). Although a robust golden standard methodology is available for calcium evaluation on noncontrast-enhanced (NCE) computed tomographic (CT) series, a standard reference for calcium assessment on contrast-enhanced CT series is currently lacking.

METHODS

Two hundred and forty-four preprocedural CT scans from patients who had received TAVI were analysed. We correlated the aortic calcium volumes obtained on CE series at three thresholds [450, 850, and 'probe + 100' Hounsfield Units (HU)] with the Agatston score obtained on NCE scans. A subgroup analysis was performed taking into account the contrast enhancement of the left ventricular outflow tract (LVOT), with a prespecified cut-off of 300 HU.

RESULTS

The overall population analysis showed higher correlation with the Agatston score using the 850 HU threshold (r = 0.45, P < 0.0001); no correlation was found with the 450 HU threshold, whilst the 'probe + 100' HU threshold showed a weaker correlation (r = 0.30, P < 0.0001). In patients with LVOT enhancement less than 300 HU, 450 HU showed the highest accuracy in calcium identification (r = 0.70, P < 0.0001), whereas in patients with LVOT enhancement of at least 300 HU, the most accurate threshold was 850 HU (r = 0.46, P < 0.0001).

CONCLUSION

The thresholds for correct calcium identification using the automatic 3Mensio software depend on the contrast enhancement of aortic and cardiac structures, which can be estimated by measuring the HU in the LVOT. In patients with LVOT HU of less than 300, the correct threshold to be set in the software is 450 HU, whereas in patients with LVOT HU of at least 300 the correct threshold is 850 HU.

Transcatheter Aortic Valve Replacement in Patients With a Small Annulus - From the Japanese Nationwide Registry (J-TVT)

BACKGROUND

The details and consequences of a small aortic annulus among transcatheter aortic valve replacement (TAVR) patients remain uncertain. This study investigated the short-term outcomes in patients with small annular size and compared the 30-day outcome between intra- and supra-annular devices, with similar outer casing diameter in this subgroup.Methods and Results:Cases registered in the Japanese national TAVR registry between August 2013 and December 2017 were analyzed. Among a total of 5,870 registered patients, 647 (11.0%) had small annulus (area ≤314 mm²) measured by multi-detector computed tomography. Patients with a small annulus had a significantly smaller indexed effective orifice area (iEOA, 1.10 cm²/m²[0.92-1.35] vs. 1.16 cm²/m²[0.96-1.39], P<0.001) and higher mean pressure gradient (mPG, 10.0 mmHg [6.9-14.2] vs. 8.5 mmHg [6.0-11.5], P<0.001) compared with a normal-sized annulus. Among patients with a small annulus, those receiving a 20 mm intra-annular device had a smaller iEOA (0.94 cm²/m²[0.78-1.06] vs. 1.07 cm²/m²[0.8-1.24], P=0.001) and higher mPG (14.0 mmHg [10.0-18.5] vs. 11.0 [7.0-14.0], P<0.001) compared with those receiving a 23-mm supra-annular device, although the incidence of paravalvular leakage (≥moderate) was similar (14.4% vs. 16.5%, P=0.69).

CONCLUSIONS

Patients with a small annulus were associated with less hemodynamic improvement. A supra-annular device is associated with better echocardiographic improvement in patients with a small annulus, without increasing paravalvular leakage.

Clinical utility of intraprocedural three-dimensional integrated image guided transcatheter aortic valve implantation using novel automated computed tomography software: A single-center preliminary experience

OBJECTIVES

Novel automated computed tomography (CT) software (Valve ASSIST 2) has been developed for transcatheter aortic valve implantation (TAVI), which not only provides three-dimensional (3D) reconstruction of multidetector (MD) CT images, but also enables intraprocedural real-time fusion of fluoroscopic and MDCT images. We aimed to clarify the reproducibility and accuracy of this software in the aortic annulus assessment and verify the potential of intraprocedural integrated MDCT imaging for TAVI.

METHODS AND RESULTS

We examined 50 patients with severe aortic stenosis undergoing transfemoral TAVI. Aortic annulus measurements were performed using 3mensio and the novel planning software. For intraprocedural imaging, preoperative CT dataset was overlaid onto fluoroscopy with the fusion software. The two images were aligned using the aortic root anatomy visible on both modalities. Novel planning software provided excellent reproducibility for the measurement of aortic annulus area (intraobserver intraclass correlation coefficients [ICC] 0.959, interobserver ICC 0.941), and perimeter (intraobserver ICC 0.915, interobserver ICC 0.912). Excellent correlation was found between novel planning software and 3mensio (ICC 0.952 for aortic annulus area, and 0.923 for perimeter). Intraprocedural fusion image of CT aortography and fluoroscopic aortic root aortography generated by this novel software identified coronary orifices and the distribution of aortic valve calcification during the device positioning. Fusion image displayed coronary orifices after device implantation.

CONCLUSIONS

Novel planning software showed excellent reproducibility and accuracy in the assessment of aortic root anatomy. Furthermore, the integrated 3D fusion image might have a potential as an intraprocedural imaging modality to contribute to the development of a safer TAVI procedure.

Prognostic Impact of Calcium Score after Transcatheter Aortic Valve Implantation Performed With New Generation Prosthesis

Calcium score (CS) is a well-known prognostic factor after transcatheter aortic valve implantation (TAVI) performed with first generation prosthesis but few data are available concerning new generation valves. The aim of this study was to evaluate if CS remains a prognostic factor after Sapien 3 and Evolut R valves implantation. Agatston CS was evaluated on multislice computed tomography before TAVI in 346 patients implanted with Sapien XT (n = 61), CoreValve (n = 57) devices, (group 1, n = 118), and with new generation Sapien 3 (n = 147), Evolut R (n = 81) prosthesis, (group 2, n = 228). Major adverse cardiovascular events and aortic regurgitation (AR) were evaluated at 1 month. The 2 groups were similar at baseline except for logistic Euroscore (20.1% in group 1 vs 15.0 % in group 2; p = 0.001), chronic renal failure (44.1% vs 37.2% respectively, p = 0.007) and preprocedural CS (4,092 ± 2,176 vs 3,682 ± 2,109 respectively, p = 0.022). In group 1, 28 patients (23.7%) had adverse clinical events vs 21 (9.2%) in group 2 (p <0.01). In multivariate analysis, a higher CS was predictive of adverse events in group 1 (5,785 ± 3,285 vs 3,565 ± 1,331 p <0.0001) but not in group 2 (p = 0.28). A higher CS was associated with AR in group 1 (6,234 ± 2711 vs 3,429 ± 1,505; p <0.001) and in patients implanted with an Evolut R device from group 2 (4,085 ± 3,645 vs 2,551 ± 1,356; p = 0.01). In conclusion, CS appears as an important prognostic factor of major events after TAVI with first generation valves but not with new generation devices. CS remains associated with AR only with new generation self-expandable Evolut R devices.

Predictors of Paravalvular Regurgitation After Transcatheter Aortic Valve Implantation for Aortic Stenosis Using New-Generation Balloon-Expandable SAPIEN 3

Paravalvular regurgitation (PVR) is a common and serious complication after transcatheter aortic valve implantation (TAVI). New-generation balloon-expandable SAPIEN 3 has an outer sealing skirt to minimize PVR. However, the predictors of PVR after SAPIEN 3 transcatheter heart valve (THV) implantation have not been well investigated. We sought to clarify the determinants of PVR after TAVI using SAPIEN 3 with quantitative multidetector computed tomography (MDCT) assessment. This study analyzed 281 patients with severe symptomatic aortic stenosis who underwent TAVI using SAPIEN 3. Quantitative assessment of aortic root dimensions and calcium volume for leaflet, annulus, and left ventricular outflow tract were retrospectively performed with MDCT. MDCT nominal area oversizing was calculated using the following formula: % oversizing = (THV nominal area/MDCT derived annular area - 1) × 100. Logistic regression analysis was performed to determine the predictors of PVR greater than or equal to mild. PVR greater than or equal to mild was observed in 19% (53 of 281). Quantity and asymmetry of aortic valve calcium of annulus, left ventricular outflow tract, and leaflet were associated with higher incidence of PVR greater than or equal to mild, except leaflet asymmetry. Lower percentage of THV oversizing was also associated with PVR. Multivariable logistic regression analysis showed that larger calcification volume of annulus and lower percentage of THV oversizing were independent predictors of PVR greater than or equal to mild. These results suggest that prosthesis/annulus incongruence and aortic annulus calcification predicted PVR greater than or equal to mild after TAVI using SAPIEN 3.