A Simplified Fluoroscopic Method for Commissural Alignment Assessment With a Balloon-Expandable Transcatheter Heart Valve.

We sought to assess commissural alignment of the balloon-expandable valve on fluoroscopy. Commissural alignment was defined on fluoroscopy in 20 patients according to alignment of the valve commissural posts in the 3-cusp and the cusp-overlap view and correlated with post-transcatheter aortic valve replacement computed tomography. Agreement was strong between computed tomography and fluoroscopy (weighted Cohen's kappa coefficient: 0.88). (Level of Difficulty: Advanced.).

A comparative assessment of the performance of a state-of-the art small footprint dedicated cardiovascular CT scanner.

INTRODUCTION: With increasing adoption of CT coronary angiography (CTA) there is increasing demand for cost-effective, small footprint, dedicated cardiac scanners. We compared a state-of-the-art, small footprint dedicated cardiac scanner (DCCT) to a standard multidetector scanner (MDCT). METHODS: The study was a retrospective unblinded single centre study. A total of 800 patients were included, with 400 undergoing a DCCT and MDCT coronary CTA scanning, respectively. Image quality was assessed using a 4-point grading score. Image noise and artifact, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR), and acceptance rate for CT-derived fractional flow reserve (FFRct) were recorded. RESULTS: Overall image quality was higher in the DCCT group (3.8 ± 0.55 vs 3.6 ± 0.69; p = 0.042). There was no difference in overall image noise (p = 0.131) or artifact (p = 0.295). SNR was superior in the DCCT group (14.2 ± 6.85 vs 11.4 ± 3.32; p < 0.005) as was CNR (12.7 ± 6.77 vs 11.9 ± 3.29; p < 0.005). The heart rate was lower in the DCCT group (56 ± 9.1 vs 59 ± 8.1; p < 0.005). No difference in the dose length product (DLP median 244.53 (IQR 105.6) vs 237.63 (IQR 160.1); p = 0.313) or FFRCT acceptance rate (100 vs 97.7%; p > 0.05) was noted. Independent predictors of excellent quality regardless of scanner type were age (p = 0.011), heart rate <65 bpm (p < 0.005), and body mass index < 35 (p < 0.005). CONCLUSION: A DCCT scanner is capable of image quality similar to modern current generation general purpose CT technology. Such technology appears to be a viable option to serve the increasing demand for CTCA imaging.

Impact of sublingual nitroglycerin dosage on FFRCT assessment and coronary luminal volume-to-myocardial mass ratio.

OBJECTIVES: Fractional flow reserve computed tomography (FFRCT) depends upon nitroglycerin (NTG) inducing maximal hyperemia. However, the impact of NTG dosages on FFRCT analysis including coronary volume-to-mass ratio (V/M) is unknown. METHODS: Eighty patients with repeat coronary CT angiograms (CCTAs) with different sublingual spray NTG doses (0.4 mg and 0.8 mg) were retrospectively analyzed with 45 patients excluded. Patient and scan demographics, post-stenosis and nadir FFRCT values, coronary volume, and coronary volume-to-mass ratio (V/M) were compared at initial CCTA (0.4 mg NTG) and follow-up CCTA (0.8 mg NTG). Differences were compared by Wilcoxon signed-rank test. RESULTS: Thirty-five patients were included (time between CCTAs, 3.9 ± 1.6 years). Segment involvement score was 2.4 ± 3.3 and 2.8 ± 3.4 at initial and repeat CCTA (0.4 and 0.8 mg NTG), respectively (p = 0.004). There was similar image quality (4.1 ± 0.7 vs 4.1 ± 0.8; p = 0.51). Nadir FFRCT values did not differ in the left (0.4 mg, 0.80 ± 0.08 vs 0.8 mg, 0.80 ± 0.03; p = 0.66), right (0.4 mg, 0.90 ± 0.04 vs 0.8 mg, 0.90 ± 0.06; p = 0.25), or circumflex coronaries (0.4 mg, 0.87 ± 0.06 vs 0.8 mg, 0.88 ± 0.06; p = 0.34). Post-stenosis FFRCT values did not differ (p = 0.65). Coronary volume increased with 0.8 mg of NTG (2639 ± 753 mm3 vs 2844.8 ± 827 mm3; p = 0.009) but V/M ratio did not (p = 0.20). CONCLUSIONS: Use of 0.8 mg versus 0.4 mg of NTG in routine clinical CCTAs significantly increased coronary volume determined from FFRCT analysis but did not alter FFRCT or V/M. Further evaluation of repeat CCTAs in a more contemporaneous fashion using varied nitrate doses and disease severity is needed. KEY POINTS: • Fractional flow reserve from computed tomography (FFRCT) is a noninvasive method for evaluating the coronary arteries and relies on nitroglycerin (NTG) to induce coronary vasodilation, but the impact of different NTG dosages is unknown. • Retrospective analysis evaluated use of different NTG doses on FFRCT. • Increased NTG dose increased coronary luminal volume on FFRCTanalysis, but did not change FFRCTvalues.

Comprehensive Echocardiographic Assessment of Normal Transcatheter Valve Function.

OBJECTIVES: This study aims to establish parameters for identifying normal function for each of the 3 iterations of balloon-expandable valves and 2 iterations of self-expanding valves. BACKGROUND: Expected transthoracic echocardiographic Doppler-derived hemodynamic data for transcatheter aortic valves inform pre-implant decision-making and post-implanted monitoring of longitudinal valve function. METHODS: We collected the echocardiography core Lab measured mean gradients and effective orifice area (EOA) from discharge or 30-day echocardiograms from randomized trials; the PARTNER (Placement of Aortic Transcatheter Valves) trials for the balloon-expandable valves and the Medtronic CoreValve US Pivotal trial and Medtronic CoreValve Evolut R United States IDE Clinical Study for the self-expanding valves. RESULTS: For all SAPIEN (Edwards Lifesciences, Irvine, California) valve sizes, mean EOA is 1.70 ± 0.49 cm2 with a mean gradient of 9.36 ± 4.13 mm Hg. For all SAPIEN XT valve sizes, mean EOA is 1.67 ± 0.46 cm2 with a mean gradient of 9.52 ± 3.64 mm Hg. For all SAPIEN 3 valve sizes, the mean EOA is 1.66 ± 0.38 cm2 with a mean gradient of 11.18 ± 4.35 mm Hg. For all CoreValve valve sizes, the mean EOA is 1.88 ± 0.56 cm2 with a mean gradient of 8.85 ± 4.14 mm Hg. For all Evolut R valve sizes, the mean EOA is 2.01 ± 0.65 cm2 with a mean gradient of 7.52 ± 3.19 mm Hg. The SAPIEN 3 post-implant EOA was progressively larger for each quintile of baseline annular area by computed tomography (p < 0.001). Similarly, for the Evolut R valve, post-implantation EOA was significantly larger for each quintile of baseline annular perimeter (p < 0.001). CONCLUSIONS: Tables of expected mean transcatheter aortic valve hemodynamics by valve type and size are essential in evaluating the function of these transcatheter prosthetic valves. Tables of expected EOA by the native annular anatomy may be useful for pre-implantation decision making. Criteria for defining structural valve dysfunction are proposed.

Coronary CT Angiography Derived Fractional Flow Reserve: The Game Changer in Noninvasive Testing.

PURPOSE OF REVIEW: To summarize the scientific basis of CT derived fractional flow reserve (FFRCT) and present an updated review on the evidence from clinical trials and real-world observational data RECENT FINDINGS: In prospective multicenter studies of patients with stable coronary artery disease (CAD), FFRCT showed high diagnostic performance. More recently, FFRCT has advanced to the realm of clinical utility and real-world clinical practice with emerging data showing that FFRCT when compared to standard care is efficient in safely reducing downstream utilization of invasive coronary angiography (ICA), and costs, as well as improving the diagnostic yield of ICA. Moreover, FFRCT may broaden applicability of frontline coronary CTA testing to patients with high pre-test risk of CAD. Introducing FFRCT into clinical practice has the potential to significantly improve the management of patients with stable CAD. The optimal FFRCT testing interpretation strategy, as well as the relative cost-efficiency of FFRCT against standard noninvasive functional testing, need further investigation.

Computed tomography assessment for transcatheter aortic valve in valve implantation: The vancouver approach to predict anatomical risk for coronary obstruction and other considerations.

Valve-in-valve implantation of a transcatheter heart valve into a failed bioprosthetic heart valve has emerged as a treatment alternative to repeat conventional surgery. This requires careful pre-procedural assessment using non-invasive imaging to identify patients at risk for procedure related adverse events, such as ostial coronary occlusion. Herein we report how to comprehensively assess aortic root anatomy using computed tomography prior to transcatheter valve implantation for failed bioprosthetic aortic valves.

Clinical Outcomes and Imaging Findings in Women Undergoing TAVR.

Transcatheter aortic valve replacement (TAVR) has become the standard of care for patients with hemodynamically severe aortic stenosis who are symptomatic but deemed too high risk for surgery. Recent reports suggest that sex differences exist in outcomes following TAVR and in the diagnostic imaging evaluation of patients being considered for TAVR. In this review, the authors explore the differences between men and women in baseline characteristics and outcomes following TAVR, as well as sex differences in the imaging findings of severe aortic stenosis (AS) including the diagnostic challenges in the hemodynamic assessment of severe AS in elderly women, differences in aortic valvular calcification and in the associated myocardial response to severe AS. Additionally, sex differences in imaging findings as they relate to post-TAVR complications including coronary obstruction, annular rupture and prosthesis-patient mismatch are also discussed.

Quantitative multi-slice computed tomography assessment of the mitral valvular complex for transcatheter mitral valve interventions part 1: systematic measurement methodology and inter-observer variability.

AIMS: Transcatheter mitral valve replacement (TMVR) is an emerging technology with the potential to treat patients with severe mitral regurgitation at excessive risk for surgical mitral valve surgery. Multimodality imaging of the mitral valvular complex and surrounding structures will be an important component for patient selection for TMVR. Our aim was to describe and evaluate a systematic multi-slice computed tomography (MSCT) image analysis methodology that provides measurements relevant for transcatheter mitral valve replacement. METHODS AND RESULTS: A systematic step-by-step measurement methodology is described for structures of the mitral valvular complex including: the mitral valve annulus, left ventricle, left atrium, papillary muscles and left ventricular outflow tract. To evaluate reproducibility, two observers applied this methodology to a retrospective series of 49 cardiac MSCT scans in patients with heart failure and significant mitral regurgitation. For each of 25 geometrical metrics, we evaluated inter-observer difference and intra-class correlation. The inter-observer difference was below 10% and the intra-class correlation was above 0.81 for measurements of critical importance in the sizing of TMVR devices: the mitral valve annulus diameters, area, perimeter, the inter-trigone distance, and the aorto-mitral angle. CONCLUSIONS: MSCT can provide measurements that are important for patient selection and sizing of TMVR devices. These measurements have excellent inter-observer reproducibility in patients with functional mitral regurgitation.

Quantitative multi-slice computed tomography assessment of the mitral valvular complex for transcatheter mitral valve interventions part 2: geometrical measurements in patients with functional mitral regurgitation.

AIMS: Transcatheter mitral valve replacement (TMVR) is an emerging technology with the potential to treat patients with mitral regurgitation at excessive risk for mitral valve surgery. Geometrical measurements of the mitral valvular complex may have implications for the design of TMVR devices and for patient selection. This study sought to quantify the dynamic geometry of the mitral valvular complex in patients with significant functional mitral regurgitation (FMR) using multi-slice computed tomography (MSCT). METHODS AND RESULTS: MSCT images were acquired in 32 patients with symptomatic, significant FMR. Two independent observers analysed image sets using a dedicated software package and a standard measurement methodology. In patients with FMR, the mean mitral annulus intercommissural and aorto-mural diameters were, respectively, 41.5±5.2 mm and 38.7±5.9 mm in systole, and were 41.5±4.4 mm and 40.0±4.7 mm in diastole. In patients without MR, the diameters were, respectively, 33.6±5.1 mm and 28.8±8.0 mm in systole, and 36.2±4.5 mm and 31.6±7.9 mm in diastole. The obstacle-free zone below the mitral annulus averaged more than 20.0 mm and varied by less than 1 mm between systole and diastole, which is not statistically significant. The aorto-mitral angle was 129.7±10.5° in systole and 131.0±9.4° in diastole. CONCLUSIONS: The mitral annulus is larger in dimension, more circular, and less dynamic in patients with FMR. The obstacle-free zone below the mitral annulus is relatively constant during the cardiac cycle. Measurements of the mitral valvular apparatus vary considerably between patients, which suggests that tridimensional imaging will play an important role in the sizing of TMVR devices.

Pre-procedural assessment of aortic annulus dimensions for transcatheter aortic valve replacement: comparison of a non-contrast 3D MRA protocol with contrast-enhanced cardiac dual-source CT angiography.

AIMS: To evaluate the feasibility of a non-contrast three-dimensional (3D)-FLASH magnetic resonance angiography (MRA) protocol for pre-procedural aortic annulus assessment for transcatheter aortic valve replacement (TAVR) in comparison with cardiac dual-source computed tomography angiography (CTA). METHODS AND RESULTS: In this prospective study, 69 of 104 consecutive patients (mean age 81.8 ± 5.4 years, 37.7% arrhythmic) with severe aortic stenosis who had undergone pre-TAVR cardiac CTA received a respiratory and ECG-triggered, non-contrast 3D-FLASH MRA at 3 T. Annular area measurements were obtained at mid-diastole for both modalities whereas maximum systolic area was assessed by CTA only. Systolic MRA dimensions were modelled, by adding the relative difference of systolic and diastolic CTA area dimensions as a corrective factor. Hypothetical prosthesis sizing was performed based on systolic CTA, diastolic, and modelled systolic MRA area measurements. MR image quality and degree of annular calcifications were evaluated using 4-point-grading scales. The mean acquisition time was 14 ± 4.2 min. The mean image quality was 3.1 ± 0.9 with only two examinations rated non-diagnostic. The mean degree of calcifications was equal. As assessed by Bland-Altman analysis, there was no relevant systematic difference between area measurements for modelled systolic MRA and systolic CTA [the mean difference -3.1 mm(2) (limits of agreement -44.4 mm(2); 38.2 mm(2))]. Agreement for hypothetical prosthesis sizing was found in 63 of 67 (94%) patients for systolic CTA and modelled systolic MRA. CONCLUSION: The employed non-contrast 3D-FLASH MRA protocol allows for reliable assessment of aortic annulus dimensions and calcifications even in the presence of arrhythmias in an all-comers pre-TAVR population. Implementation of this technique appears legitimate in patients at an increased risk for contrast-induced nephropathy.

In-hospital resource utilization in surgical and transcatheter aortic valve replacement.

BACKGROUND: Little is known about preoperative predictors of resource utilization in the treatment of high-risk patients with severe symptomatic aortic valve stenosis. We report results from the prospective, medical-economic "TAVI Calculation of Costs Trial". METHODS: In-hospital resource utilization was evaluated in 110 elderly patients (age ≥ 75 years) treated either with transfemoral (TF) or transapical (TA) transcatheter aortic valve implantation (TAVI, N = 83), or surgical aortic valve replacement (AVR, N = 27). Overall, 22 patient-specific baseline parameters were tested for within-group prediction of resource use. RESULTS: Baseline characteristics differed between groups and reflected the non-randomized, real-world allocation of treatment options. Overall procedural times were shortest for TAVI, intensive care unit (ICU) length of stay (LoS) was lowest for AVR. Length of total hospitalization since procedure (THsP) was lowest for TF-TAVI; 13.4 ± 11.4 days as compared to 15.7 ± 10.5 and 21.2 ± 15.4 days for AVR and TA-TAVI, respectively. For TAVI and AVR, EuroScore I remained the main predictor for prolonged THsP (p <0.01). Within the TAVI group, multivariate regression analyses showed that TA-TAVI was associated with a substantial increase in THsP (55 to 61 %, p <0.01). Additionally, preoperative aortic valve area (AVA) was identified as an independent predictor of prolonged THsP in TAVI patients, irrespective of risk scores (p <0.05). CONCLUSIONS: Our results demonstrate significant heterogeneity in patients baseline characteristics dependent on treatment and corresponding differences in resource utilization. Prolonged ThsP is not only predicted by risk scores but also by baseline AVA, which might be useful in stratifying TAVI patients. TRIAL REGISTRATION: German Clinical Trial Register Nr. DRKS00000797.

Contrast-enhanced voiding urosonography phantom study: intravenous iodinated and gadolinium-based contrast agents may cause false-negative results in assessment of vesicoureteral reflux in children.

BACKGROUND: Contrast-enhanced voiding urosonography (ce-VUS) is commonly requested simultaneously to other diagnostic imaging necessitating intravenous contrast agents. To date there is limited knowldedge about intravesical interactions between different types of contrast agents. OBJECTIVE: To assess the effect of excreted intravenous iodinated and gadolinium-based contrast agents on the intravesical distribution of ultrasound contrast within contrast-enhanced voiding urosonography. MATERIALS AND METHODS: Iodinated (iomeprol, iopamidol) and gadolinium-based (gadoterate meglumine) contrast agents were diluted to bladder concentration and injected into balloons filled with saline solution. CT scans were performed to assess the contrast distribution in these phantoms. Regions of interest were placed at the top and bottom side of each balloon and Hounsfield units (HU) were measured. Three other balloons were filled with saline solution and contrast media likewise. The ultrasound contrast agent sulphur hexafluoride was added and its distribution was assessed using sonography. RESULTS: MDCT scans showed a separation of two liquid layers in all bladder phantoms with the contrast layers located at the bottom and the saline solution at the top. Significant differences of the HU measurements at the top and bottom side were observed (P < 0.001-0.007). Following injection of ultrasound contrast agent, US showed its distribution exclusively among the saline solution. CONCLUSIONS: False-negative results of contrast-enhanced voiding urosonography may occur if it is performed shortly after imaging procedures requiring intravenous contrast.

"Heart Team" decision making in elderly patients with symptomatic aortic valve stenosis who underwent AVR or TAVI - a look behind the curtain. Results of the prospective TAVI Calculation of Costs Trial (TCCT).

AIMS: Little is known about how "Heart Team" treatment decisions among patients suitable for either surgical aortic valve replacement (AVR) or transcatheter aortic valve implantation (TAVI) are made under routine conditions. METHODS AND RESULTS: The "Heart Team" decision-making process was analysed with respect to124 patients of a non-randomised prospective clinical trial that included patients aged ≥75 years: 41 patients underwent AVR and 83 underwent TAVI. By use of the non-parametric classification and regression tree (CART) methodology, 21 baseline parameters were tested to reconstruct the decision process retrospectively. Next, multivariate logistic and Cox regression models were fitted to evaluate the decision and outcome relevance (two-year survival) of the parameters as identified in the CART procedure. For patients with a baseline EuroSCORE I ≥13.48%, no further cut-off points were identified and the majority of these patients underwent TAVI. Among patients with a baseline EuroSCORE I <13.48%, age and left ventricular ejection fraction (LVEF) were identified as further relevant decision parameters. The decision relevance of EuroSCORE I (p=0.003), age (p=0.024) and LVEF (p=0.047) were confirmed by multivariate analysis; however, outcome relevance can be confirmed for EuroSCORE I (p=0.015) only, while treatment decision (TAVI or AVR) was not a significant predictor of mortality (p=0.655). CONCLUSIONS: Despite or even because of the systematic risk selection according to EuroSCORE I values, we observed two-year survival rates of about 75% regardless of whether the patient received TAVI or AVR, suggesting that the decisions made by the "Heart Team" were appropriate.

Fully automated derivation of coronary artery calcium scores and cardiovascular risk assessment from contrast medium-enhanced coronary CT angiography studies.

OBJECTIVES: Performance evaluation of a fully automated system for calculating computed tomography (CT) coronary artery calcium scores from contrast medium-enhanced coronary CT angiography (cCTA) studies. METHODS: One hundred and twenty-seven patients (58 ± 11 years, 71 men) who had undergone cCTA as well as an unenhanced CT calcium scoring study where included. Calcium scores were computed from cCTA by an automated image processing algorithm and compared with calcium scores obtained by standard manual assessment of unenhanced CT calcium scoring studies. Results were compared vis-a-vis (1) absolute calcium score values, (2) age-, gender- and race-dependent percentiles, and (3) commonly used calcium score risk classification categories. RESULTS: One hundred and nineteen out of 127 (93.7%) studies were successfully processed. Mean Agatston calcium score values obtained by traditional non-contrast CT calcium scoring studies and derived from contrast medium-enhanced cCTA did not significantly differ (235.6 ± 430.5 vs 262.0 ± 499.5; P > 0.05). Calcium score risk categories and Multi-Ethnic Study of Atherosclerosis (MESA) percentiles showed very high correlation (Spearman rank correlation coefficient = 0.97, P < 0.0001/0.95, P < 0.0001) between the two approaches. CONCLUSIONS: Calcium score values automatically computed from cCTA are highly correlated with standard unenhanced CT calcium scoring studies. These results suggest a radiation dose- and time-saving potential when deriving calcium scores from cCTA studies without a preceding unenhanced CT calcium scoring study.

Preoperative assessment of aortic annulus dimensions: comparison of noninvasive and intraoperative measurement.

BACKGROUND: Preoperative assessment of aortic annulus diameter is crucial for valve sizing in patients scheduled for transcatheter aortic valve replacement. Computed tomographic (CT) measurements of the aortic annulus are not standardized and may yield different results depending on view due to its elliptic shape. The purpose of this study was to compare the measurement of the aortic annulus during surgery in patients undergoing conventional aortic valve replacement with noninvasive methods. METHODS: In 33 patients with aortic valve stenosis (18 males, mean age 77.2 ± 7.9), aortic annulus diameter was measured with cardiac CT and TEE (transesophageal echocardiography) prior to open aortic valve replacement. In CT, aortic annulus diameter was assessed as the calculated average diameter of luminal area at the level of basal attachments of the leaflets by means of planimetry. Operative measurements were performed with a Hegar dilator. A Pearson analysis was applied to test for degree of correlation. RESULTS: Calculated average diameter by CT correlated significantly with intraoperative measurements (r = 0.923, p < 0.001) and with the size of implanted valve (r = 0.867, p < 0.001), while correlation of TEE and intraoperative measurements was weak (r = 0.523, p = 0.002). The TEE tends to underestimate the dimensions of aortic annulus. CONCLUSIONS: The CT-measured aortic annulus diameter, assessed as the calculated average diameter of planimetric annulus area, seems to provide adequate dimensions similar to operative measurements with a Hegar dilator. This approach may minimize the dependency of single-view CT measurement on the elliptic shape of the aortic annulus and appears to be a feasible alternative for aortic annulus assessment in terms of candidates' selection for transcatheter aortic valve replacement.

Combined assessment of aortic root anatomy and aortoiliac vasculature with dual-source CT as a screening tool in patients evaluated for transcatheter aortic valve implantation.

OBJECTIVE: The objective of our study was to investigate the feasibility, image quality, and clinical implications of a combined dual-source CT angiography (CTA) protocol to assess aortic root anatomy and aortoiliac vasculature in patients with severe aortic stenosis evaluated for transcatheter aortic valve implantation. SUBJECTS AND METHODS: Eighty consecutive patients (47 women and 33 men; mean age, 82.3 ± 7.8 [SD] years) with severe aortic stenosis evaluated for transcatheter aortic valve implantation underwent a combined single-dose contrast-enhanced dual-source CTA protocol (body weight < 70 kg, 110 mL of contrast medium; ≥ 70 kg, 130 mL) consisting of ECG-gated dual-source CTA of the chest with integrated cardiac CT and ungated CTA of the abdomen and pelvis. Two independent observers measured the dimensions of the aortic root and the aortoiliac vasculature and rated image quality semiquantitatively. Vessel attenuation was assessed. Amenability to transfemoral access was evaluated on the basis of vessel diameter (> 7 mm), anatomy, and the presence of vascular disease. RESULTS: Image quality of the aortic root was diagnostic in all 80 patients, and image quality of the aortoiliac vasculature was diagnostic in 79 patients. Vascular attenuation was greater than 200 HU at any vessel level. The mean diameter of the aortic annulus was 24.1 ± 2.9 (SD) mm. Inter- and intraobserver correlations for aortic root and aortoiliac measurements were high (r = 0.93-0.99). Aortic root dimensions were suitable for transcatheter aortic valve implantation in 65 patients (81%). Thirty-eight patients (48%) were deemed amenable to instant transfemoral access without another vasculature intervention. CONCLUSION: The dimensions of the aortic root and the aortoiliac vasculature can be assessed with a combined single-dose contrast-enhanced dual-source CTA protocol, thereby allowing determination of patient eligibility for transcatheter aortic valve implantation, prosthesis sizing, and evaluation of the access route in one examination.

Assessment of aortic annulus dimensions for Edwards SAPIEN Transapical Heart Valve implantation by computed tomography: calculating average diameter using a virtual ring method.

OBJECTIVE: Accurate preoperative assessment of the aortic annulus dimensions is critical in patients undergoing transcatheter aortic valve implantation (TAVI) for severe AS. Using multislice computed tomography (MSCT), we evaluated a novel approach to quantify aortic annulus dimensions using cross-sectional area (CSA) assessment and average diameter calculation compared with the commonly applied electronic caliper measurements in patients undergoing transapical implantation of the Edwards SAPIEN Transcatheter Heart Valve. METHODS: Seventy-one patients underwent pre-TAVI MSCT with the following dimensions assessed at the level of the most basal attachment points of all three aortic cusps joined by a virtual ring: CSA, calculated average annulus diameter (CAAD), and minimal, maximum, sagittal and coronal diameters. Measurements were compared with post-TAVI MSCT data sets at the level of the ventricular stent ending in 24 patients. Pre-TAVI measurements were compared to those taken post-TAVI. Eligibility to balloon-expandable TAVI was evaluated based on the different measurements. RESULTS: The Edwards SAPIEN valve (23 mm, n=8; 26 mm, n=16) was implanted 2.1±1.1 mm below the non-coronary sinus. Pre-TAVI CAAD was 23.0±1.6 mm; post-TAVI CAAD was 23.0±1.1 mm. Post-TAVI CSA was circular in 18 patients (75%) and ovoid in six (25%). Pre- and post-TAVI assessment showed strong correlation for CSA and CAAD (r=0.835, p<0.001; r=0.841, p<0.001, respectively). Minimal, maximum, coronal and sagittal dimension correlated weakly between pre- and post-TAVI measurements (r=0.435-0.632, p=0.001-0.034). CONCLUSION: Pre-TAVI CSA assessment and average diameter calculation using a virtual ring method is able to predict the post-interventional configuration of the annulus after balloon-expandable TAVI. We regard this approach as the best-available method to select the appropriate prosthesis size for balloon-expandable TAVI. Specific MSCT-based sizing recommendations should be developed.