1) To understand the typical Implantation techniques used in TAVI. 2) To learn the infomation that the interventionalist requires from pre-procedural Imaging in order to optimize the Implantation procedure. 3) To appreciate the relevance of pre-procedural imaging for prosthesis selection and outcome.

To determine the precision of CTA aortic annulus area measurements and the impact on TAVR device selection.

This retrospective study included 86 consecutive clinical TAVR screening CTAs performed on a 64-slice scanner (LightSpeed VCT, GE Healthcare) using retrospective ECG gating. A 1st year medical student (R1, after training on 10 separate CTAs), a 3D lab technologist (R2, 3 yrs experience), and a cardiothoracic radiologist (R3, 6 yrs experience) independently measured the aortic annulus in systole in a random, blinded fashion. The annular plane, containing the hinge points of all 3 valve cusps, was located using multiplanar reformats (Vitrea, Vital Images). The annular area was measured using a freely drawn contour. All measurements were repeated >2 weeks later to avoid recall bias. Bland-Altman analysis was used to assess each reader's repeatability. The difference between the 95% limits of agreement and the bias was used to estimate the measurement precision. To assess differences between readers, variance ratios (VR) were calculated along with their 95% confidence intervals and compared with an F test. The impact on device sizing was evaluated using the Edwards SAPIEN valve as an example. Annular size was grouped into 5 categories, based on the recommended device: too small, 23mm, either, 26 mm, or too large. Percent agreement between the measurements was calculated for each reader.

Bias between measurements was 6 [-1,13] (R1), -3 [-11,5] (R2), and 1 [-5,7] (R3) mm2. Precision was ±64 [52,76] (R1), ±70 [57,83] (R2), and ±55 [44,66] (R3) mm2. The difference in precision between R2 and R3 was statistically significant (VR: 1.60 [1.04,2.46], p=0.03). Device size recommendations from the 2 measurements differed in 23% (R1), 29% (R2), and 22% (R3) of the cases and differed by more than 1 category in 2% (R1), 4% (R2), and 1% (R3) of the cases.

Within reader annular area measurement imprecision results in different TAVR device size recommendations ~25% of the time, even for an experienced cardiovascular CTA reader. Reports should include estimated measurement precision to aid in the interpretation of the results.

Knowing the precision of CTA-based aortic annulus area measurements is very important for multidisciplinary TAVR treatment planning. A single point estimate of the annular area may not be sufficient.

Because of the high comorbidity of TAVR candidates, a rapid, robust, non-contrast MR technique for assessing the aortic root complex along with the entire vascular access route would be desirable for TAVR procedural planning. We tested a newly developed non-contrast, free-breathing, self-navigated 3D (SN3D) MR sequence for assessing the entire aorta, from the root to the ilio-femoral run-off. A non-contrast steady-state free-precession (SSFP) sequence which has previously been shown to enable accurate aortic valve assessment was used for comparison.

We performed non-contrast MR angiography on a 1.5T system (Avanto, Siemens) using the novel SN3D and the SSFP sequence in 6 healthy subjects. The SN3D sequence was applied to assess the aorta from its root to the ilio-femoral arteries. The parameters for the SN3D acquisitions were: FOV 220/370mm, ST 1.15mm, IM 1922, slices 192, TR 265.2ms, TE 1.5ms, and FA 90°. Both the thoracic and abdominal acquisitions were ECG gated. The parameters for the SSFP sequence were: FOV 340mm, ST 6mm, IM 1922, NS 15, reconstructed phases 25, TR 39.7ms, TE 1.1ms, FA 77°, averages 3, acceleration factor 2. With SSFP only the thoracic acquisitions were ECG gated. Systolic aortic root measurements and subjective image quality (5-point scale) were compared. Vessel diameter and area measurements down to the level of the ilio-femoral arteries were obtained from the SN3D dataset. Acquisition times were recorded.

The mean area-derived effective diameter in the aortic annular plane was comparable between SSFP and SN3D (26.7±0.7mm vs. 26.1±0.9mm, P=0.23). Median image quality of the aortic valve was rated slightly (p=0.03) higher with SSFP (4 - interquartile ranges, IQR; 4-4) than with SN3D (3 - IQR, 2-4). No significant differences were observed between the diameter and area of the thoracic and abdominal aorta, and the ileo-femoral run-off (p>0.05). The acquisition time of the SN3D sequence for the whole aorta was 12.1±2.7min.

These preliminary results in healthy volunteers suggest that the proposed SN3D acquisition technique enables rapid, free-breathing assessment of the aortic root, the aorta and the ilio-femoral arteries without the administration of contrast medium.

The features of the proposed SN3D sequence appear well suited to address the requirements for TAVR procedural planning in a population which frequently suffers from renal insufficiency and dyspnea.

Aortic valve calcium is a predictor for aortic regurgitation (AR) after transcatheter aortic valve implantation (TAVI) and is associated with adverse outcome. 2nd generation devices promise to reduce residual AR, so we evaluated aortic valve calcium and post-procedual AR in 1st and 2nd generation transcatheter aortic valves as well as among different 2nd generation devices.

TAVI was performed using 1st and 2nd generation devices in 156 patients with severe aortic stenosis and high surgical risk. Devices implanted were Edwards SapienXT(n=52), Medtronic CoreValve (n=33), Symetis Acurate(n=25), JenaValve(n=20) and Medtronic Engager(n=26) valves. All patients received preoperative contrast-enhanced CT scans with prospective ECG gating. 3D-reconstructions were performed by 3Mensio software (3MensioMedical Imaging, Bilthoven).Calcium load was quantified within the device-landing area, sub-divided into zone 1 (left coronary artery ostium to aortic annulus and zone 2 (aortic annulus to 10mm below). A cutoff of 500HU was used to distinguish aortic calcium from intraluminal contrast agent. In another group of 138 patients receiving 2nd generation devices only, aortic calcium was measured separately for each leaflet and compared among all implanted devices with regard to residual AR.

The highest aortic valve calcium(zone1+2) among 1st generation devices was seen in patients with CoreValve(3141±2232mm3) whereas the Engager valve reveiled the highest calcium loads among 2nd generation valves(2396±1027mm3). Mean post-procedural AR was none/trace in 66% and greater trace in 34%, CoreValve showed the highest rate of AR greater trace with 59%. Only Engager valve had the highest calcium score (896±445mm³), while AR rates weren't significantly different among other valve types. Re-Dilatation rates increased with higher calcium load (p=0.01) while the number of pacemaker implantation didn't alter significantly

TAVI using 1st and 2nd generation devices revealed good hemodynamic results, irrespective of annular calcification. CoreValve was associated with highest rate of AR greater trace, while Engager valve, mostly used in patients with higher calcium load, showed no difference in post-procedural AR.

1st and 2nd generation TAVI devices are safe irrespective of aortic valve calcium. Only Engager valve reveiled low residual AR despite significantly higher aortic valve calcium.

1) Review the role of MDCT and TEE for annular sizing and device selection. 2) Discuss the role of pre-procedural CT in identifying patients at risk of TAVR related complications such as coronary occlusion and annular rupture. 3) Discuss the evolving role of MDCT to help guide transcatheter valve in valve procedures.

Cardiac CT is able to evaluate coronary artery disease with high diagnostic accuracy and provide comprehensive information regarding structural heart disease. Due to its ability to reconstruct 3-dimensional images with submilimeter isotropic resolution, cardiac CT is a uniquely suited tool for planning and appropriate selection of coronary and non-coronary interventional procedures. The detailed characterisation of coronary geometry and plaque morphology might improve the evaluation of bifurcation lesions and provide important information regarding selection of CTO PCI technique. The application of computational fluid dynamic simulation in CT datasets provides novel avenues in PCI planning through virtual stenting and post-stenting CT-derived computed fractional flow reserve (FFRCT) assessment. Other structural heart interventions might benefit from CT planning, like the evaluation of left atrial appendage, paravalvular leak and atrial or ventricular septal defects in patients candidate for closure devices.

Reduce the iodine load required for CT TAVI planning by acquiring the ECG-gated aortic root volume and the non-gated aortoiliac scan within the same single contrast media bolus injection.

50 patients (60% women, 83yo ±7) were prospectively included and underwent TAVI planning with a second-generation 320-row CT scanner. The aortic root was acquired in volume mode using retrospective ECG-gating (100kV, 0.275s rotation time, 2 beats maximum) and immediately followed by a non-gated CAP aortic ultra-fast helical acquisition (100kV, 0.275s rotation time, pitch=0.813), all within a single bolus of 40 to 70mL of Iohexol 350mgI/mL. Image quality of both cardiac and aortic acquisitions was independently assessed by two radiologists on a qualitative five-point scale, and HU enhancement measured in the aorta and the iliac arteries to calculate the signal to noise (SNR) and contrast to noise ratios (CNR). These qualitative and quantitative results were compared to 24 procedures (62% women, 84yo ±5) previously performed on a 64-row scanner with a conventional two-step protocol using two contrast media boluses. Qualitative results were analyzed by a Kruskal-Wallis nonparametric test and quantitative data were compared using a Mann-Whitney test. A p<0.05 was considered significant.

Mean iodine load was commonsensically significantly lower in the 320-row group (23.1g±3.6 vs 43.2g ±8, p<0.01). Image quality of the ECG-gated aortic root and the CAP aorta were equivalent (respectively 4.9 and 4.7 vs 4.4 and 4.9, p>0.05). Mean HU enhancement was similar (388 vs 400, p=0.4) while mean noise was significantly lower (24.5 vs 28.5, p<0.01), leading to a slightly improved SNR and CNR (16.3 and 13.9 vs 14.7 and 12.5, p=0.34 and 0.57). Radiation dose was significantly lower for both the ECG-gated acquisition (547mGy.cm vs 800, p<0.01) and the whole-body aortic scan (487mGy.cm vs 785, p<0.01).

Second-generation 320-row CT scanner enables a 47% reduction of the iodine load in TAVI planning, by subsequently acquiring the ECG-gated aortic root and the CAP aorta within a single contrast media bolus injection, while maintaining excellent aortoiliac arterial enhancement and lowering radiation dose.

TAVI planning with subsequent acquisition of the ECG-gated aortic root and the non-gated whole-body aorta is possible within a single contrast media injection when using a 320-row CT.

In vivo geometric analysis of the normal human aortic root is lacking. The aim of this study was to obtain the comprehensive geometric data of the normal aortic root using computed tomography (CT).

One hundred thirty subjects who underwent cardiac CT for atypical chest pain or health check-up were enrolled. Subjects without hypertension, diabetes, significant coronary artery disease, and cardiac valvular dysfunction were included (mean age, 51.4 years; 55 men; number of subjects in each decade - third 15, forth 20, fifth 30, sixth 21, seventh 23, and eighth 21). Mid-diastolic phase of CT images were analyzed using customized software (Omni4D). Individual volume of the aortic sinus and leaflet surface areas (LSA) of the right, left and non-coronary cusps were measured. Intercommissural (IC) distance in each aortic sinus was also investigated. All measured parameters were indexed to body surface area.

The left coronary sinus showed significantly smaller geometric parameters including sinus volume, LSA, and IC distance than the other two sinuses (left/non-coronary/right: sinus volume [ml/m2] 1.54/1.95/2.08; LSA [cm2/m2] 2.56/3.03/3.03; IC distance [cm/m2] 1.84/1.94/2.23; p <0.001). Between the right- and non-coronary sinuses, there were no significant differences other than IC distance. In the older decade of age, the volume and IC distance of all coronary sinuses showed an increasing tendency on the test for trend (p < 0.05). However, no significant difference was found in the LSA and annular area with age.

Detailed analysis of aortic root geometry reveals normal asymmetry in the aortic sinus and leaflet surface area. The size of left coronary sinus was smaller than the other two sinuses. The size of aortic sinus showed increasing tendency in older age group, however LSA did not changed with age.

Knowledge of the normal aortic root anatomy is relevant to understand the pathophysiology of the aortic regurgitation and to improve the method of surgical aortic root reconstruction.

The shape of the left ventricular outflow tract (LVOT), aortic annulus and aortic root may impact the proper sizing of a percutaneous aortic valve replacement (TAVR). We evaluated the sphericity of left ventricular outflow with ECG-gated coronary CTA from the LVOT through the sinotubular junction in both diastole and systole.

ECG-gated CTA studies were reviewed from 52 consecutive patients with normal aortic valves and 13 TAVR candidates with severe aortic stenosis and dense valvular calcification. Using a dedicated 3D workstation, orthogonal measurements of the outflow tract were obtained to define the antero-posterior (AP) and transverse diameters (short and long axis) at 4 levels: LVOT, aortic annulus, aortic root and sinotubular junction. Sphericity was defined as the ratio of the AP to transverse diameter at each level.

Analysis of variance demonstrated that both the level of the measurement and the phase of the cardiac cycle were significantly associated with sphericity (p<0.0001), while the presence of aortic stenosis was non-significant (p=0.96). Mean sphericity during diastole measured 0.61 at the LVOT, 0.77 at the aortic annulus, 0.94 at the aortic root and 1.00 at the sinutubular junction (p<0.0001 for comparison of any two adjacent levels). During systole, mean sphericity measured 0.69 at the LVOT, 0.81 at the aortic annulus, 0.93 at the aortic root and 1.00 at the sinutubular junction (p<0.0001 for comparison of any two adjacent levels). Differences in sphericity between diastole and systole were significant at the LVOT (p<0.0001) and at the aortic annulus (p=0.0061).

The shape of the left ventricular outflow changes from an oval at the level of the LVOT to a more circular shape at the level of the sinotubular junction. Although the entire outflow tract changes in size and sphericity during the cardiac cycle, this change is most pronounced at the LVOT, and is statistically significant only at the LVOT and aortic annulus levels. The sphericity of left ventricular outflow structures and the change in sphericity during the cardiac cycle is similar among patients with a normal aortic valve and those with severe aortic stenosis.

The oval shape of the proximal left ventricular outflow is not altered by the presence of aortic stenosis and calcification. This shape may have important implications for the design and positioning of aortic valve implants.

Patients referred for transcatheter aortic valve replacement (TAVR) typically undergo a CT study of the heart, aortic root and vascular access route for pre-interventional planning. In this study we evaluated the accuracy of cardiac CT, performed for TAVR planning purposes for diagnosing obstructive coronary artery disease (CAD) using coronary catheter angiography (CCA) as the reference standard.

With institutional review board approval, waiver of informed consent and in HIPAA compliance we retrospectively analyzed the data of 100 consecutive TAVR candidates (61 male, mean age 79.6±9.9 years) who underwent both TAVR planning CT and CCA. The presence and degree of coronary artery stenosis was assessed at both modalities. Additionally, in patients with coronary bypass grafts these were rated as either patent or occluded. Using CCA as the reference standard, we calculated the accuracy of CT for lesion detection on a per-vessel and per-patient basis. We further analyzed the accuracy of CT for the assessment of graft patency.

Our data show that in a per-vessel/per patient analysis, CT had 94.4/98.6% sensitivity and 68.4/55.6% specificity for the detection of >50% stenosis in the native coronary arteries. Negative and positive predictive values were 94.7/93.8% and 67.0/85.7%, respectively. On CT, the per-patient sensitivity for >70% stenosis was found to be 100.0%. Furthermore, all 12 vessels on which percutaneous coronary intervention was performed were correctly identified on CT as demonstrating >50% stenosis. Finally, there was good agreement between CT and CCA regarding graft patency in 114/115 grafts identified on CCA.

Our study indicates that TAVR planning CT does indeed have high sensitivity and negative predictive value in excluding obstructive CAD. For prospective TAVR candidates this would suggest that an additional pre-procedural CCA study may not be required in those patients with a CT negative for obstructive CAD.

Our analysis suggests a new management algorithm that would benefit the rising numbers of TAVR candidates with increases in cost effectiveness and improvements in patient safety.