Multidetector row computed tomography parameters associated with paravalvular regurgitation after transcatheter aortic valve implantation

Biomechanics of Transcatheter Aortic Valve Implant

Transcatheter aortic valve implantation (TAVI) has grown exponentially within the cardiology and cardiac surgical spheres. It has now become a routine approach for treating aortic stenosis. Several concerns have been raised about TAVI in comparison to conventional surgical aortic valve replacement (SAVR). The primary concerns regard the longevity of the valves. Several factors have been identified which may predict poor outcomes following TAVI. To this end, the lesser-used finite element analysis (FEA) was used to quantify the properties of calcifications which affect TAVI valves. This method can also be used in conjunction with other integrated software to ascertain the functionality of these valves. Other imaging modalities such as multi-detector row computed tomography (MDCT) are now widely available, which can accurately size aortic valve annuli. This may help reduce the incidence of paravalvular leaks and regurgitation which may necessitate further intervention. Structural valve degeneration (SVD) remains a key factor, with varying results from current studies. The true incidence of SVD in TAVI compared to SAVR remains unclear due to the lack of long-term data. It is now widely accepted that both are part of the armamentarium and are not mutually exclusive. Decision making in terms of appropriate interventions should be undertaken via shared decision making involving heart teams.

Temporal Change in Paravalvular Leakage after Transcatheter Aortic Valve Replacement with a Self-Expanding Valve: Impact of Aortic Valve Calcification

Background

In patients undergoing transcatheter aortic valve replacement (TAVR), the severity of paravalvular leakage (PVL) may change during follow-up, however its mechanism is poorly understood. We aimed to explore temporal changes in PVL and possible predictors following TAVR.

Methods

A retrospective analysis was performed of all patients who had received a self-expanding valve. Multi-detector computed tomography was performed as pre-TAVR evaluation, including assessment of aortic valve calcification (AVC). The patients received transthoracic echocardiography at baseline and 30 days, 6 months, and 1 year after TAVR.

Results

In total, 93 patients who had received a self-expanding valve during TAVR were identified. Various degrees of PVL were seen in 63 patients, with moderate/severe PVL in 21 (22.6%). In multivariate analysis, the predictors of moderate/severe PVL were: chronic pulmonary disease, high degree of AVC, and an increased annulus perimeter. After 1 year of follow-up, PVL deteriorated from mild to moderate in 2 patients, while an improvement of ≥ 1 grade was seen in 25 patients. Of 21 patients with post-TAVR moderate/severe PVL, 9 had an improvement of ≥ 1 grade and 12 did not. The degree of AVC was significantly lower in those with PVL improvement (Agatston score 3068 ± 1816 vs. 6418 ± 3222; p = 0.01). AVC was a good predictor for an improvement in PVL, and the area under the receiver operating characteristic curve was 0.82 (95% confidence interval = 0.63-1.00, p = 0.01), with a cut-off value of 5210.

Conclusions

In this study, 43% (9/21) of the patients with moderate/severe PVL after self-expanding TAVR had an improvement of ≥ 1 grade within 1 year, and a low degree of AVC was predictive of this improvement.

Feasibility, Accuracy, and Reproducibility of Aortic Annular and Root Sizing for Transcatheter Aortic Valve Replacement Using Novel Automated Three-Dimensional Echocardiographic Software: Comparison with Multi-Detector Row Computed Tomography

BACKGROUND

In transcatheter aortic valve replacement (TAVR), multi-detector row computed tomography (MDCT) is currently the standard imaging modality for correct prosthesis sizing, despite risks of radiation and contrast-induced renal injury. Three-dimensional (3D) transesophageal echocardiography (TEE) has been proposed as a potential alternative imaging technique, and recently, automated 3D transesophageal echocardiographic software (Aortic Valve Navigator [AVN], an unreleased prototype from Philips) has been developed for assessment of the aortic annulus and root. The aim of this study was to assess the feasibility, accuracy, and reproducibility of AVN measurements in TAVR candidates by performing a comparison with MDCT.

METHODS

In 150 patients with severe, symptomatic aortic stenosis referred for TAVR, data on aortic annular and root dimensions prospectively acquired using 3D TEE and MDCT were retrospectively analyzed. Image quality on 3D TEE and the duration of analysis with AVN were recorded, as well as the aortic valve Agatston score on MDCT.

RESULTS

Data were obtained using 3D TEE and MDCT in 100% of patients for aortic annular dimensions and in 89% for aortic root dimensions. The mean duration of analysis using AVN was 4.2 ± 1.0 min, but it was significantly shorter with better 3D echocardiographic image quality and lower Agatston score on MDCT. Correlation of measurements between 3D TEE and MDCT was good to excellent for all anatomic locations (sinotubular junction mean diameter, R = 0.71; sinus of Valsalva mean diameter, R = 0.87; aortic annular mean diameter, R = 0.75; aortic annular perimeter, R = 0.83; aortic annular area, R = 0.91), with low inter- and intraobserver variability (intraclass correlation coefficient ≥ 0.93 and r ≥ 0.90 for all locations). Comparison based on conventional prosthesis sizing charts yielded excellent agreement in prosthesis size choice (κ = 0.90).

CONCLUSIONS

New automated 3D transesophageal echocardiographic software allows accurate modeling and reproducible quantification of aortic annular and root dimensions with high feasibility. An excellent correlation between measurements with AVN and MDCT and agreement in prosthesis sizing suggests the use of AVN in clinical practice as potential alternative to MDCT before TAVR.

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

The iterations of the SAPIEN prosthesis might impact the incidence and grade of paravalvular regurgitation (PVR). The aim of this study was to assess the impact of iterations of balloon-expandable valves (SAPIEN, SAPIEN XT, and SAPIEN 3) and degree of aortic valve calcification (AVC) on the severity of PVR after transcatheter aortic valve implantation (TAVI). Comprehensive echocardiographic examinations and multidetector computed tomography (MDCT) were performed in 272 patients (127 men, 81 ± 7 years old, logistic EuroScore of 21 ± 13%) who underwent TAVI with 23- and 26-mm balloon-expandable valves. The degree of AVC was assessed with MDCT. PVR grade was assessed with echocardiography. The cover index was calculated as (prosthesis area - MDCT annulus area)/prosthesis area. SAPIEN, SAPIEN XT, and SAPIEN 3 prostheses were implanted in 103 patients (38%), 105 patients (38.5%), and 64 patients (23.5%), respectively. Significant PVR (≥moderate) occurred in 14%, 10%, and 0% of patients receiving the SAPIEN, SAPIEN XT, and SAPIEN 3, respectively (p = 0.010). Across the groups, the aortic annulus size, degree of calcification, and cover index were comparable. Larger burden of AVC was independently associated with significant PVR (odds ratio 3.48, p = 0.006) after adjusting for age, body surface area, gender, aortic annulus area, cover index, and prosthesis iteration. SAPIEN 3 was associated with lower frequency of significant PVR (odds ratio 0.31, p = 0.002). In conclusion, the incidence of significant PVR significantly decreased over time with improvement in valve design. SAPIEN 3 was associated with less significant PVR after TAVI independently of the AVC burden.

Surgical sutureless and transcatheter aortic valves: hemodynamic performance and clinical outcomes in propensity score-matched high-risk populations with severe aortic stenosis

OBJECTIVES

In propensity score-matched patients with severe aortic stenosis treated with surgical aortic valve replacement (AVR) with the 3f Enable sutureless prosthesis (Medtronic, Minneapolis, Minnesota) or transcatheter aortic valve replacement (TAVR), the hemodynamic performance of both valves and mid-term survival of patients were evaluated.

BACKGROUND

Data on hemodynamic performance of surgical sutureless bioprostheses in high operative risk patients with aortic stenosis are scarce.

METHODS

Of 258 patients undergoing TAVR or surgical aortic valve replacement with the 3f Enable valve, 80 (79 ± 5 years of age, 100% men) were included in the current analysis on the basis of propensity score 1:1 matching for baseline clinical and hemodynamic characteristics. All patients had hemodynamic echocardiographic evaluation at baseline and discharge. Mid-term survival was analyzed.

RESULTS

Compared with the 3f Enable valve, TAVR prostheses (Edwards SAPIEN XT [Edwards Lifesciences, Irvine, California] and CoreValve [Medtronic]) had larger effective orifice area index (1.00 ± 0.30 cm(2)/m(2) vs. 0.76 ± 0.22 cm(2)/m(2); p < 0.001), lower pressure gradient (8.14 ± 4.21 mm Hg vs. 10.72 ± 4.01 mm Hg; p = 0.006), less frequent prosthesis-patient mismatch (30.0% vs. 67.5%; p = 0.001), and low flow (46.2% vs. 72.5%; p = 0.02), but more frequent aortic regurgitation (87.5% vs. 20.0%; p < 0.001). The presence of prosthesis-patient mismatch was independently associated with a low-flow state at discharge (odds ratio: 4.70; p = 0.004) and independently associated with the use of the sutureless prosthesis (odds ratio: 3.90; p = 0.02). However, the survival of the 2 groups was comparable after 1.5-year (interquartile range: 0.79 to 2.01 years) follow-up (log-rank test, p = 0.95).

CONCLUSIONS

TAVR prostheses demonstrated better hemodynamics than the 3f Enable valve but a higher incidence of aortic regurgitation. However, these differences did not influence mid-term survival of patients.

Low gradient severe aortic stenosis with preserved ejection fraction: reclassification of severity by fusion of Doppler and computed tomographic data

AIMS

Low gradient severe aortic stenosis (AS) with preserved left ventricular ejection fraction (LVEF) may be attributed to aortic valve area index (AVAi) underestimation due to the assumption of a circular shape of the left ventricular outflow tract (LVOT) with 2-dimensional echocardiography. The current study evaluated whether fusing Doppler and multidetector computed tomography (MDCT) data to calculate AVAi results in significant reclassification of inconsistently graded severe AS.

METHODS AND RESULTS

In total, 191 patients with AVAi < 0.6 cm²/m² and LVEF ≥ 50% (mean age 80 ± 7 years, 48% male) were included in the current analysis. Patients were classified according to flow (stroke volume index <35 or ≥35 mL/m²) and gradient (mean transaortic pressure gradient ≤40 or >40 mmHg) into four groups: normal flow-high gradient (n = 72), low flow-high gradient (n = 31), normal flow-low gradient (n = 46), and low flow-low gradient (n = 42). Left ventricular outflow tract area was measured by planimetry on MDCT and combined with Doppler haemodynamics on continuity equation to obtain the fusion AVAi. The group of patients with normal flow-low gradient had significantly larger AVAi and LVOT area index compared with the other groups. Although MDCT-derived LVOT area index was comparable among the four groups, the fusion AVAi was significantly larger in the normal flow-low gradient group. By using the fusion AVAi, 52% (n = 24) of patients with normal flow-low gradient and 12% (n = 5) of patients with low flow-low gradient would have been reclassified into moderate AS due to AVAi ≥ 0.6 cm²/m².

CONCLUSION

The fusion AVAi reclassifies 52% of normal flow-low gradient and 12% of low flow-low gradient severe AS into true moderate AS, by providing true cross-sectional LVOT area.

Insights into new-onset rhythm conduction disorders detected by multi-detector row computed tomography after transcatheter aortic valve implantation

New-onset rhythm conduction disorders are frequent after transcatheter aortic valve implantation (TAVI). Multidetector row computed tomography may shed light on the pathophysiology of rhythm conduction disorders in patients who undergo TAVI with the Edwards SAPIEN valve. A total of 94 patients (mean age 81 ± 7 years, 48% men) treated with TAVI with the Edwards SAPIEN valve who underwent pre- and post-TAVI multidetector row computed tomography were included. Patients with preexisting right bundle branch block or left bundle branch block (LBBB) and permanent pacemakers were excluded. Pacemaker implantation or new-onset LBBB at 1-month follow-up was the combined end point. Overall, 1 pacemaker was implanted, and 14 cases of new-onset LBBB were recorded. Among several clinical and multi-detector row computed tomographic variables, overexpansion of the transcatheter valve >15% of native annular area (odds ratio 5.277, 95% confidence interval 1.398 to 19.919, p = 0.014) and depth of frame into the left ventricular outflow tract (odds ratio 1.401, 95% confidence interval 1.066 to 1.770, p = 0.010) were independently related to the need for a pacemaker or new-onset LBBB. In conclusion, overexpansion of the transcatheter prosthesis by >15% of native aortic annular area and implantation depth of the frame into the left ventricular outflow tract were independently associated with the need for a pacemaker or new-onset LBBB in patients who underwent TAVI with the Edwards SAPIEN valve.

Pericardial effusion following transcatheter aortic valve implantation: echocardiography and multi-detector row computed tomography evaluation

Although pericardial effusion (PE) early after transcatheter aortic valve implantation (TAVI) has been reported in few registries, late PE at follow-up remains unexplored. Particularly, after transapical TAVI, diagnosis of PE with transthoracic echocardiography (TTE) may be challenging. The present evaluation assessed the incidence of PE early after TAVI and at 1 month follow-up using TTE and multi-detector computed tomography (MDCT). The agreement between TTE and MDCT to diagnose the presence and severity of PE at 1 month follow-up was evaluated. Overall 293 patients undergoing TAVI were included. Pre-discharge TTE was performed in all patients. At 1 month, repeat TTE was performed in 234 patients and additional MDCT evaluation in 143 patients. Pre-discharge small and moderate PE was observed in 74.1 and 4.1 % of patients, respectively, whereas significant PE was diagnosed in 8 (2.7 %) patients without differences between procedural access: 1.6 versus 3.6 % for transfemoral and transapical respectively, p = 0.474. At 1 month new-onset moderate PE was noted in 6 (2.5 %) patients all of who underwent transapical TAVI. MDCT and TTE disagreed on the grade of PE in 38 patients. Importantly, one patient with small PE on TTE was considered having moderate PE and two patients with small and moderate PE were considered having large PE. Also, two patients with moderate PE on echocardiography were considered small PE on MDCT. In conclusions, significant PE early after TAVI is infrequent. The prevalence of small and moderate PE remains stable at 1 month follow-up. MDCT refines the diagnosis of significant PE.