Functional classification of aortic regurgitation using cardiac computed tomography: comparison with surgical inspection

Computed tomography anatomical characteristics based on transcatheter aortic valve replacement in aortic regurgitation

This study analyzed computed tomography (CT) measurement characteristics and anatomical classifications based on transcatheter aortic valve replacement (TAVR) in patients with aortic regurgitation (AR) to establish a preliminary summary of CT anatomical characteristics and to design a novel self-expanding transcatheter heart valve (THV). This single-center retrospective cohort study included 136 patients diagnosed with moderate-to-severe AR at Fuwai Hospital from July 2017 to April 2022. Patients were classified into four anatomical classifications according to dual-anchoring multiplanar measurement of where THV anchoring took place. Types 1-3 were considered candidates for TAVR, whereas type 4 was not. Among 136 patients with AR, there were 117 (86.0%) tricuspid, 14 bicuspid, and five quadricuspid valves. Dual-anchoring multiplanar measurement showed that the annulus was smaller than left ventricular outflow tract (LVOT) at 2, 4, 6, 8, and 10 mm on the annulus. The ascending aorta (AA) 40 mm was wider than AA 30 mm and AA 35 mm, but narrower than AA 45 mm and AA 50 mm. For 10% oversize of the THV, the proportions of the annulus, LVOT, and AA unable to meet the diameter were 22.8%, 37.5%, and 50.0%, respectively, and the proportions of anatomical classification types 1-4 were 32.4%, 5.9%, 30.1%, and 31.6%, respectively. The novel THV could significantly improve the type 1 proportion (88.2%). Existing THVs cannot meet the anatomical characteristics of patients with AR. Conversely, based on anatomical characteristics, the novel THV could theoretically facilitate TAVR.

Can Measuring the 'Dual Anchors of Aorta' Enhance the Success Rate of TAVR?-A Single-Center Experience

INTRODUCTION

Chronic severe aortic regurgitation (AR) has a poor long-term prognosis, especially among old-age patients. Considering their advancing age, the surgical approach of aortic valve replacement may not always be the best alternative modality of treatment in such patients. Therefore, this study's primary goal was to provide an initial summary of the medium- and short-term clinical effectiveness of transcatheter aortic valve replacement (TAVR) guided by accurate multi-detector computed tomography (MDCT) measurements in patients with severe and chronic AR, especially in elderly patients.

METHODS

The study enrolled retrospectively and prospectively patients diagnosed with severe AR who eventually underwent TAVR procedure from January 2019 to September 2022 at Fuwai cardiovascular Hospital, Beijing. Baseline information, MDCT measurements, anatomical classification, perioperative, and 1-year follow-up outcomes were collected and analyzed. Based on a novel anatomical categorization and dual anchoring theory, patients were divided into four categories according to the level of anchoring area. Type 1, 2, and 3 patients (with at least two anchoring regions) will receive TAVR with a transcatheter heart valve (THV), but Type 4 patients (with zero or one anchoring location) will be deemed unsuitable for TAVR and will instead receive medical care (retrospectively enrolled patients who already underwent TAVR are an exception).

RESULTS

The mean age of the 37 patients with severe chronic AR was 73.1 ± 8.7 years, and 23 patients (62.2%) were male. The American Association of Thoracic Surgeons' score was 8.6 ± 2.1%. The MDCT anatomical classification included 17 cases of type 1 (45.9%), 3 cases of type 2 (8.1%), 13 cases of type 3 (35.1%), and 4 cases of Type 4 (10.8%). The VitaFlow valve (MicroPort, Shanghai, China) was implanted in 19 patients (51.3%), while the Venus A valve (Venus MedTech, Hangzhou, China) was implanted in 18 patients (48.6%). Immediate TAVR procedural and device success rates were 86.5% and 67.6%, respectively, while eight cases (21.6%) required THV-in-THV implantation, and nine cases (24.3%) required permanent pacemaker implantation. Univariate regression analysis revealed that the major factors affecting TAVR device failure were sinotubular junction diameter, THV type, and MDCT anatomical classification (p < 0.05). Compared with the baseline, the left ventricular ejection fraction gradually increased, while the left ventricular end-diastolic diameter remained small, and the N-terminal-pro hormone B-type natriuretic peptide level significantly decreased within one year.

CONCLUSION

According to the results of our study, TAVR with a self-expanding THV is safe and feasible for patients with chronic severe AR, particularly for those who meet the criteria for the appropriate MDCT anatomical classification with intact dual aortic anchors, and it has a significant clinical effect for at least a year.

Valve Repair in Aortic Insufficiency: A State-of-the-art Review

Aortic valve insufficiency (AI) describes the pathology of blood leaking through the aortic valve to the left ventricle during diastole and is classified as mild, moderate or severe according to the volume of regurgitating blood. Intervention is required in severe AI when the patient is symptomatic or when the left ventricular function is impaired. Aortic valve replacement has been considered the gold standard for decades for these patients, but several repair techniques have recently emerged that offer exceptional stability and long-term outcomes. The appropriate method of repair is selected based on the mechanism of AI and each patient's anatomic variations. This review aims to describe different pathologies of AI based on its anatomy, along with the different surgical techniques of aortic repair and their reported results.

Aortic regurgitation: A multimodality approach

Aortic regurgitation (AR) is a common valvular pathology. Multimodality noninvasive cardiovascular imaging is routinely used to assess the mechanism of AR, degree, and its hemodynamic impact on the cardiovascular system. Collecting this information is crucial in establishing the prognosis and in guiding patient management and follow-up. While echocardiography remains the primary test to assess AR, a comprehensive assessment of this valvulopathy can be obtained by combining the information from different techniques. This state-of-the-art review is intended to provide an update ed overview of the applications, strengths, and limits of transthoracic echocardiography, cardiac magnetic resonance, and cardiac computed tomography in patients with AR.

Multimodality Evaluation of Aortic Insufficiency and Aortitis in Rheumatologic Diseases

Aortic insufficiency is commonly observed in rheumatologic diseases such as ankylosing spondylitis, systemic lupus erythematosus, antiphospholipid syndrome, Behçet's disease, granulomatosis with polyangiitis, and Takayasu arteritis. Aortic insufficiency with an underlying rheumatologic disease may be caused by a primary valve pathology (leaflet destruction, prolapse or restriction), annular dilatation due to associated aortitis or a combination of both. Early recognition of characteristic valve and aorta morphology on cardiac imaging has both diagnostic and prognostic importance. Currently, echocardiography remains the primary diagnostic tool for aortic insufficiency. Complementary use of computed tomography, cardiac magnetic resonance imaging and positron emission tomography in these systemic conditions may augment the assessment of underlying mechanism, disease severity and identification of relevant non-valvular/extracardiac pathology. We aim to review common rheumatologic diseases associated with aortic insufficiency and describe their imaging findings that have been reported in the literature.

Aortic annulus sizing in bicuspid and tricuspid aortic valves using CT in patients with surgical aortic valve replacement

The purpose of this study was to evaluate whether bicuspid anatomy affects the discrepancy between CT-derived annular size and intraoperative size. We retrospectively analyzed annular measurements in 667 patients who underwent surgical aortic valve replacement (AVR). Preoperative CT measurements of the aortic annulus were compared to surgically implanted valve sizes. To evaluate whether the bicuspid valve affects the differences between CT annulus diameter and surgical AVR size, patients with diameter larger by > 10% (CT-Lg group) on CT, compared to surgical AVR size, were compared with those having size difference < 10% (CT-Sim group). Propensity score matching yielded 183 matched patients from each group. Bicuspid aortic valve annulus parameters significantly correlated with surgical aortic valve size (r = 0.52-0.71; for all, p < 0.01). The most representative measurements corresponded to surgical aortic valve size were area-derived diameters in tricuspid aortic valve (r = 0.69, p < 0.001) and bicuspid without raphe (r = 0.71, p < 0.001), and perimeter-derived diameter in bicuspid with raphe (r = 0.63, p < 0.001). After propensity score matching, native valve type was not different between CT-Sim and CT-Lg groups. In multivariable analysis, the difference between CT-derived diameter and surgical AVR size was affected by the operator factor and types of prosthesis. Bicuspid aortic annulus diameters measured on CT showed a significant correlation with surgical aortic valve size. The difference between CT-derived diameter and surgical AVR size is affected by operator factor and the types of prosthesis but not affected by the bicuspid valve.

3-Dimensional computed tomographic assessment predicts conduction block and paravalvular leakage after rapid-deployment aortic valve replacement

OBJECTIVES

Complications like complete atrioventricular block (CAVB) and paravalvular leakage (PVL) following rapid deployment aortic valve (AV) replacement (RDAVR) remain unresolved. Selecting an optimal size of the valve might be important to minimize the incidence of these complications. We sought to determine the impact of prosthesis size relative to the anatomic profile of the AV on the occurrence of CAVB or PVL after RDAVR.

METHODS

Preoperative computed tomographic (CT) images were evaluated in patients receiving RDAVR (INTUITY ELITE) between February 2016 and December 2019. The occurrence of CAVB requiring permanent pacemaker implantation and PVL (≥ mild) was evaluated. The relative size of implants against the cross-sectional dimensions of recipients' AV annulus and left ventricular outflow tract (LVOT) were calculated.

RESULTS

Among 187 eligible patients, CAVB and PVL (≥ mild) occurred in 12 (6.4%) and 11 patients (5.9%), respectively. CAVB was associated with oversized RDAVR (RDAVR frame width minus average diameter of LVOT calculated from the cross-sectional area [ΔLVOTarea]: odds ratio, 2.05; 95% confidence interval, 1.28-3.30): this was with an area under the curve of 0.78 (P = 0.005). The projected probability of CAVB was <3% when the ΔLVOTarea was <1.3. In contrast, PVL was associated with under-sized RDAVR (RDAVR size divided by the longest diameter of AV annulus [index Annlong]: odds ratio, 0.64; 95% confidence interval, 0.51-0.79): This was with an area under curve of 0.94 (P < 0.001).

CONCLUSIONS

CT parameters of the AV annulus and LVOT are highly reliable in the prediction of CAVB or PVL after RDAVR. Our data might justify CT-based sizing of prosthesis for RDAVR.

Preoperative Cardiac Computed Tomography Characteristics Associated with Recurrent Aortic Regurgitation after Aortic Valve Re-Implantation

Objective

To identify the preoperative cardiac computed tomography (CT) factors influencing postoperative recurrent aortic regurgitation (AR) in patients who underwent aortic valve repair with the re-implantation technique (David operation) due to AR.

Materials and Methods

A total of 117 patients (age, 49.4 ± 15.6 years; 83 males) who underwent the David operation for AR were included in this retrospective study. Aortic root profiles including the aortic regurgitant orifice area (ARO) and the aortic cusp asymmetry ratio of the areas (ASR_area), which is defined as the maximum/minimum areas among the three cusp areas at the level of the commissures, were measured on preoperative cardiac CT scans. Clinical and CT findings were compared between a group with recurrent AR grade < 3 (no, trivial, or mild AR) and recurrent ≥ 3 + AR. To determine the optimal cut-off values of ASR and ARO, the receiver operating characteristic (ROC) curve was used. Cox regression analysis was used for the analysis of the factors affecting recurrent 3 + AR.

Results

Postoperatively, recurrent 3 + AR developed in 17 (14.5%) patients and occurred within a median of 268 days (interquartile range: 78–582 days). The cut-off ARO value for discriminating the patients with recurrent 3 + AR was > 24 mm² (sensitivity, 76.5%; specificity 64.8%), and the area under the ROC curve (AUC) was 0.72. For ASR_area, the cut-off value was > 1.58 (sensitivity, 76.5%; specificity, 58.0%) and the AUC was 0.64. Multivariable Cox regression showed that ARO > 24 mm² (hazard ratio = 3.79, p = 0.020) was a potential independent parameter for recurrent 3 + AR. ROC for the linear regression model showed that the AUC for both ARO and ASR_area was 0.73 (95% confidence interval, 0.64–0.81, p < 0.001).

Conclusion

ARO and ASR_area detected on preoperative cardiac CT would be potentially helpful for identifying AR patients who may benefit from the David operation.

Determinants of effective orifice area in aortic valve replacement: anatomic and clinical factors

Background

Obtaining adequate effective orifice area (EOA) in surgical aortic valve replacement (SAVR) is important to minimize pressure gradients across the prosthetic aortic valve (AV) and improve clinical outcomes. However, the predictors of EOA are unclear.

Methods

From July 2011 to March 2016, patients undergoing SAVR who were preoperatively evaluated using a computed tomography (CT) on the aortic root were enrolled. Indexed EOA (iEOA) was used as an indicator of prosthetic AV opening area. The aortic root parameters investigated were the annular diameter (max and min), annular perimeter, annular area, and maximal dimensions of the proximal ascending aorta. These variables were evaluated as predictors of EOA, and an individual surgeon was incorporated in analysis for verifying surgeon dependent factors.

Results

Among the 710 patients included in this study [age: 64.9±10.8 years; females: n=285 (40.1%)], 370 (52.1%) were implanted with bio-prosthesis. Mean prosthetic iEOA was 1.1±0.3 cm²/m². Univariable linear regression analysis showed that all indexed aortic root parameters (maximal and minimal annular diameters, annular perimeter, annular area, and sinus dimensions) were significantly associated with iEOA (P<0.001). Multivariable analysis showed that indexed aortic annular area, indexed maximal diameter of the Valsalva sinus, female sex, and bio-prosthesis, supra-annular type prosthesis and surgeon were significant and independent determinants of iEOA (adjusted R²=0.513, P<0.001).

Conclusions

Aortic annular area and Valsalva sinus diameter are independent determinants for iEOA measured by preoperative CT; surgeon-dependent factors are also significant determinants in SAVR.