Article ID: CJ-24-1003
Background: To consider transcatheter aortic valve-in-surgical aortic valve (TAV-in-SAV) as a secondary intervention, the risk of coronary obstruction during future TAV-in-SAV should be assessed prior to initial SAV replacement (SAVR), especially in Japanese patients with a small body size and aortic root anatomy. In this study we simulated the risk of coronary obstruction and identified associated anatomical factors.
Methods and Results: We retrospectively analyzed pre- and post-SAVR computed tomography scans of 115 patients and simulated the risk of coronary obstruction. High risk was defined as postoperative coronary arteries located below the risk plane (RP) and a valve-to-coronary distance <4 mm or a valve-to-aorta distance <2 mm; 28.7% of patients were classified as high risk. Preoperative right and left coronary artery heights of ≥22 and ≥18 mm, respectively, were important parameters for classifying patients with postoperative coronary arteries located above or below the RP. An expected valve-to-sinotubular junction (STJ) distance (defined as the difference between the preoperative STJ diameter and the expected internal valve diameter) ≥7 mm was another important parameter to stratify patients into low- and high-risk categories.
Conclusions: TAV-in-SAV was anatomically unfeasible in 28.7% of patients, and the coronary obstruction risk was associated with aortic root anatomy and implanted valve size. These results may provide a basis for considering TAV-in-SAV as a secondary option in Japanese patients with a small body size and aortic root anatomy.
The concept of lifetime management in aortic valve therapy has been widely advocated in recent years; indications for bioprosthetic surgical aortic valve replacement (SAVR) and transcatheter aortic valve replacement (TAVR) are extending to young and low-risk patients,1,2 and, in either SAVR or TAVR, the initial treatment plan should be formulated with an eye towards the second and possibly third treatment for structural valve deterioration (SVD).3 For patients undergoing bioprosthetic SAVR, transcatheter aortic valve (TAV) implantation in the surgical aortic valve (SAV; TAV-in-SAV) is an important secondary treatment option for SVD, along with redo SAVR. TAV-in-SAV has been reported to have lower early mortality and morbidity rates and a shorter length of hospitalization than redo SAVR;4,5 however, a high postoperative valve gradient and coronary obstruction are key problems. In particular, coronary obstruction must be avoided, because the 30-day mortality in patients with coronary obstruction has been reported to be as high as approximately 50%.5,6 From a lifetime management perspective, an initial SAVR that ensures safe future TAV-in-SAV without coronary obstruction is essential to preserve many treatment options for secondary interventions. This issue is particularly important in patients who have a small body size and a small aortic root, such as Japanese individuals, but tailored treatment strategies for initial SAVR have rarely been developed for these patients to avoid coronary obstruction during future TAV-in-SAV.
Previous studies have reported 2 main mechanisms of coronary obstruction during TAV-in-SAV: a deficient sinus of Valsalva (SOV) and sinus sequestration.7,8 A deficient SOV is caused by the leaflets of the bioprosthetic valve implanted in the initial SAVR, which rise and directly occlude the coronary ostium. Sinus sequestration occurs in patients with low takeoff coronary arteries and a narrow sinotubular junction (STJ), which indirect impair coronary flow. The risk of coronary obstruction by either of these mechanisms is estimated on preprocedural (post-SAVR) cardiac computed tomography (CT) images by assessing the location of the coronary ostium and the risk plane (RP) of the valve, where the leaflet of the bioprosthesis implanted in the initial SAVR rises and is fixed vertically by the metallic frame of the transcatheter heart valve implanted inside it, the valve-to-coronary distance (VTC), and the valve-to-aorta distance (VTA) at the RP or the valve-to-STJ distance (VTSTJ).7,9–12 However, no study has investigated predicting the risk of future coronary obstruction based on pre-SAVR anatomy.
The aims of this study were to evaluate the risk of coronary obstruction during future TAV-in-SAV based on post-SAVR cardiac CT images and to identify risk factors for coronary obstruction based on pre-SAVR aortic root anatomy.
This study was conducted according to the principles of the Declaration of Helsinki and was approved by the Institutional Ethics Committee of the University of Osaka Hospital (Approval no. 16105-4; February 11, 2016). Written informed consent was obtained from all patients.
We retrospectively evaluated 115 adult patients who underwent isolated or concomitant SAVR with stented valves with internally mounted leaflets for the treatment of aortic stenosis (AS) or aortic regurgitation (AR) of the native aortic valve at the Department of Cardiovascular Surgery, The University of Osaka Hospital between May 2010 and December 2022 and who underwent both pre- and postoperative contrast-enhanced cardiac CT. Patients with annular enlargement or patch augmentation of the SOV or STJ, graft replacement of the ascending aorta, or redo surgeries were excluded from the study.
The valves implanted in this study included the Carpentier-Edwards PERIMOUNT (CEP) Magna/CEP Magna EASE/INSPIRIS RESILIA (Edwards Lifesciences, Irvine, CA, USA), Mosaic/Mosaic Ultra/Avalus (Medtronic Plc, Dublin, Ireland), and Epic/Epic Supra (Abbott Laboratories, Abbott Park, IL, USA). The choice of valve and size depended was left to the discretion of individual surgeons. All valves were sutured in the supra-annular position using non-everting mattress sutures with predgeds through oblique aortotomy. Some patients underwent minimally invasive cardiac surgery through a right intercostal thoracotomy. Patient data were collected from the medical records.
CT EvaluationContrast-enhanced cardiac CT was performed before and after SAVR to assess coronary artery lesions, patency of the coronary artery bypass graft, leaflet thrombosis, or the feasibility of TAV-in-SAV and redo surgery. If CT was performed several times, the scan closest to the SAVR was used in the analysis.
Perimeter-derived annular diameters, SOV diameters, short diameters of the STJ, and coronary heights were measured using pre- and postoperative contrast-enhanced cardiac CT. The internal diameter (ID) of the prosthetic valves was measured on postoperative CT images and confirmed to be approximately equivalent to the true ID of the valve-in-valve app (=expected true ID).13 The VTC, VTA, and commissural angles were measured using postoperative CT with previously reported methods.14 The expected VTSTJ was defined as the difference between the preoperative STJ diameter and the expected true ID. Only in the case of the INSPIRIS RESILIA valve did the measured ID differ from the expected true ID by approximately 2 mm and was nearly equal to the expected true ID of the CEP Magna valve; therefore, the expected true ID of the CEP Magna valve was used instead. Details of the measurement methods are summarized in Supplementary Figure 1. All measurements were performed using an Aquarius NET (TeraRecon Inc., Durham, NC, USA).
Risk Classification of Coronary Obstruction Simulation During Future TAV-in-SAVPatients were divided into 2 categories, low risk or high risk, according to the schema shown in Figure 1. Patients with a center of the coronary ostium above the RP who were expected to safely undergo future TAV-in-SAV were classified as low risk. Those with a center of the coronary ostium below the RP but with a VTA ≥2 mm and a VTC ≥4 mm who were at a low risk of deficient SOV or sinus sequestration were also classified as low risk. All other patients were classified as high risk. After classifying patients according to these risk categories for both the right coronary artery (RCA) and left coronary artery (LCA), the more severe risk category was adopted as the final risk category.
Risk classification for coronary obstruction during future transcatheter aortic valve-in-surgical aortic valve (TAV-in-SAV). Patients were classified as low risk or high risk for coronary obstruction during future TAV-in-SAV according to parameters of the aortic root anatomy after surgical aortic valve replacement. Patients with coronary arteries located below the risk plane (RP) and a valve-to-coronary distance (VTC) <4 mm or a valve-to-aorta distance (VTA) <2 mm were classified as high risk. In all, 71.3% of patients were classified as low risk and 28.7% were classified as high risk.
Statistical Analyses
Continuous variables are reported as median with interquartile range and categorical variables are reported as frequencies. Continuous variables were compared using Student’s t-test or one-way analysis of variance with Tukey’s honestly significant difference (HSD); categorical variables were compared using Fisher’s exact test. Two-tailed P<0.050 was considered statistically significant.
A logistic regression model was used to calculate odds ratios (ORs) with 95% confidence intervals (CIs) for the risks of coronary obstruction, and the Wald test was used to test its significance. The area under the curve (AUC) and cut-off value for each parameter were calculated using receiver operating characteristic (ROC) curves. All statistical analyses were performed using JMP Pro ver.14.0 (SAS Institute, Cary, NC, USA).
The characteristics of the 115 patients enrolled in the study are summarized in Table 1. The median patient age was 75 years, and 61.7% of patients were male. The median body surface area (BSA) was 1.58 m2 and the median body mass index was 22.5 kg/m2; 92 (80.0%) patients were indicated for surgery due to AS, whereas 23 (20.0%) were indicated for surgery due to AR. The operative procedures and details of the valves used in the surgery are summarized in Table 2. Isolated aortic valve replacement accounted for 24.3% of cases. Among the other patients, the most common concomitant procedure was coronary artery bypass grafting (62.6%). The most-used valve size was 21 mm (41.7%).
Baseline Characteristics of Patients Enrolled in This Study (n=115)
Age (years) | 75 [69–78] |
Male sex | 71 (61.7) |
BSA (m2) | 1.58 [1.42–1.67] |
BMI | 22.5 [20.6–25.0] |
Hypertension | 77 (67.0) |
Diabetes | 39 (33.9) |
Dyslipidemia | 56 (48.7) |
Hemodialysis | 13 (11.3) |
COPD | 24 (20.9) |
CVD | 12 (10.4) |
Indication for surgery | |
AS | 92 (80.0) |
AR | 23 (20.0) |
IE | 5 (4.3) |
Bicuspid | 20 (17.4) |
NYHA Class ≥III | 30 (26.3) |
LVEF <30% | 5 (4.3) |
STS score (%) | 3.0 [2.0–4.7] |
Data are given as the median [interquartile range] or n (%). AS, aortic stenosis; AR, aortic regurgitation; BMI, body mass index; BSA, body surface area; COPD, chronic obstructive pulmonary disease; CVD, cerebrovascular disease; IE, infective endocarditis; LVEF, left ventricular ejection fraction; NYHA, New York Heart Association; STS, Society of Thoracic Surgeons.
Details of the Operative Procedures (n=115 Patients)
Isolated AVR | 28 (24.3) |
Concomitant procedure | |
CABG | 72 (62.6) |
MVR | 6 (5.2) |
MVP | 10 (8.7) |
TAP | 8 (7.0) |
Maze/PVI | 8 (7.0) |
LAA closure | 17 (14.8) |
Myectomy | 1 (0.9) |
Extirpation of myxoma | 1 (0.9) |
Coronary-PA fistula closure | 1 (0.9) |
Median sternotomy | 110 (95.7) |
MICS | 5 (4.3) |
Emergency operation | 10 (8.7) |
Operation time (min) | 310 [257–376] |
ACC time (min) | 92 [72–121] |
CPB time (min) | 173 [131–205] |
Valve | |
CEP Magna/CEP Magna EASE | 38 (33.0) |
INSPIRIS RESILIA | 25 (21.7) |
Avalus | 7 (6.1) |
Epic/Epic Supra | 15 (13.0) |
Mosaic/Mosaic Ultra | 30 (26.1) |
Size | |
19 mm | 25 (21.7) |
21 mm | 48 (41.7) |
23 mm | 27 (23.5) |
25 mm | 14 (12.2) |
27 mm | 1 (0.9) |
Data are given as the median [interquartile range] or n (%). ACC, aortic cross-clamp; AVR, aortic valve replacement; CABG, coronary artery bypass grafting; CPB, cardiopulmonary bypass; LAA, left atrial appendage; MICS, minimally invasive cardiac surgery; MVP, mitral valve plasty; MVR, mitral valve replacement; PA, pulmonary artery; PVI, pulmonary vein isolation; TAP, tricuspid annuloplasty.
Risk Classification of Coronary Obstruction During Future TAV-in-SAV
The pre- and postoperative measurements of the aortic root are summarized in Table 3. Based on postoperative measurements, the risk categories for coronary obstruction during future TAV-in-SAV were classified as low or high risk, as shown in Figure 1. In this study, 14.8% of patients had postoperative coronary arteries located above the RP. Among patients whose coronary arteries were located below the RP, 56.5% had VTC ≥4 mm and VTA ≥2 mm, whereas 28.7% had VTC <4 mm or VTA <2 mm. Overall, 71.3% of patients were classified as low risk and 28.7% were classified as high risk.
Pre- and Postoperative CT Measurements of the Aortic Root (n=115 Patients)
Preoperative CT measurements | |
Annulus diameter (mm) | 24.3 [22.6–26.3] |
LVOT diameter (mm) | 24.3 [22.0–27.1] |
SOV diameters (mm) | |
Right | 30.7 [27.9–33.3] |
Left | 31.1 [28.9–34.2] |
Non | 32.6 [29.9–35.5] |
Average | 31.4 [29.0–33.9] |
STJ diameter (mm) | 26.8 [24.4–30.4] |
Coronary height (mm) | |
RCA | 18.1 [15.7–21.1] |
LCA | 16.7 [14.8–18.3] |
Sinus of Valsalva height (mm) | 19.4 [18.0–22.5] |
Postoperative CT measurements | |
ID (mm) | 18.7 [17.3–20.6] |
SOV diameters (mm) | |
Right | 29.7 [26.8–32.5] |
Left | 29.2 [27.0–32.3] |
Non | 30.2 [27.4–32.8] |
Average | 29.7 [27.2–32.6] |
STJ (mm) | 26.0 [23.5–28.7] |
Stent-RCA angle (°) | 42.9 [33.4–48.1] |
Stent-LCA angle (°) | 48.8 [41.5–54.0] |
Right commissural misalignment (<20°) | 6 (5.2) |
Left commissural misalignment (<20°) | 3 (2.6) |
Coronary height (mm) | |
RCA | 13.1 [10.6–15.7] |
LCA | 12.2 [10.8–14.9] |
Data are given as the median [interquartile range] or n (%). CT, computed tomography; ID, inner diameter; LCA, left coronary artery; LVOT, left ventricular outflow tract; RCA, right coronary artery; SOV, sinus of Valsalva; STJ, sinotubular junction.
Among AS patients, 65.2% and 34.8% were categorized as low and high risk, respectively. Conversely, among AR patients, 95.6% were categorized as low risk and only 4.4% were categorized as high risk (Supplementary Figure 2). Details of the pre- and postoperative parameters of the aortic root in patients with AS and AR are summarized in Supplementary Table 1.
Preoperative Anatomical Factors Associated With a High Risk of Coronary ObstructionPatients were analyzed to predict postoperative risk classification based on pre-SAVR anatomical factors. First, the differences in preoperative anatomical factors between patients with postoperative coronary ostium above (n=17) and below (n=98) the RP were analyzed (Table 4). Preoperative RCA and LCA heights were significantly higher in those with a postoperative coronary ostium above rather than below the RP (P<0.050). According to ROC curve analysis, the cut-off value for RCA height was 21.6 mm (AUC 0.835; P<0.001), whereas that for LCA height was 17.9 mm (AUC 0.791; P<0.001; Supplementary Figure 3). Of the patients with both RCA height ≥22 mm and LCA height ≥18 mm, 90.9% had a postoperative coronary ostium above the RP, whereas 93.3% of patients with coronary height lower than these cut-off values had a coronary ostium below the RP (Figure 2).
Preoperative Anatomical Factors Associated With the Coronary Ostium Above or Below the RP
Coronary ostium | OR (95% CI) |
P value | AUC | Cut-off value |
|||
---|---|---|---|---|---|---|---|
Above the RP (n=17) |
Below the RP (n=98) |
P value | |||||
RCA height (mm) | 24.4 [19.8–25.7] | 17.5 [15.5–19.8] | <0.001 | 1.55 (1.278–1.89) | <0.001 | 0.835 | 21.6 |
LCA height (mm) | 19.7 [17.5–22.5] | 16.4 [14.5–17.8] | 0.003 | 1.50 (1.20–1.88) | <0.001 | 0.791 | 17.9 |
Unless indicated otherwise, data are given as the median [interquartile range]. AUC, area under the curve; CI, confidence interval; LCA, left coronary artery; OR, odds ratio; RCA, right coronary artery; RP, risk plane.
Classification of groups with a postoperative coronary ostium above or below the risk plane (RP) according to preoperative right coronary artery (RCA) and left coronary artery (LCA) heights. Preoperative RCA and LCA heights were analyzed for classification of patients with a postoperative coronary ostium above or below the RP. Of the patients with both an RCA height ≥22 mm and an LCA height ≥18 mm, 90.9% had a postoperative coronary ostium above the RP, whereas 93.3% of patients with an RCA height <22 mm or an LCA height <18 mm had a coronary ostium below the RP.
Next, in patients with a coronary ostium below the RP, preoperative parameters of the aortic root anatomy were compared between low- and high-risk patients (Table 5). Preoperative SOV and STJ diameters were significantly smaller in the high-risk group than in the low-risk group (P<0.050). In addition, the expected VTSTJ (i.e., the difference between the preoperative STJ diameter and the expected true ID based on the valve-in-valve app13), was significantly lower in high-risk patients than in low-risk patients (P<0.050; Table 5). Among these parameters, the expected VTSTJ was considered to be the most important index in the ROC curve analysis, with the highest AUC. The cut-off value of the expected VTSTJ was 7.4 mm (AUC 0.851; P<0.001; Supplementary Figure 4). When the expected VTSTJ was ≥7 mm, 89.5% of patients were classified as low risk (Figure 3).
Analysis of Risk Factors for a High Risk of Coronary Obstruction During Future Transcatheter Aortic Valve-in-Surgical Aortic Valve
High risk (n=33) |
Low risk (n=65) |
P value | OR (95% CI) |
P value | AUC | Cut-off value |
|
---|---|---|---|---|---|---|---|
Annulus diameter (mm) | 23.6 [21.8–25.1] | 24.3 [23.0–25.7] | 0.025 | 0.78 (0.62–0.97) | 0.027 | 0.626 | 22.4 |
average SOV diameter (mm) | 28.8 [26.9–30.9] | 32.2 [29.9–33.8] | <0.001 | 0.66 (0.54–0.80) | <0.001 | 0.788 | 32.2 |
STJ diameter (mm) | 24.7 [22.3–26.0] | 28.1 [24.9–30.1] | <0.001 | 0.66 (0.53–0.80) | <0.001 | 0.787 | 26.2 |
Expected true ID (mm) | 19.0 [17.0–19.0] | 19.0 [17.0–19.0] | 0.554 | 0.93 (0.75–1.17) | 0.568 | ||
Expected VTSTJ (mm) | 5.7 [4.6–6.8] | 8.7 [7.4–10.3] | <0.001 | 0.47 (0.34–0.65) | <0.001 | 0.851 | 7.4 |
Unless indicated otherwise, data are given as the median [interquartile range]. VTSTJ, valve-to-sinotubular junction distance. Other abbreviations as in Tables 3,4.
Classification of low- and high-risk patients according to the expected valve-to-sinotubular junction (VTSTJ). The expected VTSTJ was analyzed to classify low- and high-risk patients. When the expected VTSTJ was ≥7 mm, 89.5% of patients were classified as low risk. ID, internal diameter; STJ, sinotubular junction.
For subgroup analysis, patients were divided into 2 groups: those with a larger body size (BSA >1.58 m2) and those with a smaller body size (BSA ≤1.58 m2). The same analyses were performed for each group. The percentage of high-risk patients did not differ significantly between the larger and smaller groups (Supplementary Figure 5), and the cut-off values for coronary artery height and expected VTSTJ were almost identical to those of the total cohort, except for RCA height in the smaller group (Supplementary Tables 2,3).
Here we analyzed pre- and postoperative anatomical parameters of the aortic root in patients treated with internally mounted bioprosthetic valves for AS and AR to evaluate the coronary obstruction risk during future TAV-in-SAV. The overall percentage of AS patients who were considered low risk for future TAV-in-SAV was 65.2%, whereas 34.8% of patients were considered high risk due to a postoperative coronary ostium below the RP and VTC <4 mm or VTA <2 mm. Conversely, only 4.4% of AR patients were at high risk, suggesting that most AR patients can safely undergo future TAV-in-SAV without detailed preoperative anatomical considerations. Preoperative anatomical factors predictive of a high risk of coronary obstruction were examined in the entire cohort, and coronary artery height and expected VTSTJ (the preoperative STJ diameter minus the true ID of the prosthetic valve to be implanted) were strongly correlated with the risk classification.
Importance of Preoperative Consideration of Future TAV-in-SAV FeasibilityIn recent years, the importance of lifetime management of patients with aortic valve replacement has been actively discussed. The use of bioprosthetic valves for initial SAVR has been increasing, with favorable long-term results, and patient age is decreasing.15,16 With the anticipated increase in future reinterventions for the treatment of failed bioprosthetic valves, TAV-in-SAV will be an important treatment option along with redo aortic valve replacement; however, there will be certain patients for whom TAV-in-SAV is not an option due to the risk of coronary obstruction. New leaflet modification techniques, such as BASILICA (Bioprosthetic Aortic Scallop Intentional Laceration to prevent Iatrogenic Coronary Artery Obstruction),17 ShortCut,18 and chimney stenting,19 are being developed, making it possible to perform TAV-in-SAV in patients who were previously ineligible for the TAV-in-SAV procedure. However, these techniques are not yet covered by insurance in Japan, are technically difficult, and are not universally applicable. Conversely, if the initial SAVR is performed in such a way that future TAV-in-SAV can be performed safely, these techniques are not necessary. To this end, it is important to predict the feasibility of future TAV-in-SAV from the pre-SAVR aortic root anatomy and to develop a treatment strategy to avoid coronary obstruction, although specific data are lacking. This study is the first attempt to simulate the risk of coronary obstruction from the pre-SAVR aortic root anatomy based on a detailed examination of pre- and post-SAVR cardiac CT images.
Risk Classification of Coronary Obstruction and Pre-SAVR Anatomical Risk FactorsThere is still debate about a classification method that accurately assesses the risk of coronary obstruction. In the past, the Valve-in-Valve International Data (VIVID) risk classification method was proposed to consider whether to use the BASILICA technique during TAV-in-SAV.20 Under the VIVID classification method, patients were categorized into 6 groups according to the position of the coronary ostium, VTC (<4 mm), and VTSTJ (<3.5 mm) measured using pre-TAV-in-SAV cardiac CT images.20 However, a recent validation study showed that among the 31.3% of patients who were classified as high risk (Type II B/III B/III C) by the VIVID classification, none had any coronary obstruction without coronary protection,21 suggesting that this classification system is not in line with actual clinical practice.
In the present study we developed a new risk classification method and classified patients as either low or high risk according to the schema shown in Figure 1. This is based on 2 main mechanisms of coronary obstruction: a deficient SOV and sinus sequestration. The cut-off values of VTC and VTA were set at 4 and 2 mm, respectively, based on previous reports.8,11 Using our system, 71.3% of patients overall were considered to be at low risk of coronary obstruction during future TAV-in-SAV. Although only 14.8% of patients had a coronary ostium above the RP, most patients had a coronary ostium below the RP and had adequate VTC and VTA. We previously reported that the coronary height is significantly (~4–5 mm) reduced after SAVR, especially after the implantation of sutured bioprosthetic valves (e.g., internally and externally mounted valves), by comparing pre- and post-SAVR cardiac CT images,22 which results in most patients having a coronary ostium below the RP of the prosthetic valve after SAVR. The percentage of patients classified as high risk in the present study (28.7%) was similar to the results of the aforementioned validation study of the VIVID classification system despite of the smaller cut-off value of VTA/VTSTJ in our classification system than in the VIVID classification system,21 which may be attributed to the narrower SOV/STJ characteristics in Japanese patients.
Analysis of preoperative anatomical factors identified that coronary artery heights, SOV and STJ diameters, and expected VTSTJ were associated with the coronary obstruction risk. In particular, preoperative RCA height ≥22 mm and LCA height ≥18 mm were proposed as indicators to predict a postoperative coronary ostium above or below the RP, and an expected VTSTJ ≥7 mm was an important parameter to classify patients as at low or high risk of future coronary obstruction. Although these parameters may not be applicable to all patients, these values would be specific enough to be immediately useful in daily practice for patients of similar body size who, like the average Japanese individual, have a small aortic root and a high risk of future coronary obstruction.
Treatment Strategies for Initial SAVR Based on Risk ClassificationIf a patient is estimated to bet at high risk of coronary obstruction based on their preoperative aortic root anatomy, the treatment plan should be reconsidered. If postoperative prosthesis–patient mismatch can be avoided by using a smaller valve, implantation of a valve with a smaller ID may be an option, especially for elderly patients; however, there may be a risk of a higher postoperative valve gradient after TAV-in-SAV. Patch augmentation of the SOV and STJ is another treatment option, although there is little published information as to whether sufficient VTA and VTC to avoid coronary obstruction is maintained after SOV and STJ patch augmentation.23 Another treatment option is changing the suture method from non-everting mattress sutures to everting mattress sutures or simple interrupted sutures and implanting a valve in an intra-annular position. For patients with AS, the use of rapid-deployment valves (e.g., the INTUITY Elite Valve System [Edwards Lifesciences]) and sutureless valves (e.g., Perceval [Corcym S.r.l., Saluggia, Italy]) may be options because the aortic root structure was better preserved in patients with the rapid-deployment/sutureless valves than in patients with sutured bioprosthetic valves.22 These concerns must be addressed in future studies.
Study LimitationsThe present study has several limitations. First, this was a single-center retrospective study, and the risk categories were defined according to the simulation of future TAV-in-SAV, not real experience. Second, the body size of the present study cohort was relatively small, with a median BSA of 1.58 m2 and a median body mass index of 22.5 kg/m2; therefore, specific cut-off values for preoperative aortic root anatomy for coronary obstruction may not be applicable to patients with a relatively large body size. Third, if an aortic valve replacement is performed using a method other than non-everting mattress sutures, as is done at our institution, the degree of change in aortic root anatomy may differ, which could alter the risk classification. Fourth, differences in the expandability of each bioprosthetic valve (e.g., the expandability of the INSPIRIS valve or the non-fracturability of the Avalus valve) were not included in the analysis. Fifth, whether the leaflet modification technique could be performed was not considered in the risk classification and commissural misalignment was not included as a risk-defining factor. Sixth, the simulation was performed using CT images in the early postoperative period after SAVR, which may be a different anatomic condition than that in the distant postoperative period when TAV-in-SAV is usually performed. Finally, the number of patients enrolled in this study was limited, and there may have been selection bias in the patients who underwent postoperative cardiac CT.
In this study cohort, 28.7% were predicted to be at high risk of coronary obstruction during future TAV-in-SAV. Preoperative coronary artery heights, SOV and STJ diameters, and expected VTSTJ were associated with the risk of coronary obstruction. In particular, RCA height ≥22 mm, LCA height ≥18 mm, and expected VTSTJ ≥7 mm were key indicators for risk classification. These results may provide important information for patients undergoing SAVR with a bioprosthetic valve to ensure the feasibility of TAV-in-SAV as a second intervention.
None.
This study did not receive any specific funding.
Y.S. is a member of Circulation Journal’s Editorial Team. The remaining authors declare no conflicts of interest.
This study was approved by the Institutional Ethics Committee of the University of Osaka Hospital (Approval no. 16105-4).
The deidentified participant data will not be shared.
Please find supplementary file(s);
https://doi.org/10.1253/circj.CJ-24-1003