Transcatheter Aortic Valve Replacement for Bicuspid Aortic Valve Stenosis: A Practical Operative Overview

Identification of congenital aortic valve malformations in juvenile natriuretic peptide receptor 2-deficient mice using high-frequency ultrasound

Mouse models of congenital aortic valve malformations are useful for studying disease pathobiology, but most models have incomplete penetrance [e.g., ∼2 to 77% prevalence of bicuspid aortic valves (BAVs) across multiple models]. For longitudinal studies of pathologies associated with BAVs and other congenital valve malformations, which manifest over months in mice, it is operationally inefficient, economically burdensome, and ethically challenging to enroll large numbers of mice in studies without first identifying those with valvular abnormalities. To address this need, we established and validated a novel in vivo high-frequency (30 MHz) ultrasound imaging protocol capable of detecting aortic valvular malformations in juvenile mice. Fifty natriuretic peptide receptor 2 heterozygous mice on a low-density lipoprotein receptor-deficient background (Npr2+/-;Ldlr-/-; 32 males and 18 females) were imaged at 4 and 8 wk of age. Fourteen percent of the Npr2+/-;Ldlr-/- mice exhibited features associated with aortic valve malformations, including 1) abnormal transaortic flow patterns on color Doppler (recirculation and regurgitation), 2) peak systolic flow velocities distal to the aortic valves reaching or surpassing ∼1,250 mm/s by pulsed-wave Doppler, and 3) putative fusion of cusps along commissures and abnormal movement elucidated by two-dimensional (2-D) imaging with ultrahigh temporal resolution. Valves with these features were confirmed by ex vivo gross anatomy and histological visualization to have thickened cusps, partial fusions, or Sievers type-0 bicuspid valves. This ultrasound imaging protocol will enable efficient, cost effective, and humane implementation of studies of congenital aortic valvular abnormalities and associated pathologies in a wide range of mouse models.NEW & NOTEWORTHY We developed a high-frequency ultrasound imaging protocol for diagnosing congenital aortic valve structural abnormalities in 4-wk-old mice. Our protocol defines specific criteria to distinguish mice with abnormal aortic valves from those with normal tricuspid valves using color Doppler, pulsed-wave Doppler, and two-dimensional (2-D) imaging with ultrahigh temporal resolution. This approach enables early identification of valvular abnormalities for efficient and ethical experimental design of longitudinal studies of congenital valve diseases and associated pathologies in mice.

Readmission-related outcomes of surgical versus transcatheter aortic valve replacement in patients aged 65 or older with bicuspid aortic valve

BACKGROUND

There continues to be debate regarding the superiority of transcatheter (TAVR) over surgical aortic valve replacement (SAVR) in patients with bicuspid aortic valves (BAV). We aimed to compare outcomes during readmissions in elderly patients with BAV who underwent SAVR or TAVR.

METHODS

Patients 65 years or older with BAV who underwent TAVR or isolated SAVR were identified using the National Readmission Database from 2012 through 2018. We compared outcomes during readmissions within 90 days after discharge from the index surgery. Propensity score matching was performed to adjust the baseline differences.

RESULTS

During the study period, 8555 and 1081 elderly patients with BAV underwent SAVR and TAVR, respectively. The number of patients who underwent TAVR went up by 179 % from 2012 to 2018. Propensity score matching yielded 573 patients in each group. A total of 111 (19.4 %) in the SAVR group and 125 (21.8 %) in the TAVR group were readmitted within 90 days after the index surgery (p = .31). The mortality during the readmissions within 90 days was equivalent between the two groups (0.9 % in the SAVR group vs. 3.2 % in the TAVR group, p = .22). However, the median hospital cost was approximately doubled in the TAVR group during the readmission (18,250 dollars vs. 9310 dollars in the SAVR group, p < .001).

CONCLUSIONS

Readmission within 90 days was common in both groups. While the mortality during the readmissions after the surgery was equivalent between the two groups, hospital cost was significantly more expensive in the TAVR group.

Transcatheter aortic valve replacement planning with cardiac computed tomography in quadricuspid aortic valve stenosis: a case series

Background

The presence of severe aortic stenosis in quadricuspid aortic valve (QAV) is an extremely rare combination, and it is unknown whether transcatheter aortic valve replacement (TAVR) is a safe option due to the low incidence.

Case summary

We present two patients diagnosed with severe aortic stenosis with QAV morphology type 1 (Nakamura classification). All patients presented to our hospital for evaluation because of worsening functional class, dyspnoea, or syncope. During tomographic planning, the aortic annulus was measured at the level of the deepest sinus for the selection of the number of devices. Due to the presence of four cusps, the smallest cusp was excluded, and three sinuses were virtualized for placement of the pigtail catheter during the procedure. Without complications, a 23 mm Edwards SAPIEN 3 was deployed through the femoral artery in both patients. Control aortography showed no valve leakage or regurgitation.

Discussion

In patients with QAV and aortic stenosis undergoing TAVR, similar to the tricuspid valve, tomographic planning can be used to ensure the success of the procedure. However, unlike the tricuspid valve, where the selection of the device number is based on the measurements of the aortic annulus at the level of the non-coronary sinus, in these QAV cases, we perform the measurements at the level of the deepest aortic sinus (right coronary sinus).

Redo-Transcatheter Aortic Valve Implantation Using the SAPIEN 3/Ultra Transcatheter Heart Valves-Expert Consensus on Procedural Planning and Techniques

Recent guidelines on valvular heart disease in Europe and the United States have expanded the indications for transcatheter aortic valve implantation (TAVI) to younger patients and those at lower surgical risk with severe symptomatic aortic stenosis. Consequently, the number of TAVI procedures will significantly increase worldwide. Patients with longer life expectancies will outlive their transcatheter heart valves (THVs) and require established treatment strategies for re-intervention. Current data have shown encouraging outcomes, including low mortality, with redo-TAVI; in contrast, surgical explantation of THVs is associated with high mortality. Redo-TAVI, therefore, is likely to be the treatment of choice for THV failure. The expected increase in the number of redo-TAVIs stands in contrast to the current lack of evidence on how this procedure should be planned and performed, including the risks and pitfalls operators need to consider. Preliminary reports stress the importance of preprocedural planning, understanding of THV skirt and leaflet characteristics, and implantation guidelines specific to different THVs. Currently, SAPIEN 3/Ultra is the only THV approved in Europe and the United States for redo-TAVI. Therefore, we gathered a panel of experts in TAVI procedures with the aim of providing operative guidance on redo-TAVI, using the SAPIEN 3/Ultra THV. This consensus article presents a step-by-step approach encompassing clinical, anatomical, and technical aspects in preprocedural planning, procedural techniques, and postprocedural care. In conclusion, the recommendations aim to improve the feasibility, safety, and long-term outcomes of redo-TAVI, including the durability of implanted THVs.

Definition of trAnscatheter heart Valve orIeNtation in biCuspId aortic valve: The DA VINCI pilot study

Objectives

To assess the impact of conventional transcatheter heart valve (THV) commissural alignment techniques on THV/coronary overlap and coronary access (CA) after transcatheter aortic valve replacement (TAVR) in bicuspid aortic valve (BAV).

Background

Specific Evolut Pro/Pro + and Acurate Neo2 THV orientations are associated with reduced neo-commissural overlap with coronary ostia in tricuspid aortic anatomy. Whether standard orientation techniques are effective also in the setting of BAV anatomy has not been studied.

Methods

The DA VINCI (Definition of trAnscatheter aortic Valve orIeNtation in biCuspId aortic valve) pilot study is a prospective registry enrolling consecutive patients with severe BAV stenosis undergoing TAVR with last generation supra-annular tall-frame THVs implanted with a cusp overlap view-based commissural alignment. Patients underwent pre- and post-TAVR computed tomography (CT) and coronary angiography. The study endpoint was the rate of favorable THV/coronary overlap, defined as an angle > 40° between the THV commissural post and coronary ostia. Other endpoints were the rates of successful THV alignment with respect to the raphe and of selective CA after TAVR. Moreover, different virtual THV alignment models were tested to identify which one would produce the lower degree of THV/coronary overlap.

Results

Thirty-four patients with type 1 BAV with right-left raphe undergoing TAVR (23 with Evolut Pro/Pro + and 11 with Acurate Neo2) were included. At pre-TAVR CT, moderate/severe cusp asymmetry was found in 50% of patients, severe coronary ostia eccentricity was observed in 47.1% for the RCA vs. 8.8% for the LCA (P < 0.007). Correct TVH orientation was achieved in 29 cases. At post-TAVR CT, optimal THV alignment/mild misalignment to the raphe was observed in 86.2%, but a moderate/severe overlap with the coronaries was seen in 13.7% for the RCA and 44.8% for the LCA (P = 0.019). After TAVR, selective RCA cannulation was possible in 82.8% vs. 75.9% for the LCA (P = 0.74), while combined selective CA of both coronaries was possible in less than two-thirds of the patients. Virtual THV alignment in the coronary ostia overlap view assuming a hypothetical circular THV expansion would produce an optimal THV/coronary overlap in almost 90% of cases.

Conclusion

Given cusp asymmetry and coronary ostia eccentricity of BAV combined with potential THV asymmetrical expansion, conventional commissural alignment techniques are associated with higher rates of THV misalignment and of moderate/severe neo-commissure overlap with the coronary ostia as compared to tricuspid aortic stenosis, resulting in lower rates of selective CA after TAVR. A modified THV orientation technique based on the coronary ostia overlap view might be preferable in BAV patients.

Annular size and interaction with trans-catheter aortic valves for treatment of severe bicuspid aortic valve stenosis: Insights from the BEAT registry

BACKGROUND

Transcatheter aortic valve replacement (TAVR) is safe and feasible in patients with bicuspid aortic valve (BAV), but whether annular size may influence TAVR results in BAV patients remains unclear. We aimed at evaluating the impact of aortic annular size on procedural and clinical outcomes of BAV patients undergoing TAVR, as well as potential interactions between annular dimension and trans-catheter heart valve (THV) type (balloon-expandable (BEV) vs. self-expanding (SEV).

METHODS

BEAT is a multicenter registry of consecutive BAV stenosis undergoing TAVR. For this sub-study patients were classified according to annular dimension in small-annulus (area < 400 mm² or perimeter <72 mm), medium-annulus (area ≥ 400 and < 575 mm², perimeter ≥72 mm and< 85 mm), large-annulus (area ≥ 575 mm² or perimeter ≥85 mm). Primary endpoint was Valve Academic Research Consortium-2 (VARC-2) device success.

RESULTS

45(15.5%) patients had small, 132(45.3%) medium, and 114(39.2%) large annuli. Compared with other groups, patients with large annuli were more frequently male, younger, with higher body mass index, larger aortic valve area, higher rate of moderate-severe calcification, lower mean trans-aortic valve gradient and lower left ventricular ejection fraction. In large-annuli SEVs were associated with a lower VARC-2 device success (75.9% vs. 90.6%, p = 0.049) driven by a higher rate of paravalvular valvular leak (PVL) compared to BEVs (20.7% vs. 1.2%, p < 0.001). However, no differences in clinical outcomes were observed according to annular size nor THV type.

CONCLUSIONS

TAVR in BAV patients is feasible irrespective of annular size. However in patients with large aortic annulus SEVs were associated with a significantly higher rate of PVLs compared to BEVs.

Temporal Trends in Diagnosis, Treatments, and Outcomes in Patients With Bicuspid Aortic Valve

Background: The population is aging and advances in multimodal imaging and transcatheter valve intervention have been prominent in the past two decades. This study investigated temporal trends in demographic characteristics, use of multimodal imaging, treatments, and outcomes in patients with bicuspid aortic valve (BAV). Methods and Results: A total of 1,497 patients (male 71.7%, 57 ± 14 years old) first diagnosed with BAV between January 2003 and December 2020, in a single tertiary center were divided into three groups according to year of diagnosis: group 1 (2003-2008, n = 269), group 2 (2009-2014, n = 594), and group 3 (2015-2020, n = 634). The patients' demographic characteristics, comorbidities, BAV morphology, BAV function, BAV-related disease, use of multimodal diagnostic imaging, treatment modality for BAV, and clinical outcomes were compared among the three groups. The ages at diagnosis and at the time of surgery/intervention increased considerably from group 1 to 3. The patients' comorbidity index also increased progressively. The proportion of non-dysfunctional BAV and significant AS increased, while that of significant AR decreased. The frequency of infective endocarditis as an initial presentation significantly decreased over time. Additionally, the use of multimodal imaging increased markedly in the most recent group. The results also indicated increasing trends in the use of bioprosthetic valves and transcatheter aortic valve replacement. Overall and cardiovascular survival rates improved from group 1 to 3 (log rank p < 0.001). Conclusions: For the past two decades, remarkable temporal changes have occurred in patient characteristics, use of multimodal diagnostic imaging, choice of treatment modality, and clinical outcomes in patients with BAV.

Force distribution within the frame of self-expanding transcatheter aortic valve: Insights from in-vivo finite element analysis

We sought to assess the amount and distribution of force on the valve frame after transcatheter aortic valve replacement (TAVR) via patient-specific computer simulation. Patients successfully treated with the self-expanding Venus A-Valve and multislice computed tomography (MSCT) pre- and post-TAVR were retrospectively included. Patient-specific finite element models of the aortic root and prosthesis were constructed. The force (in Newton) on the valve frame was derived at every 3 mm from the inflow and at every 22.5° on each level. Twenty patients of whom 10 had bicuspid aortic valve (BAV) were analyzed. The total force on the frame was 74.9 N in median (interquartile range 24.0). The maximal force was observed at level 5 that corresponds with the nadir of the bioprosthetic leaflets and was 9.9 (7.1) N in all patients, 10.3 (6.6) N in BAV and 9.7 (9.2) N for patients with tricuspid aortic valve (TAV). The level of maximal force located higher from the native annulus in BAV and TAV patients (8.8 [4.8] vs. 1.8 [7.4] mm). The area of the valve frame at the level of maximal force decreased from 437.4 (239.7) mm² at the annulus to 377.6 (114.3) mm² in BAV, but increased from 397.5 (114.3) mm² at the annulus to 406.7 (108.9) mm² in TAV. The maximum force on the bioprosthetic valve frame is located at the plane of the nadir of the bioprosthetic leaflets. It remains to be elucidated whether this may be associated with bioprosthetic frame and leaflet integrity and/or function.