Aortic stenosis in chronic kidney disease: challenges in diagnosis and treatment

Chronic kidney disease (CKD) is becoming increasingly common and is associated with development and rapid progression of aortic stenosis (AS). Patients with AS and CKD have higher mortality rates than those with AS of similar severity and normal kidney function. The diagnosis of severe AS in patients with CKD is often challenging due to alterations in haemodynamics and heart structure, and integration of data from multiple imaging modalities may be required. When indicated, the definitive treatment for severe AS is aortic valve replacement. Patients with CKD are candidates for bioprosthetic valve replacement (surgical or transcatheter aortic valve implantation) or mechanical valve replacement. However, for patients with CKD, lifetime management is complex, as patients with CKD have a higher competing risk of bioprosthetic structural valve deterioration, bleeding in the setting of systemic anticoagulation and mortality related to CKD itself. The involvement of a heart-kidney multidisciplinary team in the care of patients with CKD and severe AS is ideal to navigate the complexities of diagnosis and management decisions.

Two-Year Clinical Follow-Up Assessment of the Novel Cingular Surgical Bovine Pericardial Valve

Objectives: To evaluate the 2-year clinical safety and hemodynamic outcomes of the Cingular bovine pericardial bioprosthesis.Methods: A prospective, multicenter, single-arm trial was conducted in patients who required aortic or mitral valve replacement. From March 2016 to October 2017, 197 patients were implanted with the Cingular bovine pericardial valve at five sites in China. The clinical outcomes and hemodynamic performance were assessed through a 2-year follow-up. Clinical safety events were reviewed by an independent clinical events committee, and echocardiographic data were assessed by an independent core laboratory.Results: The mean age was 66.9 ± 4.9 years. The 2-year survival rate was 96.4%. A complete 2-year clinical follow-up was achieved in 189 of 190 survivors. No case of structural valve deterioration, major perivalvular leak, prosthetic valve endocarditis, or valve-related reoperation was seen. For the aortic valve, the mean pressure gradient observed was 12.5 ± 4.0 mm Hg, and the effective orifice area (EOA) was 2.0 ± 0.3 cm2. For the smaller size aortic valves, 19 mm and 21 mm, respective mean EOA values of 1.7 ± 0.2 cm2 and 1.8 ± 0.2 cm2 were found. The values for mean pressure gradient and mean EOA for mitral bioprostheses were 4.0 ± 1.4 mm Hg and 2.2 ± 0.3 cm2, respectively. There was no significant change between 1-year and 2-year hemodynamic performance.Conclusions: The Cingular bovine pericardial valve showed favorable clinical safety and hemodynamic outcomes over a 2-year follow-up. Further follow-up is required to validate the long-term durability.

Is Cell Regeneration and Infiltration a Double Edged Sword for Porcine Aortic Valve Deterioration: A Large Cohort of Histopathological Analysis

Background Bioprostheses are the commonest prostheses used for valve replacement in the western world. The major flaw of bioprostheses is the occurrence of structural valve deterioration (SVD). The objective of this study was to assess in a large cohort of patients the pathologic features of porcine aortic valve (PAV) SVD based on histomorphological and immunopathological features.Methods and materials 109 cases of resected PAV were observed grossly and histopathologically. The type and amount of infiltrated cells were evaluated in the different type of bioprosthetic SVD by immunohistochemical staining . Results The most common cause of SVD was calcification, leaflet dehiscence and tear (23.9%,19.3% and 18.3%, respectively). Immunohistochemical staining demonstrated that vimentin positive cells aggregated around the calcified area in calcified PAV. Macrophages infiltrated in the calcified, lacerated and dehiscence PAV. However, MMP-1 expression was mainly found in the lacerated PAV. The VIM(+)/SMA(-) and VIM(+)/CD31(-) cells were found in PAV. The endothelia rate of dehiscence leaflets were higher than that of calcified and lacerated leaflets. A large amount of CD31 positive cells aggregated in the spongy layer in the lacerated and dehiscence PAV. Conclusions Cell regeneration and infiltration is a double edged sword for the PAV deterioration. Valve interstitial cells (VIC) have essential role in PAV calcification. Macrophages infiltration maybe involve in the different type of SVD, but only MMP-1expression involves in leaflets laceration. VIM(+)/CD31(-) valve endothelial cells (VECs) protect the PAV against the formation of calcified and lacerated lesions. The existence of untransformed VECs maybe one of pathologic substrate of PAV tear and dehiscence, although they can prevent VICs activation and subsequent valve fibrosis and calcification.

External or subcomissural annuloplasty in bicuspid aortic valve repair: which is better?

Patients with a bicuspid aortic valve (BAV) are at increased risk of valvular regurgitation compared to their counterparts with a tri-leaflet aortic valve. There is now increasing emphasis to offer BAV repair to mitigate the risks of prosthesis-related complications, including thromboembolism, haemorrhage and endocarditis, as well as structural valve deterioration and future re-operation with conventional valve replacement, particularly in younger populations. Furthermore, over the preceding two decades, our greater understanding of the functional anatomy of the BAV, pathophysiological mechanisms of BAV insufficiency and the development of a functional classification of aortic regurgitation have significantly contributed to the evolution of aortic valve reconstructive surgery. In this commentary, we discuss a recent article from the Journal of Cardiac Surgery comparing external annuloplasty and subcommissural annuloplasty as techniques for BAV repair.

Surgical explantation of a failed transcatheter aortic valve

With transcatheter aortic valve replacement being increasingly utilized in a younger and lower risk population, we can expect to see larger numbers of patients presenting with structural deterioration of aortic valves replaced by the transcatheter route that now require explantation and surgical replacement. Surgical aortic valve replacement after transcatheter aortic valve replacement is associated with operative morbidity and mortality rates significantly higher than those seen in the setting of surgical replacement of the native valve, which had a 30-day mortality of 12–20% in recent series. Centers performing transcatheter aortic valve replacement in lower risk patients with longer expected lifespans and a higher probability of late structural deterioration of the transcatheter aortic valve replacement should carefully consider their choice of valve type (balloon-expandable versus self-expanding) and patient anatomy, including annulus and root diameter, at the time of the initial valve intervention. Further, one should not forget the mechanical surgical aortic valve replacement option in younger patients with risk factors for early structural valve deterioration such as obesity, metabolic syndrome, and chronic kidney disease. The objectives of this tutorial are to describe the preoperative workup for a patient with late structural valve deterioration after transcatheter aortic valve replacement, detail the explantation approach specific to self-expanding valves, and illustrate the key decisions and techniques needed for subsequent surgical aortic valve replacement.

Aortic and mitral bioprosthetic valve dysfunction: surgical or percutaneous solutions?

In the last years, there has been a trend to prefer biological prostheses, especially among young patients, with the aim to avoid anticoagulant treatment. Surgical tissue valves have so far demonstrated their solid long-term durability. However, younger age has been identified as one of the main risk factors for developing structural valve deterioration (SVD). As a consequence, the proportion of subjects at risk for valve dysfunction will constantly rise in the near future. However, while surgical reintervention has always been considered the gold standard for treatment of prosthesis deterioration, the introduction of transcatheter heart valves could offer new therapeutical options, particularly among high-risk patients, aiming a second less invasive chance. The recent standardization of valve durability definitions will soon allow a more comprehensive understanding of the mechanism underlying SVD and guide the choice of prosthesis for patients needing valve replacement.

Reintervention for the trifecta aortic bioprosthesis: large single-centre series

Introduction Aortic valve replacement with the Trifecta aortic bioprosthesis has reported favourable haemodynamic performance. However, several reports of structural valve deterioration have raised concerns of design risks and its long-term durability. Purpose We conducted this study to assess reintervention and outcomes in a large single-centre cohort of 944 patients receiving the Trifecta valve over a 10-year period. Methods Consecutive patients undergoing aortic valve replacement with the Trifecta valve between October 2011 and October 2020 in our centre were included in this study. Perioperative patient and operative characteristics were prospectively recorded in an independent database. Reintervention was recorded as a surrogate for structural valve deterioration, and survival data was analysed. Results A total of 944 patient (mean age 72.82 years ± 8.13, range 28–91, 58% male) underwent aortic valve replacement with the Trifecta valve in our centre between October 2011 and October 2020. At 10-years, 1.4% of patients required a redo operation for aortic valve replacement, giving an overall freedom reintervention of 98.6%, with a 99.3% and 99.4% freedom from reintervention due to structural valve deterioration and infection, respectively. The mean time to all-cause reintervention was 48.87 months, and the mean time to reintervention due to SVD was 68.87 months. Patients that did not require reintervention had a 97.74% freedom from mortality and those that underwent reintervention had a freedom from mortality of 84.62% with a median survival of 69-days. Conclusions In a large single-centre cohort, the Trifecta aortic bioprosthesis was safe with a 1.4% all-cause reintervention rate and a 0.7% reintervention rate for structural valve deterioration at 10-years. FUNDunding Acknowledgement Type of funding sources: None.