Thomas Meredith

Purpose of Review: This review aims to provide a comprehensive update to healthcare providers on the assessment and subsequent management of low-flow aortic stenosis. Recent Findings: An aging population with a greater burden of cardiovascular risk factors has contributed to an increasing prevalence of aortic stenosis. The classification of the discordant low-flow cohort of aortic stenosis remains difficult and sub-optimal in the face of a heterogeneous disease population. Recent research has investigated use of echocardiographic flow parameters to categorise and prognosticate the low-flow aortic stenosis cohort. There is an increased awareness of the overlap between cardiac amyloidosis and the low-flow aortic stenosis group which has treatment implications. TAVI holds promise as a safer alternative to SAVR in this multimorbid, high-risk patient cohort. Summary: Assessment and management of the low-flow aortic stenosis group needs to be highly individualised according to phenotype and comorbidities. This is best managed within the multidisciplinary Heart Team approach.

The morphology and function of the left atrium (LA) are intimately tied to left ventricular loading conditions. Data pertaining to the effect of transcatheter aortic valve replacement (TAVR) on LA function and geometry are scarce. The aim of the study was to quantify associations between TAVR and LA remodelling by pooling available data from published observational studies. A systematic review and meta-analysis were performed. Studies reporting serial LA speckle-tracking echocardiographic (STE) data, before and after TAVR, were included. Other outcome data included LA area and indexed volume (LAVi) and standard chamber measurements. Outcomes were stratified by timing of follow-up echocardiography: early (2 [95% confidence interval (CI) 1.37–4.06, P < 0.01]. LA reservoir function improved overall by a mean difference (MD) of 3.71% (95% CI 1.82–5.6, P < 0.01), although there was significant heterogeneity within the pooled studies (I² = 87.3%). Significant improvement in reservoir strain was seen in both early follow-up (MD 3.1%, P < 0.01) and late follow-up studies (MD 4.48%, P = 0.03), but heterogeneity remained high (I² = 65.23 and 94.4%, respectively). Six studies reported a change in LA contractile function, which recovered in the early follow-up studies (MD 2.26, P < 0.01), but not in the late group (MD 1.41, P = 0.05). Pooled improvement in LA booster function was 1.96% (95% CI 1.11–2.8, P < 0.01). TAVR is associated with significant negative LA remodelling, and an improvement in LA mechanics, quantified by STE. The prognostic implications of these findings require further study. LA, left atrium; STE, speckle-tracking echocardiography; TAVR, transcatheter aortic valve replacement.

Purpose of review: This review aims to update healthcare providers on contemporary diagnostic and treatment information pertaining to aortic stenosis. Recent findings: The prevalence of aortic stenosis continues to increase, and so does the burden of treatable disease. This has important implications for healthcare systems and the economy. Accurate classification of aortic stenosis severity and determining optimal treatment timing remains a prime challenge to treating physicians. Furthermore, the drastic uptake of transcatheter aortic valve replacement has generated novel issues pertaining to younger patients whose post-intervention survival now exceeds device durability. Summary: The keys to optimizing patient outcomes are delivering accuracy in disease classification, treatment selection and timing and procedural planning.

Background: The morphology and function of the left atrium (LA) are intimately tied to left ventricular loading conditions. Data pertaining to the effect of transcatheter aortic valve replacement (TAVR) on LA function and geometry are scarce. Objectives: To quantify associations between TAVR and LA remodelling by pooling available data from published observational studies. Methods: A systematic review and meta-analysis were performed. Eligible studies needed to report serial LA STE data, before and after TAVR. Other outcome data included LA area and indexed volume (LAVi) and standard chamber measurements. Outcomes were stratified by timing of follow-up echocardiography: early (2 following TAVI (95% CI 1.37-4.06, p 2 = 0%). LA reservoir function improved overall by a mean difference of 3.71% (95% CI 1.82-5.6, p2 = 87.3%). Significant improvement in reservoir strain was seen in both early follow up (MD 3.1%, p2 = 65.23% and 94.4%, respectively). Six studies reported change in LA booster/contractile function, which recovered in the early follow-up studies (MD 2.26, p2 = 0%). Conclusion: The afterload reduction afforded by TAVR is associated with significant haemodynamic and morphological up-stream LA changes. Condensed The morphology and function of the left atrium (LA) are intimately tied to left ventricular loading conditions. LA function, measured with speckle-tracking echocardiography (STE), has been demonstrated to provide independent prognostic information for a range of cardiomyopathic states and valvular diseases. We sought to better understand the effect of transcatheter aortic valve replacement (TAVR) on LA function and geometry by performing a systematic review and meta-analysis. Key findings are that, following TAVR, the left atrium negatively remodels (reduces in size), and this is associated with improved distensibility, as quantified by an improvement in reservoir function.

Objectives: To determine safety and feasibility of ex‐situ coronary angiography.Background: To cater for the perpetually growing demand for heart donors, interest in donation following circulatory death (DCD) has been rekindled. Further pursuit of donor pool expansion has led to eligibility extension to “marginal” donors who are at higher risk of coronary artery disease (CAD). Excluding CAD in potentially eligible DCD donors, for whom ante‐mortem angiography is commonly not permitted, is therefore challenging. Ex‐situ coronary angiography serves as an ethical and feasible diagnostic tool to assess for preclusive CAD.Methods: We undertook a systematic review of the published literature and institutional retrospective review of case experience with ex‐situ coronary angiography of donor hearts, supported by a portable organ care system.Results: Combined literature and institutional case review yielded nine total cases of ex‐situ coronary angiography of donor human hearts plus one experimental porcine model. Of the eight cases of ex‐situ coronary angiography performed at our institute, all were conducted without complication or injury to the allograft. Two thirds of reported human cases have proceeded to successful transplantation.Conclusions: Diagnostic coronary angiography of the ex‐situ beating donor heart is safe, feasible, and demonstrates novel clinical utility in mitigating subsequent transplantation of unsuitable allografts. In the setting of suspected coronary atherosclerosis of the donor heart, which may preclude favorable transplantation outcomes, ex‐situ coronary angiography should be considered at eligible transplant centers.