Patient selection for TAVI in 2016: should we break through the low-risk barrier?

Hematological Complications From Transcatheter Aortic Valve Replacement (TAVR): Recognition and Treatment

Transcatheter aortic valve replacement (TAVR) has emerged as a pivotal intervention for patients with severe aortic stenosis who are at high or prohibitive surgical risk. Although TAVR is a minimally invasive procedure, it is linked to serious hematological problems, most notably thrombosis and bleeding. Numerous factors, such as procedural features, patient comorbidities, and anticoagulation management techniques, contribute to these complications. Bleeding complications can be major, minor, or life-threatening. They can be caused by problems with the vascular access site, anticoagulation medication, or coexisting conditions like renal dysfunction and frailty. Hemoglobin drop, overt bleeding, and hematoma signs must all be closely watched to identify bleeding. Careful selection and modification of anticoagulation medication, the use of vascular closure devices, and timely attention to bleeding sites are examples of management techniques. Thrombotic consequences, which include cerebrovascular accidents and valve thrombosis, are caused by endothelial injury, stent implantation, and patient hypercoagulability. Imaging modalities such as computed tomography and transesophageal echocardiography are used in the crucial process of detection. The goal of preventive care is to maximize anticoagulation regimens that are customized to each patient's risk profile, frequently striking a balance between the risk of thrombosis and bleeding. A multidisciplinary strategy that integrates surgical, hematological, and cardiology expertise is necessary for the effective management of these hematological complications. To improve patient outcomes, ongoing research attempts to improve risk stratification and create safer anticoagulation protocols. This review emphasizes how critical it is to identify bleeding and thrombotic events as soon as possible and treat them promptly to reduce the risk of negative outcomes for TAVR patients.

OS-LALM-OGM Algorithm-Based Computed Tomography Image for Characteristics and Comorbidities of Patients before Transcatheter Aortic Valve Implantation

Based on the ordered subsets (OS), a linear augmentation Lagrangian method (OS-LALM) was constructed, which was then combined with the optimized gradient method (OGM) to construct the OS-LALM-OGM, so as to discuss application of the computed tomography (CT) images based on OS-LALM-OGM in evaluation of clinical manifestations and complications of patients before transcatheter aortic valve implantation (TAVI). The OS-LALM-OGM was compared with the filtered back projection (FBP) and OS-LALM. In addition, it was applied to evaluate the conditions of 128 patients before TAVI. It was found that the peak signal-to-noise ratio (PSNR) of OS-LALM-OGM was greater than that of the FBP and OS-LALM when the number of iterations was 5, 20, and 40, while the root mean square error (RMSD) was the opposite (P < 0.05). The proportion of dyspnea was the highest, 38.28%, followed by angina (19.53%) and fainting (21.09%). The long diameter of the annulus and the average inner diameter of the annulus measured by the CT image based on the OS-LALM-OGM algorithm were greatly larger than the inner diameter of the aortic annulus measured by the CT based on the FBP algorithm (P < 0.05); the evaluation sensitivity (95.24%) and specificity (85.85%) of CT based on the OS-LALM-OGM algorithm were obviously greater than those of X-ray, which were 84.43% and 76.77%, respectively (P < 0.05). In short, the OS-LALM-OGM proposed had a relatively excellent effect on CT image reconstruction. The CT image based on the OS-LALM-OGM algorithm showed a better evaluation performance for patients before TAVI than the traditional FBP algorithm, showing higher sensitivity and specificity.

Tumor necrosis factor alpha-an underestimated risk predictor in patients undergoing transcatheter aortic valve replacement (TAVR)?

BACKGROUND

Systemic inflammation has been identified as a major cardiovascular risk factor in patients undergoing transcatheter aortic valve replacement (TAVR), yet currently, it is not adequately portrayed in scores for pre-interventional risk assessment. The aim of this study was to investigate the predictive ability of TNF-α in TAVR.

METHODS

A total of 431 patients undergoing transfemoral TAVR were enrolled in this study. Blood samples were drawn prior to intervention, 24 h post-intervention, 4, 5, and 7 days post-intervention, and 1, 3, and 6 months post-TAVR.

RESULTS

In a univariate Cox proportional hazard analysis, plasma concentrations of TNF-α after 24 h and after 5 days were associated with mortality after 12 months (after 24 h: HR 1.002 (1.000-1.004), p = 0.028; after 5d: HR 1.003 (1.001-1.005), p = 0.013). This association remained significant even after correction for confounders in a multivariate Cox regression analysis. Additionally, cut-offs were calculated. Patients above the cut-off for TNF-α after 5d had a significantly worse 12-month mortality than patients below the cut-off (18.8% vs. 2.8%, p = 0.046).

CONCLUSION

Plasma levels of TNF-α after 24 h and 5 days were independently associated with 12-month mortality in patients undergoing TAVR. Thus, TNF-α could represent a novel biomarker for enhanced risk stratification in these patients.

Thromboembolic and Bleeding Complications in Transcatheter Aortic Valve Implantation: Insights on Mechanisms, Prophylaxis and Therapy

Transcatheter aortic valve implantation (TAVI) has emerged as an important alternative to surgical aortic valve repair (SAVR) for patients with severe aortic stenosis. This rapidly advancing field has produced new-generation devices being delivered with small delivery sheaths, embolic protection devices and improved retrieval features. Despite efforts to reduce the rate of thrombotic complications associated with TAVI, valve thrombosis and cerebral ischaemic events post-TAVI continue to be a significant issue. However, the antithrombotic treatments utilised to prevent these dreaded complications are based on weak evidence and are associated with high rates of bleeding, which in itself is associated with adverse clinical outcomes. Recently, experimental data has shed light on the unique mechanisms, particularly the complex haemodynamic changes at sites of TAVI, that underpin the development of post-TAVI thrombosis. These new insights regarding the drivers of TAVI-associated thrombosis, coupled with the ongoing development of novel antithrombotics which do not cause bleeding, hold the potential to deliver newer, safer therapeutic paradigms to prevent post-TAVI thrombotic and bleeding complications. This review highlights the major challenge of post-TAVI thrombosis and bleeding, and the significant issues surrounding current antithrombotic approaches. Moreover, a detailed discussion regarding the mechanisms of post-TAVI thrombosis is provided, in addition to an appraisal of current antithrombotic guidelines, past and ongoing clinical trials, and how novel therapeutics offer the hope of optimizing antithrombotic strategies and ultimately improving patient outcomes.

Aortic stenosis. Indications and results of percutaneous aortic valve implantation (TAVI)

Aortic stenosis (AS) is the most common valvular heart disease in developed countries. Its prevalence increases progressively due the aging of the population. Transcatheter aortic valve implantation (TAVI), however, has revolutionised the treatment of AS. With the current data, we can confirm that TAVI is the treatment of choice for patients with severe symptomatic AS considered inoperable or with high surgical risk. In recent years, the use of TAVI has grown exponentially and is spreading to patients of intermediate surgical risk due to the procedure's good results, the reduced number of complications and the low incidence of prosthetic degeneration. The results appear to indicate that, in the medium term, TAVI will progressively substitute conventional surgery for treating most patients with severe AS.

Transcatheter aortic valve implantation: a revolution in the therapy of elderly and high-risk patients with severe aortic stenosis

Transcatheter aortic valve implantation (TAVI) represents a real revolution in the field of interventional cardiology for the treatment of elderly or high-risk surgical patients with severe symptomatic aortic valve stenosis. Today, TAVI seems to play a key and a reliable role in the treatment of intermediate and maybe low-risk patients with severe aortic stenosis. TAVI has also evolved from a complex and hazardous procedure into an effective and safe therapy by the development of new generation devices. This article aims to review the background and future of TAVI, clinical trials and registries with old and new generation TAVI devices and to focus on some open issues related to post-procedural outcomes.