Clinical valve thrombosis and subclinical leaflet thrombosis in transcatheter aortic heart valves: clinical manifestations, diagnosis, and treatment

Prediction model for leaflet thrombosis in patients undergoing transcatheter aortic valve implantation: the EFFORT study

BACKGROUND

Leaflet thrombosis (LT) is a multifaceted and underexplored condition that can manifest following transcatheter aortic valve implantation (TAVI). The objective of this study was to formulate a prediction model based on laboratory assessments and clinical parameters, providing additional guidance and insight into this relatively unexplored aspect of post-TAVI complications.

METHODS

The present study was an observational prospective hypothesis-generating study, including 101 patients who underwent TAVI and a screening for LT (the primary endpoint) by multidetector computed tomography (MDCT). All images were acquired on a third-generation dual-source CT system. Levels of von Willebrand factor (vWF) activity, hemoglobin (Hb), and lactate dehydrogenase (LDH) were measured among other parameters. A predictive score utilizing binary logistic regression, Kaplan-Meier time-to-event analysis, and receiver operating characteristics (ROC) analysis was established.

RESULTS

LT (11 subclinical and 2 clinical) was detected in 13 of 101 patients (13%) after a median time to screening by MDCT of 105 days (IQR, 98-129 days). Elevated levels of vWF activity (> 188%) pre-TAVI, decreased Hb values (< 11.9 g/dL), as well as increased levels of LDH (> 312 U/L) post-TAVI and absence of oral anticoagulation (OAC) were found in patients with subsequent LT formation as compared to patients without LT. The established EFFORT score ranged from - 1 to 3 points, with an increased probability for LT development in patients with ≥ 2 points (85.7% of LT cases) vs < 2 points (14.3% of LT cases; p < 0.001). Achieving an EFFORT score of ≥ 2 points was found to be significantly associated with a 10.8 times higher likelihood of developing an LT (p = 0.001). The EFFORT score has an excellent c-statistic (area under the curve (AUC) = 0.89; 95% CI 0.74-1.00; p = 0.001) and a high negative predictive value (98%).

CONCLUSION

An EFFORT score might be a helpful tool to predict LT development and could be used in risk assessment, if validated in confirmatory studies. Therefore, the score has the potential to guide the stratification of individuals for the planning of subsequent MDCT screenings.

Long-term prognostic impact of paravalvular leakage on coronary artery disease requires patient-specific quantification of hemodynamics

Transcatheter aortic valve replacement (TAVR) is a frequently used minimally invasive intervention for patient with aortic stenosis across a broad risk spectrum. While coronary artery disease (CAD) is present in approximately half of TAVR candidates, correlation of post-TAVR complications such as paravalvular leakage (PVL) or misalignment with CAD are not fully understood. For this purpose, we developed a multiscale computational framework based on a patient-specific lumped-parameter algorithm and a 3-D strongly-coupled fluid-structure interaction model to quantify metrics of global circulatory function, metrics of global cardiac function and local cardiac fluid dynamics in 6 patients. Based on our findings, PVL limits the benefits of TAVR and restricts coronary perfusion due to the lack of sufficient coronary blood flow during diastole phase (e.g., maximum coronary flow rate reduced by 21.73%, 21.43% and 21.43% in the left anterior descending (LAD), left circumflex (LCX) and right coronary artery (RCA) respectively (N = 6)). Moreover, PVL may increase the LV load (e.g., LV load increased by 17.57% (N = 6)) and decrease the coronary wall shear stress (e.g., maximum wall shear stress reduced by 20.62%, 21.92%, 22.28% and 25.66% in the left main coronary artery (LMCA), left anterior descending (LAD), left circumflex (LCX) and right coronary artery (RCA) respectively (N = 6)), which could promote atherosclerosis development through loss of the physiological flow-oriented alignment of endothelial cells. This study demonstrated that a rigorously developed personalized image-based computational framework can provide vital insights into underlying mechanics of TAVR and CAD interactions and assist in treatment planning and patient risk stratification in patients.

Biomechanics of Transcatheter Aortic Valve Replacement Complications and Computational Predictive Modeling

Transcatheter aortic valve replacement (TAVR) is a rapidly growing field enabling replacement of diseased aortic valves without the need for open heart surgery. However, due to the nature of the procedure and nonremoval of the diseased tissue, there are rates of complications ranging from tissue rupture and coronary obstruction to paravalvular leak, valve thrombosis, and permanent pacemaker implantation. In recent years, computational modeling has shown a great deal of promise in its capabilities to understand the biomechanical implications of TAVR as well as help preoperatively predict risks inherent to device-patient-specific anatomy biomechanical interaction. This includes intricate replication of stent and leaflet designs and tested and validated simulated deployments with structural and fluid mechanical simulations. This review outlines current biomechanical understanding of device-related complications from TAVR and related predictive strategies using computational modeling. An outlook on future modeling strategies highlighting reduced order modeling which could significantly reduce the high time and cost that are required for computational prediction of TAVR outcomes is presented in this review paper. A summary of current commercial/in-development software is presented in the final section.

COVID-19 With Preexisting Hypercoagulability Digestive Disease

The outbreak of coronavirus disease of 2019 (COVID-19) has become a global public health and economic crisis. The advent of hypercoagulability and thrombotic complications can substantially influence the prognosis of COVID-19 patients. In this review, we elaborate on the clinical findings, potential underlying pathogenesis, and therapeutic strategy of hypercoagulability and thromboembolism in COVID-19, particularly focusing on the COVID-19 patients with preexisting digestive hypercoagulability disease.

Novel Perspective for Antithrombotic Therapy in TAVI

:

While surgical aortic valve replacement (SAVR) was for years the only available treatment for symptomatic aortic stenosis, the introduction of transcatheter aortic valve implantation (TAVI) in 2002 and the improvement of its technical aspects in the following years, has holistically changed the synchronous therapeutic approach of aortic valve stenosis. Recent evidence has expanded the indication of TAVI from high to lower surgical risk populations with symptomatic aortic stenosis. The administration of antithrombotic therapy periprocedurally and its maintenance after a successful TAVI is crucial for the prevention of complications and affects postprocedural survival. Randomized controlled trials investigating the appropriate combination and the duration of antithrombotic treatment after TAVI are for the moment scarce. This review article sheds light on the underlying pathogenetic mechanisms contributing in periprocedural TAVI thrombotic complications and discuss the efficacy of current antithrombotic policies as evaluated in randomized trials.

Early detection of transcatheter heart valve dysfunction

Introduction: Transcatheter aortic valve implantation therapy is spreading rapidly, representing the standard of care in inoperable and high-risk patients, and a valid alternative in intermediate- and low-risk patients with severe symptomatic aortic stenosis. In this subset, the development and validation of noninvasive, quantitative, in vivo imaging modality, to monitor possible valve dysfunction is mandatory, in order to plan timely therapeutic interventions before the onset of symptoms.Areas covered: The implantation of transcatheter heart valves (THV) is increasing rapidly. As a consequence, THV dysfunction will become a major cause of cardiovascular morbidity after TAVI. Emergency repeat aortic valve replacement surgery is associated with a high rate of mortality compared with elective repeat surgery. In this context, early detection of THV dysfunction is therefore highly desirable. The review aims to examine the different diagnostic method to early detect THV dysfunction.Expert opinion: Most promising innovations in the diagnosis of early detection of THV dysfunction are evaluated, and the future outlook is explored. Waiting for upcoming evidence about the utility of CT, CMR, and PET on early detection of THV dysfunction, tailoring echocardiogram follow-up based on patients' characteristics is the desirable approach.