While pulmonary embolism (PE) appears to be a major issue in COVID-19, data remain sparse. We aimed to describe the risk factors and baseline characteristics of patients with PE in a cohort of COVID-19 patients. In a retrospective multicentre observational study, we included consecutive patients hospitalized for COVID-19. Patients without computed tomography pulmonary angiography (CTPA)-proven PE diagnosis and those who were directly admitted to an intensive care unit (ICU) were excluded. Among 1240 patients (58.1% men, mean age 64 ± 17 years), 103 (8.3%) patients had PE confirmed by CTPA. The ICU transfer and mechanical ventilation were significantly higher in the PE group (for both P < 0.001). In an univariable analysis, traditional venous thrombo-embolic risk factors were not associated with PE (P > 0.05), while patients under therapeutic dose anticoagulation before hospitalization or prophylactic dose anticoagulation introduced during hospitalization had lower PE occurrence [odds ratio (OR) 0.40, 95% confidence interval (CI) 0.14–0.91, P = 0.04; and OR 0.11, 95% CI 0.06–0.18, P < 0.001, respectively]. In a multivariable analysis, the following variables, also statistically significant in univariable analysis, were associated with PE: male gender (OR 1.03, 95% CI 1.003–1.069, P = 0.04), anticoagulation with a prophylactic dose (OR 0.83, 95% CI 0.79–0.85, P < 0.001) or a therapeutic dose (OR 0.87, 95% CI 0.82–0.92, P < 0.001), C-reactive protein (OR 1.03, 95% CI 1.01–1.04, P = 0.001), and time from symptom onset to hospitalization (OR 1.02, 95% CI 1.006–1.038, P = 0.002). PE risk factors in the COVID-19 context do not include traditional thrombo-embolic risk factors but rather independent clinical and biological findings at admission, including a major contribution to inflammation.

• Subclinical leaflet thrombosis was recently linked to higher rates of stroke and transient ischemic attack after TAVR. EVs have emerged as a surrogate marker of endothelial dysfunction and cardiovascular risk. • This study demonstrates the role of EVs trapped within the native aortic valve in valvular dysfunction and thrombogenicity, and points at the contribution of the local angiotensin system/NADPH oxidases/SGLT2 pro-oxidant pathway. • Additional studies will be required to clarify the impact of SGLT2 in the limitation of EV-mediated injuries in patients with AS or following TAVR.

Aortic stenosis (AS) affects more than 10% of the population over 80 years of age and constitutes a major risk factor for heart failure, thromboembolic stroke, and death. A better understanding of the disease, including its interaction with the haemostatic system, is a prerequisite to develop prophylactic treatments. AS pathogenesis is a dynamic process involving endothelial dysfunction, inflammation, fibrosis, and calcification. Several studies support the interplay between the components of the haemostatic system such as platelets, the coagulation system, von Willebrand factor, and extracellular micro-particles at each pathophysiological stage of AS. Previous reports have evidenced persistent biological activity of the native valve after transcatheter aortic valve replacement and the subsequent development of microthrombosis that may impact the function of the newly implanted valve. Here, we review the current evidence on the interplay between AS and prothrombotic activity, and we emphasize the clinical consequences of these interactions after aortic valve replacement.

Transcatheter aortic valve replacement has emerged as a valuable alternative to surgical aortic valve replacement in patients with severe aortic stenosis. Given the expansion of transcatheter aortic valve replacement to lower‐risk and younger populations with longer life expectancy, the durability of transcatheter heart valves (THVs) has become an important issue that may impact cardiovascular outcomes. THVs share similarities with surgical valves but have unique features, including a trend to larger effective orifice area and less prosthesis–patient mismatch, interactions with the native valve, and crimping process, that may all potentially influence a THV's life span. Multiple mechanisms may lead to bioprosthetic valve dysfunction, including structural valve deterioration, thrombosis, endocarditis, and nonstructural valve deterioration. With an incidence of up to 12.3% 5 years after transcatheter aortic valve replacement, structural valve deterioration represents the ultimate consequence of fibrotic remodeling and calcification within the bioprosthesis, driven by thrombotic and inflammatory processes involving the native aortic valve and influenced by patient and procedural factors. Understanding these mechanisms is crucial for improving THV durability.

Background and Objective: Host defence mechanisms to counter virus infection include the activation of the broncho-alveolar haemostasis. Fibrin degradation products secondary to extravascular fibrin breakdown could contribute to the marked increase in D-Dimers during COVID-19. We sought to examine the prognostic value on lung injury of D-Dimers in non-critically ill COVID-19 patients without thrombotic events. Methods: This study retrospectively analysed hospitalized COVID-19 patients classified according to a D-Dimers threshold following the COVID-19 associated haemostatic abnormalities (CAHA) classification at baseline and at peak (Stage 1: D-Dimers less than three-fold above normal; Stage 2: D-Dimers three- to six-fold above normal; Stage 3: D-Dimers six-fold above normal). The primary endpoint was the occurrence of critical lung injuries on chest computed tomography. The secondary outcome was the composite of in-hospital death or transfer to the intensive care unit (ICU). Results: Among the 123 patients included, critical lung injuries were evidenced in 8 (11.9%) patients in Stage 1, 6 (20%) in Stage 2 and 15 (57.7%) in Stage 3 (p = 0.001). D-Dimers staging at peak was an independent predictor of critical lung injuries regardless of the inflammatory burden assessed by CRP levels (OR 2.70, 95% CI (1.50–4.86); p < 0.001) and was significantly associated with increased in-hospital death or ICU transfer (14.9 % in Stage 1, 50.0% in Stage 2 and 57.7% in Stage 3 (p < 0.001)). D-Dimers staging at peak was an independent predictor of in-hospital death or ICU transfer (OR 2.50, CI 95% (1.27–4.93); p = 0.008). Conclusions: In the absence of overt thrombotic events, D-Dimers quantification is a relevant marker of critical lung injuries and dismal patient outcome.