Background: Left atrial appendage closure is an established therapy in patients with atrial fibrillation. Although device-related thrombosis (DRT) is relatively rare, it is potentially linked to adverse events. As data on DRT characteristics, outcome, and treatment regimen are scarce, we aimed to assess these questions in a multicenter approach. Methods: One hundred fifty-six patients with the diagnosis of DRT after left atrial appendage closure were included in the multinational EUROC-DRT registry. Baseline characteristics included clinical and echocardiographic data. After inclusion, all patients underwent further clinical and echocardiographic follow-up to assess DRT dynamics, treatment success, and outcome. Results: DRT was detected after a median of 93 days (interquartile range, 54–161 days) with 17.9% being detected >6 months after left atrial appendage closure. Patients with DRT were at high ischemic and bleeding risk (CHA ₂ DS ₂ -VASc 4.5±1.7, HAS-BLED 3.3±1.2) and had nonparoxysmal atrial fibrillation (67.3%), previous stroke (53.8%), and spontaneous echo contrast (50.6%). The initial treatment regimens showed comparable resolution rates (antiplatelet monotherapy: 57.1%, dual antiplatelet therapy: 85.7%, vitamin K antagonists: 80.0%, novel oral anticoagulants: 75.0%, and heparin: 68.6%). After intensification or switch of treatment, complete DRT resolution was achieved in 79.5% of patients. Two-year follow-up revealed a high risk of mortality (20.0%) and ischemic stroke (13.8%) in patients with DRT. Patients with incomplete DRT resolution showed numerically higher stroke rates and increased mortality rates (stroke: 17.6% versus 12.3%, P =0.29; mortality: 31.3% versus 13.1%, P =0.05). Conclusions: A substantial proportion of DRT is detected >6 months after left atrial appendage closure, highlighting the need for imaging follow-up. Patients with DRT appear to be at a high risk for stroke and mortality. While DRT resolution was achieved in most patients, incomplete DRT resolution appeared to identify patients at even higher risk. Optimal DRT diagnostic criteria and treatment regimens are warranted.

Cardiac computed tomography (CT) is increasingly utilized during follow-up after left atrial appendage closure (LAAC). Hypoattenuated thickening (HAT) is a common finding and might represent either benign device healing or device-related thrombosis (DRT). The appearance and characteristics of HAT associated with the Watchman FLX have not been previously described. Therefore, we sought to investigate cardiac CT findings during follow-up after Watchman FLX implantation with a focus on HAT and DRT. Retrospective single-centre, observational study including all patients with successful Watchman FLX implantation and follow-up cardiac CT between March 2019 and September 2021 (n = 244). Blinded analysis of CT images was performed describing the localization, extent, and morphology of HAT and correlated to imaging and histology findings in a canine model. Relevant clinical and preclinical ethical approvals were obtained. Overall, HAT was present in 156 cases (64%) and could be classified as either subfabric hypoattenuation (n = 59), flat sessile HAT (n = 78), protruding sessile HAT (n = 16), or pedunculated HAT (n = 3). All cases of pedunculated HAT and five cases of protruding sessile HAT were considered as high-grade HAT (n = 7). Subfabric hypoattenuation and flat sessile HAT correlated with device healing and endothelialization in histological analysis of explanted devices. Subfabric hypoattenuation and flat sessile HAT are frequent CT findings for Watchman FLX, likely representing benign device healing and endothelialization. Pedunculated HAT and protruding HAT are infrequent CT findings that might represent DRT.

Aims: Transcatheter closure of patent foramen ovale (PFO) is the recommended stroke prevention treatment in patients ≤60 years with cryptogenic ischemic stroke and PFO. Atrial fibrillation or flutter (AF) is a known potential procedure-related complication, but long-term risk of developing AF remains unknown. This paper studied the long-term risk of developing AF following PFO closure. Methods and results: A Danish nationwide cohort study was conducted. During 2008–2020, this study identified a PFO closure cohort, a PFO diagnosis cohort without PFO closure, and a general population comparison cohort matched 10:1 to the PFO closure cohort on age and sex. The outcome was first-time AF diagnosis. Risk of AF and multivariable-adjusted hazard ratio (HR) of the association between PFO closure or PFO diagnosis and AF were calculated. A total of 817 patients with PFO closure, 1224 with PFO diagnosis, and 8170 matched individuals were identified. The 5 year risk of AF was 7.8% [95% confidence interval (CI): 5.5–10] in the PFO closure cohort, 3.1% (95% CI: 2.0–4.2) in the PFO diagnosis cohort, and 1.2% (95% CI: 0.8–1.6) in the matched cohort. The HR of AF comparing PFO closure with PFO diagnosis was 2.3 (95% CI: 1.3–4.0) within the first 3 months and 0.7 (95% CI: 0.3–1.7) thereafter. The HR of AF comparing PFO closure with the matched cohort was 51 (95% CI: 21–125) within the first 3 months and 2.5 (95% CI: 1.2–5.0) thereafter. Conclusion: Patent foramen ovale closure was not associated with any substantial increased long-term risk of developing AF beyond the well-known procedure-related short-term risk.

We aimed to characterize and estimate survival rates in patients diagnosed with pulmonary arterial hypertension (PAH) in western Denmark in the modern management era. All incident cases of PAH were consecutively enrolled in our single‐center prospective cohort study between January 2000 and March 2012. A total of 134 patients fulfilling the inclusion criteria were followed up from first diagnostic right heart catheterization to either death or the end of the study. Kaplan‐Meier survival analysis was used to estimate 1‐, 3‐, and 5‐year survival rates with 95% confidence intervals (CIs). Survival in the total cohort was 86.4% (95% CI, 79.3%–91.2%) after 1 year, 72.9% (95% CI, 64.1%–79.9%) after 3 years, and 65.4% (95% CI, 55.8%–73.4%) after 5 years. Significantly better survival was seen in the group of patients with PAH associated with congenital heart disease than in the group of patients with idiopathic PAH, heritable PAH, connective tissue disease, HIV infection, and portal hypertension. In conclusion, survival rates in the Danish PAH population were similar to or slightly better than survival rates estimated in other modern registries. However, PAH remains a fatal disease, despite modern targeted therapies.