Publications

Experimental outcomes in terms of accuracy, recall, and F1 for deep-learning-based supervised training of an artificial neural network for patient diagnosis prediction based on patient medication history, using hierarchical domain knowledge to guide learning.

Obesity has been linked to atrial fibrillation (AF) burden and severity, and epidemiological studies suggest that AF is more prevalent in whites than Asian. We aimed to investigate whether obesity mediates associations with AF in Europe and Asia using patient-level data comparisons of two cohort studies. Using Korean National Health Insurance Service's Health Screening (NHIS-HealS) and U.K. Biobank data, we included 401,206 Korean and 477,926 British aged 40-70 years without previous AF who received check-ups. The incidence and risk of AF were evaluated regarding different body mass index (BMI) values. The obese proportion (BMI ≥ 30.0 kg/m², 2.8% vs. 24.3%, P < 0.001) was higher in the U.K. than the Korean. In the Korean and U.K. cohort, the age- and sex-adjusted incidence rates of AF were 4.97 and 6.54 per 1000 person-years among obese individuals. Compared to Koreans, the risk of AF was higher in the British population, with adjusted hazard ratios of 1.41 (Korea, 95% CI 1.26-1.58) and 1.68 (UK, 95% CI 1.54-1.82) in obese participants (P for interaction < 0.05). Obesity was associated with AF in both populations. British subjects had a greater incidence of AF related to the high proportion of obese individuals, especially participants in the obesity category, the risk of AF also increased.

This study provides Class III evidence that for patients with IS or TIA and CMBs, statins lower the risk of any stroke or IS without increasing the risk of ICrH.

Oral anticoagulant initiation in patients with liver disease, incident new atrial fibrillation/flutter, and a high CHA2DS2-VASc-score was associated with a reduced thromboembolism risk. Bleeding risk was not increased with anticoagulation, irrespective of the type of liver disease.

Atrial fibrillation (AF) is the most common heart arrhythmia, linked to a five-fold increase in stroke risk. The left atrial appendage (LAA), prone to blood stasis, is a common thrombus formation site in AF patients. The LAA can be classified into four morphologies: broccoli, cactus, chicken wing and windsock. Stroke risk prediction in AF typically relies on demographic characteristics and comorbidities, often overlooking blood flow dynamics. We developed patient-specific non-Newtonian models of blood flow, dependent on fibrinogen and haematocrit, to predict changes in LAA viscosity, aiming to predict stroke in AF patients. We conducted 480 computational fluid dynamics (CFD) simulations using the non-Newtonian model across the four LAA morphologies for four virtual patient cohorts: AF + Covid-19, AF + pathological fibrinogen, AF + normal fibrinogen, and healthy controls. Gaussian process emulators (GPEs) were trained on this in silico cohort to predict average LAA viscosity at near-zero computational cost. GPEs demonstrated high accuracy in AF cohorts but lower accuracy when the chicken wing GPE was applied to other morphologies. Global sensitivity analysis showed fibrinogen significantly influenced blood viscosity in all AF cohorts. The chicken wing morphology exhibited the highest viscosity, while the AF + Covid-19 cohort had the highest viscosity. Our non-Newtonian model in CFD simulations confirmed fibrinogen's substantial impact on blood viscosity at low shear rates in the LAA, suggesting that combining blood values and geometric parameters of the LAA into GPE training could enhance stroke risk stratification accuracy. KEY POINTS: Fibrinogen has a significant effect on blood viscosity in the left atrial appendage (LAA) at low shear rates. Gaussian process emulators (GPEs) can predict the viscosity of blood in the LAA at near-zero computational cost. Out of all LAA morphologies, the chicken wing morphology exhibited the highest average blood viscosity. High average blood viscosity in the LAA of atrial fibrilation + Covid-19 patients was observed due to high fibrinogen levels in this cohort. Combining blood values and geometric parameters of the LAA into GPE training could enhance stroke risk stratification accuracy.

Among anticoagulated patients with AF, rhythm control was associated with a lower risk of dementia, compared with rate control. Initiating rhythm control in AF patients with fewer stroke risk factors might help prevent subsequent dementia.

Atrial high rate episode >6 min to ≤6 h were most prevalent among all AHRE duration categories. Longer AHREs were more common in patients at risk of thromboembolism. Age and history of AF/AFL were risk factors for AHRE >6 min. Furthermore, hypertension showed a strong impact on the development of AHRE >24 h rather than age.

In a population-wide screening cohort, the use of a handheld ECG machine to identify subjects with newly diagnosed atrial fibrillation was cost-effective in the general population, as well as in subjects ≥65 and subjects ≥75 years old.

Backgrounds: Alcohol consumption is one of the major and modifiable risk factors for stroke in young people. There is a paucity of information regarding the risk of drinking on stroke development, especially in young adults. We investigated the effect of alcohol consumption on the risk of stroke and its subtypes in young adults. Methods: Using the Korean National Health Insurance Service database, a total of 1,523,299 subjects aged between 20 and 39 were identified, who underwent 4 consecutive annual health examinations between 2009 and 2012, with no history of stroke, myocardial infarction, and congestive heart failure. At each annual health examination, the alcohol consumption of the subjects was divided into non, mild (&gt;0 and &lt;105g/week), moderate (≥105g and &lt;210g/week), and heavy (≥210g/week) drinking. Cumulative alcohol burdens were evaluated in the following ways: (1) cumulative number of moderate to heavy drinking at each health examination (0 to 4 times); (2) drinking patterns in each cumulative alcohol burden (total 16 patterns). The incidence of total stroke, ischemic stroke (IS) or hemorrhagic stroke, was evaluated using Cox proportional-hazards models. Results: During a median follow-up of 5.6±1.2 years, 3093 (0.20%) subjects were diagnosed with stroke (1732 with ischemic and 1513 with hemorrhagic). Heavy drinkers were associated with an increased risk of total stroke compared to non-drinker (HR 1.256, 95% CI 1.112-1.419). The hazard ratio was proportional to the cumulative alcohol burdens (Fig. panel A). This positive linear relationship was mainly driven by hemorrhagic stroke rather than IS (Fig. panel B). While most drinking patterns were not associated with an increased risk of IS, alcohol burden 3 had a significant association with an increased risk of a hemorrhagic stroke (Fig. panel C). Conclusions: Moderate to heavy alcohol consumption has a cumulative association with a higher risk of stroke, especially for hemorrhagic stroke in young adults.

Our IPD meta-analysis, reflecting trials published since 2010, highlighted that contemporary ExCR is effective in reducing risk of hospitalization and improving HRQoL in those with CHD. Importantly, we reveal treatment benefits to be robust and consistent across most participant subgroups. Together, these data support the class I recommendation of international clinical guidelines that ExCR should be offered to all people with CHD.