Early detection of atrial fibrillation (AF) can prevent AF-related complications. Radiomic analysis of epicardial adipose tissue (EAT) was shown to predict AF recurrence postablation, but only limited data exist regarding left atrial EAT (LA-EAT) radiomic analysis for predicting AF in patients with yet unknown AF. Our aim was to develop prediction model for AF, based on the association of machine learning-based radiomic analysis of LA-EAT and AF. Retrospective matched case-control study of patients with and without AF, undergoing noncontrast electrocardiographic (ECG)-gated cardiac computed tomography (CT). Segmentation of LA-EAT and extraction of LA-EAT radiomic features were performed using syngo.via Frontier (Siemens Healthineers, Forchheim, Germany). Univariate analysis identified radiomic features associated with AF. Predictive models for AF were developed via logistic regression and machine learning-based random forest analyses. Models were validated on external cohort of patients with 1:1 AF : control ratio and deployed in a real-world setting with an AF : control ratio of 15:85. The study included 280 patients, 120 with documented AF and 160 matched controls. Based on LA-EAT radiomic features, which were significantly associated with AF, logistic regression and random forest models were constructed and tested on separate internal cohort of patients, yielding area under the curve (AUC) of 0.88 and 0.86, respectively, for prediction of AF. External validation verified these results (AUC 0.84 and 0.78, respectively). Both models were further validated in a real-world setting cohort (AUC 0.85 and 0.81, respectively). Models, based on LA-EAT radiomic features extracted from noncontrast ECG-gated cardiac CT, could accurately predict AF, suggesting a potential widespread noninvasive method for predicting the presence of AF. 0281-23-ASF.

Hypoxemia is a hallmark of coronavirus disease 2019 (COVID-19) severity. We sought to determine predictors of hypoxemia and related adverse outcomes among patients hospitalized with COVID-19 in the two largest hospitals in Jerusalem, Israel, from 9 March through 16 July 2020. Patients were categorized as those who developed reduced (<94%) vs. preserved (≥94%) arterial oxygen saturation (SpO₂) within the first 48 h after arrival to the emergency department. Overall, 492 hospitalized patients with COVID-19 were retrospectively analyzed. Patients with reduced SpO₂ were significantly older, had more comorbidities, higher body surface area (BSA) and body mass index (BMI), lower lymphocyte counts, impaired renal function, and elevated liver enzymes, c-reactive protein (CRP), and D-dimer levels as compared to those with preserved SpO₂. In the multivariable regression analysis, older age (odds ratio (OR) 1.02 per year, p < 0.001), higher BSA (OR 1.16 per 0.10 m², p = 0.003) or BMI (OR 1.05 per 1 kg/m², p = 0.011), lower lymphocyte counts (OR 1.72 per 1 × 10³/μL decrease, p = 0.002), and elevated CRP (1.11 per 1 mg/dL increase, p < 0.001) were found to be independent predictors of low SpO₂. Severe hypoxemia requiring ventilatory support, older age, and pre-existing comorbidities, including underlying renal dysfunction and heart failure, were found to be significantly associated with in-hospital mortality. These findings suggest that assessment of predictors of hypoxemia early at the time of hospitalization with COVID-19 may be helpful in risk stratification and management.

Background: Prior studies evaluating post-atrial fibrillation (AF) ablation pulmonary vein (PV) ostial gaps via magnetic resonance imaging (MRI) have shown circumferential PV fibrosis in a minority of patients, and their correlation with AF recurrence was weak. These studies were mostly based on radio-frequency AF ablations. Aim: We aimed to assess cryoballoon ablation-induced PV fibrosis via MRI and its correlation with AF recurrence. Methods and Results: This was a prospective study of consecutive patients with symptomatic AF who underwent pre- and post-ablation MRI to assess baseline and ablation-induced fibrosis, respectively. Post-ablation PV gaps were assessed by new semi-quantitative visual analysis assisted by computerized ADAS analysis. AF recurrence monitored via multiple ECGs and event monitoring at 6 and 12 months post ablation. Nineteen patients with 80 PVs were included, age 56 ± 11, with paroxysmal and persistent AF in 17/19 and 2/19 patients, respectively. Baseline MRI showed minimal LA fibrosis. All patients underwent successful cryoballoon PV electrical isolation. Post-ablation MRI revealed circumferential PV fibrosis among 63/80 (78.8%) PVs and partial fibrosis with major gaps among 17/80 (21.2%) PVs. AF recurred within one year in 5/9 (55.5%) patients with partial PV fibrosis, while no AF recurred among the 10 patients in whom all PVs had circumferential fibrosis (p < 0.01). Similarly, there were significantly more PVs without circumferential fibrosis (due to major gaps) among patients with AF recurrence as compared with patients without AF recurrence (42.9% vs. 13.5%; p < 0.01). Conclusion: Cryoballoon AF ablation results in circumferential PV fibrosis in the majority of PVs, as assessed by a new clinically relevant MRI-LGE analysis. Significant correlation was found between major PV gaps on post-ablation MRI and AF recurrence, suggesting that MRI might have the ability to predict AF recurrence.

Current guidelines advocate for the use of prophylactic implantable cardioverter defibrillators (ICDs) for all patients with symptomatic heart failure (HF) with low ejection fraction (EF). As many patients will never use their device and some are prone to device-related complications, scoring systems for delineating subgroups with differential ICD survival benefits are crucial to maximize ICD benefit and mitigate complications. This review summarizes the main scores, including MADIT trial-based Risk Stratification Score (MRSS) and Seattle Heart Failure Model (SHFM), which are based on randomized trials with a control group (HF medication only) and validated on large cohorts of ‘real-world’ HF patients. Recent studies using cardiac MRI (CMR) to predict ventricular arrhythmia (VA) are mentioned as well. The review shows that most scores could not delineate sustained VA incidence, but rather mortality without prior appropriate ICD therapies. Multiple scores could identify high-risk subgroups with extremely high probability of early mortality after ICD implant. On the other hand, low-risk subgroups were defined, in whom a high ratio of appropriate ICD therapy versus death without prior appropriate ICD therapy was found, suggesting significant ICD survival benefit. Moreover, MRSS and SHFM proved actual ICD survival benefit in low- and medium-risk subgroups when compared with control patients, and no benefit in high-risk subgroups, consisting of 16–20% of all ICD candidates. CMR reliably identified areas of myocardial scar and ‘channels’, significantly associated with VA. We conclude that as for today, multiple scoring models could delineate patient subgroups that would benefit differently from prophylactic ICD. Due to their modest-moderate predictability, these scores are still not ready to be implemented into clinical guidelines, but could aid decision regarding prophylactic ICD in borderline cases, as elderly patients and those with multiple co-morbidities. CMR is a promising technique which might help delineate patients with a low- versus high-risk for future VA, beyond EF alone. Lastly, genetic analysis could identify specific mutations in a non-negligible percent of patients, and a few of these mutations were found to predict an increased arrhythmic risk.

Intravenous (IV) fluid is frequently used to treat patients who have been admitted with an acute infection; among these patients, some will experience pulmonary congestion and will need diuretic treatment. Consecutive admissions to the Internal Medicine Department of patients with an acute infection were included. Patients were divided based on IV furosemide treatment within 48 h after admission. A total of 3556 admissions were included: In 1096 (30.8%), furosemide was administered after ≥48 h, and in 2639 (74.2%), IV fluid was administered within 48 h after hospital admission. In-hospital mortality was higher in patients with furosemide treatment (15.9% vs. 6.8%, p < 0.001). Treatment with furosemide in patients admitted with an infection was found to be associated with prolonged hospital stay and increased in-hospital mortality.