Identification of Distinct Clinical Subphenotypes in Critically Ill Patients With COVID-19.

BackgroundSubphenotypes have been identified in patients with sepsis and ARDS and are associated with different outcomes and responses to therapies.Research questionCan unique subphenotypes be identified among critically ill patients with COVID-19?Study design and methodsUsing data from a multicenter cohort study that enrolled critically ill patients with COVID-19 from 67 hospitals across the United States, we randomly divided centers into discovery and replication cohorts. We used latent class analysis independently in each cohort to identify subphenotypes based on clinical and laboratory variables. We then analyzed the associations of subphenotypes with 28-day mortality.ResultsLatent class analysis identified four subphenotypes (SP) with consistent characteristics across the discovery (45 centers; n = 2,188) and replication (22 centers; n = 1,112) cohorts. SP1 was characterized by shock, acidemia, and multiorgan dysfunction, including acute kidney injury treated with renal replacement therapy. SP2 was characterized by high C-reactive protein, early need for mechanical ventilation, and the highest rate of ARDS. SP3 showed the highest burden of chronic diseases, whereas SP4 demonstrated limited chronic disease burden and mild physiologic abnormalities. Twenty-eight-day mortality in the discovery cohort ranged from 20.6% (SP4) to 52.9% (SP1). Mortality across subphenotypes remained different after adjustment for demographics, comorbidities, organ dysfunction and illness severity, regional and hospital factors. Compared with SP4, the relative risks were as follows: SP1, 1.67 (95% CI, 1.36-2.03); SP2, 1.39 (95% CI, 1.17-1.65); and SP3, 1.39 (95% CI, 1.15-1.67). Findings were similar in the replication cohort.InterpretationWe identified four subphenotypes of COVID-19 critical illness with distinct patterns of clinical and laboratory characteristics, comorbidity burden, and mortality

Two Thin Film Polymorphs of the Singlet Fission Compound 1,3-Diphenylisobenzofuran

Polycrystalline thin films of 1,3-diphenylisobenzofuran (<b>1</b>) with a morphology referred to here as α exhibit highly efficient singlet fission, producing two triplet states for every absorbed photon at 77 K, and about 1.4 triplet states per absorbed photon at room temperature. However, the triplet yield depends strongly on the specific crystalline form of <b>1</b>, and for the morphology referred to as β the triplet yields are roughly an order of magnitude smaller. In this study, α, β, and mixed α/β films of <b>1</b> are prepared by thermal evaporation and solution drop-casting, and the structural and photophysical differences that may account for the very different triplet quantum yields are explored. The crystallites of <b>1</b> in thin films have been identified with two bulk crystal polymorphs grown from solution and structurally characterized. Analysis of absorption spectra of the films reveals a 600 cm^–1 blue shift in the onset and a unique spectral profile for the form α crystallites as compared to form β. Intermolecular interactions between columns of slip-stacked molecules are different in the two polymorphs, and this likely gives rise to the much smaller triplet quantum yield for β-<b>1</b>

Identification of distinct clinical subphenotypes in critically ill patients with COVID-19

Subphenotypes have been identified in patients with sepsis and acute respiratory distress syndrome (ARDS), and are associated with different outcomes and response to therapies. Can unique subphenotypes be identified among critically ill patients with coronavirus disease 2019 (COVID-19)? & Methods: Using data from a multicenter cohort study that enrolled critically ill patients with COVID-19 from 67 hospitals across the United States, we randomly divided centers into Discovery and Replication cohorts. We utilized latent class analysis independently in each cohort to identify subphenotypes based on clinical and laboratory variables. We then analyzed the associations of subphenotypes with 28-day mortality. Latent class analysis identified four subphenotypes (SP) with consistent characteristics across Discovery (45 centers, n=2,188) and Replication (22 centers, n=1,112) cohorts. SP1 was characterized by shock, acidemia, and multi-organ dysfunction, including acute kidney injury treated with renal replacement therapy. SP2 was characterized by high C-reactive protein, early need for mechanical ventilation, and the highest rate of ARDS. SP3 had the highest burden of chronic diseases, while SP4 had limited chronic disease burden and mild physiologic abnormalities. 28-day mortality in the Discovery cohort ranged from 20.6% (SP4) to 52.9% (SP1). Mortality across subphenotypes remained different after adjustment for demographics, comorbidities, organ dysfunction and illness severity, regional and hospital factors: compared with SP4, SP1 relative risk (RR) 1.67 (95% CI 1.36-2.03); SP2 RR 1.39 (1.17-1.65); SP3 RR 1.39 (1.15-1.67). Findings were similar in the Replication cohort. We identified four subphenotypes of COVID-19 critical illness with distinct patterns of clinical and laboratory characteristics, comorbidity burden, and mortality

Fetal MRI of the heart and brain in congenital heart disease

Antenatal assessment of congenital heart disease and associated anomalies by ultrasound has improved perinatal care. Fetal cardiovascular MRI and fetal brain MRI are rapidly evolving for fetal diagnostic testing of congenital heart disease. We give an overview on the use of fetal cardiovascular MRI and fetal brain MRI in congenital heart disease, focusing on the current applications and diagnostic yield of structural and functional imaging during pregnancy. Fetal cardiovascular MRI in congenital heart disease is a promising supplementary imaging method to echocardiography for the diagnosis of antenatal congenital heart disease in weeks 30–40 of pregnancy. Concomitant fetal brain MRI is superior to brain ultrasound to show the complex relationship between fetal haemodynamics in congenital heart disease and brain development.</p