Left atrial 4D flow cardiovascular magnetic resonance: a reproducibility study in sinus rhythm and atrial fibrillation.

BACKGROUND: Four-dimensional (4D) flow cardiovascular magnetic resonance (CMR) allows sophisticated quantification of left atrial (LA) blood flow, and could yield novel biomarkers of propensity for intra-cardiac thrombus formation and embolic stroke. As reproducibility is critically important to diagnostic performance, we systematically investigated technical and temporal variation of LA 4D flow in atrial fibrillation (AF) and sinus rhythm (SR). METHODS: Eighty-six subjects (SR, n = 64; AF, n = 22) with wide-ranging stroke risk (CHA2DS2VASc 0-6) underwent LA 4D flow assessment of peak and mean velocity, vorticity, vortex volume, and stasis. Eighty-five (99%) underwent a second acquisition within the same session, and 74 (86%) also returned at 30 (27-35) days for an interval scan. We assessed variability attributable to manual contouring (intra- and inter-observer), and subject repositioning and reacquisition of data, both within the same session (same-day scan-rescan), and over time (interval scan). Within-subject coefficients of variation (CV) and bootstrapped 95% CIs were calculated and compared. RESULTS: Same-day scan-rescan CVs were 6% for peak velocity, 5% for mean velocity, 7% for vorticity, 9% for vortex volume, and 10% for stasis, and were similar between SR and AF subjects (all p > 0.05). Interval-scan variability was similar to same-day scan-rescan variability for peak velocity, vorticity, and vortex volume (all p > 0.05), and higher for stasis and mean velocity (interval scan CVs of 14% and 8%, respectively, both p < 0.05). Longitudinal changes in heart rate and blood pressure at the interval scan in the same subjects were associated with significantly higher variability for LA stasis (p = 0.024), but not for the remaining flow parameters (all p > 0.05). SR subjects showed significantly greater interval-scan variability than AF patients for mean velocity, vortex volume, and stasis (all p < 0.05), but not peak velocity or vorticity (both p > 0.05). CONCLUSIONS: LA peak velocity and vorticity are the most reproducible and temporally stable novel LA 4D flow biomarkers, and are robust to changes in heart rate, blood pressure, and differences in heart rhythm.

Clinical trial results in context: comparison of baseline characteristics and outcomes of 38,510 RECOVERY trial participants versus a reference population of 346,271 people hospitalised with COVID-19 in England.

BACKGROUND: Randomised trials are essential to reliably assess medical interventions. Nevertheless, interpretation of such studies, particularly when considering absolute effects, is enhanced by understanding how the trial population may differ from the populations it aims to represent. METHODS: We compared baseline characteristics and mortality of RECOVERY participants recruited in England (n = 38,510) with a reference population hospitalised with COVID-19 in England (n = 346,271) from March 2020 to November 2021. We used linked hospitalisation and mortality data for both cohorts to extract demographics, comorbidity/frailty scores, and crude and age- and sex-adjusted 28-day all-cause mortality. RESULTS: Demographics of RECOVERY participants were broadly similar to the reference population, but RECOVERY participants were younger (mean age [standard deviation]: RECOVERY 62.6 [15.3] vs reference 65.7 [18.5] years) and less frequently female (37% vs 45%). Comorbidity and frailty scores were lower in RECOVERY, but differences were attenuated after age stratification. Age- and sex-adjusted 28-day mortality declined over time but was similar between cohorts across the study period (RECOVERY 23.7% [95% confidence interval: 23.3-24.1%]; vs reference 24.8% [24.6-25.0%]), except during the first pandemic wave in the UK (March-May 2020) when adjusted mortality was lower in RECOVERY. CONCLUSIONS: Adjusted 28-day mortality in RECOVERY was similar to a nationwide reference population of patients admitted with COVID-19 in England during the same period but varied substantially over time in both cohorts. Therefore, the absolute effect estimates from RECOVERY were broadly applicable to the target population at the time but should be interpreted in the light of current mortality estimates. TRIAL REGISTRATION: ISRCTN50189673- Feb. 04, 2020, NCT04381936- May 11, 2020.

Dimethyl fumarate in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial.

Dimethyl fumarate (DMF) inhibits inflammasome-mediated inflammation and has been proposed as a treatment for patients hospitalised with COVID-19. This randomised, controlled, open-label platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing multiple treatments in patients hospitalised for COVID-19 (NCT04381936, ISRCTN50189673). In this assessment of DMF performed at 27 UK hospitals, adults were randomly allocated (1:1) to either usual standard of care alone or usual standard of care plus DMF. The primary outcome was clinical status on day 5 measured on a seven-point ordinal scale. Secondary outcomes were time to sustained improvement in clinical status, time to discharge, day 5 peripheral blood oxygenation, day 5 C-reactive protein, and improvement in day 10 clinical status. Between 2 March 2021 and 18 November 2021, 713 patients were enroled in the DMF evaluation, of whom 356 were randomly allocated to receive usual care plus DMF, and 357 to usual care alone. 95% of patients received corticosteroids as part of routine care. There was no evidence of a beneficial effect of DMF on clinical status at day 5 (common odds ratio of unfavourable outcome 1.12; 95% CI 0.86-1.47; p = 0.40). There was no significant effect of DMF on any secondary outcome.

Reduced Left Atrial Rotational Flow Is Independently Associated With Embolic Brain Infarcts.

BACKGROUND: Up to 25% of embolic strokes occur in individuals without atrial fibrillation (AF) or other identifiable mechanisms. OBJECTIVES: This study aims to assess whether left atrial (LA) blood flow characteristics are associated with embolic brain infarcts, independently of AF. METHODS: The authors recruited 134 patients: 44 with a history of ischemic stroke and 90 with no history of stroke but CHA2DS2VASc score ≥1. Cardiac magnetic resonance (CMR) evaluated cardiac function and LA 4-dimensional flow parameters, including velocity and vorticity (a measure of rotational flow), and brain magnetic resonance imaging (MRI) was performed to detect large noncortical or cortical infarcts (LNCCIs) (likely embolic), or nonembolic lacunar infarcts. RESULTS: Patients (41% female; age 70 ± 9 years) had moderate stroke risk (median CHA2DS2VASc = 3, Q1-Q3: 2-4). Sixty-eight (51%) had diagnosed AF, of whom 58 (43%) were in AF during CMR. Thirty-nine (29%) had ≥1 LNCCI, 20 (15%) had ≥1 lacunar infarct without LNCCI, and 75 (56%) had no infarct. Lower LA vorticity was significantly associated with prevalent LNCCIs after adjustment for AF during CMR, history of AF, CHA2DS2VASc score, LA emptying fraction, LA indexed maximum volume, left ventricular ejection fraction, and indexed left ventricular mass (OR: 2.06 [95% CI: 1.08-3.92 per SD]; P = 0.027). By contrast, LA flow peak velocity was not significantly associated with LNCCIs (P = 0.21). No LA parameter was associated with lacunar infarcts (all P > 0.05). CONCLUSIONS: Reduced LA flow vorticity is significantly and independently associated with embolic brain infarcts. Imaging LA flow characteristics may aid identification of individuals who would benefit from anticoagulation for embolic stroke prevention, regardless of heart rhythm.

Decoding the radiomic and proteomic phenotype of epicardial adipose tissue associated with adverse left atrial remodelling and post-operative atrial fibrillation in aortic stenosis.

AIMS: Epicardial adipose tissue (EAT) volume and attenuation on computed tomography (CT) have been associated with atrial fibrillation. Beyond these conventional CT measures, radiomics allows extraction of high-dimensional data and deep quantitative adipose tissue phenotyping, which may capture its underlying biology. We aimed to explore the EAT proteomic and CT-radiomic signatures associated with impaired left atrial (LA) remodelling and post-operative atrial fibrillation (POAF). METHODS AND RESULTS: We prospectively included 132 patients with severe aortic stenosis with no prior atrial fibrillation referred for aortic valve replacement. Pre-operative non-contrast CT images were obtained for extraction of EAT volume and other radiomic features describing EAT texture. The LA function was assessed by 2D-speckle-tracking echocardiography peak atrial longitudinal strain and peak atrial contraction strain. The EAT biopsies were performed during surgery for proteomic analysis by sequential windowed acquisition of all theoretical fragment ion mass spectra (SWATH-MS). The POAF incidence was monitored from surgery until discharge. Impaired LA function and incident POAF were associated with EAT up-regulation of inflammatory and thrombotic proteins, and down-regulation of cardioprotective proteins with anti-inflammatory and anti-lipotoxic properties. The EAT volume was independently associated with LA enlargement, impaired function, and POAF risk. On CT images, EAT texture of patients with POAF was heterogeneous and exhibited higher maximum grey-level values than sinus rhythm patients, which correlated with up-regulation of inflammatory and down-regulation of lipid droplet-formation EAT proteins. The CT radiomics of EAT provided an area under the curve of 0.80 (95% confidence interval: 0.68-0.92) for discrimination between patients with POAF and sinus rhythm. CONCLUSION: Pre-operative CT-radiomic profile of EAT detected adverse EAT proteomics and identified patients at risk of developing POAF.

Making trials part of good clinical care: lessons from the RECOVERY trial.

When COVID-19 hit the UK in early 2020, there were no known treatments for a condition that results in the death of around one in four patients hospitalised with this disease. Around the world, possible treatments were administered to huge numbers of patients, without any reliable assessments of safety and efficacy. The rapid generation of high-quality evidence was vital. RECOVERY is a streamlined, pragmatic, randomised controlled trial, which was set up in response to this challenge. As of April 2021, over 39,000 patients have been enrolled from 178 hospital sites in the UK. Within 100 days of its initiation, RECOVERY demonstrated that dexamethasone improves survival for patients with severe disease; a result that was rapidly implemented in the UK and internationally saving hundreds of thousands of lives. Importantly, it also showed that other widely used treatments (such as hydroxychloroquine and azithromycin) have no meaningful benefit for hospitalised patients. This was only possible through randomisation of large numbers of patients and the adoption of streamlined and pragmatic procedures focused on quality, together with widespread collaboration focused on a single goal. RECOVERY illustrates how clinical trials and healthcare can be integrated, even in a pandemic. This approach provides new opportunities to generate the evidence needed for high-quality healthcare not only for a pandemic but for the many other conditions that place a burden on patients and the healthcare system.

The impact of atrial fibrillation and stroke risk factors on left atrial blood flow characteristics.

AIMS: Altered left atrial (LA) blood flow characteristics account for an increase in cardioembolic stroke risk in atrial fibrillation (AF). Here, we aimed to assess whether exposure to stroke risk factors is sufficient to alter LA blood flow even in the presence of sinus rhythm (SR). METHODS AND RESULTS: We investigated 95 individuals: 37 patients with persistent AF, who were studied before and after cardioversion [Group 1; median CHA2DS2-VASc = 2.0 (1.5-3.5)]; 35 individuals with no history of AF but similar stroke risk to Group 1 [Group 2; median CHA2DS2-VASc = 3.0 (2.0-4.0)]; and 23 low-risk individuals in SR [Group 3; median CHA2DS2-VASc = 0.0 (0.0-0.0)]. Cardiac function and LA flow characteristics were evaluated using cardiac magnetic resonance. Before cardioversion, Group 1 displayed impaired left ventricular (LV) and LA function, reduced LA flow velocities and vorticity, and a higher normalized vortex volume (all P < 0.001 vs. Groups 2 and 3). After restoration of SR at ≥4-week post-cardioversion, LV systolic function and LA flow parameters improved significantly (all P < 0.001 vs. pre-cardioversion) and were no longer different from those in Group 2. However, in the presence of SR, LA flow peak and mean velocity, and vorticity were lower in Groups 1 and 2 vs. Group 3 (all P < 0.01), and were associated with impaired LA emptying fraction (LAEF) and LV diastolic dysfunction. CONCLUSION: Patients at moderate-to-high stroke risk display altered LA flow characteristics in SR in association with an LA myopathic phenotype and LV diastolic dysfunction, regardless of a history of AF.

Left ventricular reverse remodeling and function by strain analysis in aortic stenosis: A CMR analysis of the EPICHEART study.

INTRODUCTION AND OBJECTIVES: In severe aortic stenosis (AS), the impact of aortic valve replacement (AVR) on left ventricular (LV) systolic function assessed by strain and measured by echocardiography or cardiac magnetic resonance (CMR) has been controversial. We aimed to investigate LV systolic myocardial function changes six months after AVR using global longitudinal (GLS), circumferential (GCS) and radial (GRS) strain derived from CMR imaging. METHODS: We included 39 severe AS patients (69.3±7.8 years; 61.5% male) with preserved LV ejection fraction (LVEF) who were recruited as part of the EPICHEART study and underwent successful AVR (aortic valvular area: 0.8 cm2 (IQR: 0.2) pre- to 1.8 cm2 (IQR:0.5) post-AVR). Structural and functional parameters were assessed at baseline and six months after AVR, including LV GRS, GCS and GLS analysis by CMR, using cine short-axial and two-, three-, and four-chamber long-axial view. Comparison between baseline and postoperative LV remodeling was performed using Student t-test and Wilcoxon test. RESULTS: At six-month follow-up, LV mass, end-diastolic and end-systolic volumes, stroke volume, cardiac output, lateral E/e', tricuspid annular plane systolic excursion, right ventricular (RV) S wave velocity, GLS [-15.6% (IQR: 4.39) to -13.7% (IQR: 4.62)] and GCS [-17.8±3.58% to -16.1±2.94%] reduced significantly, while LVEF and GRS remained unchanged and lateral e' velocity increased. CONCLUSIONS: Despite favorable reverse LV structural and diastolic functional remodeling six months following AVR, GLS and GCS assessed by CMR reduced compared to baseline, LVEF remained unchanged. The clinical utility and timing of assessment of postoperative strain changes as a marker of systolic function progression needs further research.

Admission of patients with STEMI since the outbreak of the COVID-19 pandemic: a survey by the European Society of Cardiology.

AIMS: The COVID-19 pandemic required a significant redeployment of worldwide healthcare resources. Fear of infection, national lockdowns and altered healthcare priorities have the potential to impact utilisation of healthcare resources for non-communicable diseases. To survey health professionals' views of the impact of the COVID-19 pandemic on the rate and timing of admission of patients with ST-elevation myocardial infarction (STEMI), the European Society of Cardiology (ESC) administered an internet-based questionnaire to cardiologists and cardiovascular nurses across 6 continents. METHODS AND RESULTS: 3101 responses were received from 141 countries across 6 continents. 88.3% responded that their country was in "total lockdown" and 7.1% in partial lockdown. 78.8% responded that the number of patients presenting with STEMI was reduced since the coronavirus outbreak and 65.2% indicated that the reduction in STEMI presentations was >40%. Approximately 60% of all respondents reported that STEMI patients presented later than usual and 58.5% that >40% of STEMI patients admitted to hospital presented beyond the optimal window for primary percutaneous intervention (PCI) or thrombolysis. Independent predictors of the reported higher rate of delayed STEMI presentation were a country in total lockdown, >100 COVID-19 cases admitted locally, and the complete restructuring of the local cardiology service. CONCLUSION: The survey indicates that the impact of COVID-19 on STEMI presentations is likely to be substantial, with both lower presentations and a higher rate of delayed presentations occurring. This has potentially important ramifications for future healthcare and policy planning in the event of further waves of this pandemic.

Epicardial adipose tissue volume and annexin A2/fetuin-A signalling are linked to coronary calcification in advanced coronary artery disease: Computed tomography and proteomic biomarkers from the EPICHEART study.

BACKGROUND & AIMS: The role of epicardial adipose tissue (EAT) in the pathophysiology of late stage-coronary artery disease (CAD) has not been investigated. We explored the association of EAT volume and its proteome with advanced coronary atherosclerosis. METHODS: The EPICHEART Study prospectively enrolled 574 severe aortic stenosis patients referred to cardiac surgery. Before surgery, EAT volume was quantified by computed tomography (CT). During surgery, epicardial, mediastinal (MAT) and subcutaneous (SAT) adipose tissue samples were collected to explore fat phenotype by analyzing the proteomic profile using SWATH-mass spectrometry; pericardial fluid and peripheral venous blood were also collected. CAD presence was defined as coronary artery stenosis ≥50% in invasive angiography and by CT-derived Agatston coronary calcium score (CCS). RESULTS: EAT volume adjusted for body fat was associated with higher CCS, but not with the presence of coronary stenosis. In comparison with mediastinal and subcutaneous fat depots, EAT exhibited a pro-calcifying proteomic profile in patients with CAD characterized by upregulation of annexin-A2 and downregulation of fetuin-A; annexin-A2 protein levels in EAT samples were also positively correlated with CCS. We confirmed that the annexin-A2 gene was overexpressed in EAT samples of CAD patients and positively correlated with CCS. Fetuin-A gene was not detected in EAT samples, but systemic fetuin-A was higher in CAD than in non-CAD patients, suggesting that fetuin-A was locally downregulated. CONCLUSIONS: In an elderly cohort of stable patients, CCS was associated with EAT volume and annexin-A2/fetuin-A signaling, suggesting that EAT might orchestrate pro-calcifying conditions in the late phases of CAD.

Influence of EPICardial adipose tissue in HEART diseases (EPICHEART) study: Protocol for a translational study in coronary atherosclerosis.

INTRODUCTION: Accumulation of epicardial adipose tissue (EAT) is associated with coronary artery disease (CAD) and increased risk of coronary events in asymptomatic subjects and low-risk patients, suggesting that EAT promotes atherosclerosis in its early stage. Recent studies have shown that the presence of CAD affects the properties of adjacent EAT, leading to dynamic changes in the molecular players involved in the interplay between EAT and the coronary arteries over the history of the disease. The role of EAT in late-stage CAD has not been investigated. OBJECTIVES: In a comparative analysis with mediastinal and subcutaneous adipose tissue, we aim to investigate whether the volume of EAT assessed by computed tomography and its proteome assessed by SWATH-MS mass spectrometry are associated with late stages of CAD in an elderly cohort of severe aortic stenosis patients. METHODS: The EPICHEART study (NCT03280433) is a prospective study enrolling patients with severe degenerative aortic stenosis referred for elective aortic valve replacement, whose protocol includes preoperative clinical, nutritional, echocardiographic, cardiac computed tomography and invasive coronary angiographic assessments. During cardiac surgery, samples of EAT and mediastinal and subcutaneous thoracic adipose tissue are collected for proteomics analysis by SWATH-MS. In addition, pericardial fluid and peripheral and coronary sinus blood samples are collected to identify circulating and local adipose tissue-derived biomarkers of CAD. CONCLUSION: We designed a translational study to explore the association of EAT quantity and quality with advanced CAD. We expect to identify new biochemical factors and biomarkers in the crosstalk between EAT and the coronary arteries that are involved in the pathogenesis of late coronary atherosclerosis, especially coronary calcification, which might be translated into new therapeutic targets and imaging tools by biomedical engineering.

Impaired Left Atrial Strain as a Predictor of New-onset Atrial Fibrillation After Aortic Valve Replacement Independently of Left Atrial Size.

INTRODUCTION AND OBJECTIVES: Left atrial dysfunction in aortic stenosis may precede atrial enlargement and predict the occurrence of atrial fibrillation (AF). To test this hypothesis, we assessed left atrial function and determined its impact on the incidence of AF after aortic valve replacement. METHODS: A total of 149 severe aortic stenosis patients (74±8.6 years, 51% men) with no prior AF were assessed using speckle-tracking echocardiography. Left atrial function was evaluated using peak atrial longitudinal strain (PALS), peak atrial contraction strain (PACS), and phasic left atrial volumes. The occurrence of AF was monitored in 114 patients from surgery until hospital discharge. RESULTS: In multiple linear regression, PALS and PACS were inversely correlated with left atrial dilation, left ventricular hypertrophy, and diastolic function. Atrial fibrillation occurred in 36 patients within a median time of 3 days [interquartile range, 1-4] after aortic valve replacement. In multiple Cox regression, PALS and PACS were independently associated with the incidence of AF (HR, 0.946; 95%CI, 0.910-0.983; P=.005 and HR, 0.932; 95%CI, 0.883-0.984; P=.011, respectively), even after further adjustment for left atrial dimensions. Both reduced PALS and PACS were associated with the incidence of AF in patients with nondilated left atria (P value for the interaction of PALS with left atrial dimensions=.013). CONCLUSIONS: In severe aortic stenosis, left atrial dysfunction predicted the incidence of postoperative AF independently of left atrial dilation, suggesting that speckle-tracking echocardiography before surgery may help in risk stratification, particularly in patients with nondilated left atria.

Alteración del strain auricular izquierdo como predictor de fibrilación auricular de nuevo comienzo tras recambio valvular aórtico, independientemente del tamaño de la aurícula izquierda / Impaired left atrial strain as a predictor of new-onset atrial fibrillation after aortic valve replacement independently of left atrial size

Introducción y objetivos: La disfunción de la aurícula izquierda en la estenosis aórtica puede preceder a la dilatación y predecir la aparición de fibrilación auricular (FA). Para analizar esta hipótesis, se estudió la función auricular izquierda y se determinó su impacto en la incidencia de FA tras recambio valvular aórtico. Métodos: Se estudió mediante ecocardiografía con speckle-tracking a 149 pacientes (74 ± 8,6 años; el 51% varones) con estenosis aórtica grave sin FA previa. La función auricular izquierda se evaluó con el pico de strain longitudinal auricular (PSLA), el pico de strain de la contracción auricular (PSCA) y el volumen de la aurícula izquierda en cada fase de la contracción auricular. En 114 pacientes se detectó la aparición de FA entre la cirugía y el alta hospitalaria. Resultados: En el análisis de regresión lineal múltiple, el PSLA y el PSCA tenían correlación inversa con la dilatación auricular, la hipertrofia ventricular izquierda y la función diastólica; 36 pacientes presentaron FA una media de 3 [intervalo intercuartílico, 1-4] días tras el recambio valvular aórtico. En la regresión de Cox, la incidencia de FA se asoció de manera independiente con ambos parámetros (HR = 0,946; IC95%, 0,910-0,983; p = 0,005; HR = 0,932; IC95%, 0,883-0,984; p = 0,011) incluso después de ajustar los resultados según las dimensiones de la aurícula izquierda. Tanto la reducción del PSLA como del PSCA se asociaron con la incidencia de FA en los pacientes con aurícula izquierda no dilatada (PSLA con las dimensiones de la aurícula izquierda, p = 0,013). Conclusiones: En la estenosis aórtica grave, la disfunción auricular predijo la incidencia de FA posoperatoria independientemente de la dilatación auricular, lo que indica que la ecocardiografía con speckle-tracking antes de la cirugía puede ser de ayuda en la estratificación del riesgo, particularmente en aquellos con aurícula izquierda no dilatada

Introduction and objectives: Left atrial dysfunction in aortic stenosis may precede atrial enlargement and predict the occurrence of atrial fibrillation (AF). To test this hypothesis, we assessed left atrial function and determined its impact on the incidence of AF after aortic valve replacement. Methods: A total of 149 severe aortic stenosis patients (74 ± 8.6 years, 51% men) with no prior AF were assessed using speckle-tracking echocardiography. Left atrial function was evaluated using peak atrial longitudinal strain (PALS), peak atrial contraction strain (PACS), and phasic left atrial volumes. The occurrence of AF was monitored in 114 patients from surgery until hospital discharge. Results: In multiple linear regression, PALS and PACS were inversely correlated with left atrial dilation, left ventricular hypertrophy, and diastolic function. Atrial fibrillation occurred in 36 patients within a median time of 3 days [interquartile range, 1-4] after aortic valve replacement. In multiple Cox regression, PALS and PACS were independently associated with the incidence of AF (HR, 0.946; 95%CI, 0.910-0.983; P = .005 and HR, 0.932; 95%CI, 0.883-0.984; P = .011, respectively), even after further adjustment for left atrial dimensions. Both reduced PALS and PACS were associated with the incidence of AF in patients with nondilated left atria (P value for the interaction of PALS with left atrial dimensions = .013). Conclusions: In severe aortic stenosis, left atrial dysfunction predicted the incidence of postoperative AF independently of left atrial dilation, suggesting that speckle-tracking echocardiography before surgery may help in risk stratification, particularly in patients with nondilated left atria