Predictors of in-hospital mortality in critically ill patients with COVID-19: a large dual tertiary centre study.

OBJECTIVES: The aim of this study was to investigate the relationship of echocardiographic parameters, laboratory findings and clinical characteristics with in-hospital mortality in adult patients with COVID-19 admitted to the intensive care units (ICU) in two large collaborating tertiary UK centres. DESIGN: Observational retrospective study. SETTING: The study was conducted in patients admitted to the ICU in two large tertiary centres in London, UK. PARTICIPANTS: Inclusion criteria were: (1) patients admitted to the ICU with a COVID-19 diagnosis over a period of 16 weeks. and (2) underwent a transthoracic echocardiogram on the first day of ICU admission as clinically indicated.No exclusion criteria applied.Three hundred patients were enrolled and completed the follow-up. PRIMARY AND SECONDARY OUTCOME MEASURES: The outcome measure in this study was in-hospital mortality in patients admitted to the ICU with COVID-19 infection. RESULTS: Older age (HR: 1.027, 95% CI 1.007 to 1.047; p=0.008), left ventricular (LV) ejection fraction<35% (HR: 5.908, 95% CI 2.609 to 13.376; p<0.001), and peak C reactive protein (CRP) (HR: 1.002, 95% CI 1.001 to 1.004, p=0.001) were independently correlated with mortality in a multivariable Cox regression model. Following multiple imputation of variables with more than 5% missing values, random forest analysis was applied to the imputed data. Right ventricular (RV) basal diameter (RVD1), RV mid-cavity diameter (RVD2), tricuspid annular plane systolic excursion, RV systolic pressure, hypertension, RV dysfunction, troponin level on admission, peak CRP, creatinine level on ICU admission, body mass index and age were found to have a high relative importance (> 0.7). CONCLUSIONS: In patients with COVID-19 in the ICU, both severely impaired LV function and impaired RV function may have adverse prognostic implications, but older age and inflammatory markers appear to have a greater impact. A combination of echocardiographic and laboratory investigations as well as demographic and clinical characteristics appears appropriate for risk stratification in patients with COVID-19 who are admitted to the ICU.

Human versus Artificial Intelligence-Based Echocardiographic Analysis as a Predictor of Outcomes: An Analysis from the World Alliance Societies of Echocardiography COVID Study.

BACKGROUND: Transthoracic echocardiography is the leading cardiac imaging modality for patients admitted with COVID-19, a condition of high short-term mortality. The aim of this study was to test the hypothesis that artificial intelligence (AI)-based analysis of echocardiographic images could predict mortality more accurately than conventional analysis by a human expert. METHODS: Patients admitted to 13 hospitals for acute COVID-19 who underwent transthoracic echocardiography were included. Left ventricular ejection fraction (LVEF) and left ventricular longitudinal strain (LVLS) were obtained manually by multiple expert readers and by automated AI software. The ability of the manual and AI analyses to predict all-cause mortality was compared. RESULTS: In total, 870 patients were enrolled. The mortality rate was 27.4% after a mean follow-up period of 230 ± 115 days. AI analysis had lower variability than manual analysis for both LVEF (P = .003) and LVLS (P = .005). AI-derived LVEF and LVLS were predictors of mortality in univariable and multivariable regression analysis (odds ratio, 0.974 [95% CI, 0.956-0.991; P = .003] for LVEF; odds ratio, 1.060 [95% CI, 1.019-1.105; P = .004] for LVLS), but LVEF and LVLS obtained by manual analysis were not. Direct comparison of the predictive value of AI versus manual measurements of LVEF and LVLS showed that AI was significantly better (P = .005 and P = .003, respectively). In addition, AI-derived LVEF and LVLS had more significant and stronger correlations to other objective biomarkers of acute disease than manual reads. CONCLUSIONS: AI-based analysis of LVEF and LVLS had similar feasibility as manual analysis, minimized variability, and consequently increased the statistical power to predict mortality. AI-based, but not manual, analyses were a significant predictor of in-hospital and follow-up mortality.

The role of expert focus echocardiography during the COVID-19 pandemic.

BACKGROUND: Focus Echocardiography has routinely been used to offer quick diagnosis in critical care environments, predominantly by clinicians with limited training. During the COVID-19 pandemic, international guidance recommended all echocardiography scans were performed as focus studies to limit operator viral exposure in both inpatient and outpatient settings. The aim of this study was to assess the effectiveness of eFoCUS, a focus scan performed by fully trained echocardiographers following a minimum dataset plus full interrogation of any pathology found. METHODS: All diagnostic echocardiograms, performed by fully trained echocardiographers during an 8-week period during the first UK COVID-19 wave, were included. The number of images acquired was compared in the following categories: admission status, COVID status, image quality, indication, invasive ventilation, pathology found, echocardiographer experience, and whether eFoCUS was deemed adequate to answer the clinical question. RESULTS: In 87.4% of the 698 scans included, the operator considered that the eFOCUS echo protocol, with additional images when needed, was sufficient to answer the clinical question on the request. Echocardiographer experience did not affect the number of images acquired. Less images were acquired in COVID-19 positive patients compared to negative/asymptomatic (38 ± 12 vs. 42 ± 12, p = .001), and more images were required when a valve pathology was identified. CONCLUSION: eFoCUS echocardiography is an effective protocol for use during the COVID-19 pandemic. It provides sufficient diagnostic information to answer the clinical question but differs from standard focus/limited protocols by enabling the identification and interrogation of significant pathology and incidental findings, preventing unnecessary repeat scans and viral exposure of operators.

Ventricular Changes in Patients with Acute COVID-19 Infection: Follow-up of the World Alliance Societies of Echocardiography (WASE-COVID) Study.

BACKGROUND: COVID-19 infection is known to cause a wide array of clinical chronic sequelae, but little is known regarding the long-term cardiac complications. We aim to report echocardiographic follow-up findings and describe the changes in left (LV) and right ventricular (RV) function that occur following acute infection. METHODS: Patients enrolled in the World Alliance Societies of Echocardiography-COVID study with acute COVID-19 infection were asked to return for a follow-up transthoracic echocardiogram. Overall, 198 returned at a mean of 129 days of follow-up, of which 153 had paired baseline and follow-up images that were analyzable, including LV volumes, ejection fraction (LVEF), and longitudinal strain (LVLS). Right-sided echocardiographic parameters included RV global longitudinal strain, RV free wall strain, and RV basal diameter. Paired echocardiographic parameters at baseline and follow-up were compared for the entire cohort and for subgroups based on the baseline LV and RV function. RESULTS: For the entire cohort, echocardiographic markers of LV and RV function at follow-up were not significantly different from baseline (all P > .05). Patients with hyperdynamic LVEF at baseline (>70%), had a significant reduction of LVEF at follow-up (74.3% ± 3.1% vs 64.4% ± 8.1%, P < .001), while patients with reduced LVEF at baseline (<50%) had a significant increase (42.5% ± 5.9% vs 49.3% ± 13.4%, P = .02), and those with normal LVEF had no change. Patients with normal LVLS (<-18%) at baseline had a significant reduction of LVLS at follow-up (-21.6% ± 2.6% vs -20.3% ± 4.0%, P = .006), while patients with impaired LVLS at baseline had a significant improvement at follow-up (-14.5% ± 2.9% vs -16.7% ± 5.2%, P < .001). Patients with abnormal RV global longitudinal strain (>-20%) at baseline had significant improvement at follow-up (-15.2% ± 3.4% vs -17.4% ± 4.9%, P = .004). Patients with abnormal RV basal diameter (>4.5 cm) at baseline had significant improvement at follow-up (4.9 ± 0.7 cm vs 4.6 ± 0.6 cm, P = .019). CONCLUSIONS: Overall, there were no significant changes over time in the LV and RV function of patients recovering from COVID-19 infection. However, differences were observed according to baseline LV and RV function, which may reflect recovery from the acute myocardial injury occurring in the acutely ill. Left ventricular and RV function tends to improve in those with impaired baseline function, while it tends to decrease in those with hyperdynamic LV or normal RV function.

Echocardiographic Correlates of In-Hospital Death in Patients with Acute COVID-19 Infection: The World Alliance Societies of Echocardiography (WASE-COVID) Study.

BACKGROUND: The novel severe acute respiratory syndrome coronavirus-2 virus, which has led to the global coronavirus disease-2019 (COVID-19) pandemic is known to adversely affect the cardiovascular system through multiple mechanisms. In this international, multicenter study conducted by the World Alliance Societies of Echocardiography, we aim to determine the clinical and echocardiographic phenotype of acute cardiac disease in COVID-19 patients, to explore phenotypic differences in different geographic regions across the world, and to identify parameters associated with in-hospital mortality. METHODS: We studied 870 patients with acute COVID-19 infection from 13 medical centers in four world regions (Asia, Europe, United States, Latin America) who had undergone transthoracic echocardiograms. Clinical and laboratory data were collected, including patient outcomes. Anonymized echocardiograms were analyzed with automated, machine learning-derived algorithms to calculate left ventricular (LV) volumes, ejection fraction, and LV longitudinal strain (LS). Right-sided echocardiographic parameters that were measured included right ventricular (RV) LS, RV free-wall strain (FWS), and RV basal diameter. Multivariate regression analysis was performed to identify clinical and echocardiographic parameters associated with in-hospital mortality. RESULTS: Significant regional differences were noted in terms of patient comorbidities, severity of illness, clinical biomarkers, and LV and RV echocardiographic metrics. Overall in-hospital mortality was 21.6%. Parameters associated with mortality in a multivariate analysis were age (odds ratio [OR] = 1.12 [1.05, 1.22], P = .003), previous lung disease (OR = 7.32 [1.56, 42.2], P = .015), LVLS (OR = 1.18 [1.05, 1.36], P = .012), lactic dehydrogenase (OR = 6.17 [1.74, 28.7], P = .009), and RVFWS (OR = 1.14 [1.04, 1.26], P = .007). CONCLUSIONS: Left ventricular dysfunction is noted in approximately 20% and RV dysfunction in approximately 30% of patients with acute COVID-19 illness and portend a poor prognosis. Age at presentation, previous lung disease, lactic dehydrogenase, LVLS, and RVFWS were independently associated with in-hospital mortality. Regional differences in cardiac phenotype highlight the significant differences in patient acuity as well as echocardiographic utilization in different parts of the world.

First-Phase Ejection Fraction, a Measure of Preclinical Heart Failure, Is Strongly Associated With Increased Mortality in Patients With COVID-19.

Presence of heart failure is associated with a poor prognosis in patients with coronavirus disease 2019 (COVID-19). The aim of the present study was to examine whether first-phase ejection fraction (EF1), the ejection fraction measured in early systole up to the time of peak aortic velocity, a sensitive measure of preclinical heart failure, is associated with survival in patients hospitalized with COVID-19. A retrospective outcome study was performed in patients hospitalized with COVID-19 who underwent echocardiography (n=380) at the West Branch of the Union Hospital, Wuhan, China and in patients admitted to King's Health Partners in South London, United Kingdom. Association of EF1 with survival was performed using Cox proportional hazards regression. EF1 was compared in patients with COVID-19 and in historical controls with similar comorbidities (n=266) who had undergone echocardiography before the COVID-19 pandemic. In patients with COVID-19, EF1 was a strong predictor of survival in each patient group (Wuhan and London). In the combined group, EF1 was a stronger predictor of survival than other clinical, laboratory, and echocardiographic characteristics including age, comorbidities, and biochemical markers. A cutoff value of 25% for EF1 gave a hazard ratio of 5.23 ([95% CI, 2.85-9.60]; P<0.001) unadjusted and 4.83 ([95% CI, 2.35-9.95], P<0.001) when adjusted for demographics, comorbidities, hs-cTnI (high-sensitive cardiac troponin), and CRP (C-reactive protein). EF1 was similar in patients with and without COVID-19 (23.2±7.3 versus 22.0±7.6%, P=0.092, adjusted for prevalence of risk factors and comorbidities). Impaired EF1 is strongly associated with mortality in COVID-19 and probably reflects preexisting, preclinical heart failure.

Impact of COVID-19 on UK stress echocardiography practice: insights from the EVAREST sites.

INTRODUCTION: Healthcare delivery is being transformed by COVID-19 to reduce transmission risk but continued delivery of routine clinical tests is essential. Stress echocardiography is one of the most widely used cardiac tests in the NHS. We assessed the impact of the first (W1) and second (W2) waves of the pandemic on the ability to deliver stress echocardiography. METHODS: Clinical echocardiography teams in 31 NHS hospitals participating in the EVAREST study were asked to complete a survey on the structure and delivery of stress echocardiography as well as its impact on patients and staff in July and November 2020. Results were compared to stress echocardiography activity in the same centre during January 2020. RESULTS: 24 completed the survey in July, and 19 NHS hospitals completed the survey in November. A 55% reduction in the number of studies performed was reported in W1, recovering to exceed pre-COVID rates in W2. The major change was in the mode of stress delivery. 70% of sites stopped their exercise stress service in W1, compared to 19% in W2. In those still using exercise during W1, 50% were wearing FFP3/N95 masks, falling to 38% in W2. There was also significant variability in patient screening practices with 7 different pre-screening questionnaires used in W1 and 6 in W2. CONCLUSION: Stress echocardiography delivery restarted effectively after COVID-19 with adaptations to reduce transmission that means activity has been able to continue, and exceed, pre-COVID-19 levels during the second wave. Further standardization of protocols for patient screening and PPE may help further improve consistency of practice within the United Kingdom.