Risultati per: Vaccinare l’adulto ai tempi del COVID-19

Circulation, Volume 150, Issue Suppl_1, Page A4143094-A4143094, November 12, 2024. Background:Peripartum cardiomyopathy (PPCM) is defined as a dilated form of cardiomyopathy that occurs within the last month of pregnancy and up to 5 months postpartum. The etiology is likely multifactorial and viral infections may account for up to a third of PPCM cases. We aimed to examine the impact of concurrent COVID-19 infection on in-hospital outcomes of women with PPCM.Methods:National Inpatient Sample was queried to identify women admitted with PPCM with COVID-19 (group A) between the years 2020-2021 and without (group B) concurrent COVID-19 infection between the years 2016-2019.Results:A total of 19135 women were admitted with PPCM between the years 2016-2021, of whom 420 (2%) had concurrent COVID-19 infection. Group A PPCM followed a seasonal pattern with peak incidence in fall (43%) followed by winter (31%), spring (13%) and summer (13%) [p=0.002]. Group A was more often Hispanic (20.3% -vs- 10.8%, p

Circulation, Volume 150, Issue Suppl_1, Page A4137878-A4137878, November 12, 2024. Background:The COVID-19 pandemic in 2020 was marked by a sharp decrease in out-of-hospital cardiac arrest (OHCA) survival. Whether OHCA survival has recovered to pre-pandemic levels, and whether changes in OHCA survival are similar across communities of different racial and ethnic composition, is unknown.Methods:We included adult patients with non-traumatic OHCA from 2015-2022 in the Cardiac Arrest Registry to Enhance Survival registry. Using hierarchical multivariable regression, we calculated risk-adjusted rates of survival to hospital discharge during 2015-2019 (reference period) and compared this to survival rates during 2020, 2021, and 2022. We also examined whether the trajectory of survival over this period differed based on the racial/ethnic composition of the community served by the emergency medical service (EMS) agency, defined as predominantly White ( >80% White residents), majority Black or Hispanic ( >50% Black or Hispanic residents), or integrated (neither).Results:Of 485,079 patients with OHCA, mean age was 61.9 years; 64% were male, and 22% were of Black race with 7% of Hispanic ethnicity. Overall, risk-adjusted survival rates to hospital discharge for OHCA decreased from 10.1% in 2015-2019 to 8.4% in 2020 (P

Circulation, Volume 150, Issue Suppl_1, Page ASa807-ASa807, November 12, 2024. Background:Despite the lack of evidence supporting the use of chest compression-only cardiopulmonary resuscitation (CO-CPR) emphasizing the importance of rescue breathing for pediatric out-of-hospital cardiac arrest (OHCA), prehospital CO-CPR is increasing. The COVID-19 pandemic may have led more bystanders to perform CO-CPR, even for pediatric OHCA. However, studies on the dissemination of CO-CPR and outcomes in pediatric OHCA are limited.Hypothesis:Spread of CO-CPR led to increased mortality in pediatric OHCA.Aims:Investigate the mortality of nationwide pediatric OHCA patients with the dissemination of CO-CPR pre- and post-COVID-19.Methods:We conducted a retrospective study using a Utstein-Style population cohort database (Japanese National Registry). Pediatric OHCA patients (≤17 years old) with bystander resuscitation attempts registered between the pre-COVID-19 era (2017-2019) and the post-COVID-19 era (2020-2021) were included. The primary outcome was 30-day mortality after OHCA. The secondary outcome was 30-day poor neurological outcomes, defined as Cerebral Performance Category scores of 3, 4, or 5. We used Poisson regression with robust variance to estimate adjusted risk ratio (aRR) with 95% confidence interval (CI) and the population attributable fraction (PAF, %) with a focus on the post-COVID-19 period.Results:A total of 3,352 pediatric OHCA, 2,023 pre-COVID-19, and 1,329 post-COVID-19 patients received bystander CPR and were registered in the database. CO-CPR was more common than CPR with rescue breathing (RB-CPR) during the pre- and post-COVID-19 periods [pre-COVID-19: 1,356 (67.0%) vs. 667 (33.0%), post-COVID-19: 1,048 (78.9%) vs. 281 (21.1%)]. Comparison of CO-CPR vs. RB-CPR showed increased 30-day mortality in both periods [pre-COVID-19: 1,081/1,356 (79.7%) vs. 420/667 (63.0%), post-COVID-19: 841/1,048 (80.2%) vs. 181/281 (64.4%)]. In the overall cohort, mortality increased with CO-CPR (aRR: 1.16, 95% CI: 1.09-1.23, PAF:1.60%). Due to the increased number of patients receiving CO-CPR, we estimated 21.2 excess deaths over the two-year post-COVID-19 period. Similar results were observed for poor neurological outcome (aRR: 1.10, 95% CI: 1.05-1.16, PAF: 1.10%, excess poor outcome: 14.6]).Conclusion:With the spread of CO-CPR for pediatric OHCA, an estimated 10.6 excess deaths per year attributed to CO-CPR may have occurred in the post-COVID-19 period compared to the pre-COVID-19 period in Japan.

Circulation, Volume 150, Issue Suppl_1, Page A4139661-A4139661, November 12, 2024. Introduction:Troponin-defined myocardial injury or N-terminal pro-B-type natriuretic peptide (NT-proBNP) elevation frequently coincides with coronavirus disease 2019 (COVID-19). Our prior study (COVID-MI Registry Cohort-1) confirmed that high-sensitive troponin I (HsTnI) and NT-proBNP effectively stratified mortality risk. However, variants of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) change rapidly, and it remains unclear whether these biomarkers are consistently effective in predicting prognosis of COVID-19 patients irrespective of epidemic periods.Research Questions:Can HsTnI or NT-proBNP stratify mortality risk in recent COVID-19 cohorts?Aims:To assess the potential of HsTnI and NT-proBNP levels for risk stratification in the recent COVID-19 waves.Methods:In the COVID-MI Registry Cohort-2, we enrolled 1115 consecutive COVID-19 patients admitted between October 2021 and October 2022, during the Omicron variant endemic. We collected data of HsTnI or NT-proBNP levels from hospital charts or using the samples in our hospital’s serum/plasma bank if the data were not available. The primary outcome measure was all-cause mortality.Results:On admission, more than one-third of patients were classified as having severe COVID-19. HsTnI and NT-proBNP levels were available for 427 and 414 patients, respectively. The median HsTnI and NT-proBNP levels were 16 (interquartile range [IQR]: 5-57) ng/L and 524 (IQR: 140-2056) pg/mL, respectively. We stratified the patients into three groups by HsTnI level:

Circulation, Volume 150, Issue Suppl_1, Page A4134935-A4134935, November 12, 2024. Introduction:Recent data demonstrated that the COVID-19 pandemic adversely affected cardiovascular fellows in training (cFIT) and faculty in terms of educational disruption and search for job prospects, respectively. However, less is known about the pandemic’s effect on cFIT and faculty in terms of general well-being, shifts in personal and professional priorities, quantitative measures of stress levels, and research productivity.Methods:A national survey targeting cFIT and faculty was developed to assess the effect of the pandemic two years later on these parameters. Fifty-four participants, including 21 cFIT and 33 faculty, responded to the survey. The survey was distributed between October 2021 and May 2022 to program directors of ACGME-accredited general cardiology fellowship programs in the United States.Results:30% of cFITs perceived impaired clinical training during the pandemic; 36% of fellows experienced a decline in their clinical skills in the cardiac catheterization lab, while 27% experienced a decrease in their echocardiographic skills. Additionally, a significant percentage of cFIT reported negative interference in their competencies in nuclear cardiology (27%) and electrophysiology (12%). Most participants (76%), including faculty and fellows, reported several health issues such as sleep problems, low energy, changes in appetite, difficulty concentrating, and restlessness due to the pandemic. 43% of the faculty and 61% of cFIT reported high rates of impaired short-term productivity (Figure).Conclusion:In this national survey, we found that two years after the onset of the COVID-19 pandemic, cardiology fellows and faculty continued to experience significant concerns for decreased hands-on training and diminished research productivity. While faculty were not distressed regarding decreased clinical competencies, concerns about short-term and long-term research productivity persisted. Faculty and fellows all experienced increased stress levels and impaired productivity. Although limited by a small sample size, which can introduce bias, these results signal the importance of performing a follow-up study on the impact of COVID-19 on wellness as well as the impact on career.

Circulation, Volume 150, Issue Suppl_1, Page A4141163-A4141163, November 12, 2024. Background:The rising incidence of stroke among young adults is partly explained by underdiagnosis of risk factors such as hypertension. Current blood pressure cutoff values for hypertension diagnosis in adolescence are not based on cardiovascular outcomes and lack specificity for sex, even though female adolescents have lower blood pressure values.Methods:A nationwide, population-based, retrospective cohort study including data of all Israeli adolescents (16-19 years) who were evaluated prior to mandatory military service in 1985 through 2013. The medical evaluation included routine measurements of height, weight, and blood pressure. The primary outcome was the first occurrence of a stroke at a young age (≤52 years) as documented in the National Stroke Registry. Cox proportional hazard models were applied separately for males and females and adjusted for adolescent body mass index and sociodemographic variables. Diabetes status in adulthood, as documented in the National Diabetes Registry, was also accounted. Several sensitivity analyses were conducted, including the evaluation of ischemic stroke cases only as the outcome and stroke occurrence at a very young age (≤45 years).Results:The cohort comprised 1,897,048 adolescents (42.4% females). During 11,355,476 person-years of follow-up, there were 1,470 first stroke events, 1,233 (83.8%) cases were of ischemic etiology. In male adolescents, a diastolic blood pressure of ≥80 mmHg was associated with an adjusted hazard ratio (aHR) for stroke at a young age of 1.28 (95% confidence interval 1.05-1.58) (Image 1). In male adolescents with blood pressure of 70-79 mmHg, the aHR was comparable to that of the reference group (

Circulation, Volume 150, Issue Suppl_1, Page A4138301-A4138301, November 12, 2024. Background:Hyperlipidemia (HLD) is a major risk factor for cardiovascular disease (CVD). Little is known regarding temporal variation in CVD mortality related to HLD. The COVID-19 pandemic added complexity to factors influencing CVD mortality.Question:What are the yearly trends and impact of the COVID-19 pandemic on HLD-related CVD mortality in the United States?Methods:Mortality and demographic data for adults were obtained from CDC repository from 1999-2020, using ICD-10 codes HLD (E78.0-E78.5) and CVD (I00-I99). Age adjusted mortality rates (AAMR) per 1,000,000 population was standardized to the 2000 US population. Log-linear regression models evaluated mortality shifts. Average annual percentage change (AAPC) from 1999-2019 was used to calculate projected AAMR in 2020, subsequently compared to actual 2020 death rates to estimate pandemic-attributed excess deaths.Results:A total of 483,155 HLD-related CVD deaths were recorded between 1999-2020. Despite the CVD mortality decline in general population, HLD-related CVD AAMR rose from 36.33 [95% CI, 35.52-37.13] in 1999 to 99.77 [98.67-100.87] in 2019. Ischemic heart diseases (AAMR 49.39) were the most common causes of death while hypertension had the highest annual mortality increase (AAPC +10.23%) in populations with HLD. Higher HLD-related CVD mortality was observed in males (AAMR 104.87) than females (AAMR 61.93), in those ≥75 years (AAMR 646.45) than 35-75 years (AAMR 54.11), in non-Hispanic (NH) (AAMR 82.49) than Hispanic (AAMR 58.98) populations, and in rural (AAMR 89.98) than urban (AAMR 78.94) regions. NH Black populations (AAMR 84.35) and Western US regions (AAMR 96.88) had the highest HLD-related CVD. The first year of COVID-19 pandemic resulted in 10.55% excess HLD-related CVD death, with the most prominent increase in the 35-75 years age group (14.23%), Hispanic (17.96%), Black (14.82%), and urban (11.68%) populations.Conclusions:Our study revealed an increase in HLD-related CVD mortality which was exacerbated by the COVID-19 pandemic. Higher CVD mortality disproportionately affected males, Black, elderly (≥75 years), and rural populations with HLD. Further research is needed to validate our findings and identify contributing factors.

Circulation, Volume 150, Issue Suppl_1, Page ASa907-ASa907, November 12, 2024. Background:Different from the negative impact of COVID-19 pandemic on outcomes after out-of-hospital cardiac arrest (OHCA) collapsed before emergency medical service (EMS) arrival, there was a report suggested that COVID-19 pandemic did not affect outcomes after OHCA witnessed by EMS personnel. However, no large-scale studies have examined the impact of COVID-19 pandemic after EMS-witnessed OHCA, focusing on favorable neurological outcomes.Research Questions:Does COVID-19 pandemic affect favorable neurological outcomes after EMS-witnessed OHCA?Aims:To assess COVID-19’s impact on favorable neurological outcomes after EMS-witnessed OHCA.Methods:We performed an interrupted time series analysis (ITSA) with a prospective, nationwide, population-based registry in Japan to assess trends of incidence and favorable neurological outcome (Cerebral Performance Category 1 or 2) at 30 days with adult EMS-witnessed OHCA between pre-pandemic (January 2016-March 2020) and pandemic (April 2020-December 2021) periods. Subgroup analyses were performed by stratifying regions by infection spread status defined by whether a state of emergency has been declared. To assess whether there are differences in trends between areas with and without COVID-19 spread, we performed a controlled ITSA between the two areas.Results:We identified 58,315 patients with adult EMS-witnessed OHCA, 41,112 during the pre-pandemic period and 17,203 during the pandemic period. There was no significant increase in the incidence of EMS-witnessed OHCA during the pandemic period (0.03 per 100,000 person-years; 95% confidence interval [CI], –0.02 to 0.08; p = 0.21). Favorable neurological outcome significantly decreased (relative risk [RR], 0.80; 95% CI, 0.71 to 0.91; p < 0.01). In subgroup analysis, favorable neurological outcome significantly decreased in areas with COVID-19 spread (RR, 0.67; 95% CI, 0.56 to 0.81; p < 0.01), while there was no significant difference in areas without COVID-19 spread (RR, 0.91; 95% CI, 0.77 to 1.07; p = 0.24). A controlled ITSA showed that favorable neurological outcome significantly decreased in areas with COVID-19 spread compared to without COVID-19 spread (RR, 0.77; 95% CI, 0.60 to 0.98; p = 0.04).Conclusion:Unlike previous studies, our research with a nationwide, population-based registry showed that COVID-19 pandemic influenced favorable neurological outcome in EMS-witnessed OHCA. This trend appears to be more pronounced in areas with widespread infection.

Circulation, Volume 150, Issue Suppl_1, Page A4139757-A4139757, November 12, 2024. Background:The COVID-19 pandemic has significantly exacerbated sleep problems. Pandemic-related lockdowns and drastic changes in daily life have disrupted sleep patterns, resulting in a marked increase in sleep disturbances.Research questions:This study aims to investigate the primary factors contributing to the increase in sleep disturbances during the COVID-19 pandemic in Korea. By utilizing nationally representative data encompassing various variables, this study seeks to identify COVID-19-related factors associated with sleep disturbances during the pandemic.Method:We analyzed data from the nationally representative Korea Community Health Survey conducted in 2020, including 216,809 adults. Changes in daily life due to COVID-19 were assessed by asking participants to score their current situation compared to their pre-pandemic situation, ranging from 100 (no change) to 0 (complete cessation of daily activities). COVID-19 concerns were assessed with five questions: 1) fear of contracting the virus; 2) fear of mortality if infected; 3) fear of blame from others; 4) concerns about the health of vulnerable family members; and 5) concerns about economic impacts. Sleep disturbances were defined as sleeping 5 hours or less per night on average. Logistic regression analyses with a complex sample design were performed to examine the relationship between COVID-19-related factors and sleep disturbances, adjusting for socioeconomic and health-related variables.Results:A high level of lifestyle changes due to COVID-19 (OR = 1.15, 95% CI = 1.11–1.19) and high COVID-19 concerns (OR = 1.04, 95% CI = 1.01–1.08) were associated with an increased likelihood of sleep disturbances. Conversely, resting during COVID-19 symptoms (OR = 0.81, 95% CI = 0.76–0.87), having support during quarantine (OR = 0.93, 95% CI = 0.89–0.97), and trust in the government and neighbors (OR = 0.92, 95% CI = 0.89–0.96) were associated with a decreased likelihood of sleep disturbances.Conclusion:These findings suggest that sleep disturbances during the COVID-19 pandemic were mediated by lifestyle disruptions and high levels of concern. Social support and trust mitigated the impact of COVID-19-related risk factors. As part of preparedness, improving the environment to facilitate adequate rest during illness, ensuring strong social support, and fostering high levels of trust in the government and neighbors may be important to protect sleep health during future public health emergencies.

Circulation, Volume 150, Issue Suppl_1, Page A4141946-A4141946, November 12, 2024. INTRODUCTION:Mechanisms contributing to the post-acute sequelae of SARS-CoV-2 (PASC, aka Long COVID) and associated functional limitations are unclear.RESEARCH QUESTION:Determine cardiovascular, autonomic and exercise physiology among patients with Long COVID.METHODS:Twenty-one Long COVID patients (16 females, 41±12yrs) underwent cardiovascular assessment during head-up tilt at supine, 30oand 60o, a 10-minute upright standing orthostatic challenge and cardiopulmonary exercise testing (CPET). Baroreceptor sensitivity was determined with Valsalva maneuver. Heart rate (HR) and blood pressure (BP) were monitored continuously. Plasma norepinephrine (NE) was monitored during tilt.RESULTS:During tilt, HR increased with transition from supine to 30oand 60o(72±12 v. 80±14 v. 90±15bpm, P

Circulation, Volume 150, Issue Suppl_1, Page A4126581-A4126581, November 12, 2024. Background:Coronavirus Disease-19 (COVID-19) pandemic had a significant impact on emergent and elective treatment strategies in patients with cardiovascular disease. We aimed to examine the impact of COVID-19 on septal reduction therapy (SRT) in hypertrophic cardiomyopathy (HCM).Methods:National Inpatient Sample 2019-2021 was queried to identify patients with HCM and SRT using appropriate ICD codes. Temporal trends for SRT were obtained before and after COVID-19 outset.Results:There was a significant decline in the number of SRT from 2019 to 2020 (1505 vs. 1180, p

Circulation, Volume 150, Issue Suppl_1, Page A4146890-A4146890, November 12, 2024. Background:COVID-19 has introduced new complexities in the management of patients undergoing the transcatheter edge-to-edge repair (TEER) procedure of the mitral valve. This study compares outcomes of mitral valve TEER in patients with and without COVID-19, utilizing data from the National Inpatient Sample (2020-2021).Methods:We conducted a retrospective cohort study on 23,465 patients without COVID-19 and 85 patients with COVID-19 undergoing mitral valve TEER. Multivariate logistic regression was employed to compare outcomes, adjusting for potential confounders. Primary outcomes included mortality and major complications, while secondary outcomes encompassed specific procedural complications.Results:Patients with COVID-19 were younger (mean age: 73.176 vs. 76.178 years, p-value

Circulation, Volume 150, Issue Suppl_1, Page A4127513-A4127513, November 12, 2024. Background:SARS-CoV-2 infection affects the cardiopulmonary system in both the acute and long-term phase. This study aimed to comprehensively assess symptoms and potential long-term impairments 6, 18 and 30 months in patients previously hospitalized for severe Covid-19 infection.Methods:This prospective registry included patients hospitalized for PCR-confirmed Covid-19 infection. Approximately 6 months post-discharge, follow-up examination included patient history, clinical examination, echocardiography, electrocardiogram, cardiac magnetic resonance imaging (cMRI), chest computed tomography (CT) scan, pulmonary function test (PFT), six-minute walk test (6MWT) and a comprehensive laboratory panel. Patients with pathologic findings during the first visit underwent a second (at 18 months) and third (at 30 months) follow-up examination. Those without pathologic findings or who refused further medical examinations were contacted via phone to inquire about symptoms.Results:Between July 2020 and April 2022, 200 patients (91% general ward, 9% intensive care unit) were recruited. Due to dropouts, the second visit was conducted in 170 patients, and the third visit in 139 (74 in person, 65 via telephone). Long Covid criteria were fulfilled by 73% at 6 months, 52% at 18 months and 49% at 30 months post-discharge, with fatigue being the most common symptom (Figure 1). Echocardiography at 6 months showed impaired left ventricular function in 15 patients, with normalization in 80% at 18 months and further 66% at 30 months (Figure 2). cMRI revealed pericardial effusions in 28 patients at 6 months, which resolved in 47% at 18 months and in further 60% at 30 months. Signs of peri- or myocarditis were present in 7 patients at 6 months and were resolved in all 4 patients who attended control studies at 18 months. Chest CT scans at 6 months identified post-infectious residues in 41 patients, with full recovery in 20% at 18 months without further normalization after 30 months.The length of in-hospital stay was identified as a significant predictor for persisting Long Covid 6 months after discharge (95% CI: 1.005 – 1.12, p=0.03).Conclusion:While the prevalence of Long Covid decreased over time, a significant symptom burden persisted at 6, 18 and even 30 months after severe Covid-19 infection. Structural and functional abnormalities were less frequent compared to reported symptoms, posing a challenge in substantiating the causes of these symptoms.

Circulation, Volume 150, Issue Suppl_1, Page A4141859-A4141859, November 12, 2024. Background:Field activation of patients with ST-segment elevation myocardial infarction (STEMI) by Emergency Medical Services (EMS) during the COVID-19 (COVID) pandemic era involved a change in policy whereby patients underwent COVID-19 testing in the emergency department (ED) prior to Percutaneous Coronary Intervention (PCI) versus bypassing the ED to the Catheterization (Cath) Lab.Research Question:We aimed to compare In-Hospital Mortality and other performance metrics of field activated STEMI patients at a large rural health system during the COVID era to pre and post pandemic periods.Methods:Retrospective single-center (Essentia Health, Duluth, MN, USA) cohort study of consecutive patients with STEMI activation identified in the field by EMS prior to the COVID era (5/27/2018–3/26/2020), during the 22 months of the COVID testing policy (3/27/2020–1/25/2022), and post-COVID when ED bypass resumed (1/ 26/2022–11/26/2023). The main outcomes of this study were in-hospital mortality and common STEMI system performance metrics.Results:A total of 373 consecutive field activated STEMI cases were included (pre COVID [N =132], COVID [N = 104], post COVID [N = 137]). Pre COVID, 40.9% of EMS activated STEMI cases stopped in the ED prior to the Cath Lab, 97.1% during the COVID era, and 51.1% in the post-COVID era (p

Circulation, Volume 150, Issue Suppl_1, Page A4146939-A4146939, November 12, 2024. Background:New onset AF during acute illness has a high rate of AF recurrence within 5-yr. However, little is known about AF progression in patients with new onset AF during COVID illness. It is also unknown whether the time of COVID diagnosis (early vs late) impacts AF progression. More specifically, did the potentially different immune and inflammatory responses during early vs late COVID produce structural and electrical cardiac remodeling that would increase the likelihood of AF progression.Objective:We sought to compare AF progression in patients with new onset AF during early vs late COVID and hypothesized that early COVID was associated with increased AF progression compared to late COVID.Methods:From Apr 2020 to Feb 2024, patients receiving a SARS-2-CoV test without a history of AF with new onset AF and at least 3-mo of follow up were included (N=11,767). Patients were subdivided based on pos vs neg SARS-2-CoV test and time of diagnosis. Early COVID diagnosis (n=3052) included Apr 2020-Aug 2021 and late COVID (n=8715) included Sep 2021-Feb 2024. AF progression endpoints at 3-, 6- and 12-mo included AF hospitalization, AF emergency department (ED) visit, cardioversion and AF ablation.Results:Patients with late COVID were more likely females with hypertension, coronary artery disease and hyperlipidemia compared to early COVID patients. At 3- and 6-mo follow-up there was no difference in AF progression between the early and late COVID groups for any endpoint. In contrast, at 12-mo follow up there was in increase in late diagnosis group AF ED visits (11% vs 7.6%,p

Circulation, Volume 150, Issue Suppl_1, Page A4144056-A4144056, November 12, 2024. Background:COVID-19 infections have been associated with cardiovascular autonomic dysfunction (AD). Clinical findings include fatigue, cognitive impairment, and postural intolerance. However, quantitative post-COVID AD assessments are lacking.Objective:Compare autonomic testing measures of post-COVID-19 subjects to controls and those with pure autonomic failure (PAF).Methods:Autonomic testing included 1) change in heart rate (HR) and blood pressure (BP) with active standing (AS) and tilt table testing (TT), 2) time to BP nadir and recovery during AS and TT, 3) Valsalva ratio (VR), and 4) respiratory sinus arrhythmia (RSA). Comparisons between two groups were made using t-tests, Kruskal-Wallis, or chi-square tests. Multivariable linear regression was used to adjust findings for age and sex. A p-value of