Deep-Learning for Epicardial Adipose Tissue Assessment With Computed Tomography: Implications for Cardiovascular Risk Prediction.

BACKGROUND: Epicardial adipose tissue (EAT) volume is a marker of visceral obesity that can be measured in coronary computed tomography angiograms (CCTA). The clinical value of integrating this measurement in routine CCTA interpretation has not been documented. OBJECTIVES: This study sought to develop a deep-learning network for automated quantification of EAT volume from CCTA, test it in patients who are technically challenging, and validate its prognostic value in routine clinical care. METHODS: The deep-learning network was trained and validated to autosegment EAT volume in 3,720 CCTA scans from the ORFAN (Oxford Risk Factors and Noninvasive Imaging Study) cohort. The model was tested in patients with challenging anatomy and scan artifacts and applied to a longitudinal cohort of 253 patients post-cardiac surgery and 1,558 patients from the SCOT-HEART (Scottish Computed Tomography of the Heart) Trial, to investigate its prognostic value. RESULTS: External validation of the deep-learning network yielded a concordance correlation coefficient of 0.970 for machine vs human. EAT volume was associated with coronary artery disease (odds ratio [OR] per SD increase in EAT volume: 1.13 [95% CI: 1.04-1.30]; P = 0.01), and atrial fibrillation (OR: 1.25 [95% CI: 1.08-1.40]; P = 0.03), after correction for risk factors (including body mass index). EAT volume predicted all-cause mortality (HR per SD: 1.28 [95% CI: 1.10-1.37]; P = 0.02), myocardial infarction (HR: 1.26 [95% CI:1.09-1.38]; P = 0.001), and stroke (HR: 1.20 [95% CI: 1.09-1.38]; P = 0.02) independently of risk factors in SCOT-HEART (5-year follow-up). It also predicted in-hospital (HR: 2.67 [95% CI: 1.26-3.73]; P ≤ 0.01) and long-term post-cardiac surgery atrial fibrillation (7-year follow-up; HR: 2.14 [95% CI: 1.19-2.97]; P ≤ 0.01). CONCLUSIONS: Automated assessment of EAT volume is possible in CCTA, including in patients who are technically challenging; it forms a powerful marker of metabolically unhealthy visceral obesity, which could be used for cardiovascular risk stratification.

Racial differences in management and outcomes of acute myocardial infarction during COVID-19 pandemic.

OBJECTIVE: There are concerns that healthcare and outcomes of black, Asian and minority ethnic (BAME) communities are disproportionately impacted by the COVID-19 pandemic. We investigated admission rates, treatment and mortality of BAME with acute myocardial infarction (AMI) during COVID-19. METHODS: Using multisource national healthcare records, patients hospitalised with AMI in England during 1 February-27 May 2020 were included in the COVID-19 group, whereas patients admitted during the same period in the previous three consecutive years were included in a pre-COVID-19 group. Multilevel hierarchical regression analyses were used to quantify the changes in-hospital and 7-day mortality in BAME compared with whites. RESULTS: Of 73 746 patients, higher proportions of BAME patients (16.7% vs 10.1%) were hospitalised with AMI during the COVID-19 period compared with pre-COVID-19. BAME patients admitted during the COVID-19 period were younger, male and likely to present with ST-elevation acute myocardial infarction. COVID-19 BAME group admitted with non-ST-elevation acute myocardial infarction less frequently received coronary angiography (86.1% vs 90.0%, p<0.001) and had a longer median delay to reperfusion (4.1 hours vs 3.7 hours, p<0.001) compared with whites. BAME had higher in-hospital (OR 1.68, 95% CI 1.27 to 2.28) and 7-day mortality (OR 1.81 95% CI 1.31 to 2.19) during COVID-19 compared with pre-COVID-19 period. CONCLUSION: In this multisource linked cohort study, compared with whites, BAME patients had proportionally higher hospitalisation rates with AMI, less frequently received guidelines indicated care and had higher early mortality during COVID-19 period compared with pre-COVID-19 period. There is a need to develop clinical pathways to achieve equity in the management of these vulnerable populations.

Impact of Coronavirus Disease 2019 Pandemic on the Incidence and Management of Out-of-Hospital Cardiac Arrest in Patients Presenting With Acute Myocardial Infarction in England.

Background Studies have reported significant reduction in acute myocardial infarction-related hospitalizations during the coronavirus disease 2019 (COVID-19) pandemic. However, whether these trends are associated with increased incidence of out-of-hospital cardiac arrest (OHCA) in this population is unknown. Methods and Results Acute myocardial infarction hospitalizations with OHCA during the COVID-19 period (February 1-May 14, 2020) from the Myocardial Ischaemia National Audit Project and British Cardiovascular Intervention Society data sets were analyzed. Temporal trends were assessed using Poisson models with equivalent pre-COVID-19 period (February 1-May 14, 2019) as reference. Acute myocardial infarction hospitalizations during COVID-19 period were reduced by >50% (n=20 310 versus n=9325). OHCA was more prevalent during the COVID-19 period compared with the pre-COVID-19 period (5.6% versus 3.6%), with a 56% increase in the incidence of OHCA (incidence rate ratio, 1.56; 95% CI, 1.39-1.74). Patients experiencing OHCA during COVID-19 period were likely to be older, likely to be women, likely to be of Asian ethnicity, and more likely to present with ST-segment-elevation myocardial infarction. The overall rates of invasive coronary angiography (58.4% versus 71.6%; P<0.001) were significantly lower among the OHCA group during COVID-19 period with increased time to reperfusion (mean, 2.1 versus 1.1 hours; P=0.05) in those with ST-segment-elevation myocardial infarction. The adjusted in-hospital mortality probability increased from 27.7% in February 2020 to 35.8% in May 2020 in the COVID-19 group (P<.001). Conclusions In this national cohort of hospitalized patients with acute myocardial infarction, we observed a significant increase in incidence of OHCA during COVID-19 period paralleled with reduced access to guideline-recommended care and increased in-hospital mortality.

Expert consensus and evidence-based recommendations for the assessment of flow-mediated dilation in humans.

Endothelial dysfunction is involved in the development of atherosclerosis, which precedes asymptomatic structural vascular alterations as well as clinical manifestations of cardiovascular disease (CVD). Endothelial function can be assessed non-invasively using the flow-mediated dilation (FMD) technique. Flow-mediated dilation represents an endothelium-dependent, largely nitric oxide (NO)-mediated dilatation of conduit arteries in response to an imposed increase in blood flow and shear stress. Flow-mediated dilation is affected by cardiovascular (CV) risk factors, relates to coronary artery endothelial function, and independently predicts CVD outcome. Accordingly, FMD is a tool for examining the pathophysiology of CVD and possibly identifying subjects at increased risk for future CV events. Moreover, it has merit in examining the acute and long-term impact of physiological and pharmacological interventions in humans. Despite concerns about its reproducibility, the available evidence shows that highly reliable FMD measurements can be achieved when specialized laboratories follow standardized protocols. For this purpose, updated expert consensus guidelines for the performance of FMD are presented, which are based on critical appraisal of novel technical approaches, development of analysis software, and studies exploring the physiological principles underlying the technique. Uniformity in FMD performance will (i) improve comparability between studies, (ii) contribute to construction of reference values, and (iii) offer an easy accessible and early marker of atherosclerosis that could complement clinical symptoms of structural arterial disease and facilitate early diagnosis and prediction of CVD outcomes.

Multimorbidity and survival for patients with acute myocardial infarction in England and Wales: Latent class analysis of a nationwide population-based cohort.

BACKGROUND: There is limited knowledge of the scale and impact of multimorbidity for patients who have had an acute myocardial infarction (AMI). Therefore, this study aimed to determine the extent to which multimorbidity is associated with long-term survival following AMI. METHODS AND FINDINGS: This national observational study included 693,388 patients (median age 70.7 years, 452,896 [65.5%] male) from the Myocardial Ischaemia National Audit Project (England and Wales) who were admitted with AMI between 1 January 2003 and 30 June 2013. There were 412,809 (59.5%) patients with multimorbidity at the time of admission with AMI, i.e., having at least 1 of the following long-term health conditions: diabetes, chronic obstructive pulmonary disease or asthma, heart failure, renal failure, cerebrovascular disease, peripheral vascular disease, or hypertension. Those with heart failure, renal failure, or cerebrovascular disease had the worst outcomes (39.5 [95% CI 39.0-40.0], 38.2 [27.7-26.8], and 26.6 [25.2-26.4] deaths per 100 person-years, respectively). Latent class analysis revealed 3 multimorbidity phenotype clusters: (1) a high multimorbidity class, with concomitant heart failure, peripheral vascular disease, and hypertension, (2) a medium multimorbidity class, with peripheral vascular disease and hypertension, and (3) a low multimorbidity class. Patients in class 1 were less likely to receive pharmacological therapies compared with class 2 and 3 patients (including aspirin, 83.8% versus 87.3% and 87.2%, respectively; ß-blockers, 74.0% versus 80.9% and 81.4%; and statins, 80.6% versus 85.9% and 85.2%). Flexible parametric survival modelling indicated that patients in class 1 and class 2 had a 2.4-fold (95% CI 2.3-2.5) and 1.5-fold (95% CI 1.4-1.5) increased risk of death and a loss in life expectancy of 2.89 and 1.52 years, respectively, compared with those in class 3 over the 8.4-year follow-up period. The study was limited to all-cause mortality due to the lack of available cause-specific mortality data. However, we isolated the disease-specific association with mortality by providing the loss in life expectancy following AMI according to multimorbidity phenotype cluster compared with the general age-, sex-, and year-matched population. CONCLUSIONS: Multimorbidity among patients with AMI was common, and conferred an accumulative increased risk of death. Three multimorbidity phenotype clusters that were significantly associated with loss in life expectancy were identified and should be a concomitant treatment target to improve cardiovascular outcomes. TRIAL REGISTRATION: ClinicalTrials.gov NCT03037255.

Management errors in adults with congenital heart disease: prevalence, sources, and consequences.

Aims: Improved survival has resulted in increasing numbers and complexity of adults with congenital heart disease (ACHD). International guidelines recommend specialized care but many patients are still not managed at dedicated ACHD centres. This study analysed referral sources and appropriateness of management for patients referred to our tertiary ACHD Centre over the past 3 years. Methods and results: We compared differences in care between patients referred from paediatric/ACHD-trained vs. general adult cardiologists, according to Adherence (A) or Non-Adherence (NA) with published guidelines. Non-Adherent cases were graded according to the severity of adverse outcome or risk of adverse outcome. Of 309 consecutively referred patients (28 ± 14 years, 51% male), 134 (43%) were from general cardiologists (19% highly complex CHD) and 115 (37%) were from paediatric cardiology or ACHD specialists (33% highly complex CHD). Sixty referrals (20%) were from other medical teams and of those, 31 had been lost to follow-up. Guideline deviations were more common in referrals from general compared to CHD-trained cardiologists (P < 0.001). Of general cardiology referrals, 49 (37%) were NA; 18 had catastrophic or major complications (n = 2, 16 respectively). In contrast, only 12 (10%) of the paediatric/ACHD referrals were NA, but none of these were catastrophic and only 3 were major. Simple, moderate, and highly complex CHD patients were at increased risk of adverse outcome when not under specialized CHD cardiology care (P = 0.04, 0.009, and 0.002, respectively). Conclusion: Non-adherence with guidelines was common in the ACHD population, and this frequently resulted in important adverse clinical consequences. These problems were more likely in patients who had not been receiving specialized CHD care. Configuring healthcare systems to optimize 'whole of life' care for this growing population is essential.

Online self-assessment of cardiovascular risk using the Joint British Societies (JBS3)-derived heart age tool: a descriptive study.

OBJECTIVE: A modified version of the Joint British Societies (JBS3) 'heart age' tool was introduced online to broaden access to personalised risk assessment to the general population and encourage participation in the National Health Service (NHS) Health Check programme. This study reports on its early uptake and the profiles of those who used the self-assessment tool to determine their own cardiovascular risk. DESIGN: Observational, retrospective analysis of online tool use. SETTING: Between February and July 2015, user data collected from the NHS Choices website, where the tool was hosted, were analysed anonymously using standard analytic packages. RESULTS: The online tool landing page was viewed 1.4 million times in the first 5 months, with increased activity following limited media coverage. Of the 575 782 users completing the data journey with a valid 'heart age' result, their demographic and risk factor profiles broadly resembled the population of England, although both younger users and males (60%) were over-represented. Almost 50% and 79% did not know or enter their blood pressure or total cholesterol values, respectively. Estimated heart age was higher than chronological age for 79% of all users, and also for 69% of younger users under 40 years who are at low 10-year risk and not invited for NHS Health Checks. CONCLUSIONS: These data suggest a high level of public interest in self-assessment of cardiovascular risk when an easily understood metric is used, although a large number of users lack awareness of their own risk factors. The heart age tool was accessed by a group not easily reached by conventional approaches yet is at high cardiovascular risk and would benefit most from early and sustained risk reduction. These are both important opportunities for interventions to educate and empower the public to manage better their cardiovascular risk and promote population-level prevention.

Comparison of hospital variation in acute myocardial infarction care and outcome between Sweden and United Kingdom: population based cohort study using nationwide clinical registries.

OBJECTIVE: To assess the between hospital variation in use of guideline recommended treatments and clinical outcomes for acute myocardial infarction in Sweden and the United Kingdom. DESIGN: Population based longitudinal cohort study using nationwide clinical registries. SETTING AND PARTICIPANTS: Nationwide registry data comprising all hospitals providing acute myocardial infarction care in Sweden (SWEDEHEART/RIKS-HIA, n=87; 119,786 patients) and the UK (NICOR/MINAP, n=242; 391,077 patients), 2004-10. MAIN OUTCOME MEASURES: Between hospital variation in 30 day mortality of patients admitted with acute myocardial infarction. RESULTS: Case mix standardised 30 day mortality from acute myocardial infarction was lower in Swedish hospitals (8.4%) than in UK hospitals (9.7%), with less variation between hospitals (interquartile range 2.6% v 3.5%). In both countries, hospital level variation and 30 day mortality were inversely associated with provision of guideline recommended care. Compared with the highest quarter, hospitals in the lowest quarter for use of primary percutaneous coronary intervention had higher volume weighted 30 day mortality for ST elevation myocardial infarction (10.7% v 6.6% in Sweden; 12.7% v 5.8% in the UK). The adjusted odds ratio comparing the highest with the lowest quarters for hospitals' use of primary percutaneous coronary intervention was 0.70 (95% confidence interval 0.62 to 0.79) in Sweden and 0.68 (0.60 to 0.76) in the UK. Differences in risk between hospital quarters of treatment for non-ST elevation myocardial infarction and secondary prevention drugs for all discharged acute myocardial infarction patients were smaller than for reperfusion treatment in both countries. CONCLUSION: Between hospital variation in 30 day mortality for acute myocardial infarction was greater in the UK than in Sweden. This was associated with, and may be partly accounted for by, the higher practice variation in acute myocardial infarction guideline recommended treatment in the UK hospitals. High quality healthcare across all hospitals, especially in the UK, with better use of guideline recommended treatment, may not only reduce unacceptable practice variation but also deliver improved clinical outcomes for patients with acute myocardial infarction. Clinical trials registration Clinical trials NCT01359033.

Novel coronary heart disease risk factors at 60-64 years and life course socioeconomic position: the 1946 British birth cohort.

Social disadvantage across the life course is associated with a greater risk of coronary heart disease (CHD) and with established CHD risk factors, but less is known about whether novel CHD risk factors show the same patterns. The Medical Research Council National Survey of Health and Development was used to investigate associations between occupational socioeconomic position during childhood, early adulthood and middle age and markers of inflammation (C-reactive protein, interleukin-6), endothelial function (E-selectin, tissue-plasminogen activator), adipocyte function (leptin, adiponectin) and pancreatic beta cell function (proinsulin) measured at 60-64 years. Life course models representing sensitive periods, accumulation of risk and social mobility were compared with a saturated model to ascertain the nature of the relationship between social class across the life course and each of these novel CHD risk factors. For interleukin-6 and leptin, low childhood socioeconomic position alone was associated with high risk factor levels at 60-64 years, while for C-reactive protein and proinsulin, cumulative effects of low socioeconomic position in both childhood and early adulthood were associated with higher (adverse) risk factor levels at 60-64 years. No associations were observed between socioeconomic position at any life period with either endothelial marker or adiponectin. Associations for C-reactive protein, interleukin-6, leptin and proinsulin were reduced considerably by adjustment for body mass index and, to a lesser extent, cigarette smoking. In conclusion, socioeconomic position in early life is an important determinant of several novel CHD risk factors. Body mass index may be an important mediator of these relationships.

Body mass index and height from infancy to adulthood and carotid intima-media thickness at 60 to 64 years in the 1946 British Birth Cohort Study.

OBJECTIVE: Atherosclerosis begins early in life and obesity is a key determinant. We investigated the role of body mass index (BMI) and height from infancy to adulthood in presenting with high adulthood carotid intima-media thickness. APPROACH AND RESULTS: Odds ratios of BMI, and height Z scores at 2, 4, 6, 7, 11, 15, and 20 years, and changes between 2 and 4, 4 and 7, 7 and 15, and 15 and 20 years, for carotid intima-media thickness at 60 to 64 years in the upper quartile were estimated for 604 men and 669 women. Confounding by early-life environments, mediating by body size and cardiometabolic measures at 60 to 64 years, and effect modification were investigated. In men, there was positive association of BMI at 4 years (odds ratio, 1.256; 95% confidence interval, 1.026-1.538) and 20 years (1.282; 1.022-1.609), negative association of height at 4 years (0.780; 0.631-0.964), and negative association of height growth between 2 and 4 years (0.698; 0.534-0.913) with high carotid intima-media thickness. The childhood estimates were robust, but the estimate for BMI at 20 years was attenuated by adjustment for BMI at 60 to 64 years. The protective influence of greater early childhood height was strongest in those with the lowest systolic blood pressure at 60 to 64 years. In women, there was no pattern of association and all confidence intervals crossed 1. CONCLUSIONS: Early childhood in men might be a sensitive developmental period for atherosclerosis, in which changes in BMI and height represent 2 distinct biological mechanisms. The maintenance of healthy weight in men from adolescence onward may be a useful strategy to avoid the atherosclerotic complications of adiposity tracking.

An assessment of composite measures of hospital performance and associated mortality for patients with acute myocardial infarction. Analysis of individual hospital performance and outcome for the National Institute for Cardiovascular Outcomes Research (NICOR).

AIM: To investigate whether a hospital-specific opportunity-based composite score (OBCS) was associated with mortality in 136,392 patients with acute myocardial infarction (AMI) using data from the Myocardial Ischaemia National Audit Project (MINAP) 2008-2009. METHODS AND RESULTS: For 199 hospitals a multidimensional hospital OBCS was calculated on the number of times that aspirin, thienopyridine, angiotensin-converting enzyme inhibitor (ACEi), statin, ß-blocker, and referral for cardiac rehabilitation was given to individual patients, divided by the overall number of opportunities that hospitals had to give that care. OBCS and its six components were compared using funnel plots. Associations between OBCS performance and 30-day and 6-month all-cause mortality were quantified using mixed-effects regression analysis. Median hospital OBCS was 95.3% (range 75.8-100%). By OBCS, 24.1% of hospitals were below funnel plot 99.8% CI, compared to aspirin (11.1%), thienopyridine (15.1%), ß-blockers (14.7%), ACEi (19.1%), statins (12.1%), and cardiac rehabilitation (17.6%) on discharge. Mortality (95% CI) decreased with increasing hospital OBCS quartile at 30 days [Q1, 2.25% (2.07-2.43%) vs. Q4, 1.40% (1.25-1.56%)] and 6 months [Q1, 7.93% (7.61-8.25%) vs. Q4, 5.53% (5.22-5.83%)]. Hospital OBCS quartile was inversely associated with adjusted 30-day and 6-month mortality [OR (95% CI), 0.87 (0.80-0.94) and 0.92 (0.88-0.96), respectively] and persisted after adjustment for coronary artery catheterization [0.89 (0.82-0.96) and 0.95 (0.91-0.98), respectively]. CONCLUSIONS: Multidimensional hospital OBCS in AMI survivors are high, discriminate hospital performance more readily than single performance indicators, and significantly inversely predict early and longer-term mortality.

Impact on clinical and cost outcomes of a centralized approach to acute stroke care in London: a comparative effectiveness before and after model.

BACKGROUND: In July 2010 a new multiple hub-and-spoke model for acute stroke care was implemented across the whole of London, UK, with continuous specialist care during the first 72 hours provided at 8 hyper-acute stroke units (HASUs) compared to the previous model of 30 local hospitals receiving acute stroke patients. We investigated differences in clinical outcomes and costs between the new and old models. METHODS: We compared outcomes and costs 'before' (July 2007-July 2008) vs. 'after' (July 2010-June 2011) the introduction of the new model, adjusted for patient characteristics and national time trends in mortality and length of stay. We constructed 90-day and 10-year decision analytic models using data from population based stroke registers, audits and published sources. Mortality and length of stay were modelled using survival analysis. FINDINGS: In a pooled sample of 307 patients 'before' and 3156 patients 'after', survival improved in the 'after' period (age adjusted hazard ratio 0.54; 95% CI 0.41-0.72). The predicted survival rates at 90 days in the deterministic model adjusted for national trends were 87.2% 'before' % (95% CI 86.7%-87.7%) and 88.7% 'after' (95% CI 88.6%-88.8%); a relative reduction in deaths of 12% (95% CI 8%-16%). Based on a cohort of 6,438 stroke patients, the model produces a total cost saving of £5.2 million per year at 90 days (95% CI £4.9-£5.5 million; £811 per patient). CONCLUSION: A centralized model for acute stroke care across an entire metropolitan city appears to have reduced mortality for a reduced cost per patient, predominately as a result of reduced hospital length of stay.

Detailed assessment of the hemodynamic response to psychosocial stress using real-time MRI.

PURPOSE: To demonstrate that combining the Montreal Imaging Stress Task (MIST) with real-time cardiac magnetic resonance imaging (MRI) allows detailed assessment of the cardiovascular mental stress response. MATERIALS AND METHODS: 22 healthy volunteers (1:1 M:F, 26-64 years) underwent MRI during rest and the MIST. Real-time spiral phase contrast MR, accelerated with sensitivity encoding (SENSE) was used to assess stroke volume (SV), and radial k-t SENSE was used to assess ventricular volumes. Simultaneous heart rate (HR) and blood pressure (BP) measures allowed calculation of cardiac output (CO), systemic vascular resistance (SVR), and arterial compliance (TAC). Endocrine responses were assessed using salivary cortisol. RESULTS: In response to stress, BP increased due to increased CO and reduced TAC but not increased SVR, which fell. HR, not SV, determined CO increases. Greater BP responses occurred in men due to greater CO increases and relatively higher SVR. Older participants had greater BP responses due to greater falls in TAC. Greater cortisol response was correlated with greater falls in TAC but resting cortisol and TAC were not related. CONCLUSION: This new approach allows detailed, accurate assessment of stress physiology. Preliminary findings suggest stress exposes relationships, not seen at rest, of cardiovascular function with age, sex, and endocrine function.

Comparison of two automatic methods for the assessment of brachial artery flow-mediated dilation.

OBJECTIVES: Brachial artery flow-mediated dilation (FMD) is associated with risk factors providing information on cardiovascular prognosis. Despite the large effort to standardize the methodology, the FMD examination is still characterized by problems of reproducibility and reliability that can be partially overcome with the use of automatic systems. We developed real-time software for the assessment of brachial FMD (FMD Studio, Institute of Clinical Physiology, Pisa, Italy) from ultrasound images. The aim of this study is to compare our system with another automatic method (Brachial Analyzer, MIA LLC, IA, USA) which is currently considered as a reference method in FMD assessment. METHODS: The agreement between systems was assessed as follows. Protocol 1: Mean baseline (Basal), maximal (Max) brachial artery diameter after forearm ischemia and FMD, calculated as maximal percentage diameter increase, have been evaluated in 60 recorded FMD sequences. Protocol 2: Values of diameter and FMD have been evaluated in 618 frames extracted from 12 sequences. RESULTS: All biases are negligible and standard deviations of the differences are satisfactory (protocol 1: -0.27 ± 0.59%; protocol 2: -0.26 ± 0.61%) for FMD measurements. Analysis times were reduced (-33%) when FMD Studio is used. Rejected examinations due to the poor quality were 2% with the FMD Studio and 5% with the Brachial Analyzer. CONCLUSIONS: In conclusion, the compared systems show a optimal grade of agreement and they can be used interchangeably. Thus, the use of a system characterized by real-time functionalities could represent a referral method for assessing endothelial function in clinical trials.

Assessment of atherosclerosis: the role of flow-mediated dilatation.

Evidence suggests that endothelial dysfunction is on the causal pathway for both atherogenesis and destabilization of established plaques. In this review, the role of flow-mediated dilatation (FMD) as a non-invasive method to assess endothelial function is discussed. Technical modifications and development of analysis software have significantly improved the variability of the method. Following a strict standardized protocol enables reproducible measurements to be achieved and export of the technique from specialized laboratories to population studies and multicentre settings. Endothelial function assessed by FMD has been shown to be affected by cardiovascular risk factors, to be related to structural arterial disease and to cardiovascular outcome, validating its use for studying the pathophysiology of arterial disease. Numerous studies have also demonstrated that it is responsive to physiological and pharmacological interventions. Flow-mediated dilatation provides unique opportunities in drug development programmes to assess an early rapidly responsive signal of risk or benefit, complementing endpoints of structural arterial disease and cardiovascular outcomes that take much longer and are more expensive.

Real-time assessment of right and left ventricular volumes and function in patients with congenital heart disease by using high spatiotemporal resolution radial k-t SENSE.

PURPOSE: The purpose of this study was to compare ventricular volumes in patients with congenital heart disease measured by using (a) a cardiac gated sequence, (b) a standard real-time sequence, and (c) a radial real-time k-space and time (k-t) sensitivity encoding (SENSE) sequence. MATERIALS AND METHODS: The local research ethics committee approved this study, and written consent was obtained from all participants. Of 40 patients with congenital heart disease, ventricular volumes were measured by using the three sequences. Global image quality and motion fidelity were scored and compared with a Wilcoxon signed rank test. Image contrast, edge sharpness, and summed perimeters (the total length of the endocardial tracings for a given ventricle at systole and diastole) were quantified and compared by using paired t tests. Ventricular volumes were compared with paired t tests, Bland-Altman analysis, and correlation coefficients. RESULTS: Global image quality, motion fidelity, image contrast, edge sharpness, and summed perimeters were all greater for radial real-time k-t SENSE imaging compared with standard real-time imaging (P < .05). However, the gated acquisitions were significantly superior to radial real-time k-t SENSE (P < .05). For cardiac gated versus radial k-t real-time acquisitions, there was no difference between right ventricular (RV) volumes and ejection fraction (EF) (P > .15). There was a small difference in left ventricular (LV) end-diastolic volume (EDV) and thus, LV stroke volume and EF (P < .05). For cardiac gated versus standard real-time acquisitions, both RV and LV EDV and thus, stroke volume and EF were significantly lower (P < .05). CONCLUSION: Ventricular volumes and function can be accurately quantified by using radial k-t SENSE real-time imaging.

Non-invasive assessment of endothelial function: which technique?

OBJECTIVES: The purpose of this study was to compare 3 non-invasive techniques for assessment of endothelial function in adults and children and evaluate their utility in acute inflammation. BACKGROUND: Endothelial dysfunction is a key early event in pre-clinical atherosclerosis. Flow-mediated dilation (FMD), although the established technique, is expensive and technically demanding. Measurements of vascular responses to inhaled salbutamol by pulse wave analysis (PWA) or pulse contour analysis (PCA) are potential alternatives. METHODS: Sixteen adults (mean age 28 years, range 18 to 39) and 16 children (mean age 13 years, range 7 to 17) underwent concurrent vascular function testing on 2 occasions with ultrasound, PWA, and PCA. Eighteen men were also studied before and after typhoid vaccination. RESULTS: Reproducibility of FMD was high in adults and children (coefficient of variation [CV] = 7.1 and 6.3, respectively). Salbutamol responses were more variable with PWA (adults CV = 11.5, children CV = 17.1) and PCA particularly in children (adults CV = 18.2, children CV = 36.3). Flow-mediated dilation (p < 0.001) and PWA with salbutamol (p = 0.03) responses fell after typhoid vaccination, and PCA (p = 0.7) was unchanged. CONCLUSIONS: Vascular dysfunction during acute inflammation can be measured by FMD and by PWA with salbutamol. Flow-mediated dilation is less variable than PWA. Variability of PCA makes this technique currently unsuited to serial measures of endothelial function in children. Flow-mediated dilation remains the most reproducible method.

Endothelial function and dysfunction. Part I: Methodological issues for assessment in the different vascular beds: a statement by the Working Group on Endothelin and Endothelial Factors of the European Society of Hypertension.

An enormous number of studies in the last two decades have been devoted to investigating the role of the endothelium in cardiovascular diseases. Nonetheless, the optimal methodology for investigating the multifaceted aspects of endothelial dysfunction is still under debate. Biochemical markers, molecular genetic tests and invasive and non-invasive tools with and without pharmacological and physiological stimuli have been introduced. Furthermore newer pharmacological tools have been proposed. However, the application of these methodologies should fulfil a number of requirements in order to provide conclusive answers in this area of research. Thus, the most relevant methodological issues in the research on endothelial function and dysfunction are summarized in this paper.