Blinded, randomized trial of sonographer versus AI cardiac function assessment.

Artificial intelligence (AI) has been developed for echocardiography1-3, although it has not yet been tested with blinding and randomization. Here we designed a blinded, randomized non-inferiority clinical trial (ClinicalTrials.gov ID: NCT05140642; no outside funding) of AI versus sonographer initial assessment of left ventricular ejection fraction (LVEF) to evaluate the impact of AI in the interpretation workflow. The primary end point was the change in the LVEF between initial AI or sonographer assessment and final cardiologist assessment, evaluated by the proportion of studies with substantial change (more than 5% change). From 3,769 echocardiographic studies screened, 274 studies were excluded owing to poor image quality. The proportion of studies substantially changed was 16.8% in the AI group and 27.2% in the sonographer group (difference of -10.4%, 95% confidence interval: -13.2% to -7.7%, P < 0.001 for non-inferiority, P < 0.001 for superiority). The mean absolute difference between final cardiologist assessment and independent previous cardiologist assessment was 6.29% in the AI group and 7.23% in the sonographer group (difference of -0.96%, 95% confidence interval: -1.34% to -0.54%, P < 0.001 for superiority). The AI-guided workflow saved time for both sonographers and cardiologists, and cardiologists were not able to distinguish between the initial assessments by AI versus the sonographer (blinding index of 0.088). For patients undergoing echocardiographic quantification of cardiac function, initial assessment of LVEF by AI was non-inferior to assessment by sonographers.

A new approach to improve the hemodynamic assessment of cardiac function independent of respiratory influence.

Cardiovascular and respiratory systems are anatomically and functionally linked; inspiration produces negative intrathoracic pressures that act on the heart and alter cardiac function. Inspiratory pressures increase with heart failure and can exceed the magnitude of ventricular pressure during diastole. Accordingly, respiratory pressures may be a confounding factor to assessing cardiac function. While the interaction between respiration and the heart is well characterized, the extent to which systolic and diastolic indices are affected by inspiration is unknown. Our objective was to understand how inspiratory pressure affects the hemodynamic assessment of cardiac function. To do this, we developed custom software to assess and separate indices of systolic and diastolic function into inspiratory, early expiratory, and late expiratory phases of respiration. We then compared cardiac parameters during normal breathing and with various respiratory loads. Variations in inspiratory pressure had a small impact on systolic pressure and function. Conversely, diastolic pressure strongly correlated with negative inspiratory pressure. Cardiac pressures were less affected by respiration during expiration; late expiration was the most stable respiratory phase. In conclusion, inspiration is a large confounding influence on diastolic pressure, but minimally affects systolic pressure. Performing cardiac hemodynamic analysis by accounting for respiratory phase yields more accuracy and analytic confidence to the assessment of diastolic function.

Relationship between extreme obesity and mortality in patients with reduced ejection fraction.

AIMS: Although obesity is associated with increased mortality, epidemiologic studies in heart failure have reported lower mortality in obese patients compared with matched nonobese patients (the 'obesity paradox'). However, the relationship between survival and extreme (morbid) obesity (BMI ≥ 40) is poorly understood. We evaluate survival in low ejection fraction patients across a range of BMI categories, including extreme obesity. METHODS: In a retrospective review, 12 181 consecutive patients receiving nuclear stress testing at a tertiary care center were stratified based on BMI and ejection fraction. Eight-year mortality data were collected using the social security death index. RESULTS: Normal ejection fraction patients (internal control, ejection fraction ≥50%) exhibited the J-shaped association between mortality and BMI that is observed in the general population. Among patients with reduced ejection fraction (<50%), survival improved as obesity increased (P < 0.0001). Those with extreme obesity had the lowest mortality (n = 1134, P < 0.05). CONCLUSION: In this cohort of reduced Ejection fraction patients, the obesity paradox was observed in all weight categories, with the highest survival of all observed in the extremely obese BMI category. This further supports hypotheses that an obesity-related physiologic phenomenon affects mortality in reduced ejection fraction patients.

Preoperative cardiac risk factors associated with in-hospital mortality in elderly patients without heart failure undergoing hip fracture surgery: a single-centre study.

INTRODUCTION: In the present study, our aim was to ascertain the preoperative cardiac risk factors related to the in-hospital mortality in the elderly patients (aged over 65 years) who required preoperative cardiology consultation for hip fracture surgery. MATERIAL AND METHODS: The present study was a retrospective, single-centre study, which enrolled consecutive elderly patients without heart failure scheduled for hip fracture surgery in our institution. In all patients, an anesthesiologist performed a detailed preoperative evaluation and decided the need for the cardiac consultation. Patients underwent preoperative cardiac evaluation by a trained cardiologist using the algorithms proposed in the recent preoperative guidelines. The in-hospital mortality was the main outcome of the study. RESULTS: In total, 277 elderly patients undergoing hip fracture surgery were enrolled in this analysis. The overall in-hospital mortality rate was 12.1% (n=30 cases). In a multivariate analysis, we found that insulin dependency, cancer, urea, presence of atrial fibrillation (AF) (OR: 3.906; 95% CI 1.470 to 10.381; p=0.006) and pulmonary artery systolic pressure (PASP) (OR: 1.057; 95% CI 1.016 to 1.100; p=0.006) were the predictors of in-hospital mortality. The receiver operating characteristic curve analysis revealed that the optimal value of PASP in predicting the in-hospital mortality was 35 mm Hg (area under the curve=0.71; 95% CI 0.60 to 0.81, p<0.001) with sensitivity of 87.7% and specificity of 59.5%. CONCLUSION: The present research found that the preoperative cardiac risk factors, namely AF and PASP, might be associated with increased in-hospital mortality in elderly patients without heart failure undergoing hip fracture surgery.

Hemodynamic assessment of diastolic function for experimental models.

Traditionally, the evaluation of cardiac function has focused on systolic function; however, there is a growing appreciation for the contribution of diastolic function to overall cardiac health. Given the emerging interest in evaluating diastolic function in all models of heart failure, there is a need for sensitivity, accuracy, and precision in the hemodynamic assessment of diastolic function. Hemodynamics measure cardiac pressures in vivo, offering a direct assessment of diastolic function. In this review, we summarize the underlying principles of diastolic function, dividing diastole into two phases: 1) relaxation and 2) filling. We identify parameters used to comprehensively evaluate diastolic function by hemodynamics, clarify how each parameter is obtained, and consider the advantages and limitations associated with each measure. We provide a summary of the sensitivity of each diastolic parameter to loading conditions. Furthermore, we discuss differences that can occur in the accuracy of diastolic and systolic indices when generated by automated software compared with custom software analysis and the magnitude each parameter is influenced during inspiration with healthy breathing and a mild breathing load, commonly expected in heart failure. Finally, we identify key variables to control (e.g., body temperature, anesthetic, sampling rate) when collecting hemodynamic data. This review provides fundamental knowledge for users to succeed in troubleshooting and guidelines for evaluating diastolic function by hemodynamics in experimental models of heart failure.

A novel index equivalent to the myocardial performance index for right ventricular functional assessment in children and adolescent patients.

The aims of the present study were to develop and check the utility and feasibility of a novel right ventricular (RV) functional index (RV angular velocity; RVω, s-1) derived from the angular velocity in harmonic oscillator kinematics obtained from the RV pressure waveform. We hypothesized that RVω reflects the myocardial performance index (MPI), which represents global RV function. A total of 132 consecutive patients, ranging in age from 3 months to 34 years with various cardiac diseases were included in this prospective study. RVω was defined as the difference between the peak derivative of pressure (dP/dt_max - dP/dt_min) divided by the difference between the maximum and minimum pressure (Pmax - Pmin). RVω showed significant negative correlations with the pulsed-wave Doppler-derived myocardial performance index (PWD-MPI) and the tissue Doppler imaging-derived MPI (TDI-MPI) (r = -0.52 and -0.51, respectively; both p < 0.0001). RVω also showed significant positive correlations with RV fractional area change (RVFAC) and RV ejection fraction (RVEF) (r = 0.41 and 0.39, respectively; both p < 0.0001), as well as a significant negative correlation with tricuspid E/e' (r = -0.19, p = 0.0283). The clinical feasibility and utility of RVω for assessing global RV performance, incorporating both systolic and diastolic function, were demonstrated.

R-Wave Modified Tissue Doppler Imaging Myocardial Performance Index for the Assessment of Cardiac Function in Children with Congestive Heart Failure: A Feasibility Study.

BACKGROUND The aim of this study was to evaluate the feasibility of an R-wave modified tissue Doppler imaging (TDI) myocardial performance index (MPI), or MPI TDI-R, for the assessment of cardiac function in children with congestive heart failure (CHF). MATERIAL AND METHODS Forty children with CHF and 40 normal children were evaluated using the modified pediatric Ross heart failure grading system. TDI recorded the spectrum of diastolic function at the mitral valve annulus to measure the MPI. Twelve-lead electrocardiogram (ECG) measured the R-wave in the QRS complex, resulting in the modified MPI TDI-R. Correlation between the MPI TDI-R, other echocardiographic indices, and the Ross heart failure grades were analyzed, with reproducibility analysis. RESULTS Compared with normal children, the MPI TDI and MPI TDI-R were significantly increased in the pediatric CHF group (P<0.01). The MPI TDI-R was significantly correlated with other indices of cardiac function and Ross grading for CHF in children (r=0.769). The MPI TDI-R showed good correlation with the findings of the MPI TDI, calculated by traditional methods. Receiver-operating characteristic (ROC) curve analysis showed that the MPI TDI-R had a sensitivity of 67.5%, and a specificity of 97.5%. The reproducibility of the MPI TDI-R was confirmed to be superior when compared with the non-modified MPI TDI. CONCLUSIONS This feasibility study showed that the modified MPI TDI-R, formed by combining the MPI TDI with synchronous surface ECG measurements, was simple to perform, reproducible, and provided a specific index for the assessment of cardiac function in children with CHF.

Cardiovascular Tests for Risk Assessment in Asymptomatic Adults and Implications for Pilots.

BACKGROUND: This study aims to examine which marker or testing protocols have been suggested for cardiovascular disease (CVD) risk assessment in asymptomatic populations, at which CVD risk level, and how this can be implemented for CVD risk assessment in pilot populations. METHODS: A systematic search was performed using Systematic Reviews Subset on PubMed; the OvidSP interface, including all EBM reviews and EMBASE databases; and the G-I-N International Guideline Library. From each recommendation, we extracted data on consideration of the use of a marker or test for cardiovascular risk assessment in asymptomatic populations. RESULTS: Included were 45 guidelines, systematic reviews, or meta-analyses relevant to cardiovascular risk assessment in asymptomatic populations. The majority (9/12) of the citations recommend coronary artery calcium score (CACS) for CVD risk assessment in intermediate-risk (10-yr CVD risk score of 10-20%) asymptomatic adults. Other cardiac and vascular tests that may also be considered include the measurements of carotid-intima media thickness, supplemented by carotid plaque, and the ankle brachial index for prevention of peripheral artery disease and stroke. Stress myocardial perfusion scan is the potential cardiac functional test to be used with pilots with 5-yr risk of ≥15%. Among laboratory markers, only hs-CRP has a potency to be used in CVD risk assessment in intermediate-risk asymptomatic adults; however, the strength of the recommendation is not adequate. DISCUSSION: Among the cardiac and vascular testing available, CACS is the most frequently suggested test. The implications of findings for CVD risk assessment in airline pilots are highlighted in this paper.Wirawan IMA, Griffiths RF, Larsen PD. Cardiovascular tests for risk assessment in asymptomatic adults and implications for pilots. Aerosp Med Hum Perform. 2018; 89(7):648-656.

Prognostic impact of reducing myocardial ischemia identified using ECG-gated myocardial perfusion SPECT in Japanese patients with coronary artery disease: J-ACCESS 4 study.

AIM: Whether myocardial ischemia identified using myocardial perfusion imaging (MPI) can be an alternative target of coronary revascularization to reduce the incidence of cardiac events remains unclear. METHODS AND RESULTS: This multicenter, prospective cohort study aimed to clarify the prognostic impact of reducing myocardial ischemia. Among 494 registered patients with possible or definite coronary artery disease (CAD), 298 underwent initial pharmacological stress 99mTc-tetrofosmin MPI before, and eight months after revascularization or medical therapy, and were followed up for at least one year. Among these, 114 with at least 5% ischemia at initial MPI were investigated. The primary endpoints were cardiac death, non-fatal myocardial infarction and hospitalization for heart failure. Ischemia was reduced ≥5% in 92 patients. Coronary revascularization reduced ischemia (n = 89) more effectively than medical therapy (n = 25). Post-stress cardiac function also improved after coronary revascularization. Ejection fraction significantly improved at stress (61.0% ±â€¯10.7% vs. 65.4% ±â€¯11.3%; p < 0.001) but not at rest (67.1% ±â€¯11.3% vs. 68.3% ±â€¯11.6%; p = 0.144), among patients who underwent revascularization. Rates of coronary revascularization and cardiac events among the 114 patients were significantly higher (13.6%, p = 0.035) and lower (1.1% p = 0.0053), respectively, in patients with, than without ≥5% ischemia reduction. Moreover, patients with complete resolution of ischemia at the time of the second MPI had a significantly better prognosis. CONCLUSIONS: Reducing ischemia by ≥5% and the complete resolution of ischemia could improve the prognosis of patients with stable CAD.

Laboratory mouse housing conditions can be improved using common environmental enrichment without compromising data.

Animal welfare requires the adequate housing of animals to ensure health and well-being. The application of environmental enrichment is a way to improve the well-being of laboratory animals. However, it is important to know whether these enrichment items can be incorporated in experimental mouse husbandry without creating a divide between past and future experimental results. Previous small-scale studies have been inconsistent throughout the literature, and it is not yet completely understood whether and how enrichment might endanger comparability of results of scientific experiments. Here, we measured the effect on means and variability of 164 physiological parameters in 3 conditions: with nesting material with or without a shelter, comparing these 2 conditions to a "barren" regime without any enrichments. We studied a total of 360 mice from each of 2 mouse strains (C57BL/6NTac and DBA/2NCrl) and both sexes for each of the 3 conditions. Our study indicates that enrichment affects the mean values of some of the 164 parameters with no consistent effects on variability. However, the influence of enrichment appears negligible compared to the effects of other influencing factors. Therefore, nesting material and shelters may be used to improve animal welfare without impairment of experimental outcome or loss of comparability to previous data collected under barren housing conditions.

Role of Invasive Functional Assessment in Surgical Revascularization of Coronary Artery Disease.

In patients with stable coronary artery disease, percutaneous coronary intervention is associated with improved outcomes if the lesion is deemed significant by invasive functional assessment using fractional flow reserve. Recent studies have shown that a revascularization strategy using instantaneous wave-free ratio is noninferior to fractional flow reserve in patients with intermediate-grade stenoses. The decision to perform coronary artery bypass grafting surgery is usually based on anatomic assessment of stenosis severity by coronary angiography. The data on the role of invasive functional assessment in guiding surgical revascularization are limited. In this review, we discuss the diagnostic and prognostic significance of invasive functional assessment in patients considered for coronary artery bypass grafting. In addition, we critically discuss ongoing and future clinical trials on the role of invasive functional assessment in surgical revascularization.

Assessment of right atrial function with speckle tracking echocardiography after percutaneous closure of an atrial septal defect.

INTRODUCTION: Speckle tracking echocardiography (STE) for two-dimensional (2D) strain analysis is a new tool to assess myocardial function. The aim of this study was to assess right atrial (RA) function using STE in patients with an atrial septal defect (ASD) before and one month after percutaneous closure. METHODS: We prospectively examined 32 consecutive patients (nine male, 23 female) who underwent percutaneous transcatheter closure of a secundum ASD between June 2013 and December 2015. Echocardiography was performed on admission, prior to cardiac catheterization and then one month after ASD closure. Peak global RA longitudinal strain was analyzed by 2D-STE. RESULTS: Patients' mean age was 34.6±8.2 years. The mean diameter of the occlusive devices was 18.5±7.5 mm. Right ventricular (RV) end-diastolic diameters were significantly increased but decreased significantly after ASD closure (43±5 vs. 38±4 mm, p<0.05). Left atrial (LA) diameters (40±8 vs. 37±6 mm, p<0.05) decreased significantly after the intervention, whereas left ventricular (LV) end-diastolic diameters (45±5 vs. 46±4 mm, NS) remained unchanged. Tricuspid annular plane systolic excursion increased significantly (17.6±5.4 vs. 22.3±8.1 mm, p<0.05). After closure of the defect, a significant increase was observed in longitudinal RA strain (26.5±9.6% vs. 35.3±10.5%, p<0.001). CONCLUSIONS: After percutaneous transcatheter closure of a secundum ASD, there was an increase in RA longitudinal strain. 2D-STE strain analysis appears to be helpful for the assessment of RA function and of response to correction of volume overload after percutaneous transcatheter closure of a secundum ASD.

Technological advances shed light on left ventricular cardiac disturbances in cystic fibrosis.

Cystic fibrosis (CF), the most common autosomal recessive lethal disease in Caucasians, causes chronic pulmonary disease and can lead to cor pulmonale with right ventricular dysfunction. The presence of the cystic fibrosis transmembrane conductance regulator (CFTR) in cardiac myocardia has prompted debate regarding possible defective ion channel-induced cardiomyopathy. Clinical heart disease in CF is considered rare and is restricted to case reports. It has been unclear if this is due to the lack of physiological importance of CFTR in the heart, the relatively short lifespan of those with CF, or a technical inability to detect subclinical disease. Extensive echocardiographic investigations have yielded contradictory results, leading to the dogma that left ventricular defects in CF occur secondary to lung disease. In this review, we consider why studies examining heart function in CF have not provided clarity on this topic. We then focus on data from new echocardiographic and magnetic resonance imaging technology, which are providing greater insight into cardiac function in CF and demonstrating that, in addition to secondary effects from pulmonary disease, there may be an intrinsic primary defect in the CF heart. With advancing lifespans and activity levels, understanding the risk of cardiac disease is vital to minimizing morbidity in adults with CF.

The usefulness of combined assessment of E/E' ratio and transmitral flow pattern to interpret cardiac condition.

BACKGROUND: High mitral inflow early (E) velocity to tissue Doppler E' ratio (E/E') and an E to late diastolic filling velocity ratio (E/A) are used to evaluate left ventricular (LV) diastolic function and filling pressure, but the usefulness of combined assessment of E/E' and E/A is not fully understood.　Methods: We retrospectively analyzed 1,266 patients who underwent echocardiography to assess cardiac function.　Patients were grouped based on the values of E/E' (low E/E'<15, high E/E'≥15) and E/A (low E/A≤0.8, high E/A>0.8).　Results: High E/E' with both high and low E/A groups showed lower LV ejection fraction and higher LV mass index compared to low E/E' with both high and low E/A groups.　High E/E' with both high and low E/A groups showed slower E' velocity and larger left atrial volume index compared to low E/E' with both high and low E/A groups, but high E/E' with low E/A group exhibited smaller left atrial volume index and higher pulmonary venous systolic to diastolic peak velocity ratio compared to high E/E' with high E/A group.　Moreover, high E/E' with low E/A group displayed lower tricuspid regurgitant pressure gradient than the high E/E' with high E/A group.　Conclusion: Even in the situation of high E/E', low E/A condition indicated lower LV filling pressure and controlled fluid retention.

Cost-effectiveness of diagnostic evaluation strategies for individuals with stable chest pain syndrome and suspected coronary artery disease.

PURPOSE: To determine lifetime cost-effectiveness of diagnostic evaluation strategies for individuals with stable chest pain and suspected coronary artery disease (CAD). METHODS: Exercise treadmill testing (ETT), stress echocardiography (SE), myocardial perfusion scintigraphy (MPS), coronary computed tomographic angiography (CCTA), and invasive coronary angiography (ICA) were assessed alone, or in succession to each other. RESULTS: Initial ETT followed by imaging wherein ETT was equivocal or unable to be performed appeared more cost-effective than any strategy employing initial testing by imaging. CONCLUSION: As pre-test likelihood of CAD varies, different modalities including SE, CCTA, and MPS result in improved costs and enhanced effectiveness.

Highly-accelerated self-gated free-breathing 3D cardiac cine MRI: validation in assessment of left ventricular function.

OBJECTIVE: This work presents a highly-accelerated, self-gated, free-breathing 3D cardiac cine MRI method for cardiac function assessment. MATERIALS AND METHODS: A golden-ratio profile based variable-density, pseudo-random, Cartesian undersampling scheme was implemented for continuous 3D data acquisition. Respiratory self-gating was achieved by deriving motion signal from the acquired MRI data. A multi-coil compressed sensing technique was employed to reconstruct 4D images (3D+time). 3D cardiac cine imaging with self-gating was compared to bellows gating and the clinical standard breath-held 2D cine imaging for evaluation of self-gating accuracy, image quality, and cardiac function in eight volunteers. Reproducibility of 3D imaging was assessed. RESULTS: Self-gated 3D imaging provided an image quality score of 3.4 ± 0.7 vs 4.0 ± 0 with the 2D method (p = 0.06). It determined left ventricular end-systolic volume as 42.4 ± 11.5 mL, end-diastolic volume as 111.1 ± 24.7 mL, and ejection fraction as 62.0 ± 3.1%, which were comparable to the 2D method, with bias ± 1.96 × SD of -0.8 ± 7.5 mL (p = 0.90), 2.6 ± 3.3 mL (p = 0.84) and 1.4 ± 6.4% (p = 0.45), respectively. CONCLUSION: The proposed 3D cardiac cine imaging method enables reliable respiratory self-gating performance with good reproducibility, and provides comparable image quality and functional measurements to 2D imaging, suggesting that self-gated, free-breathing 3D cardiac cine MRI framework is promising for improved patient comfort and cardiac MRI scan efficiency.

A Novel Method for Estimating Myocardial Strain: Assessment of Deformation Tracking Against Reference Magnetic Resonance Methods in Healthy Volunteers.

We developed a novel method for tracking myocardial deformation using cardiac magnetic resonance (CMR) cine imaging. We hypothesised that circumferential strain using deformation-tracking has comparable diagnostic performance to a validated method (Displacement Encoding with Stimulated Echoes- DENSE) and potentially diagnostically superior to an established cine-strain method (feature-tracking). 81 healthy adults (44.6 ± 17.7 years old, 47% male), without any history of cardiovascular disease, underwent CMR at 1.5 T including cine, DENSE, and late gadolinium enhancement in subjects >45 years. Acquisitions were divided into 6 segments, and global and segmental peak circumferential strain were derived and analysed by age and sex. Peak circumferential strain differed between the 3 groups (DENSE: -19.4 ± 4.8%; deformation-tracking: -16.8 ± 2.4%; feature-tracking: -28.7 ± 4.8%) (ANOVA with Tukey post-hoc, F-value 279.93, p < 0.01). DENSE and deformation-tracking had better reproducibility than feature-tracking. Intra-class correlation co-efficient was >0.90. Larger magnitudes of strain were detected in women using deformation-tracking and DENSE, but not feature-tracking. Compared with a reference method (DENSE), deformation-tracking using cine imaging has similar diagnostic performance for circumferential strain assessment in healthy individuals. Deformation-tracking could potentially obviate the need for bespoke strain sequences, reducing scanning time and is more reproducible than feature-tracking.

Speckle tracking echocardiography in the critically ill: enticing research with minimal clinical practicality or the answer to non-invasive cardiac assessment?

Echocardiography is developing rapidly. Speckle tracking echocardiography is the latest semi-automatic tool that has potential to quantitatively describe cardiac dysfunction that may be unrecognised by conventional echocardiography. It is a non-Doppler, angle-independent, feasible and reproducible method to evaluate myocardial function in both non-critically ill and critically ill populations. Increasingly it has become a standard measure of both left and right ventricle function in specific patient groups, e.g. chemotherapy-induced cardiomyopathy or pulmonary hypertension. To date there are few studies in the critically ill, predominantly in sepsis, yet all describe dysfunction beyond standard measures. Other areas of interest include heart-lung interactions, right ventricle function and twist and torsion of the heart. A word of caution is required, however, in that speckle tracking echocardiography is far from perfect and is more challenging, particularly in the critically ill, than implied by many published studies. It takes time to learn and perform and most values are not validated, particularly in the critically ill. We should be cautious in accepting that the latest software used in cardiology cohorts will automatically be the answer in the critically ill. Even with these limitations the technology is enticing and results fascinating. We are uncovering previously undescribed dysfunction and although it currently is essentially a research-based activity, there is great promise as a clinical tool as echocardiography analysis becomes more automated, and potentially speckle tracking echocardiography could help describe cardiac function in critical illness more accurately than is possible with current techniques.

The patient with left ventricular systolic dysfunction now and in the future.

This review provides a concise overview of the current understanding of chronic heart failure, focusing on the landmark clinical trials that form the basis of clinical management of patients with left ventricular systolic dysfunction.