A Shifting Paradigm: The Role of Focused Cardiac Ultrasound in Bedside Patient Assessment

The diagnostic accuracy of cardiac ultrasound for acute myocardial ischemia in the emergency department: a systematic review and meta-analysis

BACKGROUND

Chest pain is responsible for millions of visits to the emergency department (ED) annually. Cardiac ultrasound can detect ischemic changes, but varying accuracy estimates have been reported in previous studies. We synthetized the available evidence to yield more precise estimates of the accuracy of cardiac ultrasound for acute myocardial ischemia in patients with chest pain in the ED and to assess the effect of different clinical characteristics on test accuracy.

METHODS

A systematic search for studies assessing the diagnostic accuracy of cardiac ultrasound for myocardial ischemia in the ED was conducted in MEDLINE, EMBASE, CENTRAL, CINAHL, LILACS, Web of Science, two trial registries and supplementary methods, from inception to December 6th, 2022. Prospective cohort, cross-sectional, case-control studies and randomized controlled trials (RCTs) that included data on diagnostic accuracy were included. Risk of bias was assessed with the QUADAS-2 tool and a bivariate hierarchical model was used for meta-analysis with paired Forest and SROC plots used to present the results. Subgroup analyses was conducted on clinically relevant factors.

RESULTS

Twenty-nine studies were included, with 5043 patients. The overall summary sensitivity was 79.3% (95%CI 69.0-86.8%) and specificity was 87.3% (95%CI 79.9-92.2%), with substantial heterogeneity. Subgroup analyses showed increased sensitivity in studies where ultrasound was conducted at ED admission and increased specificity in studies that excluded patients with previous heart disease, when the target condition was acute coronary syndrome, or when final chart review was used as the reference standard. There was very low certainty in the results based on serious risk of bias and indirectness in most studies.

CONCLUSIONS

Cardiac ultrasound may have a potential role in the diagnostic pathway of myocardial ischemia in the ED; however, a pooled accuracy must be interpreted cautiously given substantial heterogeneity and that important patient and test characteristics affect its diagnostic performance.

PROTOCOL REGISTRATION

PROSPERO (CRD42023392058).

Diagnostic accuracy of Point Of Care UltraSound (POCUS) in clinical practice: A retrospective, emergency department based study

AIMS

Point-of-care ultrasound (POCUS) is the acquisition and interpretation of ultrasound imaging at the bedside to solve specific clinical questions based on signs and symptoms of presentation. While several studies evaluated POCUS diagnostic accuracy for a variety of clinical pictures in the emergency department (ED), only a few data are available on POCUS diagnostic accuracy performed by physicians with different POCUS skills. The objective of this research was to evaluate the diagnostic accuracy of POCUS compared to standard diagnostic imaging in the ED.

MATERIALS AND METHODS

This was a retrospective study conducted in the ED of a third-level university hospital. Patients who underwent cardiac, thoracic, abdominal, or venous lower limb POCUS and a standard imaging examination between June 2021 and January 2022 were included.

RESULTS

1047 patients were screened, and 844 patients included. A total of 933 POCUS was included (102, 12.09%, cardiac; 466, 55.21%, thoracic; 336, 39.8%, abdominal; 29, 3.44%, lower limb venous POCUS), accounting for 2029 examinations. POCUS demonstrated 96.6% (95% CI 95.72-97.34) accuracy, 47.73 (95% CI 33.64-67.72) +LR, 0.09 (95% CI 0.06-0.12) -LR. +LR was greater than 10 for all investigations but for hydronephrosis (5.8), and -LR never exceeded 0.4.

CONCLUSIONS

POCUS exhibited high diagnostic accuracy for virtually all conditions when performed by emergency department physicians.

Point-of-Care Echocardiographic Evaluation of the Pericardium

Acute pericardial conditions, such as tamponade, are often rapidly progressive and can become life-threatening without timely diagnosis and intervention. In this review, we aim to describe bedside ultrasonographic evaluation of the pericardium and diagnostic criteria for tamponade, identify confounders in the diagnosis of pericardial tamponade, and delineate procedural details of ultrasound-guided pericardiocentesis.

Impact of an enhanced focused cardiac ultrasound on treatment changes in a population of internal medicine patients

BACKGROUND

Hospitalized patients with acute shortness of breath (SOB) could benefit from an enhanced focused cardiac ultrasound (eFoCUS) with Doppler measurements to reassess treatment and diagnosis.

METHODS

This was a retrospective observational study performed in a medical ward. Included patients were those hospitalized for acute SOB. The objectives were to assess therapeutic and diagnosis changes associated with eFoCUS. The primary endpoint of the analysis was a composite of introduction or discontinuation of diuretics, antibiotics or anticoagulation following eFoCUS.

RESULTS

Between January 2018 and July 2021, 119 patients were included, 67 women and 52 men, mean age 84 ± 11 years old. The eFoCUS was performed within a median time of 55 h (1st-3rd IQ: 21-107) following hospital admission. Overall, eFoCUS was associated with a change in diagnostic in 40 patients (34% [CI 95%: 25%-43%], p < 10-4 ) and a change in treatment in 53 patients (45% [CI 95%: 35%-54%], p < 10-4 ). Diuretics were prescribed in 94 patients before eFoCUS and in 56 after (p = 10-4 ), antibiotics in 34 before and 27 after and anticoagulation in 30 before and 40 after.

CONCLUSION

eFoCUS was associated with both therapeutic and diagnostic changes in patients with SOB. Such results should be confirmed in multicentric prospective studies.

Guidance for clinical practice using emergency and point-of-care ultrasonography

Owing to the miniaturization of diagnostic ultrasound scanners and their spread of their bedside use, ultrasonography has been actively utilized in emergency situations. Ultrasonography performed by medical personnel with focused approaches at the bedside for clinical decision-making and improving the quality of invasive procedures is now called point-of-care ultrasonography (POCUS). The concept of POCUS has spread worldwide; however, in Japan, formal clinical guidance concerning POCUS is lacking, except for the application of focused assessment with sonography for trauma (FAST) and ultrasound-guided central venous cannulation. The Committee for the Promotion of POCUS in the Japanese Association for Acute Medicine (JAAM) has often discussed improving the quality of acute care using POCUS, and the "Clinical Guidance for Emergency and Point-of-Care Ultrasonography" was finally established with the endorsement of JAAM. The background, targets for acute care physicians, rationale based on published articles, and integrated application were mentioned in this guidance. The core points include the fundamental principles of ultrasound, airway, chest, cardiac, abdominal, and deep venous ultrasound, ultrasound-guided procedures, and the usage of ultrasound based on symptoms. Additional points, which are currently being considered as potential core points in the future, have also been widely mentioned. This guidance describes the overview and future direction of ultrasonography for acute care physicians and can be utilized for emergency ultrasound education. We hope this guidance will contribute to the effective use of ultrasonography in acute care settings in Japan.

Diagnostic accuracy of point-of-care ultrasound with artificial intelligence-assisted assessment of left ventricular ejection fraction

Focused cardiac ultrasound (FoCUS) is becoming standard practice in a wide spectrum of clinical settings. There is limited data evaluating the real-world use of FoCUS with artificial intelligence (AI). Our objective was to determine the accuracy of FoCUS AI-assisted left ventricular ejection fraction (LVEF) assessment and compare its accuracy between novice and experienced users. In this prospective, multicentre study, participants requiring a transthoracic echocardiogram (TTE) were recruited to have a FoCUS done by a novice or experienced user. The AI-assisted device calculated LVEF at the bedside, which was subsequently compared to TTE. 449 participants were enrolled with 424 studies included in the final analysis. The overall intraclass coefficient was 0.904, and 0.921 in the novice (n = 208) and 0.845 in the experienced (n = 216) cohorts. There was a significant bias of 0.73% towards TTE (p = 0.005) with a level of agreement of 11.2%. Categorical grading of LVEF severity had excellent agreement to TTE (weighted kappa = 0.83). The area under the curve (AUC) was 0.98 for identifying an abnormal LVEF (<50%) with a sensitivity of 92.8%, specificity of 92.3%, negative predictive value (NPV) of 0.97 and a positive predictive value (PPV) of 0.83. In identifying severe dysfunction (<30%) the AUC was 0.99 with a sensitivity of 78.1%, specificity of 98.0%, NPV of 0.98 and PPV of 0.76. Here we report that FoCUS AI-assisted LVEF assessments provide highly reproducible LVEF estimations in comparison to formal TTE. This finding was consistent among senior and novice echocardiographers suggesting applicability in a variety of clinical settings.

Need of Point of Care Ultrasound Training in Pediatric Emergency Medicine Practice: A Wake-Up Call for the Low-Income Countries

POCUS is the acquisition, interpretation, and rapid clinical integration of ultrasonographic imaging performed by the treating physician at the patient's bedside. It is used in the field Emergency Medicine to assist in diagnosing and managing various clinical conditions ranging from undifferentiated shock, respiratory failure, and cardiac arrest, which have shown a positive impact on clinical decision-making, resulting in a decreased emergency department and hospital length of stay. POCUS is also a valuable diagnostic tool in managing pediatric patients for whom radiation exposure is a significant concern. It is used to aid in diagnosing and managing various pediatric medical and surgical emergencies. Despite the evident literature regarding the utility of POCUS in Pediatric Emergency Medicine (PEM) practice, there is a lack of specialized training for pediatric emergency physicians, especially in low-income countries. Therefore, this comment emphasizes the need for POCUS training in PEM.

Hand-held echocardiography during complex electrophysiologic procedures

Introduction

Complex electrophysiologic (EP) procedures are time consuming and open to complications. Accurate and rapid recognition of cardiac pathologies is essential before, during, and immediately after such procedures. In this study, we aimed to compare hand-held echocardiography (HHE) with standard echocardiography (SE) to determine whether HHE can be used as a practical and reliable diagnostic tool during such procedures.

Methods

One hundred consecutive patients undergoing complex EP procedures and catheter ablation were included in the study. All patients were evaluated with SE or HHE in terms of main cardiac pathologies at the beginning and immediately after the procedure. The diagnostic accuracy and evaluation time of both methods were compared at the beginning and after the procedure. The agreement between both methods was calculated.

Results

At the beginning and after the procedure, opening and evaluation times with HHE were significantly shorter than with SE (P<0.001 for all). There was significant agreement between the two methods in the diagnosis of cardiac pathologies (Agreement was 95% for minimal mild aortic regurgitation (AR), 99% for moderate/ severe AR, 93% for minimal/ mild mitral regurgitation (MR), 95% for moderate/ severe MR, 100% for pericardial effusion, and 100% for left ventricular thrombus at the beginning of the procedure).

Conclusion

With the use of HHE during complex EP procedures, cardiac pathologies can be diagnosed with similar accuracy as SE. In addition, HHE has a significant advantage over SE in terms of time to diagnosis.

Diagnostic accuracy of point-of-care ultrasound for shock: a systematic review and meta-analysis

BACKGROUND

 Circulatory failure is classified into four types of shock (obstructive, cardiogenic, distributive, and hypovolemic) that must be distinguished as each requires a different treatment. Point-of-care ultrasound (POCUS) is widely used in clinical practice for acute conditions, and several diagnostic protocols using POCUS for shock have been developed. This study aimed to evaluate the diagnostic accuracy of POCUS in identifying the etiology of shock.

METHODS

We conducted a systematic literature search of MEDLINE, Cochrane Central Register of Controlled Trials, Embase, Web of Science, Clinicaltrial.gov, European Union Clinical Trials Register, WHO International Clinical Trials Registry Platform, and University Hospital Medical Information Network Clinical Trials Registry (UMIN-CTR) until June 15, 2022. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and assessed study quality using the Quality Assessment of Diagnostic Accuracy Studies 2 tool. Meta-analysis was conducted to pool the diagnostic accuracy of POCUS for each type of shock. The study protocol was prospectively registered in UMIN-CTR (UMIN 000048025).

RESULTS

Of the 1553 studies identified, 36 studies were full-text reviewed, and 12 studies with 1132 patients were included in the meta-analysis. Pooled sensitivity and specificity were 0.82 [95% confidence interval (CI) 0.68-0.91] and 0.98 [95% CI 0.92-0.99] for obstructive shock, 0.78 [95% CI 0.56-0.91] and 0.96 [95% CI 0.92-0.98] for cardiogenic shock, 0.90 [95% CI 0.84-0.94] and 0.92 [95% CI 0.88-0.95] for hypovolemic shock, and 0.79 [95% CI 0.71-0.85] and 0.96 [95% CI 0.91-0.98] for distributive shock, respectively. The area under the receiver operating characteristic curve for each type of shock was approximately 0.95. The positive likelihood ratios for each type of shock were all greater than 10, especially 40 [95% CI 11-105] for obstructive shock. The negative likelihood ratio for each type of shock was approximately 0.2.

CONCLUSIONS

 The identification of the etiology for each type of shock using POCUS was characterized by high sensitivity and positive likelihood ratios, especially for obstructive shock.

Machine learning for the real-time assessment of left ventricular ejection fraction in critically ill patients: a bedside evaluation by novices and experts in echocardiography

BACKGROUND

Machine learning algorithms have recently been developed to enable the automatic and real-time echocardiographic assessment of left ventricular ejection fraction (LVEF) and have not been evaluated in critically ill patients.

METHODS

Real-time LVEF was prospectively measured in 95 ICU patients with a machine learning algorithm installed on a cart-based ultrasound system. Real-time measurements taken by novices (LVEF_Nov) and by experts (LVEF_Exp) were compared with LVEF reference measurements (LVEF_Ref) taken manually by echo experts.

RESULTS

LVEF_Ref ranged from 26 to 80% (mean 54 ± 12%), and the reproducibility of measurements was 9 ± 6%. Thirty patients (32%) had a LVEF_Ref < 50% (left ventricular systolic dysfunction). Real-time LVEF_Exp and LVEF_Nov measurements ranged from 31 to 68% (mean 54 ± 10%) and from 28 to 70% (mean 54 ± 9%), respectively. The reproducibility of measurements was comparable for LVEF_Exp (5 ± 4%) and for LVEF_Nov (6 ± 5%) and significantly better than for reference measurements (p < 0.001). We observed a strong relationship between LVEF_Ref and both real-time LVEF_Exp (r = 0.86, p < 0.001) and LVEF_Nov (r = 0.81, p < 0.001). The average difference (bias) between real time and reference measurements was 0 ± 6% for LVEF_Exp and 0 ± 7% for LVEF_Nov. The sensitivity to detect systolic dysfunction was 70% for real-time LVEF_Exp and 73% for LVEF_Nov. The specificity to detect systolic dysfunction was 98% both for LVEF_Exp and LVEF_Nov.

CONCLUSION

Machine learning-enabled real-time measurements of LVEF were strongly correlated with manual measurements obtained by experts. The accuracy of real-time LVEF measurements was excellent, and the precision was fair. The reproducibility of LVEF measurements was better with the machine learning system. The specificity to detect left ventricular dysfunction was excellent both for experts and for novices, whereas the sensitivity could be improved.

TRIAL REGISTRATION

NCT05336448. Retrospectively registered on April 19, 2022.

Focused Cardiac Ultrasound to Guide the Diagnosis of Heart Failure in Pregnant Women in India

BACKGROUND

Cardiac complications are a leading cause of maternal death. Cardiac imaging with echocardiography is important for prompt diagnosis, but it is not available in many low-resource settings. The aim of this study was to determine whether focused cardiac ultrasound performed by trained obstetricians and interpreted remotely by experts can identify cardiac abnormalities in pregnant women in low-resource settings.

METHODS

A cross-sectional study was conducted among 301 pregnant and postpartum women recruited from 10 hospitals across three states in India. Twenty-two obstetricians were trained in image acquisition using a portable cardiac ultrasound device following a simplified protocol adapted from focus-assessed transthoracic echocardiography protocol. It included parasternal long-axis, parasternal short-axis, and apical four-chamber views on two-dimensional and color Doppler. Independent image interpretation was performed remotely by two experts, in the United Kingdom and India, using a standard semiquantitative assessment protocol. Interrater agreement between the experts was examined using Cohen's κ. Diagnostic accuracy of the method was examined in a subsample for whom both focused and conventional scans were available.

RESULTS

Cardiac abnormalities identified using the focused method included valvular abnormalities (27%), rheumatic heart disease (6.6%), derangements in left ventricular size (4.7%) and function (22%), atrial dilatation (19.5%), and pericardial effusion (30%). There was substantial agreement on the cardiac parameters between the two experts, ranging from 93.6% (κ = 0.84) for left ventricular ejection fraction to 100% (κ = 1) for valvular disease. Image quality was graded as good in 79% of parasternal long-axis, 77% of parasternal short-axis and 64% of apical four-chamber views. The chance-corrected κ coefficients indicated fair to moderate agreement (κ = 0.28-0.51) for the image quality parameters. There was good agreement on diagnosis between the focused method and standard echocardiography (78% agreement), compared in 36 participants.

CONCLUSIONS

The focused method accurately identified cardiac abnormalities in pregnant women and could be used for screening cardiac problems in obstetric settings.

Point-of-care ultrasound in pediatric nephrology

Point-of-care ultrasound (POCUS) has evolved in recent years in clinical practice, helping in early bedside diagnosis of important etiologies. Many medical schools and training programs are integrating POCUS into their curriculum. Especially with the technological advances of newer handheld ultrasound devices, POCUS has now become a component adjunct to clinical examination, in the clinic and bedside in critical care units. The diagnostic utility of POCUS lies both in early identification of critical kidney disease, and also extra-renal pathologies from a focused cardiac ultrasound, lung ultrasound, and integrated fluid assessment. There is a need to incorporate POCUS in training in pediatric nephrology and establish competency standard criteria. This review shall cover how POCUS helps in enhancing patient care in pediatric kidney disorders and critical children, and the recent advances.

Point-of-Care Ultrasound (POCUS) as an Extension of the Physical Examination in Patients with Bacteremia or Candidemia

Background: In general, transthoracic echocardiography (TTE) is the first diagnostic test used for patients with bacteremia or candidemia and clinical signs of Infective Endocarditis (IE). Point-of-care ultrasound (POCUS) may be used in addition to physical examination for the detection of structural heart disease and valve abnormalities. Objective: To determine the diagnostic accuracy of POCUS for the detection of signs suggestive of IE, including vegetation, valvular regurgitation, structural heart disease, hepatomegaly, splenomegaly and septic embolisms, in patients with bacteremia or candidemia. Design: Observational, cross-sectional, multicenter study using convenience sampling. Setting: Six Spanish academic hospitals. Patients: Adult patients with bacteremia or candidemia between 1 February 2018 and 31 December 2020. Measurements: The reference test, to evaluate vegetation, valvular regurgitation and structural heart disease, was transesophageal echocardiography (TEE). For patients who did not undergo TEE, transthoracic echocardiography (TTE) was considered the reference test. POCUS was performed by internists, while conventional echocardiography procedures were performed by cardiologists. Results: In 258 patients, for the detection of valvular vegetation, POCUS had sensitivity, specificity, and positive and negative predictive values of 77%, 94%, 82% and 92%, respectively. For valvular regurgitation (more than mild), sensitivity was ≥76% and specificity ≥85%. Sensitivity values for the detection of hepatomegaly and splenomegaly were 92% and 92%, respectively, while those for specificity were 96% and 98%. Conclusion: POCUS could be a valuable tool, as a complement to physical examination, at the hospital bedside for patients with bacteremia or candidemia, helping to identify signs suggestive of IE.

The Parasternal Long Axis View in Isolation: Is it Good Enough?

BACKGROUND

Focused cardiac ultrasound (FOCUS) is a vital tool to evaluate patients at the bedside, but its use can be limited by patient habitus, sonographer skill, and time to perform the examination.

OBJECTIVE

Our primary goal was to determine the diagnostic accuracy of the parasternal long axis (PSLA) view in isolation for identifying pericardial effusion, left ventricular (LV) dysfunction, and right ventricular (RV) dilatation compared with a four-view FOCUS examination.

METHODS

This was a retrospective study looking at FOCUS images. Examinations were blinded and randomized for review by point-of-care ultrasound faculty. The primary objective was measured by comparing ultrasound findings on PSLA view in isolation with findings on a full four-view FOCUS examination, which served as the criterion standard. Sensitivity and specificity were calculated.

RESULTS

Of 100 FOCUS examinations; 36% were normal, 16% had a pericardial effusion, 41% had an LV ejection fraction < 50%, and 7% had RV dilatation. Sensitivity and specificity for identifying pericardial effusion, LV dysfunction, and RV dilatation were 81% (confidence interval [CI] 0.54-0.95) and 98% (95% CI 0.91-0.99), 100% (95% CI 0.88-1) and 91% (95% CI 0.80-0.97), and 71% (95% CI 0.30-0.94) and 99% (95% CI 0.93-1), respectively. All moderate to large effusions were identified correctly. Overall, there were only four clinically significant disagreements between PSLA alone and the four-view interpretations.

CONCLUSIONS

In isolation, the PSLA view was highly sensitive and specific for identifying LV ejection fraction and moderate to large pericardial effusions. It was highly specific for identifying RV dilatation, but had only moderate sensitivity.

Echocardiographic Assessment of Patients with Pulmonary Tumor Thrombotic Microangiopathy First Diagnosed in the Emergency Department

Pulmonary tumor thrombotic microangiopathy (PTTM) is a fatal disease that obstructs pulmonary vessels, leading to pulmonary hypertension (PH) and right-sided heart failure causing rapid progressive dyspnea in patients with cancer. This retrospective chart review involved nine patients with PTTM who were first clinically diagnosed in a tertiary emergency department (ED) between January 2015 and June 2021. They underwent laboratory tests, chest radiography, chest computed tomography (CT), and echocardiography. All patients presented with severe and rapidly progressive dyspnea within a few days, a high oxygen demand. The right ventricle (RV): left ventricle ratio was >1 on chest CT, and no life-threatening pulmonary thromboembolism (PTE) was observed. Echocardiographic findings indicated that all patients had moderate-to-severe RV dilatation with a D-shaped LV. The median tricuspid regurgitation maximum velocity was 3.8 m/s, and the median RV systolic pressure was 63 mmHg, indicating severe PH. The median value of tricuspid annular plane systolic excursion was 15 mm, showing a decrease in RV systolic function, and McConnell’s sign was observed in five patients. Two patients immediately underwent chemotherapy and are currently alive. PTTM should be suspected and evaluated using echocardiography in patients with cancer presenting to the ED with acute dyspnea and RV failure without PTE.