Contrast-Enhanced Echocardiographic Measurement of Left Ventricular Wall Thickness in Hypertrophic Cardiomyopathy: Comparison with Standard Echocardiography and Cardiac Magnetic Resonance

Myocardial perfusion improvement and mechanism after percutaneous intramyocardial septal radiofrequency ablation in obstructive hypertrophic cardiomyopathy: a study of myocardial contrast echocardiography

The data on myocardial perfusion of the percutaneous intramyocardial septal radiofrequency ablation (PIMSRA) for obstructive hypertrophic cardiomyopathy (HOCM) are still lacking, although PIMSRA have been proved to be of great safety and efficacy. The aim of this study was to quantitatively analyze the changes in myocardial perfusion after PIMSRA using myocardial contrast echocardiography (MCE). 27 HOCM patients treated with PIMSRA were retrospectively analyzed, and their echocardiographic parameters and perfusion parameters of MCE were collected before and 12 months after PIMSRA. A reperfusion curve was used to quantify microvascular blood volume (A), microvascular flux rate (β), and microvascular blood flow (MBF) of each segment. Then the value difference (Δ) of parameters between post- and pre-operation were calculated. Finally, the correlation between the changes in MBF and in each echocardiographic parameter was analyzed. (1) Compared with baseline, the global A, β and MBF were significantly increased in HOCM patients after PIMSRA (all P < 0.001). The β, MBF were increased in the interventricular septum (P < 0.001, respectively), and the A, β, MBF were increased in the left ventricular wall (all P < 0.001). (2) Correlation analysis showed that the ΔMBF of interventricular septum was mainly negatively correlated with the maximum interventricular septum thickness (ΔIVSTmax, r=-0.670, P < 0.001), mean interventricular septum thickness (ΔIVSTmean, r=-0.690, P < 0.001), and left ventricular mass index (ΔLVMI, r=-0.774, P < 0.001), while the ΔMBF of left ventricular wall was positively correlated with left ventricular end-diastolic volume index (ΔLVEDVI, r = 0.621, P = 0.001) and stroke volume index (ΔSVI, r = 0.810, P < 0.001). Myocardial perfusion was improved at both interventricular septum and ventricular wall in HOCM patients after PIMSRA. MCE can provide a new dimension for the efficacy evaluation to PIMSRA procedure.

Contrast Echocardiography in Heart Failure: Update 2023

PURPOSE OF REVIEW

The application of ultrasound-enhancing agents (contrast agents) has improved the accuracy and reproducibility of echocardiography. The review focuses on the currently approved and evolving indications for contrast echocardiography in patients with heart failure, specifically examining clinical studies conducted after the publication of the guidelines in 2017 and 2018.

RECENT FINDINGS

The current ASE/EACVI recommendations for contrast echocardiography are based on its accuracy and reproducibility in comparison to non-enhanced echocardiography or other imaging modalities like cardiac MRI. However, tissue characterization remains limited with contrast echocardiography. During the last few years, several studies have demonstrated the clinical impact of using contrast agents on the management of patients with heart failure. There is growing evidence on the benefit of using contrast echocardiography in critically ill patients where echocardiography without contrast agents is often suboptimal and other imaging methods are less feasible. There is no risk of worsening renal function after the administration of ultrasound-enhancing agents, and these agents can be administered even in patients with end-stage renal disease. Contrast echocardiography has become a valuable tool for first-line imaging of patients with heart failure across the spectrum of patients with chronic heart failure to critically ill patients.

Clinical phenotypic characteristics in patients carrying MYH7-R143Q mutation with hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) represents one of the most common inherited cardiac conditions, and more than 50 % have a tendency of familial aggregation. However, there is a lack of plenty pedigrees to analyze the clinical characteristics. This study collected 1023 unrelated HCM probands, conducted Sanger sequencing on whom carrying MYH7-R143Q and analyzed the clinical data. The detection rate of MYH7-R143Q was 2.54 % (26/1023). In patients with HCM carrying MYH7-R143Q, the diagnosis age is often concentrated in 31-40 years with moderate hypertrophy and fibrosis, which usually concentrate in the anterior and inferior septum of the basal and mid regions, representing moderate risk of SCD. Besides, this variant represented different genetic characteristics, including incomplete penetrance of autosomal dominant inheritance, polygenic cumulative effect and et al. It is the first time to investigate clinical phenotypes in multiple families carrying the same variant locus MYH7-R143Q, providing a theoretical basis for genetic counseling in clinical practice.

Hypertrophic Cardiomyopathy-Advances in Imaging and Diagnostic Strategies

Hypertrophic cardiomyopathy (HCM) is the most important and prevalent cardiac disease in cats. Due to the highly variable nature of HCM, a multimodal approach including physical examination, genetic evaluation, cardiac biomarkers, and imaging are all essential elements to appropriate and timely diagnosis. These foundational elements are advancing rapidly in veterinary medicine. Newer biomarkers such as galectin-3 are currently being researched and advances in tissue speckle-tracking and contrast-enhanced echocardiography are readily available. Advanced imaging techniques, such as cardiac MRI, are providing previously unavailable information about myocardial fibrosis and paving the way for enhanced diagnostic capabilities and risk-stratification in cats with HCM.

Imaging in Hypertrophic Cardiomyopathy: Beyond Risk Stratification

A multimodality imaging evaluation in hypertrophic cardiomyopathy is often used for risk stratification. Recent developments in imaging have allowed for better diagnosis, prognosis, and decision-making for a variety of therapies from medical to interventional. Echocardiography and magnetic resonance have been integral in evaluating subtype, left ventricular function, tissue characterization, left atrial measurements, valvular function, and presence of left ventricular aneurysm and outflow tract obstruction. These factors have helped to quantify risk of atrial fibrillation and determine the likely usefulness of pharmacologic therapy and septal reduction therapy. This review covers these in detail.

Ultrasound Enhancing Agents with Transthoracic Echocardiography for Maximal Wall Thickness in Hypertrophic Cardiomyopathy

Objectives

To determine whether ultrasound enhancing agent (UEA) changes maximal wall thickness (WT) in hypertrophic cardiomyopathy (HCM), and if it improves correlation with magnetic resonance imaging (MRI).

Patients and Methods

A total of 107 patients with HCM were prospectively enrolled at a single tertiary referral center between July 10, 2014, and August 31, 2017, and underwent transthoracic echocardiography (TTE) with and without UEA and MRI. Maximal WT measurements were compared, and variability among the 3 modalities was evaluated using a simple linear regression analysis and paired t tests and Bland-Altman plots. Interobserver variability for each technique was assessed.

Results

Most (63%) of cardiac imagers found UEA helpful in determining maximal WT by TTE, with 49% reporting change in WT. Of 52 patients where UEA changed WT measurement, 32 (62%) reported an increase and 20 (38%) reported a decrease in WT. The UEA did not alter the median discrepancy in WT between MRI and TTE. However, where UEA increased reported WT, the difference between MRI and TTE improved in 79% of cases (P=.001) from 2.0-0.5mm. In those with scar on MRI, UEA improved agreement of WT between TTE and MRI compared with that of TTE without UEA (79% vs 39%; P=.011). Interclass correlation coefficient for WT for TTE without UEA, with UEA, and MRI was 0.84; (95% CI, 0.61-0.92), 0.88; (95%CI, 0.82-0.92), and 0.97; (95%CI, 0.96-0.98), respectively.

Conclusion

Although use of UEA did not eliminate differences in WT discrepancy between modalities, the addition of UEA to TTE aided in WT determination and improved correlation with MRI in those with greater WT and in all patients with myocardial scars.

Cardiac Multimodality Imaging in Hypertrophic Cardiomyopathy: What to Look for and When to Image

Hypertrophic cardiomyopathy (HCM), now recognized as a common cardiomyopathy of complex genomics and pathophysiology, is defined by the presence of left ventricular hypertrophy of various morphologies and severity, significant hemodynamic consequences, and diverse phenotypic, both structural and clinical, profiles. Advancements in cardiac multimodality imaging, including echocardiography, cardiac magnetic resonance imaging, and cardiac computed tomography, with and without angiography have greatly improved the diagnosis of HCM, and enable precise measurements of cardiac mass, volume, wall thickness, function, and physiology. Multimodality imaging provides comprehensive and complementary information and hasemerged as the bedrock for the diagnosis, clinical assessment, serial monitoring, and sudden cardiac death risk stratification of patients with HCM. This review highlights the role of cardiac multimodality imaging in the modern diagnosis and management of HCM.

Assessment and Treatment for Coronary Microvascular Dysfunction by Contrast Enhanced Ultrasound

With growing evidence in clinical practice, the understanding of coronary syndromes has gradually evolved out of focusing on the well-established link between stenosis of epicardial coronary artery and myocardial ischemia to the structural and functional abnormalities at the level of coronary microcirculation, known as coronary microvascular dysfunction (CMD). CMD encompasses several pathophysiological mechanisms of coronary microcirculation and is considered as an important cause of myocardial ischemia in patients with angina symptoms without obstructive coronary artery disease (CAD). As a result of growing knowledge of the understanding of CMD assessed by multiple non-invasive modalities, CMD has also been found to be involved in other cardiovascular diseases, including primary cardiomyopathies as well as heart failure with preserved ejection fraction (HFpEF). In the past 2 decades, almost all the imaging modalities have been used to non-invasively quantify myocardial blood flow (MBF) and promote a better understanding of CMD. Myocardial contrast echocardiography (MCE) is a breakthrough as a non-invasive technique, which enables assessment of myocardial perfusion and quantification of MBF, exhibiting promising diagnostic performances that were comparable to other non-invasive techniques. With unique advantages over other non-invasive techniques, MCE has gradually developed into a novel modality for assessment of the coronary microvasculature, which may provide novel insights into the pathophysiological role of CMD in different clinical conditions. Moreover, the sonothrombolysis and the application of artificial intelligence (AI) will offer the opportunity to extend the use of contrast ultrasound theragnostics.

Recommendations for Multimodality Cardiovascular Imaging of Patients with Hypertrophic Cardiomyopathy: An Update from the American Society of Echocardiography, in Collaboration with the American Society of Nuclear Cardiology, the Society for Cardiovascular Magnetic Resonance, and the Society of Cardiovascular Computed Tomography

Hypertrophic cardiomyopathy (HCM) is defined by the presence of left ventricular hypertrophy in the absence of other potentially causative cardiac, systemic, syndromic, or metabolic diseases. Symptoms can be related to a range of pathophysiologic mechanisms including left ventricular outflow tract obstruction with or without significant mitral regurgitation, diastolic dysfunction with heart failure with preserved and heart failure with reduced ejection fraction, autonomic dysfunction, ischemia, and arrhythmias. Appropriate understanding and utilization of multimodality imaging is fundamental to accurate diagnosis as well as longitudinal care of patients with HCM. Resting and stress imaging provide comprehensive and complementary information to help clarify mechanism(s) responsible for symptoms such that appropriate and timely treatment strategies may be implemented. Advanced imaging is relied upon to guide certain treatment options including septal reduction therapy and mitral valve repair. Using both clinical and imaging parameters, enhanced algorithms for sudden cardiac death risk stratification facilitate selection of HCM patients most likely to benefit from implantable cardioverter-defibrillators.

Echocardiographic evaluation of hypertrophic cardiomyopathy: A review of up-to-date knowledge and practical tips

Hypertrophic cardiomyopathy (HCM) is the most frequent cardiac disease with genetic substrate, affecting about .2%-.5% of the population. The proper diagnosis is important for optimal management and follow-up. Echocardiography plays an essential role in the assessment of patients with HCM including diagnosis, screening, management formulation, prognosis, and follow up. It also helps to differentiate HCM from other diseases. The advancement of software and probe technology added many echo modalities and techniques that helped in refining the diagnostic and assessing the prognosis of patients with HCM. In this review, we briefly summarize how to integrate the different echocardiographic modalities to obtain comprehensive assessment supported by an updated knowledge of the latest guidelines and recently published articles. Many practical tips and tricks are included in this review to improve the diagnostic accuracy of echocardiography and minimize errors during interpretation.

Deep Learning Analysis of Echocardiographic Images to Predict Positive Genotype in Patients With Hypertrophic Cardiomyopathy

Genetic testing provides valuable insights into family screening strategies, diagnosis, and prognosis in patients with hypertrophic cardiomyopathy (HCM). On the other hand, genetic testing carries socio-economical and psychological burdens. It is therefore important to identify patients with HCM who are more likely to have positive genotype. However, conventional prediction models based on clinical and echocardiographic parameters offer only modest accuracy and are subject to intra- and inter-observer variability. We therefore hypothesized that deep convolutional neural network (DCNN, a type of deep learning) analysis of echocardiographic images improves the predictive accuracy of positive genotype in patients with HCM. In each case, we obtained parasternal short- and long-axis as well as apical 2-, 3-, 4-, and 5-chamber views. We employed DCNN algorithm to predict positive genotype based on the input echocardiographic images. We performed 5-fold cross-validations. We used 2 reference models—the Mayo HCM Genotype Predictor score (Mayo score) and the Toronto HCM Genotype score (Toronto score). We compared the area under the receiver-operating-characteristic curve (AUC) between a combined model using the reference model plus DCNN-derived probability and the reference model. We calculated the p-value by performing 1,000 bootstrapping. We calculated sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). In addition, we examined the net reclassification improvement. We included 99 adults with HCM who underwent genetic testing. Overall, 45 patients (45%) had positive genotype. The new model combining Mayo score and DCNN-derived probability significantly outperformed Mayo score (AUC 0.86 [95% CI 0.79–0.93] vs. 0.72 [0.61–0.82]; p < 0.001). Similarly, the new model combining Toronto score and DCNN-derived probability exhibited a higher AUC compared to Toronto score alone (AUC 0.84 [0.76–0.92] vs. 0.75 [0.65–0.85]; p = 0.03). An improvement in the sensitivity, specificity, PPV, and NPV was also achieved, along with significant net reclassification improvement. In conclusion, compared to the conventional models, our new model combining the conventional and DCNN-derived models demonstrated superior accuracy to predict positive genotype in patients with HCM.

Routine Use of Contrast on Admission Transthoracic Echocardiography for Heart Failure Reduces the Rate of Repeat Echocardiography during Index Admission

BACKGROUND

The authors retrospectively evaluated the impact of ultrasound enhancing agent (UEA) use in the first transthoracic echocardiographic (TTE) examination, regardless of baseline image quality, on the number of repeat TTEs and length of stay (LOS) during a heart failure (HF) admission.

METHODS

There were 9,115 HF admissions associated with admission TTE examinations over a 4-year period (5,337 men; mean age, 67.6 ± 15.0 years). Patients were grouped into those who received UEAs (contrast group) in the first TTE study and those who did not (noncontrast group). Repeat TTE examinations were classified as justified if performed for concrete clinical indications during hospitalization.

RESULTS

In the 9,115 admissions for HF (5,600 in the contrast group, 3,515 in the noncontrast group), 927 patients underwent repeat TTE studies (505 in the contrast group, 422 in the noncontrast group), which were considered justified in 823 patients. Of the 104 patients who underwent unjustified repeat TTE studies, 80 (76.7%) belonged to the noncontrast group and 24 to the contrast group. Also, UEA use increased from 50.4% in 2014 to 74.3%, and the rate of unjustified repeat studies decreased from 1.3% to 0.9%. The rates of unjustified repeat TTE imaging were 2.3% and 0.4% (in the noncontrast and contrast groups, respectively), and patients in the contrast group were less likely to undergo unjustified repeat examinations (odds ratio, 0.18; 95% CI, 0.12-0.29; P < .0001). The mean LOS was significantly lower in the contrast group (9.5 ± 10.5 vs 11.1 ± 13.7 days). The use of UEA in the first TTE study was also associated with reduced LOS (linear regression, β₁ = -0.47, P = .036), with 20% lower odds for odds of prolonged (>6 days) LOS.

CONCLUSIONS

The routine use of UEA in the first TTE examination for HF irrespective of image quality is associated with reduced unjustified repeat TTE testing and may reduce LOS during an index HF admission.

Sudden cardiac death risk in hypertrophic cardiomyopathy: comparison between echocardiography and magnetic resonance imaging

In hypertrophic cardiomyopathy (HCM) patients, left ventricular (LV) maximal wall thickness (MWT) is one of the most important factors determining sudden cardiac death (SCD) risk. In a large unselected sample of HCM patients, we aimed to simulate what changes would occur in the calculated SCD risk according to the European HCM Risk-SCD calculator when MWT measured using echocardiography was changed to MWT measured using MRI. All consecutive patients with HCM who underwent cardiac MRI were included. MWT measured with echocardiography and MRI were compared, and 5-year SCD risk according to the HCM Risk-SCD calculator was computed using four different models. The final population included 673 patients [389 (57.8%) males, median age 50 years, interquartile range (36-60)]. The median MWT was lower measured by echocardiography than by MRI [20 (17-24) mm vs 21 (18-24) mm; p < 0.0001]. There was agreement between echocardiography and MRI in the measurement of maximal LV wall thickness in 96 patients (14.3%). The largest differences between echo and MRI were - 13 mm and + 9 mm. The differences in MWT by echocardiography and MRI translated to a maximal difference of 8.33% in the absolute 5-year risk of SCD, i.e., the echocardiography-based risk was 8.33% lower than the MRI-based estimates. Interestingly, 13.7% of patients would have been reclassified into different SCD risk categories if MRI had been used to measure MWT instead of echocardiography. In conclusion, although there was high general intermodality agreement between echocardiography and MRI in the MWT measurements, the differences in MWT translated to significant differences in the 5-year risk of SCD.