Echocardiography-quantified myocardial strain-a marker of global and regional infarct size that stratifies likelihood of left ventricular thrombus

An attention-based deep learning method for right ventricular quantification using 2D echocardiography: Feasibility and accuracy

AIM

To test the feasibility and accuracy of a new attention-based deep learning (DL) method for right ventricular (RV) quantification using 2D echocardiography (2DE) with cardiac magnetic resonance imaging (CMR) as reference.

METHODS AND RESULTS

We retrospectively analyzed images from 50 adult patients (median age 51, interquartile range 32-62 42% women) who had undergone CMR within 1 month of 2DE. RV planimetry of the myocardial border was performed in end-diastole (ED) and end-systole (ES) for eight standardized 2DE RV views with calculation of areas. The DL model comprised a Feature Tokenizer module and a stack of Transformer layers. Age, gender and calculated areas were used as inputs, and the output was RV volume in ED/ES. The dataset was randomly split into training, validation and testing subsets (35, 5 and 10 patients respectively). Mean RVEDV, RVESV and RV ejection fraction (EF) were 163 ± 70 mL, 82 ± 42 mL and 51% ± 8% respectively without differences among the subsets. The proposed method achieved good prediction of RV volumes (R2  = .953, absolute percentage error [APE] = 9.75% ± 6.23%) and RVEF (APE = 7.24% ± 4.55%). Per CMR, there was one patient with RV dilatation and three with RV dysfunction in the testing dataset. The DL model detected RV dilatation in 1/1 case and RV dysfunction in 4/3 cases.

CONCLUSIONS

An attention-based DL method for 2DE RV quantification showed feasibility and promising accuracy. The method requires validation in larger cohorts with wider range of RV size and function. Further research will focus on the reduction of the number of required 2DE to make the method clinically applicable.

A systematic review and meta-analysis of transthoracic echocardiogram vs. cardiac magnetic resonance imaging for the detection of left ventricular thrombus

Transthoracic echocardiography (TTE) is the most commonly used imaging modality to diagnose left ventricular thrombus (LVT), however, cardiac magnetic resonance (CMR) remains the gold standard investigation. A comparison of the diagnostic performance between two modalities is needed to inform guidelines on a diagnostic approach towards LVT. We performed a systematic review and meta-analysis to investigate the diagnostic performance of three methods of TTE (non-contrast, contrast, and apical wall motion scoring) for the detection of LVT compared to CMR as a reference test. Studies comprising 2113 patients investigated for LVT using both TTE and CMR were included in the meta-analysis. For non-contrast TTE, pooled sensitivity and specificity were 47% [95% confidence interval (CI): 32-62%], and 98% (95% CI: 96-99%), respectively. In contrast, TTE pooled sensitivity and specificity values were 58% (95% CI: 46-69%), and 98% (95% CI: 96-99%), respectively. Apical wall motion scoring on non-contrast TTE yielded a sensitivity of 100% [95% CI: 93-100%] and a specificity of 54% (95% CI: 42-65%). The area under the curve (AUC) values from our summary receiver operating characteristic curve (SROC) for non-contrast and contrast TTE were 0.87 and 0.86 respectively, with apical wall motion studies having the highest AUC of 0.93. Despite high specificity, routine contrast and non-contrast TTE are likely to miss a significant number of LVT, making it a suboptimal screening tool. The addition of apical wall motion scoring provides a promising method to reliably identify patients requiring further investigations for LVT, whilst excluding others from unnecessary testing.

Association between the E-wave propagation index and left ventricular thrombus formation after ST-elevation myocardial infarction

OBJECTIVE

To explore the association between E-wave propagation index (EPI) as a marker of apical washout and the risk of left ventricular thrombus (LVT) formation in patients with ST-elevation myocardial infarction (STEMI).

METHODS

We performed a post-hoc analysis on 364 prospectively enrolled STEMI patients from a single-center. Non-contrast transthoracic echocardiographic examinations were performed a median of 2 days (IQR:1-3 days) after PCI. The endpoint was LVT formation, identified retrospectively. Univariable and multivariable logistic regression was applied to assess the association between EPI and LVT formation. Multivariable adjustments included LVEF, LAD culprit, prior myocardial infarction, heart rate, and early myocardial relaxation velocity. Area under receiver operating characteristic curves (AUC) was used to assess the diagnostic ability.

RESULTS AND CONCLUSIONS

Among 364 patients, 31 (8.5%) developed LVT. The mean age was 62 years, 75% were men, and mean LVEF was 46%. Patients developing LVT had increased heart rate, lower LVEF, impaired GLS, and more frequently had prior myocardial infarction. Variables associated with low values of EPI included, among others, LVEF, LV aneurysm, and GLS. EPI and LVT formation were significantly associated in the univariable model (OR = 1.87 (1.53-2.28), p < 0.001), and EPI showed an AUC of 0.90. After multivariable adjustments, EPI and LVT formation remained significantly associated (OR = 1.79 (1.42-2.27), p < 0.001). Patients with an EPI < 1.0 had a 23 times higher likelihood of LVT formation (OR = 23.41 (10.06-54.49), p < 0.001). EPI and LVT formation are strongly associated in patients with STEMI, with low values of EPI indicating a markedly increased probability of LVT formation.

Transcatheter MitraClip repair alters mitral annular geometry - device induced annular remodeling on three-dimensional echocardiography predicts therapeutic response

Background

Echocardiography (echo) is widely used to guide therapeutic decision-making for patients being considered for MitraClip. Relative utility of two- (2D) and three-dimensional (3D) echo predictors of MitraClip response, and impact of MitraClip on mitral annular geometry, are uncertain.

Methods

The study population comprised patients with advanced (> moderate) MR undergoing MitraClip. Mitral annular geometry was quantified on pre-procedural 2D transthoracic echocardiography (TTE) and intra-procedural 3D transesophageal echocardiography (TEE); 3D TEE was used to measure MitraClip induced changes in annular geometry. Optimal MitraClip response was defined as ≤mild MR on follow-up (mean 2.7 ± 2.5 months) post-procedure TTE.

Results

Eighty patients with advanced MR underwent MitraClip; 41% had optimal response (≤mild MR). Responders had smaller pre-procedural global left ventricular (LV) end-diastolic size and mitral annular diameter on 2D TTE (both p ≤ 0.01), paralleling smaller annular area and circumference on 3D TEE (both p = 0.001). Mitral annular size yielded good diagnostic performance for optimal MitraClip response (AUC 0.72, p < 0.01). In multivariate analysis, sub-optimal MitraClip response was independently associated with larger pre-procedural mitral annular area on 3D TEE (OR 1.93 per cm²/m² [CI 1.19–3.13], p = 0.007) and global LV end-diastolic volume on 2D TTE (OR 1.29 per 10 ml/m² [CI 1.02–1.63], p = 0.03). Substitution of 2D TTE derived mitral annular diameter for 3D TEE data demonstrated a lesser association between pre-procedural annular size (OR 5.36 per cm/m² [CI 0.95–30.19], p = 0.06) and sub-optimal MitraClip response. Matched pre- and post-procedural TEE analyses demonstrated MitraClip to acutely decrease mitral annular area and circumference (all p < 0.001) as well as mitral tenting height, area, and volume (all p < 0.05): Magnitude of MitraClip induced reductions in mitral annular circumference on intra-procedural 3D TEE was greater among patients with, compared to those without, sub-optimal MitraClip response (>mild MR) on followup TTE (p = 0.017); greater magnitude of device-induced annular reduction remained associated with sub-optimal MitraClip response even when normalized for pre-procedure annular circumference (p = 0.028).

Conclusions

MitraClip alters mitral annular geometry as quantified by intra-procedural 3D TEE. Pre-procedural mitral annular dilation and magnitude of device-induced reduction in mitral annular size on 3D TEE are each associated with sub-optimal therapeutic response to MitraClip.

Role of Imaging for Suspected Cardiac Thrombus

PURPOSE OF REVIEW

Cardiac thrombus formation is a frequent complication of a variety of prevalent diseases. Embolism of cardiac thrombus has the potential to result in significant morbidity and mortality from cerebrovascular and peripheral vascular events.

RECENT FINDINGS

Echocardiography is the most commonly used imaging modality for diagnosing intracardiac thrombus. However, technological advances in computed tomography and magnetic resonance imaging have allowed newer noninvasive modalities to evolve into robust tools for the clinical evaluation of patients suspected of disease. Complimentary use of these imaging techniques is crucial in the diagnosis of cardiac thrombus and initiation of anticoagulation therapy.

Incremental Utility of Right Ventricular Dysfunction in Patients With Myeloproliferative Neoplasm-Associated Pulmonary Hypertension

BACKGROUND

Myeloproliferative neoplasm (MPN) has been associated with pulmonary hypertension (PH) on the basis of small observational studies, but the mechanism and clinical significance of PH in MPN are not well established. The aims of this study were to expand understanding of PH in a well-characterized MPN cohort via study of PH-related symptoms, mortality risk, and cardiac remodeling sequalae of PH using quantitative echocardiographic methods.

METHODS

The population comprised a retrospective cohort of patients with MPN who underwent transthoracic echocardiography: Doppler-derived pulmonary arterial systolic pressure applied established cutoffs for PH (≥35 mm Hg) and advanced PH (≥50 mm Hg); right ventricular (RV) performance was assessed via conventional indices (tricuspid annular plane systolic excursion [TAPSE], S') and global longitudinal strain. Symptoms and mortality were discerned via standardized review.

RESULTS

Three hundred one patients were studied; 56% had echocardiography-demonstrated PH (20% advanced) paralleling a high prevalence (67%) among patients with invasively quantified PASP. PH was associated with adverse left ventricular (LV) remodeling indices, including increased myocardial mass and diastolic dysfunction (P ≤ .001 for all): LV mass and filling pressure (P < .01) were associated with PH independent of LV ejection fraction. RV dysfunction by strain and TAPSE and S' increased in relation to PH (P ≤ .001) and was about threefold greater among patients with advanced PH compared with those without PH. Patients with RV dysfunction were more likely to report dyspnea, as were those with advanced PH (P < .05). During median follow-up of 2.2 years, all-cause mortality was 27%. PH grade (hazard ratio, 1.9; 95% CI, 1.1-3.0; P = .012) and TAPSE- and S'-demonstrated RV dysfunction (hazard ratio, 3.3; 95% CI, 1.3-8.2; P = .01) were independently associated with mortality; substitution of global longitudinal strain for TAPSE and S' yielded similar associations of RV dysfunction with death (hazard ratio, 3.2; 95% CI, 1.5-6.7; P = .003) independent of PH.

CONCLUSIONS

PH is highly prevalent in patients with MPN and is linked to LV diastolic dysfunction; echocardiography-quantified RV dysfunction augments risk for mortality independent of PH.