Improved detection of left ventricular thrombi and spontaneous echocontrast by tissue harmonic imaging in patients with myocardial infarction

The prevalence, predictors, and outcomes of spontaneous echocardiographic contrast or left ventricular thrombus in patients with HFrEF

Aims

This study aimed to determine prevalence, predictors, and association with ischaemic stroke risk of spontaneous echocardiographic contrast (SEC) or left ventricular thrombus (LVT) in patients with heart failure with reduced ejection fraction (HFrEF).

Methods and results

Clinical, echocardiographic, and follow‐up data from January 2009 through February 2019 were retrospectively extracted from electronic medical records of patients with heart failure with left ventricular ejection fraction < 40% by echocardiography on admission, with follow‐up to February 2020. Of 9485 consecutive patients with HFrEF, 123 (1.3%) presented LVT and 331 (3.5%) presented SEC. Patients with vs. those without SEC/LVT had larger left ventricular end‐diastolic volume (199.5 ± 77.7 vs. 165.8 ± 61.3 mL, P < 0.001), lower left ventricular ejection fractions (29.5 ± 7.0% vs. 33.7 ± 5.5%, P < 0.001), and more often ischaemic cardiomyopathy, apical aneurysm, chronic kidney diseases, and smoking habit. In Cox regression analysis, SEC and LVT were independent predictors for ischaemic stroke occurrence [hazard ratio (HR) = 2.40, 95% confidence interval (CI): 1.74–3.31; HR = 4.52, 95% CI: 2.77–7.40, both P < 0.001]. In patients with those without SEC or LVT, stroke risk was higher among those not on anticoagulants (HR = 2.55, 95% CI: 1.85–3.53; HR = 4.71, 95% CI: 2.84–7.81, both P < 0.001), but similar among those on anticoagulants (P > 0.05). In patients with sinus rhythm, the associations between SEC/LVT and ischaemic stroke persist with HRs of 2.57 (95% CI: 1.69–3.92) and 5.74 (95% CI: 3.38–9.75).

Conclusions

In patients with HFrEF, SEC was not uncommon and increased risk of ischaemic stroke as well as LVT. Anticoagulants could play a role in the reduction of stroke risk, suggesting that patients with SEC/LVT, even those in sinus rhythm, would benefit from systemic anticoagulation treatment.

Prognostic significance of spontaneous echocardiographic contrast detected by transthoracic and transesophageal echocardiography in the era of harmonic imaging

INTRODUCTION

Echocardiographic diagnosis of spontaneous intracardiac contrast is the reflection of interactions between erythrocytes and plasma proteins. Underlying conditions are associated with low blood flow velocities in the heart. We sought to determine whether spontaneous echo contrast (SEC) detected in the era of widespread use of harmonic imaging still reflects poor prognosis and risk of thromboembolism.

MATERIAL AND METHODS

We retrospectively analyzed the database of a tertiary cardiology centre echocardiographic laboratory and identified 60 patients with SEC, but without solid intracardiac structures, and subsequently selected 60 sex- and age-matched controls without SEC. Data regarding baseline characteristics, treatment and clinical course during follow-up (median: 33.5 months; 95% CI: 24.79-40) were gained based on hospital and out-patient clinic documentation and telephone interviews. The clinical end-points included: all-cause death, cardiovascular death, stroke or transient ischemic attack (TIA), pulmonary embolism, peripheral embolism and composite thromboembolic end-point.

RESULTS

We observed that in the whole study group (p = 0.0016) and in the subgroup evaluated by TTE (p = 0.005) SEC predicted higher mortality. In the group assessed by TEE, SEC correlated with higher probability of stroke or TIA (p = 0.04). By multivariate analysis, in all patients SEC was a predictor of cardiovascular death (OR = 7.63; p = 0.008) and its localization in the left atrium independently predisposed to thromboembolism (OR = 10.15; p = 0.012). Furthermore, left ventricular SEC detected by TTE also emerged as an independent determinant of higher mortality (OR = 5.26; p = 0.015).

CONCLUSIONS

Despite a lower threshold of detection using harmonic imaging SEC is still a risk factor of poor prognosis, especially when observed on transthoracic examination.

Short-lag spatial coherence imaging of cardiac ultrasound data: initial clinical results

Short-lag spatial coherence (SLSC) imaging is a novel beamforming technique that reduces acoustic clutter in ultrasound images. A clinical study was conducted to investigate clutter reduction and endocardial border detection in cardiac SLSC images. Individual channel echo data were acquired from the left ventricle of 14 volunteers, after informed consent and institutional review board approval. Paired B-mode and SLSC images were created from these data. Contrast, contrast-to-noise, and signal-to-noise ratios were measured in paired images, and these metrics were improved with SLSC imaging in most cases. Three cardiology fellows rated the visibility of endocardial segments in randomly ordered B-mode and SLSC cine loops. SLSC imaging offered 22%-33% improvement (p < 0.05) in endocardial border visibility when B-mode image quality was poor (i.e., 80% or more of the endocardial segments could not be visualized by the three reviewers). The percentage of volunteers with poor-quality images was decreased from 21% to 7% with the SLSC beamformer. Results suggest that SLSC imaging has the potential to improve clinical cardiac assessments that are challenged by clutter.