Cardiac CT for intra-cardiac thrombus detection in embolic stroke of undetermined source (ESUS)

Complex left appendage morphology is associated with Embolic Stroke of Undetermined Source

INTRODUCTION

Variations in the left atrial appendage (LAA) morphology are associated with different embolic risk in patients with atrial fibrillation (AF). Data are scarce regarding the association between LAA morphology and Embolic stroke of undetermined source (ESUS).

PATIENTS AND METHODS

Using cardiac computed tomography (CCT) scans, LAA morphology was categorized as either chicken wing (CW), cactus, windsock, or cauliflower. Furthermore, we examined the presence of large secondary lobes arising from the main lobe, considering their existence as indicative of a complex LAA morphology. LAA morphologies were compared between ESUS (n = 134) and AF patients (n = 120); and between ESUS patients with (n = 24) and without (n = 110) subsequent AF diagnosis during long-term follow-up.

RESULTS

ESUS patients had a significantly higher prevalence of cauliflower morphology compared to AF group (52% vs 34%, respectively, p = 0.01); however, no significant difference was found between the groups when categorizing LAA morphology to either CW or non-CW. ESUS patients had significantly higher prevalence of large secondary lobes compared with AF patients (50% vs 29%, respectively, p = 0.001). When comparing ESUS patients with and without AF diagnosis during follow-up (20-48 months of follow-up, median 31 months), there were no significant differences in the prevalence of the "classical" morphologies, but large secondary lobes were significantly more prevalent among those without subsequent AF diagnosis.

CONCLUSION

ESUS patients have a high prevalence of complex LAA morphology, which might be associated with an increased risk for thrombus formation even in the absence of AF.

The Role of Multimodality Imaging in Cardiomyopathy

PURPOSE OF REVIEW

There has been increasing use of multimodality imaging in the evaluation of cardiomyopathies.

RECENT FINDINGS

Echocardiography, cardiac magnetic resonance (CMR), cardiac nuclear imaging, and cardiac computed tomography (CCT) play an important role in the diagnosis, risk stratification, and management of patients with cardiomyopathies. Echocardiography is essential in the initial assessment of suspected cardiomyopathy, but a multimodality approach can improve diagnostics and management. CMR allows for accurate measurement of volumes and function, and can easily detect unique pathologic structures. In addition, contrast imaging and parametric mapping enable the characterization of tissue features such as scar, edema, infiltration, and deposition. In non-ischemic cardiomyopathies, metabolic and molecular nuclear imaging is used to diagnose rare but life-threatening conditions such amyloidosis and sarcoidosis. There is an expanding use of CCT for planning electrophysiology procedures such as cardioversion, ablations, and device placement. Furthermore, CCT can evaluate for complications associated with advanced heart failure therapies such as cardiac transplant and mechanical support devices. Innovations in multimodality cardiac imaging should lead to increased volumes and better outcomes.

Extended Computed Tomography Angiography for the Successful Diagnosis of Cardioaortic Thrombus in Acute Ischemic Stroke and TIA: Study Protocol for a Randomized Controlled Trial

INTRODUCTION

Cardiac imaging is one of the main components of the etiological investigation of ischemic strokes. However, basic and advanced cardiac imaging remain underused in most stroke centers globally. Computed tomography angiography (CTA) of the supra-aortic and intracranial arteries is the most frequent imaging modality applied during the evaluation of patients with acute ischemic stroke to identify the presence of a large vessel occlusion. Recent evidence from retrospective observational studies has shown a high detection of cardiac thrombi, ranging from 6.6 to 17.4%, by extending a CTA a few cm below the carina to capture cardiac images. However, this approach has never been prospectively compared against usual care in a randomized controlled trial. The Extended Computed Tomography Angiography for the Successful Screening of Cardioaortic Thrombus in Acute Ischemic Stroke and TIA (DAYLIGHT) prospective, randomized, controlled trial evaluates whether an extended CTA (eCTA) + standard-of-care stroke workup results in higher detection rates of cardiac and aortic source of embolism compared to standard-of-care CTA (sCTA) + standard-of-care stroke workup.

METHODS

DAYLIGHT is a single-center, prospective, randomized, open-blinded endpoint trial, aiming to recruit 830 patients with suspected acute ischemic stroke or transient ischemic attack (TIA) being assessed under acute code stroke at the emergency department or at a dedicated urgent stroke prevention clinic. Patients are randomized 1:1 to eCTA versus sCTA. The eCTA expands image acquisition caudally, 6 cm below the carina. All patients receive standard-of-care cardiac imaging and diagnostic stroke workup. The primary efficacy endpoint is the diagnosis of a cardioaortic thrombus after at least 30 days of follow-up. The primary safety endpoint is door-to-CTA completion time. The diagnosis of a qualifying ischemic stroke or TIA is independently adjudicated by a stroke neurologist, blinded to the study arm allocation. Patients without an adjudicated ischemic stroke or TIA are excluded from the analysis. The primary outcome events are adjudicated by a board-certified radiologist with subspecialty training in cardiothoracic radiology and a cardiologist with formal training in cardiac imaging. The primary analysis is performed according to the modified intention-to-diagnose principle and without adjustment by logistic regression models. Results are presented with odds ratios and 95% confidence intervals.

CONCLUSION

The DAYLIGHT trial will provide evidence on whether extending a CTA to include the heart results in an increased detection of cardioaortic thrombi compared to standard-of-care stroke workup.

Neurologists Preferences on Basic and Advanced Cardiac Imaging Utilization in Ischemic Stroke Patients

INTRODUCTION

It is unknown how cardiac imaging studies are used by neurologists to investigate cardioembolic sources in ischemic stroke patients.

METHODS

Between August 12, 2023, and December 8, 2023, we conducted an international survey among neurologists from Europe, North America, South America, and Asia, to investigate the frequency of utilization of cardiac imaging studies for the detection of cardioembolic sources of ischemic stroke. Questions were structured into deciles of percentage utilization of transthoracic echocardiography (TTE), transesophageal echocardiography (TEE), ECG-gated cardiac computed tomography (G-CCT), and cardiac magnetic resonance imaging (CMRI). We estimated the weighted proportion (x¯) of utilization of each cardiac imaging modality, both globally and by continent. We also investigated the use of head and neck computed tomography angiography (CTA) as an emerging approach to the screening of cardioembolic sources.

RESULTS

A total of 402 neurologists from 64 countries completed the survey. Globally, TTE was the most frequently used cardiac imaging technology (x¯ = 71.2%), followed by TEE (x¯ = 15.8%), G-CCT (x¯ = 10.9%), and CMRI (x¯ = 7.7%). Findings were consistent across all continents. A total of 288 respondents routinely used a CTA in the acute ischemic stroke phase (71.6%), but the CTA included a non-gated CCT in only 15 cases (5.2%).

CONCLUSIONS

This survey suggests that basic cardiac imaging is not done in all ischemic stroke patients evaluated in 4 continents. We also found a substantially low utilization of advanced cardiac imaging studies. Easier to adopt screening methods for cardioembolic sources of embolism are needed.

Ischemic Stroke and Reduced Left Ventricular Ejection Fraction: A Multidisciplinary Approach to Optimize Brain and Cardiac Health

Reduced left ventricular ejection fraction ≤40%, a known risk factor for adverse cardiac outcomes and recurrent acute ischemic stroke, may be detected during an acute ischemic stroke hospitalization. A multidisciplinary care paradigm informed by neurology and cardiology expertise may facilitate the timely implementation of an array of proven heart failure-specific therapies and procedures in a nuanced manner to optimize brain and cardiac health.

Safety of dobutamine or adenosine stress cardiac magnetic resonance imaging in patients with left ventricular thrombus

BACKGROUND

Left ventricular (LV) thrombus formation is a common but potentially serious complication, typically occurring after myocardial infarction. Due to perceived high thromboembolic risk and lack of safety data, stress cardiac magnetic resonance (CMR) imaging especially with dobutamine is usually avoided despite its high diagnostic yield. This study aimed to investigate the characteristics, safety and outcome of patients with LV thrombus undergoing dobutamine or vasodilator stress CMR.

METHODS

Patients undergoing stress CMR with concomitant LV thrombus were retrospectively included. Risk factors, comorbidities, and previous embolic events were recorded. Periprocedural safety was assessed for up to 48 h following the examination. Major adverse cardiac events (MACE) 12 months before the diagnosis were compared to 12 months after the exam and between patients and a matched control group. Additionally, patients were followed up for all-cause mortality.

RESULTS

95 patients (78 male, 65 ± 10.7 years) were included. Among them, 43 patients underwent dobutamine (36 high-dose, 7 low-dose) and 52 vasodilator stress CMR. Periprocedural safety was excellent with no adverse events. During a period of 24 months, 27 MACE (14.7%) occurred in patients and controls with no statistical difference between groups. During a median follow-up of 33.7 months (IQR 37.6 months), 6 deaths (6.3%) occurred. Type of stress agent, thrombus mobility, or protrusion were not correlated to embolic events or death.

CONCLUSION

The addition of a stress test to a CMR exam is safe and does increase the generally high cardioembolic event rate in LV thrombus patients. Therefore, it is useful to support reperfusion decision-making.

Routine transthoracic echocardiography in ischaemic stroke or transient ischaemic attack of undetermined cause: a prospective multicentre study

BACKGROUND

Guidelines recommend routine transthoracic echocardiography (TTE) after ischaemic stroke or transient ischaemic attack of undetermined cause; yet, only limited scientific evidence exists. Therefore, we aimed to determine in these patients the prevalence of TTE-detected major cardiac sources of embolism (CSE), which are abnormalities leading to therapeutic changes.

METHODS

Six Dutch hospitals conducted a prospective observational study that enrolled patients with ischaemic stroke or transient ischaemic attack of undetermined cause. Patients underwent TTE after comprehensive diagnostic evaluation on stroke units, including blood chemistry, 12-lead electrocardiogram (ECG), ≥ 24 h continuous ECG monitoring, brain imaging and cervical artery imaging. Primary outcome measure was the proportion of patients with TTE-detected major CSE.

RESULTS

From March 2018 to October 2020, 1084 patients, aged 66.6 ± 12.5 years, were enrolled; 456 (42.1%) patients were female and 869 (80.2%) had ischaemic stroke. TTE detected major CSE in only 11 (1.0%) patients. Ten (90.9%) of these patients also had major ECG abnormalities (previous infarction, major repolarisation abnormalities, or previously unknown left bundle branch block) that would have warranted TTE assessment regardless of stroke evaluation. Such ECG abnormalities were present in 11.1% of the total study population. A single patient (0.1%) showed a major CSE despite having no ECG abnormality.

CONCLUSIONS

This multicentre cross-sectional study in patients who-after workup on contemporary stroke units-were diagnosed with ischaemic stroke or transient ischaemic attack of undetermined cause found TTE-detected major CSE in only 1% of all patients. Most of these patients also had major ECG abnormalities. These findings question the value of routine TTE assessment in this clinical setting.

Coronary Computed Tomography Angiography and Abdominal Aortic Calcification Screening among High-Risk Living Kidney Donors

BACKGROUND

A unique scanning protocol combining coronary computed tomography angiography (CTA) with routine abdominal CTA is being used at the Rabin Medical Center as a method of screening high-risk candidates for living kidney donation. We aim to evaluate the potential impact of coronary CTA on the decision regarding eligibility for kidney donation and its correlation with abdominal aortic calcification (AAC).

METHODS

CCTA and abdominal CTA results of potential living kidney donors evaluated for donation between September 2020 and November 2021 were retrieved. A retrospective analysis of the abdominal CTA was used to calculate the AAC. Patients' demographic, clinical, and imaging data were collected from the electronic files, as well as the final decision regarding eligibility for donation.

RESULTS

A total of 62 potential kidney donors were evaluated for donation using the combined scan. The mean age was 53.8 years, with male predominance (59.7%). Significant coronary artery stenosis (≥70% luminal stenosis) was present in two patients (3.2%), whereas five patients (8%) had moderate stenosis (50-69%). Thirteen patients (21%) were disqualified from donation due to moderate-to-significant coronary artery disease or abdominal atherosclerosis. The correlation between the coronary artery calcium score and the AAC was found to be positive, with a Pearson correlation coefficient of 0.88 (p < 0.001).

CONCLUSIONS

The use of coronary CTA in the evaluation of potential kidney donors may has a potential impact on the decision regarding eligibility for donation. A high correlation between the coronary artery calcium score and the AAC was found.

Massive Biventricular Thrombi in a Patient with Endometrial Adenocarcinoma Diagnosed on Computed Tomography Angiography

Biventricular thrombi are a rare clinical entity and only reported in several case reports. Given ventricular thrombi are high risk for cardioembolic events, accurate detection and therapeutic management has an important influence on clinical outcomes. We present a case of a patient with biventricular thrombi that was initially diagnosed on computed tomography angiography, emphasizing its clinical utility as a rapid, non-invasive imaging modality for early detection.

Spectral cardiac CT in acute stroke patients

Cardiac CT obtained in acute ischemic stroke patients can facilitate timely detection of cardiac sources of embolism and guide secondary prevention strategies. Spectral CT exploiting the simultaneous acquisition of separate higher-energy and lower-energy photon spectrum datasets has the potential to improve contrast between thrombi and cardiac structures. This study aimed to investigate the diagnostic value of spectral cardiac CT compared to conventional CT for the detection of cardiac thrombi in acute stroke patients. Patients with acute ischemic stroke undergoing spectral cardiac CT were retrospectively included. Conventional CT images, virtual 55 keV monoenergetic (monoE55), z-effective (zeff), and iodine density images were evaluated for the presence of thrombi. Diagnostic certainty was rated on a 5-point Likert scale. Contrast ratios were calculated for all reconstructions. 63 patients with 20 thrombi were included. Four thrombi were missed on conventional images but detected on spectral reconstructions. MonoE55 achieved the highest scores for diagnostic certainty. Contrast ratios were highest on iodine density images, followed by monoE55, conventional and zeff (p < 0.005). Spectral cardiac CT adds diagnostic benefit for the detection of intra-cardiac thrombi in acute ischemic stroke patients compared to conventional CT.

Embolic Stroke of Undetermined Source: Current Perspectives on Diagnosis, Investigations, and Management

In 2014, Hart et al. introduced the concept of "embolic stroke of undetermined source" (ESUS) to the clinical-research stroke community. The hypothesis underlying the development of the ESUS construct was that this potentially heterogenous group of stroke mechanisms were largely thromboembolic, and would thus benefit from anticoagulation over antiplatelet for secondary prevention. Since then, 2 large clinical trials have shown that, to date, there is not a clear uniform antithrombotic strategy for secondary prevention after ESUS as it was originally broadly defined. However, this work has yielded valuable information about the patient phenotypes that experience ESUS strokes, as well as hypothesis-generating substudies that have given rise to the next generation of secondary prevention trials aimed at more personalized approaches for different suspected mechanisms of embolic stroke. In parallel with the evolution of ESUS, several studies aimed at screening for atrial fibrillation in the secondary stroke prevention population have generated additional questions about the mechanistic relevance of atrial fibrillation detected after stroke, and how this should inform poststroke workup, and secondary prevention strategies. Herein, we provide a synthesis of the current understanding surrounding the patient phenotypes that experience ESUS strokes, and previous, ongoing, and anticipated clinical trials that will guide earlier and later secondary prevention strategies and poststroke cardiac investigations.