Can echocardiography improve the prediction of thromboembolic risk in atrial fibrillation? Evidences and perspectives

A Review of Biomarkers for Ischemic Stroke Evaluation in Patients With Non-valvular Atrial Fibrillation

Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia worldwide and results in a significantly increased ischemic stroke (IS) risk. IS risk stratification tools are widely being applied to guide anticoagulation treatment decisions and duration in patients with non-valvular AF (NVAF). The CHA₂DS₂-VASc score is largely validated and currently recommended by renowned guidelines. However, this score is heavily dependent on age, sex, and comorbidities, and exhibits only moderate predictive power. Finding effective and validated clinical biomarkers to assist in personalized IS risk evaluation has become one of the promising directions in the prevention and treatment of NVAF. A number of studies in recent years have explored differentially expressed biomarkers in NVAF patients with and without IS, and the potential role of various biomarkers for prediction or early diagnosis of IS in patients with NVAF. In this review, we describe the clinical application and utility of AF characteristics, cardiac imaging and electrocardiogram markers, arterial stiffness and atherosclerosis-related markers, circulating biomarkers, and novel genetic markers in IS diagnosis and management of patients with NVAF. We conclude that at present, there is no consensus understanding of a desirable biomarker for IS risk stratification in NVAF, and enrolling these biomarkers into extant models also remains challenging. Further prospective cohorts and trials are needed to integrate various clinical risk factors and biomarkers to optimize IS prediction in patients with NVAF. However, we believe that the growing insight into molecular mechanisms and in-depth understanding of existing and emerging biomarkers may further improve the IS risk identification and guide anticoagulation therapy in patients with NVAF.

Predictive value of echocardiographic left atrial size for incident stoke and stroke cause mortality: a population-based study

OBJECTIVES

To investigate the associations between echocardiographic left atrial (LA) size and incident stoke and stroke cause mortality among a rural population in China.

DESIGN

A prospective study.

SETTING AND PARTICIPANTS

Based on the Northeast China Rural Cardiovascular Health Study, we selected a total of 10 041 participants aged ≥35 years who agreed to have transthoracic echocardiography at baseline and were successfully followed up for incident stoke and stroke cause mortality.

PRIMARY OUTCOME MEASURE

The outcomes were stroke and stroke cause death according to medical records and death certificates during the follow-up period.

RESULTS

LA enlargement (LAE) group had a higher prevalence of cardiovascular disease than normal LA diameter (LAD) group. After excluding individuals who had a prior stroke, subjects with LAE showed higher incident rates of stroke and its mortality in the overall and specific stratified analyses (all p<0.05). Kaplan-Meier analysis revealed that LAE could predict stroke incidence and stroke-free survival, but the association was no longer observed after the adjustment for potential confounding factors. Cox regression analysis reported that per 1 SD increment in LAD and LAD/body surface area (BSA) was associated with an increased incidence of stroke (LAD: HR=1.20, 95% CI 1.08 to 1.33, p<0.001; LAD/BSA: HR=1.22, 95% CI 1.11 to 1.35, p<0.001) and stroke cause mortality (LAD: HR=1.27, 95% CI 1.08 to 1.50, p<0.01; LAD/BSA: HR=1.41, 95% CI 1.20 to 1.65, p<0.001) in the total population, and similar trends were found in both genders (all p<0.05). LAD or LAD/BSA was related to ischaemic and haemorrhagic stroke incidence, and the risk of ischaemic and haemorrhagic stroke mortality (all p<0.05). The dose-response curves further suggested linear associations between LAD, LAD/BSA and the incidence of stroke and subsequent mortality in the general population (all p<0.05).

CONCLUSIONS

Our population-based study implied that LA size, especially LAD and LAD/BSA, might be useful echocardiographic biomarkers that had the potential to predict incident stroke and stroke cause mortality.

Right Atrial Thrombosis and Pulmonary Embolism: A Narrative Review

Prompt diagnosis of pulmonary embolism (PE) remains challenging, which often results in a delayed or inappropriate treatment of this life-threatening condition. Mobile thrombus in the right cardiac chambers is a neglected cause of PE. It poses an immediate risk to life and is associated with an unfavorable outcome and high mortality. Thrombus residing in the right atrial appendage (RAA) is an underestimated cause of PE, especially in patients with atrial fibrillation. This article reviews achievements and challenges of detection and management of the right atrial thrombus with emphasis on RAA thrombus. The capabilities of transthoracic and transesophageal echocardiography and advantages of three-dimensional and two-dimensional echocardiography are reviewed. Strengths of cardiac magnetic resonance imaging (CMR), computed tomography, and cardiac ventriculography are summarized. We suggest that a targeted search for RAA thrombus is necessary in high-risk patients with PE and atrial fibrillation using transesophageal echocardiography and/or CMR when available independently on the duration of the disease. High-risk patients may also benefit from transthoracic echocardiography with right parasternal approach. The examination of high-risk patients should involve compression ultrasonography of lower extremity veins along with the above-mentioned technologies. Algorithms for RAA thrombus risk assessment and protocols aimed at identification of patients with RAA thrombosis, who will potentially benefit from treatment, are warranted. The development of treatment protocols specific for the diverse populations of patients with right cardiac thrombosis is important.