Aortic plaque in atrial fibrillation: prevalence, predictors, and thromboembolic implications

Long-term outcomes of patients with embolic stroke of undetermined source according to subtype

The prognosis of patients with embolic stroke of undetermined source (ESUS) may vary according to the underlying cause. Therefore, we aimed to divide ESUS into subtypes and assess the long-term outcomes. Consecutive patients with acute ischemic stroke who underwent a comprehensive workup, including transesophageal echocardiography and prolonged electrocardiography monitoring, were enrolled. We classified ESUS into minor cardioembolic (CE) ESUS, arteriogenic ESUS, two or more causes ESUS, and no cause ESUS. Arteriogenic ESUS was sub-classified into complex aortic plaque (CAP) ESUS and non-stenotic (< 50%) relevant artery plaque (NAP) ESUS. A total of 775 patients were enrolled. During 1286 ± 748 days follow-up, 116 major adverse cardiovascular events (MACE) occurred (4.2 events/100 patient-years). Among the ESUS subtypes, CAP ESUS was associated with the highest MACE frequency (9.7/100 patient-years, p = 0.021). Cox regression analyses showed that CAP ESUS was associated with MACE (hazard ratio 2.466, 95% confidence interval 1.305-4.660) and any stroke recurrence (hazard ratio 2.470, 95% confidence interval, 1.108-5.508). The prognosis of ESUS varies according to the subtype, with CAP ESUS having the worst prognosis. Categorizing ESUS into subtypes could improve patient care and refine clinical trials.

Atrial fibrillation: stroke prevention

Stroke prevention is central to the management of patients with atrial fibrillation (AF) which has moved towards a more holistic or integrative care approach. The published evidence suggests that management of AF patients following such a holistic approach based on the Atrial fibrillation Better Care (ABC) pathway is associated with a lower risk of stroke and adverse events. Risk assessment, re-assessment and use of direct oral anticoagulants (DOACs) are important for stroke prevention in AF. The stroke and bleeding risks of AF patients are not static and should be re-assessed regularly. Bleeding risk assessment is to address and mitigate modifiable bleeding risk factors, and to identify high bleeding risk patients for early review and follow-up. Well-controlled comorbidities and healthy lifestyles also play an important role to achieve a better clinical outcome. Digital health solutions are increasingly relevant in the diagnosis and management of patients with AF, with the potential to improve stroke prevention. In this review, we provide an update on stroke prevention in AF, including importance of holistic management, risk assessment/re-assessment, and stroke prevention for special AF populations. Evidence-based and structured management of AF patients would reduce the risk of stroke and other adverse events.

High-Risk Aortic Plaque in Atrial Fibrillation: A Therapeutic Dilemma

Atrial fibrillation (AF), a common cardiac arrhythmia, is often accompanied by aortic plaques that are associated with an increased risk of embolic events, including stroke. Evidence-based management in this population is lacking. We present a case of a 77-year-old female with new-onset AF who was found to have a high-risk aortic plaque at the level of the ascending aorta and ostium of the right coronary artery. Definitive treatment for AF, cardioversion, high-risk aortic plaque, and cardiothoracic surgery, could not be performed due to the elevated risk of ischemic stroke and embolic complications. Based on existing literature, the cardiologist and cardiothoracic surgeon collaboratively decided to treat both conditions with anticoagulation, statin, and periodic imaging surveillance of high-risk aortic plaque. The patient was successfully managed without any thromboembolic complications despite an elevated risk. This case report provides a comprehensive literature review of managing AF with high-risk aortic plaques. It delves into the integration of anticoagulation and antiplatelet agents in the dual challenge of stroke prevention in AF and mitigating embolic risks associated with aortic plaques. To date, there has been no consensus on managing AF and high-risk aortic plaques; thus, we aim to fill this gap.

Mitral annular calcification as a predictor of stroke in the multiethnic study of atherosclerosis

BACKGROUND

Mitral annular calcification (MAC) is associated with an increased risk for cardiovascular morbidity and mortality. This study provides recent data on the association between cardiac computed tomography (CT) derived MAC and 15 years of stroke risk in a racially diverse cohort.

METHODS

All multiethnic studies of atherosclerosis participants ( n  = 6814) who completed a cardiac CT at baseline were included in this analysis. MAC score was calculated from cardiac CT using the Agatston and volume score methods. Multivariable Cox proportional hazard regression models were used to compute hazard ratios for the association between MAC and stroke after adjusting for traditional cardiovascular risk factors, inflammatory markers, coronary artery calcium score, atrial fibrillation, and left atrial size.

RESULTS

Overall, 9% of participants (644/6814) had MAC at baseline. Over a surveillance period of 15 years, 304 strokes occurred, and 79% were ischemic strokes. After adjusting for age, sex, race/ethnicity, SBP, diabetes, smoking, fibrinogen, IL-6, high-sensitivity C-reactive protein, and coronary artery calcium score, baseline MAC was associated with increased risk for all strokes [hazard ratio 1.68; 95% confidence interval (CI) 1.22-2.30: P  = 0.0013]. When atrial fibrillation/flutter and left atrial size were included in the final multivariable model, MAC remained a predictor of all strokes (hazard ratio 1.93; 95% CI 1.22-3.05: P  < 0.0051) and ischemic stroke (hazard ratio 2.03; 95% CI 1.24-3.31: P  < 0.0046).

CONCLUSION

MAC is an independent predictor of long-term stroke risk in a racially diverse population beyond conventional cardiovascular risk factors and atrial fibrillation.

Acute Ischemic Stroke and Transient Ischemic Attack in ST-Segment Elevation Myocardial Infarction Patients Who Underwent Primary Percutaneous Coronary Intervention

BACKGROUND

Acute ischemic stroke (AIS) is a rare but critical complication following ST-elevation myocardial infarction (STEMI). The risk of AIS or transient ischemic attack (TIA) may be amplified by invasive procedures, including primary percutaneous coronary intervention (PCI). This study aimed to investigate the factors associated with in-hospital AIS/TIA in patients with STEMI who required primary PCI.

METHODS

We included 941 STEMI patients who underwent primary PCI and divided them into an AIS/TIA group (n = 39) and a non-AIS/TIA group (n = 902), according to new-onset AIS/TIA. The primary interest was to find the factors associated with AIS/TIA by multivariate logistic regression analysis. We also compared clinical outcomes between the AIS/TIA and non-AIS/TIA groups.

RESULTS

The incidence of in-hospital deaths was significantly higher in the AIS/TIA group (46.2%) than in the non-AIS/TIA group (6.3%) (p < 0.001). Multivariate analysis revealed that cardiogenic shock (OR 3.228, 95% CI 1.492-6.986, p = 0.003), new-onset atrial fibrillation (AF) (OR 2.280, 95% CI 1.033-5.031, p = 0.041), trans-femoral approach (OR 2.336, 95% CI 1.093-4.992, p = 0.029), use of ≥4 catheters (OR 3.715, 95% CI 1.831-7.537, p < 0.001), and bleeding academic research consortium (BARC) type 3 or 5 bleeding (OR 2.932, 95% CI 1.256-6.846, p = 0.013) were significantly associated with AIS/TIA.

CONCLUSION

In STEMI patients with primary PCI, new-onset AIS/TIA was significantly associated with cardiogenic shock, new-onset AF, trans-femoral approach, the use of ≥4 catheters, and BARC type 3 or 5 bleeding. We should recognize these modifiable and unmodifiable risk factors for AIS/TIA in the treatment of STEMI.

Coexisting of aortic arch atheroma and atrial fibrillation for short-term recurrence and poor functional outcome in acute stroke

BACKGROUND AND PURPOSE

Multiple embolic sources are sometimes observed simultaneously in patients with embolic stroke. The present study investigated the effects of coexisting aortic arch atheroma ≥ 4 mm thick and atrial fibrillation (AF) on short-term stroke recurrence and functional outcome.

METHODS

Transesophageal echocardiography (TEE) was performed in consecutive embolic stroke patients, and 395 patients were classified into 4 groups according to the presence of aortic arch atheroma ≥ 4 mm thick and AF: AF - /ARCH - group, AF + /ARCH - group, AF - /ARCH + group, and AF + /ARCH + group. In accordance with these 4 groups, we evaluated stroke recurrence and all-cause death for 3 months after stroke onset, and also evaluated the 3-month functional outcome using the modified Rankin scale (mRS).

RESULTS

Among the 128 AF patients, 39.1% also had aortic arch atheroma ≥ 4 mm thick. Of the 395 enrolled cases, the AF + /ARCH + group showed the highest frequencies of stroke recurrence and all-cause death during 3 months after onset. On multivariate analysis, stroke recurrence or all-cause death during 3 months after onset was relatively more frequent in the AF + /ARCH + group than in the AF + /ARCH - group (OR, 2.34; 95% CI, 0.82-6.69; p = 0.11), but that was not statistically significant, and poor functional outcome (mRS score 3-6) at 3 months was significantly more frequent in the AF + /ARCH + group than in the AF + /ARCH - group (OR, 2.59; 95% CI, 1.08-6.24; p = 0.0339).

CONCLUSIONS

Aortic arch atheroma concomitant with AF is not rare and appears associated with increased risks of stroke recurrence and poor functional outcome.

Ischemic Stroke Patients with Non-Valvular Atrial Fibrillation have a Risk for Aortogenic Embolizations

We have a great interest in the article in Journal of Atherosclerosis and Thrombosis by Suzuki et al. titled Complex Aortic Arch Atherosclerosis in Acute Ischemic Stroke Patients with Non-Valvular Atrial Fibrillation. The authors demonstrated that 38.7% transesophageal echocardiography-derived complex aortic arch plaques (CAPs) among 106 patients with acute ischemic strokes with atrial fibrillation (AF), suggesting that patients with acute ischemic stroke and AF often had CAPs. The atheromatous lesions at the aortic arch are one of the causes of ischemic strokes. The cause of acute ischemic strokes in patients with AF could not only be cardiogenic embolisms due to AF but also aortogenic embolisms due to CAPs. The possibility of concomitant CAPs should be considered for stroke patients with AF. Non-obstructive general angioscopy has the possibility to detect aortic plaques in the aortic arch more accurately than TEE and might help to diagnose atheromatous plaques and embolic materials in the aortic arch. Further studies are needed to elucidate the causes of ischemic strokes and are expected to improve the outcomes for acute ischemic strokes in patients with AF.

Effects of Ageing on Aortic Circulation During Atrial Fibrillation; a Numerical Study on Different Aortic Morphologies

Atrial fibrillation (AF) can alter intra-cardiac flow and cardiac output that subsequently affects aortic flow circulation. These changes may become more significant where they occur concomitantly with ageing. Aortic ageing is accompanied with morphological changes such as dilation, lengthening, and arch unfolding. While the recognition of AF mechanism has been the subject of numerous studies, less focus has been devoted to the aortic circulation during the AF and there is a lack of such investigation at different ages. The current work aims to address the present gap. First, we analyse aortic flow distribution in three configurations, which attribute to young, middle and old people, using geometries constructed via clinical data. We then introduce two transient inlet flow conditions representative of key AF-associated defects. Results demonstrate that both AF and ageing negatively affect flow circulation. The main consequence of concomitant occurrence is enhancement of endothelial cell activation potential (ECAP) throughout the vascular domain, mainly at aortic arch and descending thoracic aorta, which is consistent with some clinical observations. The outcome of the current study suggests that AF exacerbates the vascular defects occurred due to the ageing, which increases the possibility of cardiovascular diseases per se.

Complex Aortic Arch Atherosclerosis in Acute Ischemic Stroke Patients with Non-Valvular Atrial Fibrillation

Aim: Aortic arch atherosclerosis, particularly complex aortic arch plaques (CAPs), is an important source of cerebral emboli. CAPs and atrial fibrillation (AF) often co-exist; however, the prevalence and risk of CAPs in acute ischemic stroke patients with AF is unclear.

Methods: In patients with acute ischemic stroke with non-valvular AF admitted to Jichi Medical University Hospital during April 2016 to September 2019, we retrospectively evaluated the presence of CAPs on transesophageal echocardiography (TEE).

Results: CAPs were observed in 41 (38.7 %) of 106 patients with non-valvular AF. Older age, diabetes mellitus, chronic kidney disease, low high-density lipoprotein cholesterol (HDL-C) levels, higher levels of glycohemoglobin A1c (HbA1c), higher CHADS ₂ and CHA ₂ DS ₂ -VASc scores, and intracranial or carotid artery stenosis were more frequently observed in CAPs-positive than in CAPs-negative patients. In multivariable analyses, older age (odds ratio [OR]: 1.2 per year increase; 95% confidence interval [CI]: 1.07–1.24; P ＜0.0001), diabetes mellitus (OR: 4.7; 95%CI: 1.27-17.35; P ＜0.05), and low HDL-C (OR: 0.95 per 1 mg/dl increase; 95%CI: 0.92-0.99; P ＜0.01) were independent risk factors for CAPs. The prevalence of CAPs was age-dependent, and there was a significantly higher risk in patients aged either 75–84 years or ＞84 years than in those aged ＜65 (OR: 7.6; 95%CI: 1.50-38.62, and OR: 32.1; 95%CI: 5.14-200.11, respectively).

Conclusions: Even in patients with ischemic stroke with non-valvular AF, concomitant CAPs should be considered in older individuals and those who have diabetes or low HDL-C.

Numerical Study of Atrial Fibrillation Effects on Flow Distribution in Aortic Circulation

Atrial fibrillation (AF) is the most common type of arrhythmia, which undermines cardiac function. Atrial fibrillation is a multi-facet malady and it may occur as a result of other diseases or it may trigger other problems. One of the main complications of AF is stroke due to the possibility of clot formation inside the atrium. However, the possibility of stroke occurrence due to the AF and the location from which an embolus dispatches are subject of debate. Another hypothesis about the embolus formation during AF is thrombus formation in aorta and carotid arteries, embolus detachment and its movement. To investigate the possibility of the latter postulation, the current work suggests a parametric study to quantify the sensitivity of aortic flow to four common AF traits including lack of atrial kick, atrial remodelling, left ventricle systolic dysfunction, and high frequency fibrillation. The simulation was carried out by coupling several in-house codes and ANSYS-CFX module. The results reveal that AF traits lower flow rate at left ventricular outflow tract, which in general lowers blood perfusion to systemic, cerebral and coronary circulations. Consequently, it leads to endothelial cell activation potential (ECAP) increase and variation of flow structure that both suggest predisposed areas to atherogenesis and thrombus formation in different regions in ascending aorta, aortic arch and descending thoracic aorta.

Transesophageal echocardiographic thromboembolic risk is associated with smoking status in patients with atrial fibrillation

BACKGROUND

Smoking is a risk factor for cardiovascular diseases, but it is unclear whether smoking status, including environmental tobacco smoke, increases stroke risk in patients with atrial fibrillation (AF). Abnormalities of the left atrium (LA) and aortic atherosclerosis, as detected by transesophageal echocardiography (TEE), are risk factors for stroke and thromboembolism in AF patients. We investigated the impact of smoking status on thromboembolic risk by TEE in patients with nonvalvular AF.

METHODS

In 122 patients with AF (mean age, 63 years; chronic AF 50%) who underwent TEE before catheter ablation of AF or for detection of the potential cardioembolic source, urinary concentrations of cotinine and clinical variables including smoking status and the CHA₂DS₂-VASc score were determined.

RESULTS

Severe aortic atherosclerosis and increased aortic wall thickness were more frequently detected by TEE in current smokers than in non-smokers (p<0.05), though these findings did not significantly differ between non-smokers and environmental smokers. Patients in AF rhythm during TEE, who were environmental smokers and at relatively low risk, as stratified by their CHA₂DS₂-VASc score (≤ 2), showed lower LA appendage flow velocity than those without environmental smoking (47±22 vs. 34±13 cm/sec, p<0.05).

CONCLUSIONS

TEE findings indicated that smoking status could be associated with thromboembolic risk in patients with AF.

Atrial fibrillation as a prognostic indicator of myocardial infarction and cardiovascular death: a systematic review and meta-analysis

This study aimed to investigate whether atrial fibrillation (AF) predicts myocardial infarction (MI) or cardiovascular (CV) death. AF is a well-established risk factor for thrombotic stroke and all-cause mortality. PubMed, EmBase, and Cochrane Central were searched for articles comparing the incidence rates of MI, CV death, or CV events between AF and non-AF patients. Relative risk ratio (RR) was used as effect estimate. Crude and adjusted RRs were calculated. Data were pooled using a random-effects model. The meta-analysis included 27 studies. In the unadjusted analysis, AF patients had a nonsignificant trend toward a higher risk of MI compared with non-AF patients; however, a significant association was found. The crude data analysis showed that AF was associated with increased risk of CV death (P < 0.05) and CV events (P < 0.05). These associations remained significant after pooling data from adjusted models (CV death: RR = 1.95, 95% CI 1.51–2.51, P < 0.05; CV events: RR = 2.10, 95% CI 1.50–2.95, P < 0.05). These results showed that AF is an independent risk factor for MI, CV death, and CV events.

Cardioembolic Stroke

Cardiac embolism accounts for an increasing proportion of ischemic strokes and might multiply several-fold during the next decades. However, research points to several potential strategies to stem this expected rise in cardioembolic stroke. First, although one-third of strokes are of unclear cause, it is increasingly accepted that many of these cryptogenic strokes arise from a distant embolism rather than in situ cerebrovascular disease, leading to the recent formulation of embolic stroke of undetermined source as a distinct target for investigation. Second, recent clinical trials have indicated that embolic stroke of undetermined source may often stem from subclinical atrial fibrillation, which can be diagnosed with prolonged heart rhythm monitoring. Third, emerging evidence indicates that a thrombogenic atrial substrate can lead to atrial thromboembolism even in the absence of atrial fibrillation. Such an atrial cardiomyopathy may explain many cases of embolic stroke of undetermined source, and oral anticoagulant drugs may prove to reduce stroke risk from atrial cardiomyopathy given its parallels to atrial fibrillation. Non-vitamin K antagonist oral anticoagulant drugs have recently expanded therapeutic options for preventing cardioembolic stroke and are currently being tested for stroke prevention in patients with embolic stroke of undetermined source, including specifically those with atrial cardiomyopathy. Fourth, increasing appreciation of thrombogenic atrial substrate and the common coexistence of cardiac and extracardiac stroke risk factors suggest benefits from global vascular risk factor management in addition to anticoagulation. Finally, improved imaging of ventricular thrombus plus the availability of non-vitamin K antagonist oral anticoagulant drugs may lead to better prevention of stroke from acute myocardial infarction and heart failure.

Clinical characteristics of complex aortic plaque in patients with non-valvular atrial fibrillation

BACKGROUND

Although complex aortic plaque (CxAoP) is a component of the CHA₂DS₂-VASc score in patients with atrial fibrillation (AF), it is underestimated without detection by trans-esophageal echocardiogram (TEE). We have evaluated the incidence and significance of CxAoP among patients with non-valvular AF (NVAF).

METHODS

We included 981 patients with NVAF who underwent catheter ablation (59.1±11.1years old, 73.7% male, 70.2% paroxysmal AF). All of the patients underwent pre-procedural TEE evaluation. Left atrial (LA)-cardioembolic (CE) milieu was defined as a dense spontaneous echo-contrast or LA appendage flow velocity≤20cm/s.

RESULTS

CxAoP was present in 8.3% of patients, and independently associated with age (OR 1.07, 95% CI 1.03-1.10, p<0.001), male sex (OR 2.34, 95% CI 1.29-4.24, p=0.005), and CHA₂DS₂-VASc score≥2 (OR 3.33, 95%CI 1.42-7.77, p=0.005). The presence of LA-CE milieu overlapped with CxAoP in only 11% of patients. Patients with CxAoP had a higher prevalence of hypertension (p=0.004), smoking history (p=0.008), paroxysmal AF (PAF, p<0.001), and a smaller LA volume index (p<0.001) than those with LA-CE milieu. The prevalence of persistent AF among patients with a history of stroke was significantly lower in the presence of CxAoP than in those with LA-CE milieu (p=0.014). CHA₂DS₂-VASc score was underestimated in 11% of high-risk patients (CHA₂DS₂-VASc score≥2) due to undetected CxAoP.

CONCLUSIONS

CxAoP may contribute to the risk of stroke by a different mechanism than LA-CE milieu in patients with NVAF. Imaging assessment for CxAoP affects thromboembolic risk stratification and decision making for stroke prevention in patients with NVAF.

CHADS2 score has a better predictive value than CHA2DS2-VASc score in elderly patients with atrial fibrillation

Aim

The study aims to compare the ability of CHA₂DS₂-VASc (defined as congestive heart failure, hypertension, age ≥75 years [two scores], type 2 diabetes mellitus, previous stroke, transient ischemic attack, or thromboembolism [TE] [doubled], vascular disease, age 65–74 years, and sex category) and CHADS₂ (defined as congestive heart failure, hypertension, age ≥75 years, type 2 diabetes mellitus, previous stroke [doubled]) scores to predict the risk of ischemic stroke (IS) or TE among patients with nonvalvular atrial fibrillation (NVAF).

Methods

A total of 413 patients with NVAF aged ≥65 years, and not on oral anticoagulants for the previous 6 months, were enrolled in the study. The predictive value of the CHA₂DS₂-VASc and CHADS₂ scores for IS/TE events was evaluated by the Kaplan–Meier method.

Results

During a follow-up period of 1.99±1.29 years, 104 (25.2%) patients died and 59 (14.3%) patients developed IS/TE. The CHADS₂ score performed better than the CHA₂DS₂-VASc score in predicting IS/TE as assessed by c-indexes (0.647 vs 0.615, respectively; P<0.05). Non-CHADS₂ risk factors, such as vascular disease and female sex, were not found to be predictive of IS/TE (hazard ratio 1.518, 95% CI: 0.832–2.771; hazard ratio 1.067, 95% CI: 0.599–1.899, respectively). No differences in event rates were found in patients with the CHADS₂ scores of 1 and 2 (7.1% vs 7.8%). It was observed that patients with a CHADS₂ score of ≥3 were most in need of anticoagulation therapy.

Conclusion

In patients with NVAF aged ≥65 years, the CHADS₂ score was found to be significantly better in predicting IS/TE events when compared to the CHA₂DS₂-VASc score. Patients with a CHADS₂ score of ≥3 were associated with high risk of IS/TE events.

The use of imaging in new transcatheter interventions: an EACVI review paper

Transcatheter therapies for the treatment of valve heart diseases have expanded dramatically over the last years. The new developments and improvements in devices and techniques, along with the increasing expertise of operators, have turned the catheter-based approaches for valvular disease into an established treatment option. Various imaging techniques are used during these procedures, but echocardiography plays an essential role during patient selection, intra-procedural monitoring, and post-procedure follow-up. The echocardiographic assessment of patients undergoing transcatheter interventions places demands on echocardiographers that differ from those of the routine evaluation of patients with valve disease, and there is a need for specific expertise for those working in the cath lab. In the context of the current rapid developments and growing use of transcatheter valve therapies, this document intends to update the previous recommendations and address new advancements in imaging, particularly for those involved in any stage of the treatment of patients with valvular heart diseases.

Transesophageal Echocardiography in Atrial Fibrillation

Transesophageal echocardiography (TEE) plays an important role in atrial fibrillation (AF), mainly to detect the presence of left atrial appendage (LAA) thrombus. It is useful in direct current cardioversion (DCC) guidance and for AF ablation and LAA occlusion. With the increasing number of patients affected by AF, the use of TEE will grow and become an important screening modality for LAA thrombus. Future direction includes broader multi-institutional use; further tools to risk stratify patients; and the use of a new spectrum of oral anticoagulants and their cost-effectiveness in patients with AF undergoing DCC, AF ablation, and LAA occlusion.

Optimization Of Stroke Prophylaxis Strategies In Nonvalvular AF -Drugs, Devices Or Both?

Atrial fibrillation (AF) is the most common cardiac arrhythmia with the prevalence increasing over time. AF probably afflicts ≥2% of worldwide adult population and increases with age.[1-3] In the Framingham Heart Study, the lifetime risk of having at least one episode of AF for 40-year-old men and women was 26% and 23% respectively.[4].

Fibrotic atrial cardiomyopathy, atrial fibrillation, and thromboembolism: mechanistic links and clinical inferences

The association of atrial fibrillation (AF) with ischemic stroke has long been recognized; yet, the pathogenic mechanisms underlying this relationship are incompletely understood. Clinical schemas, such as the CHA2DS2-VASc (congestive heart failure, hypertension, age ≥ 75 years, diabetes mellitus, stroke/transient ischemic attack, vascular disease, age 65 to 74 years, sex category) score, incompletely account for thromboembolic risk, and emerging evidence suggests that stroke can occur in patients with AF even after sinus rhythm is restored. Atrial fibrosis correlates with both the persistence and burden of AF, and gadolinium-enhanced magnetic resonance imaging is gaining utility for detection and quantification of the fibrotic substrate, but methodological challenges limit its use. Factors related to evolution of the thrombogenic fibrotic atrial cardiomyopathy support the view that AF is a marker of stroke risk regardless of whether or not the arrhythmia is sustained. Antithrombotic therapy should be guided by a comprehensive assessment of intrinsic risk rather than the presence or absence of AF at a given time.

Predictors of silent brain infarction on magnetic resonance imaging in patients with nonvalvular atrial fibrillation: A transesophageal echocardiographic study

BACKGROUND

Silent brain infarction (SBI) is often found in patients with atrial fibrillation (AF) and may be related to cognitive decline. We investigated the predictors of SBI on brain magnetic resonance imaging (MRI) using transesophageal echocardiography (TEE) in patients with nonvalvular AF.

METHODS

The study population consisted of 103 neurologically asymptomatic patients with nonvalvular AF who underwent TEE before transcatheter AF ablation (76 men; mean age 63 ± 10 years). Left atrial (LA) abnormalities such as LA thrombus, spontaneous echo contrast, or abnormal LA appendage emptying velocity (<20 cm/s) and complex plaques in the aortic arch defined as large plaques ≥4 mm thickness, ulcerated plaques, or mobile plaques were evaluated by TEE. All patients were screened for SBI by brain MRI.

RESULTS

Of 103 patients, 31 (30%) showed SBI on brain MRI. Most lesions were multiple (61%) and small (<15 mm) in diameter (84%). Patients with SBI had a higher prevalence of LA abnormalities (45% vs 14%; P < .001) and complex arch plaques (45% vs 7%; P < .001) compared with those without SBI. In a multivariate logistic regression analysis including age and CHADS2 score ≥2, LA abnormalities (odds ratio 4.13; 95% CI 1.34-12.72; P = .014) and complex arch plaques (odds ratio 4.82; 95% CI 1.23-18.92; P = .024) were independent predictors of SBI.

CONCLUSIONS

Left atrial abnormalities and complex arch plaques detected by TEE were closely associated with the presence of SBI on brain MRI, suggesting that microembolization of small thrombi derived from the fibrillating LA or advanced aortic atherosclerotic lesions may be important causes of SBI in patients with nonvalvular AF.

Left atrial appendage exclusion for atrial fibrillation

Percutaneous left atrial appendage (LAA) closure is being increasingly used as a treatment strategy to prevent stroke in patients with atrial fibrillation (AF) who have contraindications to anticoagulants. Several approaches and devices have been developed in the last few years, each with their own unique set of advantages and disadvantages. In this article, the published studies on surgical and percutaneous approaches to LAA closure are reviewed, focusing on stroke mechanisms in AF, LAA structure and function relevant to stroke prevention, practical differences in procedural approach, and clinical considerations surrounding management.

Relationship between CHADS2 score and complex aortic plaques by transesophageal echocardiography in patients with nonvalvular atrial fibrillation

The CHADS2 score is widely used for risk stratification of thromboembolism in patients with non-valvular atrial fibrillation (NVAF). Although the correlation of CHADS2 score with left atrial (LA) abnormality as detected by transesophageal echocardiography (TEE) has been reported in previous studies, the relationship between CHADS2 score and complex aortic plaque, which is also a significant risk factor for thromboembolism, has not been fully investigated. We assessed aortic plaques by TEE in 150 patients age ≥ 55 y with NVAF. The prevalence of complex aortic plaques increased along with increases in CHADS2 score (p = 0.001). In a multivariate analysis that included atherosclerotic risk factors and LA abnormality, a CHADS2 score ≥2 was independently associated with the presence of complex aortic plaques (odds ratio [OR] 3.39; 95% confidence interval [CI], 1.29-8.90). A high CHADS2 score is closely associated with the presence of complex aortic plaques, which explains, in part, the increased risk of thromboembolism in NVAF patients with high CHADS2 score.

Hypercoagulability, D-dimer and atrial fibrillation: an overview of biological and clinical evidence

Atrial fibrillation (AF) is the most common among the severe cardiac arrhythmias and carries a significant risk of mortality and morbidity in the general population. The most important complication is represented by development of one or more thrombi in the left atrium of the dyskinetic heart, and their successive cerebral and peripheral embolization. The pathophysiological basis of the thromboembolic complications in AF entails the presence of a hypercoagulable state, which is mirrored by increased concentrations of a variety of prothrombotic markers. D-dimer is universally considered the gold standard among the various biomarkers that reflect activation of coagulation, fibrinolysis, or both, and several studies have assessed its diagnostic and prognostic role in AF. With a few exceptions and despite a broad heterogeneity in the study designs, published data seem to demonstrate that D-dimer values may be associated with the presence of atrial thrombosis, may be predictive of primary adverse outcomes and death, may be correlated with cerebral infarction volume, and may also be a useful parameter for assessing the degree of hypercoagulability of AF patients after cardioversion. If larger prospective studies confirm these findings, D-dimer assessment may hence become an integral part of the clinical decision-making in patients with AF.

Detecting atheromatous plaques in the aortic arch or supra-aortic arteries for more accurate stroke subtype classification

INTRODUCTION

To investigate the correlations of atheromatous plaques in the aortic arch or supra-aortic arteries with intracranial arterial stenosis and carotid plaques in stroke patients, and to determine whether taking these plaques into account will reduce the proportion of patients in the undetermined etiology group.

METHODS

We prospectively enrolled 308 ischemic stroke patients, whose clinical characteristics and A-S-C-O classifications were compared with analyses of intracranial arteries, carotid arteries, aortic arch, and supra-aortic arteries.

RESULTS

125(40.6%) patients had plaques in the aortic arch or supra-aortic arteries, of which 106 (84.8%) had complex plaques. No correlations were observed between these plaques and carotid plaques ( p = 0.283) or intracranial arterial stenosis ( p = 0.097). After detecting the mobile thrombi in the aortic arch and supra-aortic arteries, the proportion of patients in the atherothrombosis group was increased from 33.8% to 55.5% ( p = 0.00), whereas the proportion of patients in stroke of undetermined etiology group was decreased from 19.2% to 11.0% ( p = 0.00).

DISCUSSION

Examining only the carotid and intracranial arteries may not provide adequate information about large arteries in stroke patients. Therefore, it would be better to include a search for relevant plaques in the aortic arch or supra-aortic arteries in modern stroke workup, for it may lead to more accurate stroke subtype classification and guide secondary prevention.

Atrial Fibrillation and Stroke: A Neurologic Perspective

Atrial fibrillation (AF) is the most common supraventricular arrhythmia in the United States. The incidence and prevalence of AF are increasing as the population ages and associated risk factors become more prevalent. Stroke is the most severe complication of AF. Various risk stratification schemes to guide therapy and the associated risk of bleeding are described. AF is also associated with cognitive decline, which may be secondary to recurrent microemboli; microbleeds secondary to anticoagulation therapy, or progression of vascular risk factors associated with AF. Prolonged monitoring can be performed to detect AF in patients with cryptogenic stroke.

Feasibility of TEE-guided stroke risk assessment in atrial fibrillation-background, aims, design and baseline data of the TIARA pilot study

Background

Antithrombotic management in atrial fibrillation (AF) is currently based on clinical characteristics, despite evidence of potential fine-tuning with transoesophageal echocardiography (TEE). This open, randomised, multicentre study addresses the hypothesis that a comprehensive strategy of TEE-based aspirin treatment in AF patients is feasible and safe.

Methods

Between 2005 and 2009, ten large hospitals in the Netherlands enrolled AF patients with a moderate risk of stroke. Patients without thrombogenic TEE characteristics were randomised to aspirin or vitamin K antagonists (VKA). The primary objective is to show that TEE-based aspirin treatment is safe compared with VKA therapy. The secondary objective tests feasibility of TEE as a tool to detect echocardiographic features of high stroke risk. This report compares randomised to non-randomised patients and describes the feasibility of a TEE-based approach.

Results

In total, 310 patients were included. Sixty-nine patients were not randomised because of non-visualisation (n = 6) or TEE risk factors (n = 63). Compared with non-randomised patients, randomised patients (n = 241) were younger (65 ± 11 vs. 69 ± 9 years, p = 0.004), had less coronary artery disease (9 vs. 20%, p = 0.018), previous TIA (1.7 vs. 7.2%, p = 0.029), AF during TEE (25 vs. 54%, p < 0.001), mitral incompetence (55 vs. 70%, p = 0.038), VKA use (69 vs. 82%, p = 0.032), had a lower mean CHADS₂ score (1.2 ± 0.6 vs. 1.6 ± 1.0, p = 0.004), and left ventricular ejection fraction (59 ± 8 vs. 56 ± 8%, p = 0.016).

Conclusions

This study shows that a TEE-based approach for fine-tuning stroke risk in AF patients with a moderate risk for stroke is feasible. Follow-up data will address the safety of this TEE-based approach.

The impact of atherosclerotic vascular disease in predicting a stroke, thromboembolism and mortality in atrial fibrillation patients: a systematic review

BACKGROUND

Atrial fibrillation (AF) is commonly associated with vascular disease. Although atherosclerotic vascular disease (for example, defined as a myocardial infarction (MI), complex aortic plaque and peripheral arterial disease) has been proposed as a risk factor for a stroke, the co-existence of the two diseases increases the risk of future cardiovascular events. The objective of this study was to conduct a systematic review to assess the impact of atherosclerotic vascular disease on the primary end-point of a stroke, thromboembolism or mortality, in patients with AF.

METHODS

Literature searches were performed electronically, to identify studies published between January 1990and July 2012 examining stroke and thromboembolism in relation to AF and atherosclerotic vascular disease. Nineteen articles satisfied the pre-inclusion criteria. The bibliographies were subsequently screened to retrieve further relevant studies for this review.

RESULTS

Peripheral arterial disease significantly increased the stroke risk in all 10 observational studies, within a reported risk range of 1.3- to 2.5-fold. Complex aortic plaque on the descending aorta, as identified by trans-oesophageal echocardiography, was also a significant risk factor. Although a prior myocardial infarction (MI) was validated as a significant predictor of the primary end-point amongst five of the six studies, there was a degree of heterogeneity, owing to the marked difference in population sizes and the use of antithrombotic regimens between studies.

CONCLUSION

Atherosclerotic vascular disease (e.g. peripheral arterial disease, complex aortic plaque and prior MI) are significant predictors of a stroke, thromboembolism and mortality in subjects with AF.

Atherosclerosis and thromboembolic risk in atrial fibrillation: focus on peripheral vascular disease

Atrial fibrillation (AF) is the most common cardiac arrhythmia in clinical practice. It results in a 5-fold increased risk for stroke and thromboembolism and is associated with a high morbidity and mortality. AF shares several risk factors and pathophysiological features with atherosclerosis. Hence AF is often complicated by a variety of other cardiovascular conditions. Indeed, peripheral vascular disease (PVD) is highly prevalent among AF patients and associates with increased mortality. Inclusion of PVD within stroke risk scoring systems such as the CHA2DS2-VASc score improves risk stratification of AF patients. Of note, PVD has not been previously well documented nor looked for in observational studies or clinical trials. The aim of this present review article is to provide an overview of the association between atherosclerosis (with particular focus on PVD) and AF as well as its complications.

Interactions between cardiovascular and cerebrovascular disease

OPININION STATEMENT: All patients with ischemic stroke should undergo a comprehensive assessment of cardiovascular risk. Patients with carotid artery disease, symptoms of cerebral ischemia and high cardiovascular risk profiles should be considered for noninvasive testing for coronary artery disease (CAD). Routine testing for CAD before carotid endarterctomy is not recommended. Patients with coexisting coronary and carotid artery disease should be more aggressively treated for reducing their "very high" risk of cardiovascular events. In patients candidates to carotid revascularization, a preoperative coronary angiography and coronary revascularization are not recommended. Warfarin is recommended in all patients with moderate to high risk of stroke. Novel oral anticoagulants represent an attractive alternative to warfarin. However, their place in therapy in clinical practice is not yet established. Percutaneous closure of the left atrial appendage for stroke prophylaxis may be considered in selected patients with atrial fibrillation and contraindications for oral anticoagulant therapy. Warfarin is not indicated in patients with heart failure who are in sinus rhythm. Percutaneous closure of patent foramen does not seem to be superior to medical therapy for the prevention of recurrences in patients with cryptogenic stroke.

Should Atrial Fibrillation Burden Be A Feature to Guide Thromboembolism Prophylaxis?

Atrial fibrillation (AF) is a well-known risk factor for cerebrovascular events and systemic emboli. However, the frequency and duration of AF necessary to be considered at risk for thrombus formation is unknown. This review summarizes the literature regarding AF burden and risk for thromboembolism. Previously, no distinction was made between patients who had paroxysmal versus persistent AF in regards to initiation of anticoagulation. Recently though, given an enhanced ability to detect even very brief paroxysms of AF via stored device diagnostics, the issue has been readdressed. However, despite multiple studies no clear threshold for AF burden to mandate anticoagulation has been established. In addition, there is a growing body of evidence which suggests that the pathophysiology of thrombus formation in AF involves mechanisms beyond just stasis due to protracted episodes of discoordinate atrial contraction. Therefore, once AF has been diagnosed and the risk-benefit ratio favors anticoagulation, therapy should be initiated and continued indefinitely unless a bleeding contraindication develops.

ABBREVIATIONS

AF = atrial fibrillation, AT = atrial tachycardia, LAA = left atrial appendage, PAF = paroxysmal atrial fibrillation, SE = systemic emboli.

Stroke and Death Prediction with the Impact of Vascular Disease in Patients with Atrial Fibrillation

Atrial fibrillation (AF) is the most common arrhythmia encountered in the U.S. and the growing burden of AF has profound health implications due to the association of AF with an increased risk of stroke, heart failure, and mortality. AF is a significant risk factor for thromboembolic stroke; and also independently increases total mortality in patients with and without cardiovascular disease. Various risk stratification schemes such as CHADS₂ and CHA₂DS₂-VASc have been implemented in clinical practice to determine the risk of cardio-embolic stroke, and need for thrombo-prophylaxis in patients with AF. AF is also closely related to the pathophysiology of other cardiovascular and peripheral vascular disease. Many patients with AF have associated atherosclerosis given that many risk factors for atherosclerosis also predispose to AF. Myocardial infarction (MI) is also closely related to AF and its clinical course is affected by new onset AF. This review elucidates the impact of AF on major adverse cardiovascular events and mortality outcomes in relation to stroke, coronary artery disease and peripheral vascular disease.

Peripheral artery disease and atrial fibrillation: a potentially dangerous combination

Atrial fibrillation (AF) is commonly associated with a significant increase in stroke and thromboembolic risk. Many patients with AF have associated atherothrombosis given the many risk factors for atherosclerosis that also predispose to AF. Vascular disease, whether peripheral artery disease or myocardial infarction, contributes to the increased risk of stroke and thromboembolism, and has been included in stroke risk assessment schema. This review analyzes the interplay between AF and peripheral artery disease in relation to their associated pathophysiology, as well as epidemiological data linking both conditions and the associated thromboembolic complications conferred by the presence of both.

Role of echocardiography in atrial fibrillation

Atrial fibrillation (AF) is most common arrhythmia and its prevalence appears to be increasing as the population ages. Echocardiography can play a key role in risk stratification and management of patients with AF. Transthoracic echocardiography allows rapid and comprehensive assessment of cardiac anatomical structure and function. Pulmonary vein flow monitoring using echocardiography has the potential to an increasing role in the evaluation of cardiac function and AF ablation procedures. Transesophageal echocardiography also provides accurate information about the presence of a thrombus in the atria and thromboembolic risk. The novel technique of intracardiac echocardiography has emerged as a popular and useful tool in the everyday practice of interventional electrophysiology. Other imaging modalities, such as computed tomography and magnetic resonance imaging have complementary roles in risk stratification and assessment of patients with AF. Echocardiography continues to be the foundation of clinical evaluation and management of AF.

Association between plaque thickness of the thoracic aorta and recurrence of atrial fibrillation after ablation

Background and Objectives

Several predictors of recurrence of atrial fibrillation (AF) after ablation have been identified, including age, type of AF, hypertension, left atrial diameter and impaired left ventricular ejection fraction. The aim of this study was to investigate whether the atherosclerotic plaque thickness of the thoracic aorta is associated with a recurrence of AF after circumferential pulmonary vein ablation (CPVA).

Subjects and Methods

Among patients with drug-refractory paroxysmal or persistent AF, 105 consecutive (mean age 58±11 years, male : female=76 : 29) patients who underwent transesophageal echocardiography and CPVA were studied. The relationships between the recurrence of AF and variables, including clinical characteristics, plaque thickness of the thoracic aorta, laboratory findings and echocardiographic parameters were evaluated.

Results

A univariate analysis showed that the presence of diabetes {hazard ratio (HR)=3.425; 95% confidence interval (CI), 1.422-8.249, p=0.006}, ischemic heart disease (HR=4.549; 95% CI, 1.679-12.322, p=0.003), duration of AF (HR=1.010; 95% CI, 1.001-1.018, p=0.025), type of AF (HR=2.412, 95% CI=1.042-5.584, p=0.040) and aortic plaque thickness with ≥4 mm (HR=9.514; 95% CI, 3.419-26.105, p<0.001) were significantly associated with the recurrence of AF after ablation. In Cox multivariate regression analysis, only the aortic plaque thickness (with ≥4 mm) was an independent predictor of recurrence of AF after ablation (HR=7.250, 95% CI=1.906-27.580, p=0.004).

Conclusion

Significantly increased aortic plaque thickness can be a predictable marker of recurrence of AF after CPVA.