Ischemic stroke in patients with atrial fibrillation: effect of aspirin according to stroke mechanism. Stroke Prevention in Atrial Fibrillation Investigators

Resolution-promoting autacoids demonstrate promising cardioprotective effects against heart diseases

Abstract

Chronic heart diseases have in common an unresolved inflammatory status. In atherosclerosis, myocarditis, myocardial infarction, or atrial fibrillation, mounting evidence suggests that unresolved inflammation contributes to the chronicity, aggravation, and morbidity of the disease. Following cardiac injury or infection, acute inflammation is a normal and required process to repair damaged tissues or eliminate pathogens and promote restoration of normal functions and structures. However, if acute inflammation is not followed by resolution, a chronic and deleterious inflammatory status may occur, characterized by the persistence of inflammatory biomarkers, promoting aggravation of myocardial pathogenesis, abnormal structural remodeling, development of cardiac fibrosis, and loss of function. Although traditional antiinflammatory strategies, including the use of COX-inhibitors, to inhibit the production of inflammation promotors failed to promote homeostasis, mounting evidence suggests that activation of specific endogenous autacoids may promote resolution and perpetuate cardioprotective effects. The recent discovery of the active mechanism of resolution suggests that proresolving signals and cellular processes may help to terminate inflammation and combat the development of its chronic profile in cardiac diseases. This review discussed (I) the preclinical and clinical evidence of inflammation-resolution in cardiac disorders including atrial fibrillation; (II) how and why many traditional antiinflammatory treatments failed to prevent or cure cardiac inflammation and fibrosis; and (III) whether new therapeutic strategies may interact with the resolution machinery to have cardioprotective effects.

Graphical abstract

RvD D-series resolving, RvE E-series resolving, LXA4 lipoxin A4, MaR1 maresin-1

Carotid Artery Stenting in Patients with Atrial Fibrillation: Direct Oral Anticoagulants, Brief Double Antiplatelets, and Testing Strategy

Carotid endarterectomy is usually preferred over carotid artery stenting (CAS) for patients with atrial fibrillation (AF). We present our experience with short-course periprocedural triple antithrombotic therapy in 32 patients aged >18 years with nonvalvular AF undergoing CAS. There were no deaths, cardiac events, embolic strokes, hyperperfusion syndrome, intracranial hemorrhage, or stent thrombosis within 30 days. Transient intraprocedural hemodynamic instability in 15/32 (47%) and prolonged instability in 4/32 (13%) was managed conservatively. At a mean 16-month follow-up, there were no new neurological events or deterioration. Mean stenosis was reduced from 78.0% ± 9.7% to 17.3% ± 12.2%. This retrospective study included patients AF who were symptomatic (minor stroke (NIHSS ≤ 5)/TIA) with ICA stenosis >50%, or asymptomatic under DOAC therapy with carotid stenosis >80%, who underwent CAS from 6/2014–10/2020. Patients received double antiplatelets and statins. Antiplatelet therapy effectiveness was monitored. Stenting was performed when P2Y12 reaction units (PRU) were <150. DOACs were discontinued 48 h before angioplasty; one 60 mg dose of subcutaneous enoxaparin was administered in lieu. DOAC was restarted 12–24 h after intervention. Patients were discharged under DOAC and one nonaspirin antiplatelet. 32 patients on DOAC were included (26 male, mean age 71). 19 (59.4%) presented with stroke (ICA stenosis-related in 14); 13 (40.6%) were asymptomatic. Stents were deployed under filter protection following pre-angioplasty; post-angioplasty was performed at least once in 12 patients (37.5%). Our experience suggests that CAS can be safely performed in selected patients with CAS and AF requiring DOAC. The role of CAS in AF patients under DOAC warrants study in rigorous trials.

Cerebral arteriosclerosis stenosis predicts poor short-term prognosis in non-valvular atrial fibrillation related cardioembolic stroke treated by reperfusion therapy

BACKGROUND AND PURPOSE

We aimed to investigate the association between cerebral arteriosclerosis stenosis (CAS) and the short-term prognosis of non-valvular atrial fibrillation (NVAF) related cardioembolic stroke treated by reperfusion therapy.

METHODS

The data of 195 consecutive NVAF related cardioembolic stroke patients were retrospectively collected. We defined poor functional outcome as a modified Rankin scale (mRS) score of > 2 at 90 days.

RESULTS

Patients with CAS were more likely to be older (75.5 ± 6.8 vs. 72.5 ± 9.2 years, p = 0.001), more current smokers (35.6% vs. 24.1%, p = 0.018), with hypertension (88.1% vs. 65.6%, p < 0.001), diabetes mellitus (50.0% vs. 20.0%, p = 0.020), dyslipidemia (33.9% vs. 23.6%, p = 0.029), previous history of stroke (30.5% vs. 19.5%, p = 0.012), and congestive heart failure (32.2% vs. 22.6%, p = 0.041). Patients with CAS had higher National Institutes of Health Stroke Scale (NIHSS) (18 [13, 22] vs. 15 [9, 19], p < 0.001), and 90-day mRS scores (5 [3, 6] vs. 3[2, 5], p < 0.001). Multivariate logistic regression analysis showed that CAS (odds ratio [OR] 3.184, 95% confidence interval [CI] 1.314-7.713, p = 0.01), NIHSS score on admission (OR 1.228 [per 1 point], 95% CI 1.146-1.316, p < 0.001), congestive heart failure (OR 2.850, 95% CI 1.108-7.331, p = 0.030), and current smokers (OR 2.841, 95% CI 1.102-7.326, p = 0.031) were independent predictors of a poor functional outcome at 90 days.

CONCLUSION

We should give the coexistence of CAS and NVAF related cardioembolic stroke proper attention. CAS was an independent factor for predicting the short-term prognosis of NVAF associated cardioembolic stroke patients treated by reperfusion therapy.

Dual Versus Triple Therapy for Atrial Fibrillation After Percutaneous Coronary Intervention: A Systematic Review and Meta-analysis

BACKGROUND

The safety and effectiveness of dual therapy (direct oral anticoagulant [DOAC] plus P2Y12 inhibitor) versus triple therapy (vitamin K antagonist plus aspirin and P2Y12 inhibitor) in patients with nonvalvular atrial fibrillation (AF) after percutaneous coronary intervention (PCI) is unclear.

PURPOSE

To examine the effects of dual versus triple therapy on bleeding and ischemic outcomes in adults with AF after PCI.

DATA SOURCES

Searches of PubMed, EMBASE, and the Cochrane Library (inception to 31 December 2019) and ClinicalTrials.gov (7 January 2020) without language restrictions; journal Web sites; and reference lists.

STUDY SELECTION

Randomized controlled trials that compared the effects of dual versus triple therapy on bleeding, mortality, and ischemic events in adults with AF after PCI.

DATA EXTRACTION

Two independent investigators abstracted data, assessed the quality of evidence, and rated the certainty of evidence.

DATA SYNTHESIS

Four trials encompassing 7953 patients were selected. At the median follow-up of 1 year, high-certainty evidence showed that dual therapy was associated with reduced risk for major bleeding compared with triple therapy (risk difference [RD], -0.013 [95% CI, -0.025 to -0.002]). Low-certainty evidence showed inconclusive effects of dual versus triple therapy on risks for all-cause mortality (RD, 0.004 [CI, -0.010 to 0.017]), cardiovascular mortality (RD, 0.001 [CI, -0.011 to 0.013]), myocardial infarction (RD, 0.003 [CI, -0.010 to 0.017]), stent thrombosis (RD, 0.003 [CI, -0.005 to 0.010]), and stroke (RD, -0.003 [CI, -0.010 to 0.005]). The upper bounds of the CIs for these effects were compatible with possible increased risks with dual therapy.

LIMITATION

Heterogeneity of study designs, dosages of DOACs, and types of P2Y12 inhibitors.

CONCLUSION

In adults with AF after PCI, dual therapy reduces risk for bleeding compared with triple therapy, whereas its effects on risks for death and ischemic end points are still unclear.

PRIMARY FUNDING SOURCE

None.

Clinical and Imaging Characteristics of Cerebral Infarction in Patients with Nonvalvular Atrial Fibrillation Combined with Cerebral Artery Stenosis

AIMS

Nonvalvular atrial fibrillation often occurs in combination with carotid atherosclerosis, but less is known about it in combination with cerebral artery stenosis. This study investigated the characteristics of cerebral infarction in patients with nonvalvular atrial fibrillation with or without cerebral artery stenosis.

METHODS

A retrospective analysis was conducted on 172 cerebral infarction patients with nonvalvular atrial fibrillation hospitalized at the Affiliated Ganzhou Hospital of Nanchang University between December 2011 and January 2016. The patients were divided into two groups (stenosis and non-stenosis groups) based on whether the cerebral infarction was combined with cerebral artery stenosis or not. Clinical characteristics, related supplementary examination, and the imaging characteristics of cerebral infarction lesions were compared between the groups.

RESULTS

Mean age [(75.73±8.46) years vs. (63.44±9.95) years], National Institute of Health stroke scale (NIHSS) score [(8.66±6.73) vs. (4.59±3.51)], CHA2DS2-VASc score [(2.93±1.40) vs. (0.96±0.98)], history of hypertension (74.4% vs. 30.0%), and history of stroke/ transient ischemic attack (TIA) (55.8% vs. 13.3%) were higher in the stenosis group (n=107) than in the non-stenosis group (n=65) (P＜0.01). In the stenosis group, there were different types of cerebral infarction lesions, including multiple infarction (multifocal type), massive infarction, watershed infarction, and lacunar infarction; in the non-stenosis group, the 60.0% lesions were multiple infarction (multifocal type), a significantly higher proportion than the stenosis group (26.2%, P＜0.05). NIHSS score was an independent risk factor for worse prognosis at follow-up (OR (95%CI) 1.251-1.674, P＜0.001).

CONCLUSIONS

Advanced age, hypertension, and stroke/TIA were increased in patients with cerebral infarction with nonvalvular atrial fibrillation combined with cerebral artery stenosis.

Noncardioembolic Stroke in Patients with Atrial Fibrillation

Atrial fibrillation (AF) could be a coincidental finding in certain patients with ischemic stroke and increased burden of underlying cardiovascular disease. Concomitant large-vessel atheromatosis and cerebral small vessel disease may be the actual cause of stroke, and distinguishing between different pathophysiologic mechanisms could impose substantial diagnostic difficulties. Despite routine use of oral anticoagulants (OACs) in patients with AF based on their risk for embolism (ie, CHA2DS2-Vasc score), antithrombotic agents may exert differential effects depending on stroke etiology and stroke subtyping should be evaluated as an additional component of risk stratification that could facilitate optimal management. In the present study, we summarize the evidence on noncardioembolic (non-CE) stroke and treatment approaches based on different stroke subtypes in patients with AF. In particular, approximately one-third of patients with AF seem to suffer a non-CE stroke. Within this category, 11% to 24% of patients present high-grade carotid stenosis and 9% to 16% of ischemic strokes are classified as lacunar. In terms of secondary prevention, the effectiveness of OACs in preventing non-CE stroke has been disputed. Additional large-scale prospective studies are warranted to assess the pathophysiologic stroke mechanisms in patients with AF and compare the differential efficacy of antithrombotic treatment strategies in non-CE ischemic syndromes.

Should atrial fibrillation patients with hypertension as an additional risk factor of the CHA2DS2-VASc score receive oral anticoagulation?

Hypertension has been found to be increased a risk of stroke in atrial fibrillation (AF). Both the European and U.S. guidelines advocate the use of the CHA₂DS₂-VASc (congestive heart failure, hypertension, age > 75 years, diabetes mellitus, stroke/transient ischemic attack, vascular disease, age 65-74 years, sex category) scheme for risk stratification. Although vitamin K antagonists is more effective than acetylsalicylic acid at preventing ischaemic stroke, its benefit is offs by an increased haemorrhage risk. The risk of ischemic stroke in patients with AF and a CHA₂DS₂-VASc score of 1 are considered to be low risk and may be not expected to benefit from anticoagulation therapy. Hypertension carries an increased risk of ischemic stroke, however, it is also a clear risk factor for hemorrhage in AF. Therefore, the optimal antithrombotic management is highlighted in patients with AF with only one risk factor especially hypertension.

Monotherapy of acetylsalicylic acid or warfarin for prevention of ischemic stroke in low-risk atrial fibrillation: A Easter Asian population-based study

BACKGROUND

This study aimed to investigate the effectiveness of monotherapy acetylsalicylic acid (ASA) and warfarin for stroke prevention in low-risk atrial fibrillation (AF) by using a population- -based cohort study in Taiwan.

METHODS

A newly diagnosed low-risk AF patient cohort were identified by using National Health Insurance Research Database (NHIRD) in Taiwan in 2008. The study cohort was observed with a follow-up of 2 years to examine the onset of ischemic stroke (IS) (to 2010). The longitudinal data were analyzed by using generalized estimation equations (GEE).

RESULTS

A total of 8,065 newly-diagnosed low-risk AF patients were identified in 2008. 7.4% were prescribed with ASA and 4.6% were prescribed with warfarin. The GEE results showed that low-risk AF patients with hypertension who received warfarin were associated with a statistically significant 58.4% reduction of IS risk (OR = 0.416, p = 0.024, 95% CI 0.194-0.891). Additionally, low-risk AF patients with hyperlipidemia who received warfarin were associated with a 69.3% reduction of IS risk (OR = 0.307, p = 0.044, 95% CI 0.097-0.969).

CONCLUSIONS

Warfarin is suggested to be prescribed in preventing IS for low-stroke-risk AF patients with hypertension and hyperlipidemia.

Implications of CHA2DS2-VASc Score in Stroke Patients with Atrial Fibrillation: An Analysis of 938 Korean Patients

BACKGROUND AND AIMS

The aim of this study was to investigate the stroke mechanisms and associated conditions influencing the decision regarding stroke thromboprophylaxis in patients with atrial fibrillation (AF) plus ischemic stroke, according to the CHA2DS2-VASc score.

METHODS

We evaluated 938 consecutive patients with a diagnosis of AF plus transient ischemic attack/ischemic stroke. Based on the CHA2DS2-VASc scores, patients were stratified as score 0 or 1 (n = 151), score 2 (n = 146), score 3 (n = 213), score 4 (n = 185), or score ≥5 (n = 243).

RESULTS

Patients with a higher CHA2DS2-VASc score were more likely to have noncardioembolic stroke mechanism (p = 0.001). Large-artery atherosclerosis causing stenosis >50% was more frequently observed in the high CHA2DS2-VASc group (p < 0.001). Coronary artery disease and the use of antiplatelet agents were more prevalent in the higher group (p < 0.001). A high CHA2DS2-VASc score was associated with a higher frequency of cerebral microbleeds and a higher Fazekas grade for leukoaraiosis (p < 0.001). The HAS-BLED score was correlated with the CHA2DS2-VASc score (γ = 0.650; p < 0.001).

CONCLUSIONS

A higher CHA2DS2-VASc score is associated with noncardioembolic mechanisms of stroke and with a higher risk of bleeding. Strategies to treat macro/microangiopathy such as use of statin for plaque stabilization, as well as oral anticoagulants with a lower bleeding risk, are needed in these patients.

Stroke or left atrial thrombus prediction using antithrombin III and mean platelet volume in patients with nonvalvular atrial fibrillation

BACKGROUND

CHADS₂ (congestive heart failure, hypertension, age ≥ 75 years, diabetes mellitus, stroke) and CHA₂ DS₂ -VASc (congestive heart failure, hypertension, age ≥ 75 years, diabetes mellitus, stroke, vascular disease, age 65 to 74 years, sex category) scores showed just moderate discrimination ability in predicting thromboembolic complications in patients with nonvalvular atrial fibrillation (AF).

HYPOTHESIS

To determine the association of antithrombin III (AT-III) deficiency and mean platelet volume (MPV) with the development of stroke or left atrial (LA) thrombus in patients with AF.

METHODS

AT-III and MPV were analyzed in 352 patients with AF. The primary endpoint was a composite of ischemic stroke event and incidental LA thrombus.

RESULTS

There were 50 events (14.2%) during a mean 35.4 months of follow-up. A significantly higher stroke or LA thrombus rate was observed in the low-AT-III group (<70%) than that in the high-AT-III group (≥70%). A significantly higher stroke or LA thrombus rate was observed in the high-MPV group (≥7.0 fL) than that in the low-MPV group (<7.0 fL). AF patients with an MPV ≥7.0 fL and AT-III deficiency had higher stroke or LA thrombus risk than those without an MPV ≥7.0 fL and AT-III deficiency. In the Cox proportional hazard analysis, high MPV was found to be an independent predictor of stroke or LA thrombus risk (hazard ratio: 6.408; 95% confidence interval: 2.874-14.286). Although AT-III deficiency was not an independent predictor of stroke or LA thrombus risk, a trend was observed.

CONCLUSIONS

High MPV and AT-III deficiency were predictive markers for stroke or LA thrombus. Their predictive power for stroke was independent of antiplatelet treatment, anticoagulation therapy, and a high CHA₂ DS₂ -VASc score in patients with AF.

Approaches to Left Atrial Appendage Closure: Device Design, Performance, and Limitations

Up to 6.1 million people in the United States have atrial fibrillation (AF), which is associated with an increased risk of stroke. Oral anticoagulants are the mainstay of stroke prevention in AF. For decades, warfarin was the only available drug, fraught with compliance limitations, a narrow therapeutic window, and a high risk of hemorrhage. Pharmacologic developments have produced new anticoagulants that have improved the rates of stroke related to AF; however, they still confer a high risk of bleeding, making them unsuitable for some patients. Studies have shown that roughly 90% of strokes in patients with AF occur in the left atrial appendage (LAA). This understanding has prompted the development and testing of novel percutaneous strategies for LAA closure as an alternative to anticoagulation therapy. The following review examines the relative merits and shortcomings of these strategies and explores future prospects in the prevention of AF-related stroke.

Selecting antithrombotic therapy for patients with atrial fibrillation

When considering anticoagulant therapy for patients with atrial fibrillation, one must balance the reduction in risk of thromboembolism that this therapy offers against the risk of bleeding that it poses. The American Heart Association, American College of Cardiology, and Heart Rhythm Society updated their atrial fibrillation guidelines in 2014. This review outlines a rationale for clinical decision-making based on the new guidelines and summarizes the currently approved drugs.

Percutaneous Left Atrial Appendage Ligation for Stroke Prevention in Atrial Fibrillation

Prevention of thromboembolic complications in atrial fibrillation remains a tremendous clinical challenge. Knowledge that the left atrial appendage (LAA) is the most common anatomical origin of cardioembolic strokes1 has been the main motivation to develop clinical and procedural strategies to exclude the LAA from the circulation, either surgically or percutaneously. This review discusses the rationale behind these strategies, their relative merits, and future prospects for LAA exclusion strategies.

Antiplatelet therapy as a modulator of stroke aetiology: a meta-analysis

AIMS

Antiplatelet therapy reduces the incidence of ischaemic stroke. Platelet-mediated thrombosis contributes variably to the major subtypes of stroke as defined by the TOAST criteria: large artery atherosclerosis (LAA), cardioembolic (CE) and small vessel occlusion (SVO). The effect of antiplatelet therapy on the incidence of each subtype is unknown and is the subject of this meta-analysis.

METHODS

Electronic databases were searched for articles comparing the effect of antiplatelet therapy on the incidence of stroke according to aetiological subtype. Studies containing subjects prescribed anticoagulant therapy or solely investigating subjects with atrial fibrillation were excluded. Pooled odds ratios (ORs) were calculated using a fixed effects model.

RESULTS

Nine studies were included (n = 5739). In patients who had an ischaemic stroke, pre-event antiplatelet therapy was associated with significantly decreased incidence of LAA (OR 0.88, 95% CI 0.79, 0.99; P = 0.026), increased incidence of CE (OR 1.23, 95% CI 1.08, 1.41; P = 0.002) and no effect on SVO (OR 0.99, 95% CI 0.88, 1.11; P = 0.806). Concordant non-significant trends were observed in primary prevention populations (n = 751): LAA (OR 0.81, 95% CI 0.57, 1.15; P = 0.240), CE (OR 1.29, 95% CI 0.89, 1.87; P = 0.179) and SVO (OR 0.99, 95% CI 0.73, 1.36; P = 0.970). Subgroup analysis of aspirin monotherapy (n = 3786) demonstrated a significant reduction in LAA (OR 0.87, 95% CI 0.76, 1.00; P = 0.046), but non-significant effects on the incidence of CE (OR 1.17, 95% CI 0.99, 1.39; P = 0.068) and SVO (OR 1.04, 95% CI 0.91, 1.20; P = 0.570). Probability of publication bias was low (P > 0.05).

CONCLUSIONS

Antiplatelet therapy preferentially reduces the incidence of LAA stroke compared with CE and SVO subtypes.

Atrial fibrillation in heart failure: stroke risk stratification and anticoagulation

For an individual patient with both atrial fibrillation and heart failure, stroke risk is one of the most prominent mitigating factors for subsequent morbidity and mortality. Although the CHADS₂ stroke risk score is the most widely used score for risk stratification, it does not take into account the risk factors of vascular disease, female gender, or the age group 65-74 years, for which there is increasing evidence. There is also evidence that diastolic heart failure is as much a risk factor for stroke as systolic heart failure. The new oral anticoagulants dabigatran, rivaroxaban and apixaban appear to be appropriate agents in the heart failure population with atrial fibrillation and risk factors for stroke although there are dose-adjustments for renal insufficiency and these medications are contraindicated in advanced renal disease. As with the atrial fibrillation population as a whole, bleeding risk should be considered for every patient with heart failure prior to making recommendations regarding anticoagulation.

Effect of Ximelagatran and Warfarin on Stroke Subtypes in Atrial Fibrillation

Background and Purpose:

The most common stroke subtype among atrial fibrillation (AF) patients not receiving anticoagulants is cardioembolic. In the SPORTIF III and V trials, the oral direct thrombin inhibitor ximelagatran was as effective as warfarin in reducing the risk of stroke in patients with nonvalvular AF. We assessed any differential effect of warfarin versus ximelagatran on the risk and outcome of cardioembolic and noncardioembolic stroke.

Methods:

7329 patients with AF and ≥1 risk factors for stroke were randomized to treatment with warfarin (target international normalized ratio 2.0-3.0) or fixed-dose ximelagatran. Strokes were classified into specific subtypes. Therapeutic effect of warfarin and ximelagatran, adverse events, and stroke outcomes were assessed according to stroke subtype.

Results:

The annual stroke rate was low for both cardioembolic (ximelagatran, 0.39%; warfarin, 0.47%) and noncardioembolic stroke (ximelagatran, 0.57%; warfarin, 0.37%). In ischemic strokes, 33.9% (ximelagatran) and 34.3% (warfarin) had strokes of presumed cardioembolic origin. When fatal stroke, disabling stroke, myocardial infarction, and death from any cause were combined as poor outcome, patients with cardioembolic strokes had the highest rate of poor outcome (40%) but this was non- significant.

Conclusions:

In SPORTIF III and V the efficacy of warfarin and ximelagatran were similar for prevention of cardioembolic and noncardioembolic strokes. Overall outcome tended to be worse following cardioembolic stroke. Ximelagatran has been withdrawn from the market due to hepatic side effects, but similar compounds are presently being studied.

Pharmacotherapy for atrial fibrillation in elderly hospitalized patients with comorbid congestive heart failure in australia: A retrospective study

BACKGROUND

Despite the proven effectiveness of antiplatelet and anticoagulation treatment for atrial fibrillation (AF), their use has been suboptimal in practice, particularly in rural areas of Australia.

OBJECTIVE

The aim of this study was to describe medication use in the management of AF in elderly hospitalized patients with comorbid congestive heart failure (CHF).

METHODS

The hospital records of patients with a diagnosis of AF and CHF were reviewed in a rural Australian medical center. All the patients were hospitalized because of significant systolic ventricular dysfunction. The collected data included age, sex, weight, presenting symptoms of AF, and principle diagnosis on admission; medical history; and history of smoking and alcohol consumption. Electrocardiogram before hospital discharge was also retrieved from patient's medical records and was analyzed by the investigators. Cardiovascular and noncardiovascular drugs administered during the hospital stay and at discharge were also documented. Comparison of antiarrhythmic and anticoagulant drugs was made between patients who had AF while hospitalized and those who had a history of AF but were in sinus rhythm while hospitalized. When patients had ≥2 moderate risk factors (eg, age ≥75 years, hypertension, CHF, left ventricular ejection fraction ≤35%, diabetes mellitus) or ≥1 high risk factor (eg, previous stroke, transient ischemic attack or embolism, mitral valve stenosis, or prosthetic heart valve), they were defined as being eligible for anticoagulation treatment.

RESULTS

One hundred forty patients (74 men, 66 women; mean [SD] age, 77.1 [6.9] years; all were white) had a diagnosis of AF and were selected for the study. Of these, 92 patients (65.7%) (47 women, 45 men; mean [SD] age, 77.4 [9-2] years) had continuous AF and 48 patients (34.3%) (29 men, 19 women; mean [SD] age, 76.3 [12.4] years) had a history of AF but were in sinus rhythm at admission and discharge. The most commonly used antiarrhythmic drug was digoxin, which was prescribed significantly more frequently in the AF group than in the history of AF group (50 (54.3%] vs 14 [29.2%]; P < 0.01). Amiodarone was prescribed significantly less frequently in the continuous AF group than in the group with a history of AF (7 [7.6%] vs 19 [39-6%]; P < 0.01). There was no significant between-group difference in the use of β-blockers (26 [28.3%] vs 19 [39-6%]), verapamil/diltiazem (9 [9-8%] vs 3 [6.3%]), or Sotalol (2 [2.2%] vs 4 [8.3%]). The mean (SD) resting heart rate for the 140 study patients was 91 (27) bpm. The mean resting heart rate for the patients with AF was significantly higher at admission than at discharge (97 [28] vs 79 [19] bpm; P < 0.01). Of the 110 patients who were eligible for anticoagulation treatment, 64 (58.2%) were prescribed warfarin at discharge. Eligible patients not receiving oral warfarin were significantly older than those who did receive warfarin (79-7 [9-0] vs 75.8 [9.0] years; P = 0.02).

CONCLUSIONS

In these elderly hospitalized Australian patients with AF and CHF, digoxin, β-blockers, and amiodarone were the most commonly used antiarrhythmic drugs. Anticoagulation treatment was prescribed in ~60% of these patients.

Left atrial appendage occlusion and ligation devices: what is available, how to implement them, and how to manage and avoid complications

OPINION STATEMENT

Atrial fibrillation (AF) is the most common cardiac arrhythmia worldwide, and it is associated with an elevated risk of thromboembolic events, including ischemic stroke. Evidence suggests that at least 90 % of left atrial thrombi discovered in patients with AF are localized to the left atrial appendage (LAA). Surgical ligation or excision of the LAA is considered the standard of care in patients who undergo mitral valve surgery or as an adjunct to a surgical Maze procedure for treatment of AF. In addition, in selected patients with AF and an elevated risk of thromboembolic events, particularly in those with contraindication to oral anticoagulation (OAC) therapy, it is reasonable to consider LAA exclusion to offer protection against ischemic stroke and other embolic complications. This can be achieved through a number of different strategies, including surgical amputation or ligation of the LAA, percutaneous endocardial occlusion of the LAA by deployment of occlusive devices, and also ligation of the LAA via a closed-chest, percutaneous, epicardial catheter-based approach in select patients. Although results from several recent percutaneous LAA closure and ligation studies are highly promising, the evidence for long-term efficacy and safety is insufficient to presently recommend this approach to all patients other than those in whom long-term OAC is contraindicated. Future randomized studies are required to further address the long-term safety and efficacy of these therapeutic options. Finally, the role for LAA occlusion and ligation seems less clear in patients who undergo successful catheter ablation of AF, since at least in a subgroup of these patients antiplatelet therapy alone has been shown to be sufficient.

Platelet factor XIII gene expression and embolic propensity in atrial fibrillation

Nearly 15% of patients with non-valvular atrial fibrillation (NVAF) have left atrial appendage thrombus (LAAT) by transesophageal echocardiography (TEE) and yet the annual stroke rate averages 5%. The aim of this study was to identify variables influencing embolic propensity of LAAT. Platelet RNA was extracted from platelet-rich regions within formalin-fixed, paraffin-embedded specimens obtained from NVAF patients during cardiac surgery (26 LAAT from 23 patients) or peripheral embolectomy (51 thrombi from 41 patients). Platelet RNA was also assessed from whole blood from 40 NVAF patients. Expression of six platelet-predominate genes: H2A histone family, A1 domain of factor XIII, integrin α₂bβ₃; glycoprotein IX, platelet factor 4, glycoprotein Ib, was performed using TaqMan MGB-probe based quantitative real-time polymerase chain reaction. Platelet factor XIII subunit A gene expression was significantly lower in embolised compared to non-embolised thrombi as determined by normalised cycle threshold values (4.0 ± 1.2 v 2.8 ± 1.8, p=0.02). Expression of other genes did not differ by embolic status. In conclusion, RNA extracted from formalin-fixed, paraffin-embedded platelet-rich tissues can be used for analysis of platelet-predominate gene expression. Variable factor XIII gene expression in thrombi generated during NVAF may in part explain the propensity to embolisation.

Safety and efficacy of oral anticoagulation therapy in Chinese patients with concomitant atrial fibrillation and hypertension

Limited evidence is available on the safety and efficacy of anticoagulants in non-valvular atrial fibrillation (AF) patients with concomitant hypertension. We investigated the safety and efficacy of 476 consecutive anticoagulated Chinese outpatients with non-valvular AF and hypertension. Occurrence of ischaemic stroke and major bleeding, and international normalized ratio (INR) values during these events were recorded. There was no significant difference in anticoagulation control between patients with or without hypertension. INR-specific incidence rates of the events were calculated, which showed no excessive risk for ischaemic stroke (2.5 vs 1.6% per year, P=0.22) or major bleeding (3.9 vs 3.2% per year, P=0.29) in non-valvular AF patients with or without hypertension. In multivariate analysis, congestive heart failure, smoking and high CHADS2 score were independent predictors for ischaemic stroke, whereas use of antiplatelet agents was an independent predictor for bleeding. It can be noted that hypertension was not associated with ischaemic stroke or major bleeding. Hypertensive patients who achieved target blood pressure control (<130/80 mm Hg) had a lower ischaemic stroke (0.9 vs 3.1% per year, P=0.01), but similar bleeding risk compared with those not achieving target blood pressure. Our findings demonstrate the effects of hypertension on the outcomes of warfarin therapy; further investigation is needed to clarify whether more aggressive antihypertensive therapy could result in better outcomes in hypertensive patients with non-valvular AF.

Differential effect of previous antiplatelet use on stroke severity according to stroke mechanism

BACKGROUND AND PURPOSE

The effect of previous antiplatelet use on stroke severity is controversial. We assume that this controversy is attributable to its difference according to the stroke mechanism.

METHODS

Using a prospective stroke registry, patients who were hospitalized because of ischemic stroke and had relevant lesions on MRI were selected. Patients who were using anticoagulants or whose stroke subtype was categorized as stroke of other determined etiology or undetermined etiology were excluded. Baseline stroke severity was measured using the National Institutes of Health Stroke Scale scores at presentation and was compared between no previous antiplatelet users and previous antiplatelet users with stratification by stroke subtypes.

RESULTS

Among the 1622 patients, a total of 490 (30.2%) patients reported use of an antiplatelet within 1 week of stroke onset. The baseline National Institutes of Health Stroke Scale score showed no difference between the nonantiplatelet and antiplatelet groups by crude comparison. However, the interaction between previous antiplatelet use and stroke subtype was significant (P=0.023) in a multivariable analysis; when the study subjects were stratified by stroke subtype, the difference in baseline National Institutes of Health Stroke Scale between the nonantiplatelet and platelet groups was significant in the large artery atherothrombosis group but not in those with cardioembolism and small-vessel occlusion before and after adjustments.

CONCLUSIONS

Our study suggests that the reduction of initial stroke severity in the previous antiplatelet users may differ by stroke mechanism.

Predicting left atrial thrombi in atrial fibrillation

BACKGROUND

The aim of the study was to determine whether CHADS(2) score is predictive of left atrial appendage thrombus (LAAT) in nonvalvular atrial fibrillation (AF). Strategies for effective stroke prevention in AF require tools capable of identifying those patients at greatest risk for embolization of LAAT and most likely to benefit from warfarin. Nearly half of strokes in AF are due to noncardioembolic mechanisms for which antiplatelet therapy would be more appropriate. Previous attempts to develop such tools have been limited by including patients without proven cardioembolism.

METHODS

Nonanticoagulated, nonvalvular AF patients with (cases) or without (controls) LAAT by transesophageal echocardiography were identified using Mayo Clinic Echocardiography and Cardioversion Unit Databases (Rochester, MN). Type and duration of AF, CHADS(2) score, and echocardiography measures were compared to determine variables predictive of LAAT.

RESULTS

The CHADS(2) score was significantly higher for cases (n = 110, mean +/- SD 2.8 +/- 1.6) compared to controls (n = 387, 1.6 +/- 1.3). By multivariate analysis, independent predictors of LAAT included heart failure (HR 5.78, P < 0001), prior stroke/transient ischemic attack (HR 3.94, P < .0001), diabetes mellitus (HR 1.98, P = .015), permanent AF (HR 3.02, P < .05), AF duration (HR 2.24, P < .05), and spontaneous echocardiographic contrast (HR 4.35, P = .005). Using these elements, a new scoring system provided cleaner case-control separation (C-index 0.90) and higher predictive power compared to CHADS(2) (C-index 0.71).

CONCLUSIONS

The CHADS(2) score predicts the presence of LAAT in AF patients. Some, but not all, variables within this score are predictive of LAAT. By including only echo and clinical variables predictive of LAAT, our novel scoring system better identified those AF patients at greatest cardioembolic risk.

Is the left atrial appendage more than a simple appendage?

The left atrial appendage (LAA) is a cardiac structure with unique anatomic and functional features. It is significantly more than a simple chamber appended to the left atrium (LA), differing from the LA in structure, function, and hormonal activity. Unfortunately, it is the source of more than 90% of cardiac-based emboli, particularly in atrial fibrillation, mandating lifelong anticoagulation. Percutaneous LAA exclusion was developed to limit or eliminate cardioembolic events in patients with atrial fibrillation. Benign healing of the appendage occurs without adverse hemodynamic effects, and with no residual surface thrombus or tissue damage. The feasibility of this treatment is now established, suggesting that percutaneous therapy is safe, practical and possibly effective to eliminate the need for anticoagulation and significantly reduce cardioembolic events.

Strokes in paroxysmal atrial fibrillation have more favorable outcome than in permanent atrial fibrillation

OBJECTIVE

Our aim was to compare the course of IS due to ptAF and pxAF.

METHODS

A prospective, single-center study was conducted in patients with AF and acute IS with 6-month follow-up.

RESULTS

We included 178 patients: 70 (39%) with pxAF and 108 (61%) with ptAF. Compared with patients with ptAF, patients with pxAF more often presented with subcortical, mainly lacunar strokes (21% vs 8%, P = 0.01) and were less frequently dependent at discharge (16% vs 42%, P < 0.001) and after 6 months (16% vs 20%, P < 0.001). Strokes in patients with pxAF were more frequently categorized as non-cardioembolic (35% vs 18%, P = 0.01). In the multivariate analysis, after adjustment for confounding factors (diabetes, chronic heart failure, high risk of thromboembolism and lack of prestroke anticoagulation), ptAF was an important risk factor for unfavorable short-term (OR 5.4; P < 0.01) and long-term outcomes (OR 2.6, P = 0.01) of IS. In all patients with AF, the occurrence of non-cardioembolic stroke was related to a reduced risk of dependence or death in short-term outcome (OR 0.4, P = 0.04) and marginally influenced long-term outcome (OR 0.49, P = 0.09).

CONCLUSIONS

The present study suggests that, compared with patients with ptAF, ISs in patients with pxAF have better outcomes.