Mechanisms of Stroke in Atrial Fibrillation

Triglyceride-Glucose Index Predicts Major Adverse Cardiovascular and Cerebrovascular Events in Patients with Atrial Fibrillation

This study aimed to explore the relationship between the trajectory of the triglyceride-glucose (TyG) index and the occurrence of major adverse cardiovascular and cerebrovascular events (MACCE) in patients with atrial fibrillation (AF).This prospective study included 1979 patients with AF, who were initially selected from the Kailuan study. Patients of AF were split into four groups according to the value of TyG index. The clinical endpoint was MACCE, including myocardial infarction and ischemic stroke. Cox proportional hazard models were employed to examine the hazard ratio (HR) and 95% confidence interval (CI) for MACCE in various trajectory groups.The mean age of all patients with AF was 67.65 ± 11.15 years, and 1752 (88.53%) were male. Over a median follow-up duration of 5.31 years, in total 227 MACCE were recorded. MACCE cumulative incidence in Quartile 4 (26.96%) was significantly higher than those in other quartiles (P = 0.023). Multivariate Cox proportional hazards regression analysis showed that a higher TyG index (Quartile 4) was significantly and positively linked to MACCE in patients with AF (P = 0.023, HR: 2.103; 95% CI: 1.107-3.994).The evaluated TyG index is significantly associated with an increased risk of MACCE in patients with AF.

Role of the score for the targeting of atrial fibrillation (STAF) combined with D-dimer in screening ischemic stroke patients with atrial fibrillation

Background

We aim to explore the effect of the score for the targeting of atrial fibrillation (STAF) combined with the serum D-dimer (DD) level in screening acute ischemic stroke patients with atrial fibrillation (AF).

Methods

This study is a retrospective case observation study. This study consecutively selected patients with acute ischemic stroke who were hospitalized in the Department of Neurology at Zhuhai Hospital Affiliated with Jinan University from February 2019 to February 2021. Venous blood was drawn from all patients within 24 hours of hospitalization for DD detection. In accordance with the medical records, the patients were classified into an AF group and a non-AF group and were scored according to the STAF standard. A combined test method was used to estimate the diagnostic screening value of the STAF combined with the DD value for acute ischemic stroke patients with AF.

Does amiodarone impact on apixaban levels? The effect of amiodarone on apixaban level among Thai patients with non-valvular Atrial Fibrillation

BACKGROUND

Apixaban and amiodarone are drugs used for non-valvular atrial fibrillation (NVAF) in routine practice. The evidence about apixaban plasma levels in patients who receive apixaban with amiodarone, including bleeding outcomes, has been limited. This study aimed to compare the apixaban plasma levels and bleeding outcomes between apixaban monotherapy and apixaban with amiodarone groups.

METHODS

This study was a prospective, observational, and single-center research which was conducted from January 2021 to January 2022 in NVAF patients who received apixaban at a tertiary care hospital located in the center of Bangkok, Thailand.

RESULTS

Thirty-three patients were measured for their median (5th-95th percentile) apixaban plasma levels. The trough of apixaban plasma level (Ctrough) were 108.49 [78.10-171.52] and 162.05 [87.94-292.88] μg/L in the apixaban monotherapy and apixaban with amiodarone groups, respectively (p = 0.028). Additionally, the peaks of apixaban plasma level (Cpeak) were 175.36 [122.94-332.34] and 191 [116.88-488.21] μg/L in the apixaban monotherapy and apixaban with amiodarone groups, respectively (p = 0.375). There was bleeding that occurred in 7 patients (21.21%); 5 patients in the apixaban monotherapy group and 2 patients in the apixaban with amiodarone group, respectively.

CONCLUSIONS

Amiodarone may increase the peaks and troughs of apixaban plasma levels. The co-administration of apixaban with amiodarone is generally well tolerated. However, the careful observation of bleeding symptoms in individual cases is necessary to ensure safety.

Role of Malnutrition in Atrial Fibrillation: A Prospective Study including Individuals ≥ 75 Years of Age

BACKGROUND

Atrial fibrillation (AF) is the most common rhythm disorder in the elderly. The AF can cause life-threatening thromboembolic complications. Therefore, there is a need to determine the risk factors of AF. In this study, we aimed to examine the association of markers of malnutrition with AF in individuals aged 75 years and older and to find the factors that may affect mortality.

METHODS

In this prospective study, 358 consecutive individuals aged 75 years and older presenting to the cardiology outpatient clinic were included. All participants were divided into AF and sinus rhythm (SR) groups. In addition, a questionnaire and scoring system were used to assess malnutrition status. Information was obtained from all patients through outpatient clinic visits or telephone interviews for one year. Death from any cause was considered as the endpoint.

RESULTS

AF was observed in 71 (19.8%) patients. Death was higher in patients with AF (p < 0.001), high CONUT score (p = 0.018), and GLIM malnutrition (p = 0.018). GLIM malnutrition caused a 2.8-fold increase in the development of AF.

CONCLUSIONS

Screening for malnutrition in the elderly is essential. According to GLIM criteria, malnutrition may play a role in the development of AF and increase one-year mortality in the elderly.

Exploring clinician perspectives on patients with atrial fibrillation who are not prescribed anticoagulation therapy

Objective

To explore themes underlying why anticoagulants are under-prescribed for stroke prevention in atrial fibrillation (AF) patients from the clinician's perspective and characteristics of those patients.

Methods

Clinicians at the University of Utah Health system were recruited for semi-structured 15-minute interviews. An interview guide focused on anticoagulant prescribing practices for patients with AF. Interviews were transcribed verbatim. Two reviewers independently coded passages corresponding with key themes.

Results

Eleven practitioners were interviewed from cardiology, internal medicine, and family practice. Five themes were found: the role of compliance in anticoagulation decision making, the role of pharmacists in supporting clinicians, the use of shared decision making and risk communication, risk of bleeding as the main barrier to taking anticoagulants, and the variety of reasons patients have for not starting or discontinuing anticoagulants.

Conclusion

Fear of bleeding was the foremost reason underlying anticoagulant underutilization in patients with AF followed by compliance, and patient worries. Communication between patients and clinicians as well as interdisciplinary teamwork are key to understanding and improving anticoagulant prescribing in AF.

Innovation

Our study was the first to assess the role pharmacists play in prescribing clinician's decisions surrounding anticoagulant use in AF. Pharmacists could play an important collaborative role in SDM.

Temporal Association Between Episodes of Atrial Fibrillation and Risk of Ischemic Stroke

Importance

Understanding the temporal association between atrial fibrillation (AF) and ischemic stroke informs our understanding of the AF-stroke mechanism and treatment of paroxysmal AF.

Objective

To define the temporal association between episodes of AF and stroke in patients with cardiac implantable electronic devices (CIEDs).

Design, Setting, and Participants

In this case-crossover study, data from a large national electronic health record database were linked with a single-vendor database of heart rhythm records of patients with CIEDs capable of continuous heart rhythm monitoring. Patients with CIEDs who sustained an ischemic stroke who also had 120 days of continuous remote rhythm monitoring prestroke were included. Data were collected from January 2007 to March 2017, and data were analyzed from November 2019 to June 2020.

Exposure

AF for 5.5 hours or more on any given day during days 1 to 30 vs days 91 to 120 prestroke.

Main Outcomes and Measures

Odds ratio for stroke comparing AF during days 1 to 30 vs 91 to 120 prestroke. This analysis was planned prior to the study.

Results

From 466 635 patients included in both the Optum electronic health record and CareLink databases, 891 patients with CIEDs and ischemic stroke with continuous monitoring in the 120 days prestroke were identified. Of 891 included patients, 575 (64.5%) were male, and the median (interquartile range) age was 76 (67-82) years. The vast majority of patients with stroke had either no AF meeting the threshold duration of 5.5 hours or more in both the case and control periods (682 of 891 [76.5%]) or AF of 5.5 hours or more in both periods (143 of 891 [16.0%]). For those not meeting the 5.5-hour AF threshold in either period, there was no or very little AF throughout the 120 days prestroke. A total of 66 patients had informative, discordant arrhythmic states, with 52 having AF of 5.5 hours or more in the case period vs 14 in the control period (odds ratio [OR], 3.71; 95% CI, 2.06-6.70). Stroke risk was increased most in days 1 to 5 following an AF episode (OR, 5.00; 95% CI, 2.62-9.55). AF greater than 23 hours on a given day was associated with the clearest increase in stroke risk (OR, 5.00; 95% CI, 2.08-12.01).

Conclusions and Relevance

In this large cohort of patients with CIEDs and continuous rhythm monitoring prior to ischemic stroke, excess stroke risk above baseline was highest within 5 days of an episode of AF of 5.5 hours or more in duration and diminished rapidly thereafter. Our findings are consistent with the traditional view that AF is directly and transiently associated with ischemic stroke. These results provide support for trials of time-delimited anticoagulation for patients with infrequent multihour episodes of AF and rigorous, continuous rhythm monitoring.

Antithrombotic Treatment after Atrial Fibrillation Ablation

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Atrial fibrillation is a major cause of debilitating strokes and anticoagulation is an established and indispensable therapy for reducing their rate. Ablation of the arrhythmia has emerged as a putative means of disrupting its natural course by isolating its triggers and modifying its substrate, dependent on the chosen method. An important dilemma lies in the need for continuation of anticoagulation therapy in those previously receiving it following an, apparently, successful intervention, purportedly preventing arrhythmia recurrence with considerably high rates. Current guidance, given scarcity of high-quality data from randomized trials, focuses on established knowledge and recommends anticoagulation continuation based solely on estimated thromboembolic risk. In the present review, it will be attempted to summarize the pathophysiological rationale for maintaining anticoagulation post-successful ablation, along with the latter’s definition, including the two-fold effects of the procedure per se on thrombogenicity. Available evidence pointing to an overall clinical benefit of anticoagulation withdrawal following careful patient assessment will be discussed, including ongoing randomized trials aiming to offer definitive answers. Finally, the proposed mode of post-ablation anticoagulation will be presented, including the emerging, guideline-endorsed, role of direct oral anticoagulants in the field, altering cost/benefit ratio of anticoagulation and potentially affecting the very decision regarding its discontinuation.

Pattern of stroke in a rural Kenyan hospital

Background

The pattern of stroke in rural population differs from that in urban ones. Although there are many studies on this condition in sub-Saharan Africa, few studies about stroke pattern in a Kenyan rural area exist.. This study therefore aims at describing the characteristics of stroke in a rural Kenyan hospital.

Patients and Methods

The study was conducted on 227 consecutive patients admitted with a World Health Organization (WHO) diagnosis of stroke in Kangundo Hospital, a level IV facility in Machakos, Eastern Kenya, between April 2015 and September 2016. The sub-type and anatomical distribution of stroke as well as the age, gender of the patients were recorded prospectively. Diagnosis was made through physical neurological examination and confirmed by Computerized Tomography (CT) scan imaging. Only those with complete bio-data, past medical and social history, clinical and physical findings of the patients and imaging results were included. The data were entered into a pre-formatted questionnaire, analysed for means, standard deviations and frequencies, and are presented in tables and bar charts.

Results

Out of 3200 medical admissions, 227 (7.09%) had a confirmed diagnosis of stroke. Ischaemic stroke was more common (67.4%) than haemorrhagic stroke (32.6%). It affected mainly the anterior circulation, especially the middle cerebral artery (39%). The mean age of patients was 68.8 years, (Range 32–96). It was more common in females (62%) than in males (38%). Hypertension was the most common (74%) risk factor followed by alcohol abuse (63%), tobacco smoking (48%) and diabetes mellitus (42%).

Conclusion

Ischaemic stroke was the more common major cause of morbidity in the rural hospital studied in Kenya. It occurred most commonly among elderly females, with the most frequent comorbidities being hypertension. In addition, modifiable lifestyle factors like alcohol abuse and cigarette smoking contributed to the prevalence; hence we recommend the control of blood pressure and glucose as well as lifestyle modification to reduce the scourge in our studied population.

Diagnostic value of STAF score in combination with D-dimer in cardioembolism

The aim of this study was to evaluate the diagnostic value of the Score for the Targeting of Atrial Fibrillation (STAF) in combination with the serum D-dimer (DD) levels in cardioembolism(CE).This study was a retrospective case-onlystudy, consecutively including patients with acute ischemic stroke. All patients were evaluated following the STAF scoring criteria and were classified according to the Trial of ORG 10172 in Acute Stroke Treatment (TOAST) etiology classification criteria. A total of 317 patients were enrolled, including 37 CE cases (11.67%). STAF ≥5 showed a sensitivity of 89% and a specificity of 91% for the diagnosis of CE, whereas DD >791.30 ng/mL had a sensitivity of 58% and a specificity of 78%. When the STAF was used in combination with the DD level, the sensitivity was 95%, and the specificity was 100%.STAF score is an excellent tool for the diagnosis of CE when combined with DD, and can facilitate the etiological classification of acute ischemic stroke.

Catheter ablation for AF improves global thrombotic profile and enhances fibrinolysis

Patients with atrial fibrillation (AF) are at increased risk of thrombotic events despite oral anticoagulation (OAC). Radiofrequency catheter ablation (RFCA) can restore and maintain sinus rhythm (SR) in patients with AF. To assess whether RFCA improves thrombotic status. 80 patients (71% male, 64 ± 12y) with recently diagnosed AF, on OAC and scheduled to undergo RFCA or DC cardioversion (DCCV) were recruited. Thrombotic status was assessed using the point-of-care global thrombosis test (GTT), before, and 4-6 weeks after DCCV and 3 months after RFCA. The GTT first measures the time taken for occlusive thrombus formation (occlusion time, OT), while the second phase of the test measures the time taken to spontaneously dissolve this clot through endogenous thrombolysis (lysis time, LT). 3 months after RFCA, there was a significant reduction in LT (1994s [1560; 2475] vs. 1477s [1015; 1878]) in those who maintained SR, but not in those who reverted to AF. At follow-up, LT was longer in those in AF compared to those in SR (AF 2966s [2038; 3879] vs. SR 1477s [1015; 1878]). RFCA resulted in no change in OT value, irrespective of rhythm outcome. Similarly, there was no change in OT or LT in response to DCCV, irrespective of whether SR was restored. Successful restoration and maintenance of SR following RFCA of AF is associated with improved global thrombotic status with enhanced fibrinolysis. Larger studies are required to confirm these early results and investigate whether improved thrombotic status translates into fewer thromboembolic events.

Serum D-dimer Levels Are Proportionally Associated with Left Atrial Enlargement in Patients with an Acute Ischemic Stroke due to Non-valvular Atrial Fibrillation

Objective Left atrial enlargement (LAE) may predispose individuals to blood stasis in atrial fibrillation (AF), and thus play a crucial role in thrombogenesis. The D-dimer level is one of the surrogate markers for a hypercoagulable state and reflects thrombus formation in AF. Since the D-dimer level reflects hypercoagulability as well as thrombus and fibrin burdens, LAE could be associated with a D-dimer elevation. However, no studies have explored this association or which factors contribute to increases in the D-dimer levels in patients with AF. Therefore, we assessed whether the serum D-dimer levels are related to the left atrial volume index (LAVI) or other vascular risk factors and also evaluated the association between the D-dimer levels and the initial stroke severity. Methods Ninety-eight consecutive patients with an acute ischemic stroke and non-valvular AF (NVAF) who were anticoagulation-naïve were enrolled, and all patients were stratified into moderate-to-severe and mild neurologic deficit groups using the National Institutes of Health Stroke Scale on admission. The association between the initial serum D-dimer levels and the LAVI was evaluated in all enrolled patients, and the serum D-dimer levels were compared between the two groups. Results The patients were classified into two groups according to the severity of the neurologic deficit. In a partial correlation coefficient analysis adjusted for confounding factors, an increase in the initial serum D-dimer levels was significantly associated with LAVI (r=0.286; p=0.027). A linear regression analysis showed that a history of peripheral artery disease was the factor most strongly associated with the serum D-dimer level (t=3.90, p<0.001), followed by LAVI (t=2.37, p=0.021) and a history of congestive heart failure (t=2.16, p=0.035). The D-dimer levels were higher in the moderate-to-severe neurologic deficit group than in the mild deficit group, but this difference was not statistically significant (4.5±7.1 vs. 1.6±2.6 mg/L, p=0.068). Conclusion The serum D-dimer levels were significantly associated with LAE in anticoagulation-naïve patients with an acute ischemic stroke and NVAF.

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].