Although Atrial Fibrillation Patients Research Articles

Abstract 11849: The Influence of Atrial Fibrillation on Mortality Among Cancer Patients

Background: Although atrial fibrillation (AF) is associated with an increased risk of mortality in the general population, it is less studied in cancer patients. Methods: Using an observational registry in Japan, adult patients diagnosed with cancer at the Kumamoto University Hospital between 2007 and 2018 were identified. The trend in the prevalence of AF and their effects on all-cause mortality were investigated. Results: As many as 30,706 cancer patients were identified, and 19,496 patients were included after excluding patients with significant missing values. The overall median follow-up time was 4.5 years. The prevalence of AF was steady during the study period (n=250, 1.3%), and anticoagulation drugs were used in approximately 90% of patients with CHADS 2 scores ≥ 1. The Kaplan-Meier analysis revealed that AF patients had a lower survival estimate compared with non-AF patients (adjusted HR, 1.23; 95% CI, 1.01-1.49) (Figure 1). Subgroup analyses indicated that AF patients treated with warfarin or without any anticoagulation drugs were associated with poor prognosis (adjusted HR, 1.30; 95% CI, 1.05-1.61, adjusted HR, 1.91; 95% CI, 1.06-3.46, respectively), however, AF patients treated with direct oral anticoagulants were not associated with it (adjusted HR, 0.65; 95% CI, 0.36-1.17) compared with non-AF patients. Conclusions: Approximately 1.3% of cancer patients had AF, and the majority received anticoagulation treatments. AF seemed to be associated with poor prognosis among cancer patients, and the extent of association varied across anticoagulation strategies. Further studies are warranted to investigate the influence of AF and its anticoagulation strategies on cancer patients.

Differences in Stroke or Systemic Thromboembolism Readmission Risk After Hospitalization for Atrial Fibrillation and Atrial Flutter

BackgroundAlthough atrial fibrillation (AF) and atrial flutter (AFL) are different arrhythmias, they are assumed to confer the same risk of stroke and systemic thromboembolism (STE) despite a lack of available evidence. In this study, we investigated the difference in the risk of stroke or STE after AF and AFL hospitalizations.MethodologyThe National Readmission Database (NRD) 2018 was used to identify AF and AFL patients using appropriate International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) codes and were followed until the end of the calendar year to identify stroke or STE readmissions. Survival estimates were calculated, and a Cox proportional hazards model was used to calculate the adjusted hazards ratio (aHR) and compare the risk of stroke or STE readmissions between AF and AFL groups.ResultsA total of 215,810 AF and 15,292 AFL patients were identified. AFL patients were more likely to be younger (66 vs. 70 years), male (68% vs. 47%), and had higher prevalence of obesity (25% vs. 22%), obstructive sleep apnea (14% vs. 12%), diabetes mellitus (31% vs. 26%), and alcohol use (6.9% vs. 5.5%) (all p < 0.01). After adjusting for potential patient and hospital-level characteristics, there was a statistically significant decrease in one-year stroke or STE readmission risk in AFL patients compared to AF patients (aHR 0.79 (0.66-0.95); p = 0.01).ConclusionsAFL patients are commonly younger males with a higher burden of medical comorbidity. There is a decrease in the one-year risk of stroke or STE events in AFL patients compared to AF. The predictors of stroke and STE are similar in both AFL and AF groups. Further studies with longer follow-up and anticoagulation data are needed to verify the results.

LA-Net: A Multi-Task Deep Network for the Segmentation of the Left Atrium.

Although atrial fibrillation (AF) is the most common sustained atrial arrhythmia, treatment success for this condition remains suboptimal. Information from magnetic resonance imaging (MRI) has the potential to improve treatment efficacy, but there are currently few automatic tools for the segmentation of the atria in MR images. In the study, we propose a LA-Net, a multi-task network optimised to simultaneously generate left atrial segmentation and edge masks from MRI. LA-Net includes cross attention modules (CAMs) and enhanced decoder modules (EDMs) to purposefully select the most meaningful edge information for segmentation and smoothly incorporate it into segmentation masks at multiple-scales. We evaluate the performance of LA-Net on two MR sequences: late gadolinium enhanced (LGE) atrial MRI and atrial short axis balanced steady state free precession (bSSFP) MRI. LA-Net gives Hausdorff distances of 12.43 mm and Dice scores of 0.92 on the LGE (STACOM 2018) dataset and Hausdorff distances of 17.41 mm and Dice scores of 0.90 on the bSSFP (in-house) dataset without any post-processing, surpassing previously proposed segmentation networks, including U-Net and SEGANet. Our method allows automatic extraction of information about the LA from MR images, which can play an important role in the management of AF patients.

Abstract 10820: Atrial Fibrillation Catheter Ablation Reduces the Risk of Dementia: A Systematic Review and Meta-Analysis

Introduction: Although atrial fibrillation (AF) has a risk of cognitive dysfunction, it is not clear whether AF catheter ablation impacts cognitive function. Catheter ablation for AF prolongs the duration of sinus rhythm, thereby improving the quality of life and theoretically reducing the risk of dementia. Objective: We investigated the association of catheter ablation for AF with the occurrence of any dementia. Methods: A systematic search using electronic databases was performed from inception until January 15, 2021. Mantel-Haenszel risk ratio (RR) random-effects model (DerSimonian and Laird method) was used to summarize data. The primary outcome was occurrence of dementia during the follow-up period. Statistical analysis was performed using a meta-package for R version 4.0 and Rstudio version 1.2. Results: A total of 3 eligible studies (retrospective and prospective) consisting of 34,360 patients [Catheter ablation = 10,862 and medical therapy (antiarrhythmic drugs or rate-control drugs) = 23,498] were included in the meta-analysis. Patients in the ablation group were younger compared to medical therapy (59.6 ± 10.4 vs 60.3 ± 10.6 years; p&lt;0.001). Hypertension (55% vs 54.4%, p = 0.31), heart failure (23.7% vs 22.1%, p = 0.001), diabetes (14% vs 15.2%, p = 0.004), cerebrovascular accident (11% vs 10%, p = 0.005) and myocardial infarction (7.5% vs 6.5%, p&lt;0.001) were most common comorbidities, respectively. There was a lower incidence of dementia in AF patients treated with catheter ablation compared to medical therapy (2% vs 3.5%, RR 0.39, 95% CI 0.22-0.70, p&lt;0.01) during a mean follow-up period of 5.44 years. Conclusion: AF ablation patients have a significantly lower risk of dementia in comparison to AF patients without ablation.

Atrial fibrillation catheter ablation: an updated review of current guidelines and expert consensus documents.

Although atrial fibrillation (AF) is the most common cardiac arrhythmia, its management remains complex and depends on several variables. Over the past decade, catheter ablation has been widely used as an effective method for rhythm control in AF patients. Therefore, AF ablation has been the focus of many studies in recent years. Given the complexity of AF management and catheter ablation, several guidelines have been developed to regulate and direct management of AF patients. The European Society of Cardiology (ESC), together with the European Heart Rhythm Association (EHRA) and the European Association of Cardiothoracic Surgeons (EACTS), has been regulating the European guidelines, while the American Heart Association (AHA), along with the American College of Cardiology (ACC) and the Heart Rhythm Society (HRS), is publishing the US guidelines. Additionally, HRS, EHRA, and the Society of Thoracic Surgeons, along with representatives from heart rhythm societies from different parts of the world, have developed an "expert consensus statement on catheter and surgical ablation of AF." This article reviews and compares the most recent guidelines and consensus document on AF catheter ablation.

Adverse clinical events in Japanese atrial fibrillation patients with and without coronary artery disease—findings from the SAKURA AF Registry

Background: Although atrial fibrillation (AF) and coronary artery disease (CAD) are increasing in prevalence in Japan, real-world data regarding clinical outcomes in Japanese AF patients with CAD are limited.Methods: The SAKURA AF Registry is a prospective multi-center registry created to investigate outcomes of oral anticoagulant (OAC) use in Japanese AF patients. A study was conducted involving 3237 enrollees from 63 Tokyo-area institutions who were followed up for a median of 39.3 months. Clinical adverse events were compared between the patients accompanied with (n = 312) and without CAD (n = 2925).Results: The incidence of cardiovascular events and all-cause mortality rates were significantly higher among patients with CAD than among those without CAD (5.98 vs 2.52 events per 100 patient-years, respectively, p < 0.001; 3.27 vs 1.94 deaths per 100 patient-years, respectively, p = 0.012), but there was no difference in strokes/transient ischemic attacks or systemic embolisms (1.70 vs 1.34). After a multivariate adjustment, CAD remained a risk factor for cardiovascular events (hazard ratio [HR] = 1.57, 95% confidence interval [CI] = 1.08–2.25, p = 0.018). Among CAD patients, the propensity score-adjusted risk for major bleeding was significantly decreased among direct oral anticoagulant (DOAC) users in comparison to that among warfarin users (HR = 0.29, 95% CI = 0.07–0.94, p = 0.04), but other adverse clinical events did not differ significantly between these two groups.Conclusions: CAD did not appear to be a major determinant of strokes/TIAs, major bleeding, or all-cause mortality, but appeared to increase the risk of cardiovascular events in Japanese AF patients. The risk of major bleeding in CAD patients appeared to decrease when a DOAC rather than warfarin was administered. The data suggested that patients with AF and concomitant CAD require careful management and follow-up to reduce cardiovascular risks, and DOACs may be a better choice over warfarin when considering the risk of major bleeding.

Highlights From the Circulation Family of Journals.

Highlights From the Circulation Family of Journals.

Atrial Fibrillation Catheter Ablation Improves 1-Year Follow-Up Cognitive Function, Especially in Patients With Impaired Cognitive Function.

Although atrial fibrillation (AF) has a risk of cognitive dysfunction, it is not clear whether AF catheter ablation improves or worsens cognitive function. This prospective case-control study sought to assess the 1-year serial changes in the cognitive function with or without AF catheter ablation. We evaluated the Montreal Cognitive Assessment score in 308 patients (71.4% male, 60.6±9.1 years of age, 34.1% persistent AF) who underwent AF ablation (ablation group) and 50 AF patients on medical therapy who met the same indication for AF ablation (control group), at baseline and 3 and 12 months after enrollment. Cognitive impairment was defined as a published cutoff score of <23 points. To exclude any learning effects, we used the practice-adjusted reliable change index for assessing the cognitive changes. Preablation cognitive impairment was detected in 18.5% (57/308). The Montreal Cognitive Assessment score significantly improved 1 year after radiofrequency catheter ablation in both overall ablation group (24.9±2.9-26.4±2.5; P<0.001) and the propensity-matched ablation group (25.4±2.4-26.5±2.3; P<0.001), but not in the control group (25.4±2.5-24.8±2.5; P=0.012). Preablation cognitive impairment (odds ratio, 13.70; 95% CI, 4.83-38.87; P<0.001) was independently associated with an improvement in the 1-year post-ablation cognitive function. In the reliable change index analyses, 94.7% of propensity-matched ablation group showed an improved/stable cognitive function at the 1-year follow-up. Catheter ablation of AF, at least, does not deteriorate the cognitive function, but rather improves the performance on 1-year follow-up neurocognitive tests, especially in patients with a preablation cognitive impairment.

Chronic mitral regurgitation: Does atrial fibrillation impact outcome in patients managed with medical therapy only?

Background: The AHA/ACC guideline recommends surgery for symptomatic chronic severe mitral regurgitation or percutaneous mitral valve repair for high surgical risk or inoperable patients. Although atrial fibrillation (AF) is a known predictor of survival after either of these interventional procedures, its impact on the outcome of patients treated only medically is less well defined. Materials and Methods: This was a retrospective review of adult patients with chronic mitral regurgitation seen at our heart center from August 2014 to December 2017. Results: There were 102 patients, with a mean age of 58.4 ± 15.8 years and 51% were males. Major comorbidities were AF (58.8%), hypertension (HTN) (53.9%), pulmonary HTN (18.6%), and diabetes mellitus (10.8%). Sixty-seven (65.7%) patients had primary and 35 (34.3%) had secondary mitral regurgitation. Eighty-eight (86.3%) patients were in New York Heart Association Class 3/4, 92 (90.2%) in AHA/ACC Stages C/D, and 70 (68.6%) had left ventricular (LV) dysfunction with ejection fraction (EF) <60. Patients were subdivided into Group 1 – 60 (58.8%) patients with AF and Group 2 – 42 (41.2%) patients without AF. AF frequency was higher with primary or degenerative mitral regurgitation (PMR) versus secondary mitral regurgitation (SMR), 75% versus 25%, P = 0.031, whereas HTN was higher in SMR versus PMR, 77.1% versus 41.8%, P = 0.001. Four patients underwent mitral valve replacement and two patients implantable cardioverter defibrillator. All patients were treated with the AHA/ACC guideline-directed medical therapy (GDMT). All-cause mortality for Groups 1 and 2 was 25% and 14.3%, respectively, odds ratio was 2.0, and 95% confidence interval was 0.705–5.677, P = 0.285. Overall, Kaplan–Meier survival at 30 months was 63%, and log-rank analysis survival was 56% and 79% for Groups 1 and 2, respectively, P = 0.345. Conclusion: In a cohort of patients with chronic mitral regurgitation treated only medically with GDMT in a low-resource country, all-cause mortality and intermediate survival were comparable between AF and non AF patients.

Prognosis of high sinus heart rate after catheter ablation for atrial fibrillation.

Although atrial fibrillation (AF) catheter ablation increases sinus heart rate (HR), its mechanism and prognosis have not yet been clearly elucidated. We hypothesize that post-AF ablation high sinus HR (PA-HSR) is associated with a better clinical outcome of AF ablation without adverse cardiac effects. We studied 991 AF patients (75% male, 58 ± 11 years old, 70% paroxysmal AF) with HR variability (HRV) at 3 months and 1 year after catheter ablation, and pre- and post-1-year echocardiograms. Post-AF ablation high sinus HR was defined as an average HR greater than 2 SD (≥92 bpm) as measured by 24 h Holter. (1) Average HR increased significantly (P< 0.001), and PA-HSR was observed in 28 patients (2.8%) 3 months after AF ablation. At 1 year after catheter ablation, 21% were taking β-blockers and 36% maintained an average HR of ≥92 bpm. (2) Post-AF ablation high sinus HR was independently associated with pre-procedural high average HR (OR 1.097; 95% CI 1.029-1.169, P= 0.005), high left atrium (LA) electrogram voltage (OR 3.545; 95% CI 1.183-10.618, P= 0.024), and reduced root mean square of differences between successive NN intervals (rMSSD) at 3 months HRV (OR 0.959; 95% CI 0.919-0.999, P= 0.047). (3) At 1 year echocardiography, size reduction of LA (P= 0.055) or LV (P= 0.372) and the improvement in ejection fraction (P= 0.529) were not significantly different between patients with PA-HSR and those without. (4) Throughout 27 ± 17 months of follow-up, patients with PA-HSR showed significantly lower clinical recurrence than those without (log rank, P= 0.020). Post-AF ablation high sinus HR was observed in patients with smaller LA size and higher LA electrogram voltage and significant vagal modulation without adverse cardiac effects. Post-AF ablation high sinus HR was associated with a significantly lower clinical recurrence of AF after catheter ablation.

16-24: Identification of Heterogeneous Intra-Atrial Conduction Delay in Paroxysmal AF Patients by Dynamic Electrophysiological Characterization

Purpose of the Study: Although atrial fibrillation (AF) is classified by arrhythmia duration, the presentation, clinical course and response to treatment vary widely within paroxysmal AF (PAF) patients. We hypothesized that variable electrical remodeling exists between PAF patients, resulting in intra-atrial conduction delay which could be identified using a novel programmed stimulation technique. Methods Used: In 15 PAF patients undergoing index PVI, high density LA contact mapping using a 20 pole Pentaray catheter was performed during pacing from two atrial sites (BCL 470ms, S1S2 350ms to atrial ERP in -2% steps). Regional atrial conduction delay (S1S2delay), activation dispersion, and AF vulnerability were measured. Computer modeling was used to interrogate the mechanism of conduction delay. Summary of Results: Conduction delay showed a bimodal distribution (peaks for HRA / CS pacing 275 ± 11 / 271 ± 11ms and 326 ± 13 / 319 ± 16ms) and patients with inducible AF were characterized by increased activation dispersion (ΔLAT 672 ± 41ms vs 542 ± 17ms, P = 0.0446, Fig). Action potential remodeling across the population could explain observed variation in conduction delay, but resulted in insufficient conduction velocity restitution variation (3.7 ± 0.5ms-1/s vs 2.3 ± 0.5 ms-1/s, P = 0.1926) to explain the activation dispersion seen in AF-inducible patients.

Atrial fibrillation in amyloidotic cardiomyopathy: prevalence, incidence, risk factors and prognostic role

Background: Although atrial fibrillation (AF) is a known complication of amyloidotic cardiomyopathy (AC), a precise pathophysiological and prognostic characterization is not available. We therefore aimed to assess prevalence, incidence, risk factors and prognostic significance of AF in light-chain (AL), hereditary transthyretin-related (m-ATTR) and non-mutant transthyretin-related (wt-ATTR) AC.Methods: Retrospective study of 262 patients with AC (123 AL, 94 m-ATTR, 45 wt-ATTR) from a single center.Results: AF prevalence was 15% (AL 9%, m-ATTR 11%, wt-ATTR 40%). During a median follow-up of 1.2 years 11 patients developed AF (2.1% person-years). Age, heart failure (HF), left ventricular (LV) ejection fraction, renal involvement, left atrial size and right atrial pressure were independently associated with AF. AF was associated with incident HF but not with increased mortality. All AF patients were prescribed warfarin and none suffered thromboembolic events.Conclusions: In AC the prevalence of AF varies widely according to etiology with a mean value of 15% that reaches 40% in wt-ATTR amyloidosis. Age, HF, LV ejection fraction, left atrial size and right atrial pressure were the main independent risk factors, while wall thickness and etiology were not the main independent risk factors. AF does not seem to impact all-cause mortality but was strongly associated with prevalent and incident HF.

Of hammers and screws: renin-angiotensin-aldosterone system inhibition to prevent atrial fibrillation in patients with hypertension

This editorial refers to ‘Antihypertensive treatment and risk of atrial fibrillation: a nationwide study’[†][1], by S.C.W. Marott et al. , on page 1205 This editorial discusses the observation that monotherapy of uncomplicated hypertension with an ACE inhibitor or a sartan is associated with a lower risk of new-onset atrial fibrillation than treatment with a calcium channel blocker, diuretic, or beta-blocker. This association, found in a Danish nationwide database over a mean follow-up duration of 6–7 years, is put in context with the outcomes of controlled clinical trials testing similar interventions in patients without hypertension. In summary, the data suggest that different types of atrial fibrillation require different forms of preventive treatment, and that such ‘pathophysiological types of atrial fibrillation’ can be differentiated in patients using clinical characteristics supplemented by blood and ECG biomarkers, potentially opening the way towards a more personalized therapy of atrial fibrillation. Although atrial fibrillation (AF) is rarely dangerous in the acute setting, the long-term consequences are grim. Even the most modern forms of management, including adequate stroke prevention and rate control therapy,1 are not sufficient to prevent premature cardiovascular deaths in patients with AF.2,3 Furthermore, the majority of AF patients remain symptomatic,4 and many are hospitalized for AF.5,6 After its manifestation, early rhythm control treatment of AF, i.e. thorough prevention of recurrent AF after the first episode, may be useful.2 Although we do not have formal proof of this concept, preventing the first episode of AF could be an even better way to prevent these complications. The mechanisms by which AF perpetuates itself have been studied in great detail in animal models and in patients in the last … [1]: #fn-2

Prevalence, incidence, risk factors and prognostic role of atrial fibrillation in amyloidotic cardiomyopathy of different etiologies

Purpose: Although atrial fibrillation (AF) is a well known complication of amyloidotic cardiomyopathy (AC), a precise clinical, pathophysiological and prognostic characterization is not available. The aim of our study was to evaluate prevalence, incidence, risk factors for AF and prognostic significance of AF in the three main etiological subgroups of AC: light-chain (AL), hereditary transthyretin-related (ATTR) and non-mutant transthyretin-related (wtTTR). Methods: We studied 255 patients with AC (121 AL, 92 ATTR, 42 wtTTR) and assessed clinical, ECG, echocardiographic and hemodynamic details at presentation. Results: Prevalence of AF at first evaluation was 15% overall: 9% in AL, 11% in ATTR and 40% in wtTTR. During a median follow up of 1.2 (IQR 0.4–2.9) years, seven other patients developed AF (1.5% person-years). At univariate analysis, age (OR 1.1, 95% CI 1.05–1.13), NYHA class III-IV (OR 4.12, 95% CI 1.99–8.55), wtTTR etiology (OR 6.8, 95% CI 2.84–16.30), left ventricular ejection fraction (LVEF) (OR 0.95, 95% CI 0.93–0.98), right atrial pressure (OR 1.13, 95% CI 1.04–1.23) and pulmonary capillary wedge pressure (OR 1.07, 95% CI 1.01–1.14) were significantly (p<0.01) associated with the risk of AF. At multivariate analysis however, only age (OR 1.08, 95% CI 1.04–1.14), LVEF (OR 0.96, 95% CI 0.93–0.99) and right atrial pressure (OR 1.14, 95% CI 1.03–1.26) remained associated as independent variables. Left ventricular wall thickness was not associated with AF in any of the three etiological subgroups. Warfarin was prescribed to all AF patients and none suffered thromboembolic events. AF was not associated with an increased mortality even though survival free from heart failure was significantly lower in patients with AF in the ATTR (event rate 14.6% vs 1.1% person-years, p=0.0001) and wtTTR groups (event rate 15.2% vs 5.4% person-years, p=0.05). Conclusions: Prevalence of AF at presentation was 15% in the entire cohort, with a maximum rate of 40% in wtTTR patients. Left ventricular systolic and diastolic dysfunction, but not wall thickness, were associated with AF. AF was an incremental risk factor for mortality or heart failure in patients with TTR-related amyloidosis.

The Balance Between Stroke Prevention and Bleeding Risk in Atrial Fibrillation

See related article, pages 1482–1486. Although atrial fibrillation (AF) is well recognized to confer a risk of stroke, this risk is not homogeneous. Oral anticoagulation (OAC) with warfarin is highly beneficial, but such therapy is inconvenient and carries a risk of bleeding. Thus, stroke risk stratification schemes have been devised to identify “high risk” AF patients for whom the absolute benefits of OAC exceed its risks. In general, present treatment guidelines recommend OAC for those classed at high risk of stroke, and aspirin for those at “low risk.” In those at “moderate risk,” either OAC or aspirin is recommended. There are many ways of classifying stroke risk, and in a recent comparison of 12 risk stratification schemes to predict stroke in patients with nonvalvular AF, the Stroke Risk in Atrial Fibrillation Working Group1 identified 7 schemes that were based directly on event-rate analyses (largely been identified from non-OAC arms of clinical trials, and occasionally from cohort studies), whereas 5 resulted from expert panel consensus. The most frequently included features were prior stroke/TIA (in 100% of schemes), patient age, hypertension and diabetes mellitus. Of the various published schema, the CHADS2 score is probably the most popular, which is well validated and easy to use, where 1 point is given for Congestive heart failure, Hypertension, Age >75 and Diabetes, whereas 2 points are given for Stroke or transient ischemic attack (TIA).2 Based on published test study cohorts, the absolute stroke rates for the different stroke risk schema varied rather widely, and the proportions of patients categorized by the different schemes as low-risk or high risk can differ fairly substantially.1 Indeed, validation studies have shown that no published risk stratification schema is ideal and all can frequently underestimate stroke risk.2,3 The c -statistic (used to assess the predictive …

Direct treatment cost of atrial fibrillation in the elderly American population: a Medicare perspective

Objective: Although atrial fibrillation (AF) is the most commonly sustained arrhythmia in adults, few studies have examined the direct treatment cost of AF.Methods: A Medicare database of a 5% random national sample of all beneficiaries was used to identify patients diagnosed with AF in 2003 and to follow them for 1 year after diagnosis. These patients were matched on a 1:1 basis by age, gender and race. The incremental cost of treating AF was calculated with multivariate regression models adjusting for covariates.Results: In total, 55,260 subjects developed new AF, of which 69% were ≥75 years old, 54% were female and 91% were White. The adjusted mean incremental treatment cost of AF was $14,199 (95% confidence interval $13,201–15,001; p<0.01). Some of this cost was attributable to the incidence of stroke and heart failure at the 1-year post-AF diagnosis. A significantly higher proportion of AF patients experienced stroke (23.1 vs. 13.3%; p<0.01) and heart failure (36.7 vs. 10.4%; p<0.01) compared with Medicare beneficiaries without AF.Conclusions: Mean incremental direct treatment costs for Medicare beneficiaries with AF were higher than previously reported. Interventions that can reduce the incidence of AF and its complications may also reduce the national economic impact of AF.

Acute myocardial infarction complicated by atrial fibrillation in the elderly: prevalence and outcomes.

Although atrial fibrillation (AF) is a common complication of acute myocardial infarction (MI), patient characteristics and association with outcomes remain poorly defined in the elderly. We evaluated 106 780 Medicare beneficiaries > or =65 years of age from the Cooperative Cardiovascular Project treated for acute MI between January 1994 and February 1996 to determine the prevalence and prognostic significance of AF complicating acute MI in elderly patients. Patients were categorized on the basis of the presence of AF, and those with AF were further subdivided by time of AF (present on arrival versus developing during hospitalization). AF and non-AF patients were compared by univariate analysis, and logistic regression modeling was used to identify clinical predictors of AF. The influence of AF on outcomes was evaluated by unadjusted Kaplan-Meier survival curves and logistic regression models. AF was documented in 23 565 patients (22. 1%): 11 510 presented with AF and 12,055 developed AF during hospitalization. AF patients were older, had more advanced heart failure, and were more likely to have had a prior MI and undergone coronary revascularization. AF patients had poorer outcomes, including higher in-hospital (25.3% versus 16.0%), 30-day (29.3% versus 19.1%), and 1-year (48.3% versus 32.7%) mortality. AF remained an independent predictor of in-hospital (odds ratio [OR], 1. 21), 30-day (OR, 1.20), and 1-year (OR, 1.34) mortality after multivariate adjustment. Patients developing AF during hospitalization had a worse prognosis than patients who presented with AF. AF is a common complication of acute MI in elderly patients and independently influences mortality, particularly when it develops during hospitalization.

Risk factors for thromboembolism during aspirin therapy in patients with atrial fibrillation: The stroke prevention in atrial fibrillation study

Although atrial fibrillation (AF) is associated with ischemic stroke, some AF patients have an inherently low rate of thromboembolism. Additional AF patients might have a low thromboembolic rate when given aspirin. We undertook exploratory analyses to identify patient features related to thromboembolism during aspirin therapy, as the basis for the design of a clinical trial. A cohort of 854 patients given aspirin 325 mg/day and followed for a mean of 2.3 years in a clinical trial was analyzed. Clinical and echocardiographic features at study entry were correlated with subsequent arterial thromboembolism by multivariate analysis. AF patients given aspirin who had high thromboembolic rates were women over age 75 years (10.4%/year) and those of either gender with systolic blood pressure > 160 T (7.6%/year), prior thromboembolism (6.4%/year), and impaired left ventricular function (5.5%/year). AF patients with one or more of these features had a thromboembolic rate of 5.9%/year (95% CI 4.5-7.8) during aspirin therapy. Patients without these features comprised 52% of the cohort and had a thromboembolic rate of 1.9% per year (95% CI, 1.2-2.9). Most strokes in all subgroups were classified as cardioembolic; the highest rate of cardioembolic stroke occurred in elderly women (6.1%/year). These exploratory analyses suggest that many AF patients may have a relatively low thromboembolic rate when given aspirin, but the findings must be independently confirmed before being applied to clinical management. Pathogenic mediators of high-risk features and aspirin responsiveness are unclear.