Incidence and Mortality Trends of Atrial Fibrillation/Atrial Flutter in the United States 1990 to 2017.

Atrial fibrillation (AF) and flutter (AFL) are the most common clinically significant arrhythmias in older adults with an increasing disease burden due to an aging population. However, up-to-date trends in disease burden and regional variation remain unknown. In an observational study utilizing the Global Burden of Disease (GBD) database, age-standardized mortality and incidence rates for AF overall and for each state in the United States (US) from 1990 to 2017 were determined. All analyses were stratified by gender. The relative change in age-standardized incidence rate (ASIR) and age-standardized death rate (ASDR) over the observation period were determined. Trends were analyzed using Joinpoint regression analysis. The mean ASIR per 100,000 population for men was 92 (+/-8) and for women was 62 (+/-5) in the US in 2017. The mean ASDR per 100,000 population for men was 5.8 (+/-0.3) and for women was 4.4 (+/-0.4). There were progressive increases in ASIR and ASDR in all but 1 state. The states with the greatest percentage change in incidence were New Hampshire (+13.5%) and Idaho (+16.0%) for men and women, respectively. The greatest change regarding mortality was seen in Mississippi (+26.3%) for men and Oregon (+53.8%) for women. In conclusion these findings provide updated evidence of increasing AF and/or AFL incidence and mortality on a national and regional level in the US, with women experiencing greater increases in incidence and mortality rates. This study demonstrates that the public health burden related to AF in the United States is progressively worsening but disproportionately across states and among women.

Temporal Trends in Population Rates of Incident Atrial Fibrillation and Atrial Flutter Hospitalizations, Stroke Risk, and Mortality Show Decline in Hospitalizations.

BACKGROUND: Hospitalization for nonvalvular atrial fibrillation (NVAF) is common and results in substantial cost burden. Current national data trends for the incidence, stroke risk profiles, and mortality of hospitalization for NVAF and atrial flutter (AFL) are sparse. METHODS: The Canadian Institute of Health Information Discharge Abstract Database was used to identify patients ≥ 20 years with incident NVAF/AFL (NVAF, ICD-9 code 427.3 or ICD-10 I48) in any diagnosis field from 2006 to 2015 in Canada, except Québec. National and provincial trends in rate over time (rate ratio, 95% confidence interval [CI]) were calculated for age-sex standardized hospitalizations. Trends in stroke risk profiles and in-hospital mortality rates adjusted for stroke risk factors were also calculated. RESULTS: A total of 578,947 patients were hospitalized with incident NVAF/AFL. The median age was 77 years (interquartile range: 68-84), 82% were ≥ 65 years, 54% were men, 54% had a CHADS2 ≥ 2, and 69% had a CHA2DS2-Vasc ≥ 3. The overall age- and sex-standardized rate of NVAF/AFL hospitalization was 315 per 100,000 population and declined by 2% per year (P < 0.001). There was an annual rate decline in NVAF/AFL hospitalizations in every province. The majority of hospitalized patients are at high risk of stroke, and this risk remained unchanged. The average adjusted in-hospital mortality was 8.80 per 100 patients 95% CI, 8.80-8.81 with a 2% annual decline in rate (P < 0.001). CONCLUSION: Between 2006 and 2015, we found national and provincial hospitalization rates for incident NVAF/AFL are declining. The majority of patients are at high risk for stroke. In-hospital mortality has declined but remains substantial.

Outcomes and mortality associated with atrial arrhythmias among patients hospitalized with COVID-19.

INTRODUCTION: The impact of atrial arrhythmias on coronavirus disease 2019 (COVID-19)-associated outcomes are unclear. We sought to identify prevalence, risk factors and outcomes associated with atrial arrhythmias among patients hospitalized with COVID-19. METHODS: An observational cohort study of 1053 patients with severe acute respiratory syndrome coronavirus 2 infection admitted to a quaternary care hospital and a community hospital was conducted. Data from electrocardiographic and telemetry were collected to identify atrial fibrillation (AF) or atrial flutter/tachycardia (AFL). The association between atrial arrhythmias and 30-day mortality was assessed with multivariable analysis. RESULTS: Mean age of patients was 62 ± 17 years and 62% were men. Atrial arrhythmias were identified in 166 (15.8%) patients, with AF in 154 (14.6%) patients and AFL in 40 (3.8%) patients. Newly detected atrial arrhythmias occurred in 101 (9.6%) patients. Age, male sex, prior AF, renal disease, and hypoxia on presentation were independently associated with AF/AFL occurrence. Compared with patients without AF/AFL, patients with AF/AFL had significantly higher levels of troponin, B-type natriuretic peptide, C-reactive protein, ferritin and d-dimer. Mortality was significantly higher among patients with AF/AFL (39.2%) compared to patients without (13.4%; p < .001). After adjustment for age and co-morbidities, AF/AFL (adjusted odds ratio [OR]: 1.93; p = .007) and newly detected AF/AFL (adjusted OR: 2.87; p < .001) were independently associated with 30-day mortality. CONCLUSION: Atrial arrhythmias are common among patients hospitalized with COVID-19. The presence of AF/AFL tracked with markers of inflammation and cardiac injury. Atrial arrhythmias were independently associated with increased mortality.

Concomitant use of direct oral anticoagulants and aspirin versus direct oral anticoagulants alone in atrial fibrillation and flutter: a retrospective cohort.

BACKGROUND: The benefit of combining aspirin and direct oral anticoagulants on the reduction of cardiovascular events in atrial fibrillation or flutter is not well studied. We aimed to assess whether concurrent aspirin and direct oral anticoagulant therapy for atrial fibrillation or flutter will result in less coronary, cerebrovascular and systemic ischemic events compared to direct oral anticoagulant therapy alone. METHODS: Retrospective study of adult patients between 18 and 100 years old who have nonvalvular atrial fibrillation or flutter and were started on a direct oral anticoagulant (apixaban, rivaroxaban, or dabigatran), between January 1, 2010 and September 1, 2015 within the Beaumont Health System. Exclusions were history of venous thromboembolic disease and use of other antiplatelet therapies such as P2Y12 inhibitors. Patients were classified into two groups based on concurrent aspirin use and observed for a minimum of 2 years. Primary outcome was major adverse cardiac events, defined as acute coronary syndromes, ischemic strokes, and embolic events. Secondary outcomes were bleeding and death. RESULTS: Six thousand four patients were in the final analysis, 57% males and 80% Caucasians, median age 71, interquartile range (63-80). The group exposed to aspirin contained 2908 subjects, and the group unexposed to aspirin contained 3096 subjects. After using propensity scores to balance the baseline characteristics in both groups, the analysis revealed higher rate of major adverse cardiac events in the exposed group compared to the unexposed group, (HR 2.11, 95% CI (1.74-2.56)) with a number needed to harm of 11 (95% CI [9-11]). The rate of bleeding was also higher in the exposed group, (HR 1.30, 95% CI (1.11-1.52)). The rate of death was not statistically different between the groups, (HR 0.87, 95% CI (0.61-1.25)). CONCLUSIONS: In this observational analysis of patients with atrial fibrillation and flutter, the concomitant use of direct oral anticoagulants and aspirin was associated with an increased risk of both major adverse cardiac and bleeding events when compared to the use of direct oral anticoagulants alone. These findings underscore the potential harm of this combination therapy when used without a clear indication.

Dronedarone treatment following cardioversion in patients with atrial fibrillation/flutter: A post hoc analysis of the EURIDIS and ADONIS trials.

INTRODUCTION: The phase 3 EURIDIS and ADONIS studies evaluated dronedarone for atrial fibrillation (AF)/atrial flutter (AFL) recurrence in patients with nonpermanent AF. Here we assessed whether patient characteristics and/or treatment outcomes in these studies differed based on the need for cardioversion before randomization. METHODS: Time to adjudicated first AF/AFL recurrence, symptomatic recurrence, cardiovascular hospitalization/death, and AF hospitalization, and safety were assessed by cardioversion status. RESULTS: Of 1237 patients randomized (2:1 dronedarone:placebo), 364 required baseline cardioversion (dronedarone 243, placebo 121). Patients requiring cardioversion had a greater prevalence of cardiovascular comorbidities and shorter times to first AF/AFL recurrence compared with those not requiring cardioversion. Dronedarone was associated with longer median time to first AF/AFL recurrence vs placebo regardless of cardioversion status (cardioversion: 50 vs 15 days, hazard ratio [HR] 0.76; 95% confidence interval [CI], 0.59-0.97; P = .02; non-cardioversion: 150 vs 77 days, HR 0.76; 95% CI, 0.64-0.90; P < .01). Dronedarone was similarly associated with prolonged median time to symptomatic recurrence vs placebo in the cardioversion (347 vs 87 days, HR 0.65; 95% CI, 0.49-0.87) and non-cardioversion (288 vs 120 days, HR 0.74; 95% CI, 0.62-0.90) populations. Risk of cardiovascular hospitalization/death and first AF hospitalization was lower with dronedarone vs placebo regardless of cardioversion status, but differences were not statistically significant. The safety of dronedarone was similar in both groups. CONCLUSION: Patients requiring baseline cardioversion represent a distinct population, having more underlying cardiovascular disease and experiencing a shorter time to AF/AFL recurrences. Dronedarone was associated with improved efficacy vs placebo regardless of cardioversion status.

Does prior antithrombotic therapy influence recurrence and bleeding risk in stroke patients with atrial fibrillation or atrial flutter?

BACKGROUND: Whilst antithrombotic therapy is recommended in people with atrial fibrillation, little is known about the survival benefits of antithrombotic treatment in those with both high ischaemic and bleeding risk scores. We aim to describe the distribution of these risk scores in those with a prior diagnosis of atrial fibrillation who have suffered stroke and to determine the net clinical benefit of antithrombotic treatment. METHODS: We used regional stroke register data in the UK. Patients with a prior diagnosis of atrial fibrillation and ischaemic or haemorrhagic stroke patients were selected and their ischaemic stroke risk score (CHA2DS2-VASc) and bleeding risk score (HEMORR2HAGES) scores retrospectively calculated. Logistic regression and Cox proportional hazards models were constructed to determine the association between antithrombotic therapy prior to stroke and in-hospital and long-term mortality. RESULTS: A total of 1928 stroke patients (mean age 81.3 years (standard deviation 8.5), 56.8% women) with prior atrial fibrillation were included. Of these, 1761 (91.3%) suffered ischaemic stroke. The most common phenotype (64%) was of those with both high CHA2DS2-VASc (≥2) and high HEMORR2HAGES score (≥4). In our fully adjusted model, patients on antithrombotic treatment with both high ischaemic and bleeding risk had a significant reduction in odds of 31% for in-hospital mortality (odds ratio 0.69 (95% confidence interval 0.48-1.00: p = 0.049)) and 17% relative risk reduction for long-term mortality (hazard ratio 0.83 (95% confidence interval 0.71-0.97: p = 0.02)). CONCLUSIONS: Our study suggests that antithrombotic treatment has a prognostic benefit following incident stroke in those with both high ischaemic risk and high bleeding risk. This should be considered when choosing treatment options in this group of patients.

Association between serum potassium levels and short-term mortality in patients with atrial fibrillation or flutter co-treated with diuretics and rate- or rhythm-controlling drugs.

AIMS: We investigated the association between potassium levels and 90-day all-cause mortality in atrial fibrillation or flutter (AF) patients co-treated with diuretics and rate- or rhythm-controlling drugs. METHODS AND RESULTS: During 2000-12, first-time AF patients treated with beta-blockers, amiodarone, sotalol, verapamil, or digoxin combined with any diuretic within 90 days post-AF discharge were included. Following co-treatment, a potassium measurement within 90 days after initiating diuretic treatment was required. Mortality risk associated with potassium <3.5, 3.5-3.7, 3.8-4.0, 4.5-4.7, 4.8-5.0, and >5.0 mmol/L (reference: 4.1-4.4 mmol/L) was assessed using multivariable Cox regression. In total, 14 425 AF patients were included (median age: 78 years; women: 52%). Patients most often received beta-blocker monotherapy (29%), beta-blockers and digoxin combined (25%), digoxin monotherapy (24%), amiodarone monotherapy (3%), and verapamil monotherapy (3%). Increased 90-day mortality risk was associated with <3.5 mmol/L [hazard ratio (HR) 2.05, 95% confidence interval (CI) 1.68-2.50], 3.5-3.7 mmol/L (HR 1.28, 95% CI 1.05-1.57), 4.5-4.7 mmol/L (HR 1.20, 95% CI 1.02-1.41), 4.8-5.0 mmol/L (HR 1.37, 95% CI 1.14-1.66), and >5.0 mmol/L: (HR 1.84, 95% CI 1.53-2.21). Compared with beta-blocker monotherapy, rate- or rhythm-controlling drugs did not modify the association between potassium groups and mortality risk. CONCLUSION: In addition to hypo- and hyperkalaemia, low and high normal range potassium levels were associated with increased 90-day mortality risk in AF patients co-treated with diuretics and rate- or rhythm-controlling drugs. These associations were independent of rate- or rhythm-controlling drugs.

Efficacy and safety of dronedarone in patients with a prior ablation for atrial fibrillation/flutter: Insights from the ATHENA study.

BACKGROUND: The role of antiarrhythmic drugs for atrial fibrillation/atrial flutter (AF/AFL) after catheter ablation is not well established. HYPOTHESIS: We hypothesized that changing the myocardial substrate by ablation may alter the responsiveness to dronedarone. METHODS: We assessed the efficacy and safety of dronedarone in the treatment of paroxysmal/persistent atrial fibrillation/atrial flutter (AF/AFL) post-ablation, based on a post hoc analysis of the ATHENA study. A total of 196 patients (dronedarone 90, placebo 106) had an ablation for AF/AFL before study entry. In these patients, the effect of treatment on the first hospitalization because of cardiovascular (CV) events/all-cause death was assessed, as was AF/AFL recurrence in individuals with sinus rhythm at baseline. The safety of dronedarone vs placebo was also determined. RESULTS: In patients with prior ablation, dronedarone reduced the risk of AF/AFL recurrence (hazard ratio [HR]: 0.65 [95% confidence interval [CI]: 0.42, 1.00]; P < .05) as well as the median time to first AF/AFL recurrence (561 vs 180 days) compared with placebo. The HR for first CV hospitalization/all-cause death with dronedarone vs placebo was 0.98 (95% CI: 0.62, 1.53; P = .91). Rates of treatment-emergent adverse events were 83.1% vs 75.5% and rates of serious TEAEs were 27.0% vs 18.9% in the dronedarone and placebo groups, respectively. One death occurred with dronedarone (not treatment-emergent) and five occurred with placebo. CONCLUSION: In patients with prior ablation for AF/AFL, dronedarone reduced the risk of AF/AFL recurrence compared with placebo, but not the risk of first CV hospitalization/all-cause death. Safety outcomes were consistent with those of the overall ATHENA study.

Impact of atrial arrhythmia on survival in adults with tetralogy of Fallot.

BACKGROUND: Atrial arrhythmia is a late complication after tetralogy of Fallot (TOF) repair, but arrhythmia outcomes data are limited. OBJECTIVES: The purpose of the study was to describe atrial arrhythmia presentations, outcomes of antiarrhythmic therapy, and impact of arrhythmia on transplant-free survival. METHODS: We reviewed the MACHD (Mayo Adult Congenital Heart Disease) Registry and identified 113 patients (age 49 ±â€¯13 years) with documented arrhythmia, and 302 patients without history of arrhythmia, 1990-2017. We classified arrhythmias into atrial fibrillation and atrial flutter/tachycardia based on the rhythm on the first abnormal electrocardiogram. RESULTS: At the time of first documented arrhythmia, 58(51%) had atrial fibrillation while 55(49%) had atrial flutter/tachycardia. Of the 113 patients, 14(12%) received rhythm control with class I/III antiarrhythmic drugs (AAD), 79(70%) had direct current cardioversion, 9(8%) received rate control with class II/IV AAD, and 11(10%) received only anticoagulation. Successful cardioversion occurred in 100(89%) patients, and arrhythmia recurrence rate was 16 per 100 patient-years. The multivariate risk factors for death and/or heart transplant were atrial fibrillation (HR 1.94, CI 1.10-3.15, P = .031) and older age (HR 1.63, CI 1.12-2.43, P = .019) per 5 year increment. CONCLUSIONS: Atrial fibrillation, but not atrial flutter, was associated with reduced survival in our repaired TOF cohort. Further studies are required to determine if more aggressive antiarrhythmic therapy will improve survival in patients with atrial fibrillation.

Early direct current cardioversion or ablation for atrial fibrillation or atrial flutter and acute decompensated heart failure.

AIMS: Guidelines recommend initial rate control in haemodynamically stable patients with atrial fibrillation (AF) or atrial flutter (AFL) and acute decompensated heart failure (ADHF). There is limited data on early inpatient rhythm control. We investigated the outcomes of patients managed with early TOE-guided DC cardioversion (DCCV) or ablation. METHODS: We retrospectively analysed patients admitted to a single centre with AF or AFL and ADHF with LVEF≤40% that underwent inpatient TOE-guided DCCV or ablation. The primary endpoint was the one year composite outcome of mortality or rehospitalisation for heart failure. RESULTS: We identified 79 patients, including 33 with AF (32 DCCV, one ablation) and 46 with AFL (22 DCCV, 24 ablation). The primary endpoint occurred in 20%. One-year mortality was 2.5%. There were significantly fewer rehospitalisations for arrhythmia or heart failure with AFL-ablation compared to AFL-DCCV (21% vs 64%, p=<0.01). Clinical recurrence of AF or AFL was 43%. At follow-up LV assessment, LVEF>40% was found in 75% (p=<0.01), including 87% of patients without known cardiomyopathy and 82% of patients in sinus rhythm. CONCLUSION: Early inpatient DCCV or ablation for AF or AFL and ADHF had low mortality rates and rehospitalisation for heart failure with substantial improvement in LV function at follow-up.

Atrial fibrillation in elderly patients with implantable loop recorders for unexplained syncope.

BACKGROUND: An implantable loop recorder (ILR) assists in the diagnosis of unexplained syncope and atrial fibrillation (AF). Both become prevalent with age. Limited data exist describing the incidence of AF as the diagnostic rhythm underlying syncope in the elderly. This study aims to report the incidence of AF in older adults with ILRs for unexplained syncope and identify clinical characteristics associated with AF in this population. METHODS: Retrospective observational study on patients with unexplained syncope seen in syncope clinics from two Canadian centers. Participants were ≥65 years old, without a history of AF, and received an ILR for unexplained syncope. Data were collected from patient's clinic charts. Arrhythmia diagnosis was based on ILR electrocardiogram reading during syncope (symptom-rhythm correlation). Fisher's exact test and the Student's t test were used to compare participants with and without AF. RESULTS: In our cohort of 222 patients, 124 were females and 98 were males. Mean age at implant was 80 ± 8 years. Arrhythmia was diagnosed in 98 patients (44.1%). Median time to diagnosis was 18 months. AF was diagnosed in 17 (7.7%) participants. There were fewer males in the AF group than the no AF group (11.8%, 46.8%, p = 0.01). Age, baseline EKG, and prevalence of hypertension, diabetes, stroke, or ischemic heart disease were not statistically different between patients with AF and without AF. CONCLUSIONS: Atrial fibrillation was a common diagnostic rhythm in this cohort of adults, aged 65 and older, with ILRs for unexplained syncope. It was observed more frequently in females.

A Quarter of a Century Later: What is Dofetilide's Clinical Role Today?

Dofetilide is a class III antiarrhythmic agent approved by the Food and Drug Administration for the conversion of atrial fibrillation and atrial flutter and maintenance of sinus rhythm in symptomatic patients with persistent arrhythmia. Drug trials showed neutral mortality in post-myocardial infarction patients and those with heart failure. This is a review of postmarket data, including real-world efficacy and safety in a variety of populations. Dofetilide has been used off-label with success in patients with paroxysmal atrial fibrillation and atrial flutter, as well as atrial tachycardia and ventricular tachycardia. The real-world acute conversion rate of atrial fibrillation and atrial flutter is higher than that reported in clinical trials. Dofetilide has an acceptable safety profile when initiated (or reloaded) under hospital monitoring and dosed according to creatinine clearance. Dofetilide is well tolerated and a good choice for patients with acceptable renal function and a normal QT interval, especially if atrioventricular nodal blockade needs to be avoided.

Disease progression after ablation for atrial flutter compared with atrial fibrillation: A nationwide cohort study.

AIMS: The aim of this study was to study the risk of death and development of arrhythmia and/or subsequently heart failure after an atrial flutter ablation procedure compared with an atrial fibrillation (AF) ablation procedure. METHODS: This observational study is based on data from Danish nationwide health databases. Patients with a first-time ablation procedure for either atrial flutter or AF in the period 2000-2016 were included. Rates of renewed arrhythmia, heart failure or death were compared and reported as adjusted hazard ratios (HR). RESULTS: The study population consisted of 2,004 and 3,803 patients with an incident atrial flutter or AF ablation procedure, respectively. All-cause mortality among atrial flutter patients was significantly higher compared with the AF group (HR 1.80, 95% confidence interval [CI] 1.39-2.35). The incidence of renewed arrhythmia without heart failure was lower in atrial flutter (HR 0.76, 95% CI 0.69-0.84). Renewed atrial flutter ablation and pacemaker implantations were significantly more frequent (HR 2.42, 95% CI 2.02-2.91 and HR 1.42, 95% CI 1.13-1.79, respectively) in atrial flutter compared with AF. The risk of heart failure was higher for atrial flutter, both after the initial ablation (HR 1.48, 95% CI 1.08-2.03), and after a further arrhythmia management event (HR 1.98, 95% CI 1.33-2.94). CONCLUSION: There was a higher mortality risk after atrial flutter ablation procedures compared with patients undergoing AF ablation. Rates of heart failure and further renewed (non-AF) arrhythmia management were higher in atrial flutter.

In-hospital mortality of patients with atrial arrhythmias: insights from the German-wide Helios hospital network of 161 502 patients and 34 025 arrhythmia-related procedures.

Aims: Atrial fibrillation (AFib) and atrial flutter (AFlut) are common arrhythmias with increased use of invasive procedures. A steady re-evaluation of relevant safety endpoints is recommended and both quality management and pay-for-performance programs are evolving. Therefore, the aims of this study were (i) to investigate and report overall in-hospital mortality and mortality of invasive arrhythmia-related procedures and (ii) to identify mortality predictors in a German-wide hospital network. Methods and results: Administrative data provided by 78 Helios hospitals between 2010 and 2017 were examined using International Statistical Classification of Diseases and Related Health Problems- and Operations and Procedures-codes to identify patients with AFib or AFlut as main discharge diagnosis or secondary diagnosis combined with invasive arrhythmia-related interventions. In 161 502 patients, in-hospital mortality was 0.6% with a significant decrease from 0.75% to 0.5% (P < 0.01) during the observational period. In multivariable analysis, age [odds ratio (OR) 2.69, 95% confidence interval (CI) 2.36-3.05; P < 0.01], high centre volume (OR 0.57, 95% CI 0.50-0.65; P < 0.01), emergency hospital admission (OR 1.57, 95% CI 1.38-1.79; P < 0.01), and Charlson Comorbidity Index (CCI, OR 4.95, 95% CI 4.50-5.44; P < 0.01) were found as independent predictors of in-hospital mortality. Mortality rates were 0.05% for left atrial catheter ablation (CA, n = 21 744), 0.3% for right atrial CA (n = 9972), and 0.56% for implantation of a left atrial appendage occluder (n = 2309), respectively. Conclusion: We analysed for the first time in-hospital mortality rates of patients with atrial arrhythmias in a German-wide, multi-centre administrative dataset. This allows feasible, comparable, and up-to-date performance measurement of clinically important endpoints in a real-world setting which may contribute to quality management programs and towards value-based healthcare.

Intra- and interatrial conduction abnormalities: hemodynamic and arrhythmic significance.

Alterations of normal intra- and interatrial conduction are a common outcome of multiple cardiovascular conditions. They arise most commonly in the context of advanced age, cardiovascular risk factors, organic heart disease, atrial fibrosis, and left atrial enlargement. Interatrial block (IAB), the most frequent and extensively studied atrial conduction disorder, affects up to 20% of the general primary care population. IAB can be partial (P wave duration ≥ 120 ms on any of the 12 ECG leads) or advanced (P wave ≥ 120 ms and biphasic morphology (positive-negative) in inferior leads). Advanced IAB is an independent risk factor for supraventricular tachyarrhythmias and embolic stroke in a variety of clinical settings. Advanced IAB is a cause of left atrial electromechanical dysfunction and left atrioventricular dyssynchrony and has been associated with left ventricular diastolic dysfunction. P wave duration is associated with cardiovascular and all-cause mortality in the general population. Atrial conduction abnormalities should be identified as markers of atrial remodeling, prognostic indicators, and, in the case of advanced IAB, a true arrhythmologic syndrome. IAB and other P wave abnormalities should prompt the search for associated conditions, the treatment of which may partially reverse atrial remodeling or prevent it if administered upstream. Future studies will help define the role of preventive therapeutic interventions in high-risk patients, including antiarrhythmic drug therapy and oral anticoagulation. Implications for the treatment of heart failure and for pacing should also be further investigated.

Electrogram characteristics of the coronary sinus in cases requiring epicardial ablation within the coronary sinus for creating a conduction block at the left lateral mitral isthmus.

BACKGROUND: Left lateral mitral isthmus (LLMI) linear ablation is a safe and effective technique for treating left mitral flutter. LLMI linear ablation with pulmonary vein isolation may reduce the recurrence of persistent atrial fibrillation. However, epicardial ablation within the coronary sinus (CS) is often required to create the LLMI block line. If the necessity for epicardial ablation is checked before ablation, complications may be reduced. METHODS: We recruited 135 patients who underwent their first LLMI ablation and divided them into two groups, one group not requiring epicardial ablation for creating a conduction block at the LLMI (Endo group) and another requiring it (Epi group). These two groups were compared in terms of the electrogram characteristics of the CS. RESULTS: Bidirectional block through the LLMI was achieved in 94.8% of patients. In 42% of these patients, not only the endocardium but also the epicardium was ablated. As for the electrogram, the Endo group had lower atrium voltage and atrioventricular voltage ratios (p = 0.009) than the Epi group before LLMI ablation. By contrast, there were no significant differences in the atrium voltage and the atrioventricular voltage ratio between these two groups after LLMI ablation. CONCLUSIONS: For creating a conduction block at the LLMI, the atrium voltage and the atrioventricular voltage ratio in the CS before ablation are important. The atrioventricular voltage ratio is a crucial criterion for determining whether epicardial ablation is necessary; furthermore, the atrioventricular voltage ratio in the CS must be reduced with or without epicardial ablation.

Is von Willebrand factor associated with stroke and death at mid-term in patients with non-valvular atrial fibrillation?

BACKGROUND: Heart failure and atrial fibrillation share common mechanisms that may contribute to hypercoagulability and thrombotic risk. Elevated von Willebrand factor (vWF) concentration has been associated with increased risk of thromboembolism and cardiovascular events. AIM: To investigate whether increased vWF plasma concentration predicts occurrence of a composite endpoint (all-cause death and stroke) in patients with non-valvular atrial fibrillation (NVAF). METHODS: We prospectively studied 122 patients (mean age 70±14years; 46% men) hospitalized with NVAF, and followed over a median (interquartile range) of 5.4 (2.3-9.0)years. Cox proportional models were used to estimate the association of vWF concentration with time to stroke and death. RESULTS: Forty-three patients (35%) had at least a stroke or died during the 5-year follow-up. Kaplan-Meier curves using vWF plasma concentration tertiles (≤191IU/dL;>191 to≤295IU/dL;>295IU/dL) showed that vWF plasma concentrations discriminated groups of patients with higher cardiovascular event rates (log-rank P=0.01). In the multivariable analysis, higher vWF concentrations (middle tertile hazard ratio [HR] 4.59, 95% confidence interval [CI] 1.55-13.50 [P=0.006]; upper tertile HR 4.10, 95% CI 1.43-11.75 [P=0.009]), age≥75years (HR 5.02, 95% CI 1.53-16.49; P=0.008), heart failure (HR 2.05, 1.01-4.19; P=0.048), C-reactive protein, log2 per unit increase (HR 1.29, 95% CI 1.04-1.61; P=0.021), no warfarin at discharge (HR 4.96, 95% CI 2.02-12.20; P<0.0001) and no aspirin at discharge (HR 4.41, 95% CI 1.71-11.97; P=0.002) were independently associated with an increased risk of stroke and all-cause death, whereas female sex was a protective factor (HR 0.35, 0.16-0.78; P=0.01). CONCLUSIONS: High vWF plasma concentrations may discriminate patients with NVAF at greater risk of stroke or all-cause death.

Randomized controlled trial of Amigo® robotically controlled versus manually controlled ablation of the cavo-tricuspid isthmus using a contact force ablation catheter.

BACKGROUND: Radiofrequency catheter ablation (RFCA) of the cavo-tricuspid isthmus (CTI) is a common treatment for atrial flutter (AFL). However, achieving bi-directional CTI conduction block may be difficult, partly due to catheter instability. OBJECTIVE: To evaluate the safety and efficacy of the Amigo® Remote Catheter System (RCS) compared to manual catheter manipulation, during CTI ablation for AFL. METHODS: Fifty patients (pts) were prospectively randomized to robotically (25 pts) versus manually (25 pts) controlled catheter manipulation during CTI ablation, using a force-contact sensing, irrigated ablation catheter. The primary outcome was recurrence of CTI conduction after a 30-min waiting period. Secondary outcomes included total ablation, procedure, and fluoroscopy times, contact force measurement, and catheter stability. RESULTS: Recurrence of CTI conduction 30 min after ablation was less with robotically (0/25) versus manually (6/25) controlled ablation (p = 0.023). Total ablation and procedure times to achieve persistent CTI block (6.7 ± 3 vs. 7.4 ± 2.5 min and 14.9 ± 7.5 vs. 15.2 ± 7 min, respectively) were not significantly different (p = 0.35 and p = 0.91, respectively). There was a non-significant trend toward a greater force time integral (FTI in gm/s) with robotically versus manually controlled CTI ablation (571 ± 278 vs. 471 ± 179, p = 0.13). Fluoroscopy time was longer with robotically versus manually controlled CTI ablation (6.8 ± 4.4 min vs. 3.8 ± 2.3 min, p = 0.0027). There were no complications in either group. CONCLUSION: Robotically controlled CTI ablation resulted in fewer acute recurrences of CTI conduction compared to manually controlled CTI ablation, and a trend toward higher FTI. The longer fluoroscopy time during robotically controlled ablation was likely due to a steep learning curve. TRIAL REGISTRATION: Clinicaltrials.gov Identifier: NCT02467179.

Comparative Risks of Ischemic Stroke in Atrial Flutter versus Atrial Fibrillation.

INTRODUCTION: The aim of this study was to compare the risk of ischemic stroke in patients who have atrial fibrillation and patients who have atrial flutter. METHODS: Using inpatient and outpatient Medicare claims data from 2008 to 2014 for a 5% sample of all beneficiaries 66 years of age or older, we identified patients diagnosed with atrial fibrillation and those diagnosed with atrial flutter. The primary outcome was ischemic stroke. In the primary analysis, patients with atrial flutter were censored upon converting to fibrillation; in a secondary analysis, they were not. Survival statistics were used to compare incidence of stroke in patients with flutter and patients with fibrillation. Cox proportional hazards analysis was used to compare the associations of flutter and fibrillation with ischemic stroke after adjustment for demographics and risk factors. RESULTS: We identified 14,953 patients with flutter and 318,138 with fibrillation. During a mean follow-up period of 2.8 (±2.3) years, we identified 18,900 ischemic strokes. The annual incidence of ischemic stroke in patients with flutter was 1.38% (95% confidence interval [CI] 1.22%-1.57%) compared with 2.02% (95% CI 1.99%-2.05%) in patients with fibrillation. After adjustment for demographics and stroke risk factors, flutter was associated with a lower risk of stroke compared with fibrillation (hazard ratio .69; 95% CI .60-.79, P < .05). Within 1 year, 65.7% (95% CI 64.9%-66.4%) of patients with flutter converted to fibrillation but remained at a lower risk of ischemic stroke (hazard ratio .85; 95% CI .78-.92). CONCLUSIONS: Patients with atrial flutter faced a lower risk of ischemic stroke than patients with atrial fibrillation.