2011 ACCF/AHA/HRS Focused Updates Incorporated Into the ACC/AHA/ESC 2006 Guidelines for the Management of Patients With Atrial Fibrillation

Isolated left atrial cryoablation of atrial fibrillation in conventional mitral valve surgery

BACKGROUND

Recent trends of surgery for atrial fibrillation (AF) are towards more safe and effective energy sources, as well as to simplified sets of atrial lesions.

METHODS

One hundred eighteen (mean age, 67.4 ± 9.2 years) selected patients with paroxysmal/persistent AF and mitral valve (MV) disease underwent cryoablation of AF combined with conventional (not via mini-thoracotomy) MV surgery; the lesion set was limited to only the left atrium. Multivariable analyses identified predictors of cardiac rhythm at hospital discharge and follow-up.

RESULTS

There were 7 (5.9%) hospital deaths; 33 (28%) patients were discharged on AF. Higher values of preoperative left atrial volume index (odds ratio [OR] = 1.07, 95% confidence interval [95%CI]: 1.01-1.13) and mixed etiology of MV disease (OR = 4.19, 95%CI: 1.23-14.2) were predictors of hospital discharge on AF. Seventy-four (66.7%) patients were on stable sinus rhythm at follow-up (median period, 6.6 years); the 1, 5, and 10-year nonparametric estimates of adjusted freedom from AF were 98.1%, 89.2% and 45.6%, respectively. Higher values of preoperative systolic pulmonary artery pressure (hazard ratio [HR] = HR = 1.04, 95%CI: 1.01-1.08) and AF at hospital discharge (HR = 4.14, 95%CI: 1.50-11.4) were predictors of AF at follow-up.

CONCLUSIONS

During conventional MV surgery, a cryo-lesion set limited to only the left atrium may give good, immediate and long-term results. Left atrial dilation and mixed etiology of MV disease were predictors of hospital discharge on AF. Preoperative pulmonary hypertension and AF at discharge combined with an increased risk of AF at follow-up.

An effective frequency-domain feature of atrial fibrillation based on time-frequency analysis

Background

Atrial fibrillation is a type of persistent arrhythmia that can lead to serious complications. Therefore, accurate and quick detection of atrial fibrillation by surface electrocardiogram has great importance on further treatment. The practical electrocardiogram signals contain various interferences in different frequencies, such as myoelectricity interference, power interference and so on. Detection speed and accuracy largely depend on the atrial fibrillation signal features extracted by the algorithm. But some of the discovered atrial fibrillation features are not well distinguishable, resulting in poor classification effect.

Methods

This paper proposed a high distinguishable frequency feature—the frequency corresponding to the maximum amplitude in the frequency spectrum. We used the R–R interval detection method optimized with the mathematical morphology method and combined with the wavelet transform method for analysis. According to the two features—the maximum amplitude in the frequency spectrum and R–R interval irregular, we could recognize atrial fibrillation signals in electrocardiogram signals by decision tree classification algorithm.

Results

The data used in the experiment come from the MIT-BIH database, which is publicly accessible via the web and with ethical approval and consent. Based on the input of time-domain and frequency-domain features, we classified sinus rhythm signals and AF signals using the decision tree generated by classification and regression tree (CART) algorithm. From the confusion matrix, we got the accuracy was 98.9%, sensitivity was 97.93% and specificity was 99.63%.

Conclusions

The experimental results can prove the validity of the maximum amplitude in the frequency spectrum and the practicability and accuracy of the detection method, which applied this frequency-domain feature. Through the detection method, we obtained good accuracy of classifying sinus rhythm signals and atrial fibrillation signals. And the sensitivity and specificity of our method were pretty good by comparison with other studies.

Platelets Promote Ang II (Angiotensin II)-Induced Atrial Fibrillation by Releasing TGF-β1 (Transforming Growth Factor-β1) and Interacting With Fibroblasts

Hypertension is a risk factor of atrial fibrillation (AF), and a certain number of patients with hypertension were found with an enlarged left atrium. Platelet activation is found in patients with hypertension or pressure overload/Ang II (angiotensin II)-induced hypertensive animal models and contribute to ventricular fibrosis. Whether hypertension-induced atrial fibrosis is mediated by platelets remains unknown. Our previous experimental data showed that platelet-derived TGF-β1 (transforming growth factor-β1) was reduced in patients with hypertensive AF. The present study is to investigate whether platelet-derived TGF-β1 promotes Ang II-induced atrial fibrosis and AF. Platelet activation and atrial platelet accumulation were measured in sinus rhythm controls, normotensive AF, and patients with hypertensive AF. Ang II (1500 ng/kg per minute, 3 weeks) infused mice with pharmacological (clopidogrel) and genetic platelet inhibition (TGF-β1 deletion in platelets) were used. Platelet activation, atrial structural remodeling, atrial electrical transmission, AF inducibility, inflammation, and fibrosis were measured in mice. We found that circulating platelets were activated in patients with hypertensive AF. A large amount of platelet was accumulated in the atriums of patients with hypertensive AF. Both clopidogrel treatment and platelet-specific deletion of TGF-β1 attenuated Ang II-induced structural remodeling, atrial electrical transmission, AF inducibility, as well as atrial inflammation and fibrosis than mice without interventions. Furthermore, clopidogrel blocked atrial platelet accumulation and platelet-fibroblast conjugation. Platelets promoted atrial fibroblast differentiation in cell culture. Profibrotic actions of platelets are largely via activation of atrial fibroblasts by releasing TGF-β1 and inducing platelet-fibroblast conjugation, and platelet inhibition is sufficient to inhibit atrial fibrosis and AF inducibility.

Pulmonary Delivery of Antiarrhythmic Drugs for Rapid Conversion of New-Onset Atrial Fibrillation

Pharmacologic management of atrial fibrillation (AF) is a pressing problem. This arrhythmia afflicts >5 million individuals in the United States and prevalence is estimated to rise to 12 million by 2050. Although the pill-in-the-pocket regimen for self-administered AF cardioversion introduced over a decade ago has proven useful, significant drawbacks exist. Among these are the relatively long latency of effects in the range of hours along with potential for hypotension and other adverse effects. This experience prompted development of a new strategy for increasing plasma concentrations of antiarrhythmic drugs rapidly and for a limited time, namely, pulmonary delivery. In preclinical studies in Yorkshire pigs, intratracheal administration of flecainide was shown to cause a rapid, reproducible increase in plasma drug levels. Moreover, pulmonary delivery of flecainide converted AF to normal sinus rhythm by prolonging atrial depolarization, which slows intra-atrial conduction and seems to be directly correlated with efficacy in converting AF. The rapid rise in plasma flecainide levels optimizes its anti-AF effects while minimizing adverse influences on ventricular depolarization and contractility. A more concentrated and soluble formulation of flecainide using a novel cyclodextrin complex excipient reduced net drug delivery for AF conversion when compared to the acetate formulation. Inhalation of the beta-adrenergic blocking agent metoprolol slows ventricular rate and can also terminate AF. In human subjects, oral inhalation of flecainide acetate with a hand-held, breath-actuated nebulizer results in signature prolongation of the QRS complex without serious adverse events. Thus, pulmonary delivery is a promising advance in pharmacologic approach to management of AF.

Early experience of thoracoscopic vs. catheter ablation for atrial fibrillation

Aims

Video-assisted thoracoscopic surgery (VATS) ablation has been advocated as a treatment option for non-paroxysmal atrial fibrillation (AF) in recent guidelines. Real-life data on its safety and efficacy during a centre’s early experience are sparse.

Methods and results

Thirty patients (28 persistent/longstanding persistent AF) underwent standalone VATS ablation for AF by an experienced thoracoscopic surgeon, with the first 20 cases proctored by external surgeons. Procedural and follow-up outcomes were collected prospectively, and compared with 90 propensity-matched patients undergoing contemporaneous catheter ablation (CA). Six (20.0%) patients undergoing VATS ablation experienced ≥1 major complication (death n = 1, stroke n = 2, conversion to sternotomy n = 3, and phrenic nerve injury n = 2). This was significantly higher than the 1.1% major complication rate (tamponade requiring drainage n = 1) seen with CA (P < 0.001). Twelve-month single procedure arrhythmia-free survival rates without antiarrhythmic drugs were 56% in the VATS and 57% in the CA cohorts (P = 0.22), and 78% and 80%, respectively given an additional CA and antiarrhythmic drugs (P = 0.32).

Conclusion

During a centre’s early experience, VATS ablation may have similar success rates to those from an established CA service, but carry a greater risk of major complications. Those embarking on a programme of VATS AF ablation should be aware that complication and success rates may differ from those reported by selected high-volume centres.

Consequences of functional mitral regurgitation and atrial fibrillation in patients with left ventricular assist devices

BACKGROUND

Functional mitral regurgitation (MR) (FMR) and atrial fibrillation (AF) are common in patients undergoing left ventricular assist device (LVAD) implantation. However, the impact of FMR and AF on clinical outcomes is uncertain. This study aimed to investigate the characteristics and prognostic significance of FMR and AF in patients with LVADs.

METHODS

We retrospectively reviewed all patients who underwent LVAD implantation at our center between January 2010 and December 2017. We defined significant FMR as the ratio of MR color jet area to left atrial area of >20% and persistent or permanent AF (PeAF) as persistent or permanent AF at LVAD implantation.

RESULTS

A total of 380 patients were included in this analysis. Patients were divided into 6 groups: patients with no PeAF and no significant FMR (Group 1), patients with no PeAF but with significant FMR (Group 2), patients with PeAF but no significant FMR (Group 3), patients with PeAF and significant FMR (Group 4), patients with concomitant mitral valve surgery (MVS) at LVAD implantation and without PeAF (Group 5), and patients with concomitant MVS and with PeAF (Group 6). A total of 56 patients (15%) died within 2 years. Kaplan-Meier curve analysis demonstrated a 2-year survival of 81% in Group 1, 89% in Group 2, 87% in Group 3, 47% in Group 4, 87% in Group 5, and 79 % in Group 6 (log-rank test, p < 0.001). The multivariable Cox proportional-hazards model showed that classification in Group 4 was an independent predictor of mortality (hazard ratio, 4.31; 95% CI: 2.19-8.46; p < 0.001).

CONCLUSIONS

The coexistence of significant FMR and PeAF may represent a poor prognostic marker in patients undergoing LVAD implantation.

The Validation of the ATRIA and CHA2DS2-Vasc Scores in Predicting Atrial Fibrillation after Coronary Artery Bypass Surgery

Objective

The aim of this study was to evaluate the value of CHA₂DS₂-VASc and Anticoagulation and Risk Factors in Atrial Fibrillation (ATRIA) risk scores for prediction of postoperative atrial fibrillation (AF) development in patients undergoing coronary artery bypass grafting (CABG) operation.

Methods

The population of this observational study consisted of 370 patients undergoing CABG operation. CHA₂DS₂-VASc and ATRIA risk scores were calculated for all patients and their association with postoperative AF (AF episode lasting > 5 min) were evaluated. Predictors of postoperative AF were determined by multiple logistic regression analysis.

Results

During follow-up, 110 patients (29.7%) developed postoperative AF. With multiple logistic regression analysis, risk factors for postoperative AF were determined: ATRIA risk score (odds ratio [OR] 1.23; 95% confidence interval [CI] 1.11-1.36; P<0.001), fasting glucose level (OR 1.006; 95% CI 1.004-1.009; P<0.001), and 24-hour drainage amount (OR 1.002; 95% CI; 1.001-1.004; P<0.001). Receiver operating characteristic curve analyses showed that CHA₂DS₂-VASc and ATRIA risk scores were significant predictors for new-onset AF (C-statistic 0.648; 95% CI 0.59-0.69; P<0.001; and C-statistic 0.664; 95% CI 0.61-0.71; P<0.001, respectively).

Conclusion

CHA₂DS₂-VASc and ATRIA risk scores predict new AF in patients undergoing CABG.

The Predictive Value of Growth Differentiation Factor-15 in Recurrence of Atrial Fibrillation after Catheter Ablation

The mechanisms underlying the recurrence of atrial fibrillation (AF) after radiofrequency catheter ablation (RFCA) are not well concerned. The study sought to explore the association between growth differentiation factor-15 (GDF-15) and the incidence of recurrent events among AF patients after the ablation procedure. We prospectively included 150 consecutive AF patients who underwent RFCA. Clinical information about the patients was collected. Blood samples on the second morning of hospital admission and three months after RFCA were collected, and enzyme-linked immunosorbent assay (ELISA) was used to measure the concentration of GDF-15. All participants were followed up at specific times (1st/3rd/6th/12th/18th/24th months) after RFCA to record recurrences events. During a median follow-up of 14.0 months, AF recurrence occurred in 37(24.7%) patients. Baseline serum GDF-15 level in the persistent AF group was significantly higher than the paroxysmal AF group [1140(854~1701)ng/L vs. 1062(651~1374)ng/L, P = 0.039]. Baseline serum GDF-15 level in the recurrence group was significantly higher than the nonrecurrence group [1287(889~1768) ng/L vs. 1062(694~1373)ng/L, P = 0.022]. Serum GDF-15 level at three months after RFCA was significantly lower than the baseline [870 (579~1270) ng/L vs. 1155 (735~1632)ng/L, P < 0.001]. The baseline GDF-15 correlated significantly with LAP (r = 0.296, P < 0.001) and LAAV(r = −0.235, P = 0.003). Kaplan-Meier analysis showed a significantly lower event-free survival time in the high baseline GDF-15 (≥1287.3 ng/L) group than the low baseline GDF-15 (<1287.3 ng/L) group (17.1 months vs. 20.4 months, Log Rank P = 0.017). In the multivariate Cox regression, baseline GDF-15(HR 1.053, 95% CI 1.007-1.100, P = 0.022) and LAD (HR 1.124, 95% CI 1.011-1.250, P = 0.030) were independent predictors of AF recurrence after RFCA. Our study indicated increased preprocedural GDF-15 is associated with left atrial remodeling and acts as a predictor of AF recurrence after ablation.

Association between atrial fibrillation and heart failure with different ejection fraction categories and its influence on outcomes

Background: The important role of atrial fibrillation (AF) in different types of heart failure (HF) according to ejection fraction (EF) is much less explored. In this study, we compared AF in HF with preserved (HFpEF), mid-range (HFmrEF) and reduced (HFrEF) EF with regard to prevalence, association, and prognostic role.Methods and results: A total of 405 inpatients with HF between February 2014 and June 2016 were prospectively analysed in this study. Patients were divided into three groups: HFrEF group (n = 109, 26.9%), HFmrEF group (n = 94, 23.2%), and HFpEF group (n = 202, 49.8%). There was a higher prevalence of AF in patients in the HFpEF and HFmrEF groups than in patients in the HFrEF. Several baseline variables were found to be independently associated with AF, including age, coronary heart disease, heart rate, left atrial diameter, and left ventricular (LV) end-diastolic diameter, regardless of EF category after multivariable adjustment. In addition, AF was found to be a more powerful predictor of all-cause mortality, HF rehospitalisation, and the composite event of all-cause mortality or rehospitalisation in HFpEF and HFmrEF patients, but not in HFrEF patients.Conclusions: HFmrEF resembled HFpEF rather than HFrEF with regard to both a higher prevalence of AF and a greater risk of all-cause mortality, HF rehospitalisation, and the composite event of all-cause mortality or rehospitalisation.

Does the mean 24-h pulse rate from ambulatory blood pressure monitoring reflect the mean 24-h ventricular rate from Holter electrocardiogram in atrial fibrillation patients?

BACKGROUND

Ambulatory blood pressure monitoring (ABPM) on the oscillometric method is applicable in patients with atrial fibrillation, but the mean pulse rate is or not similar to the ventricular rate from the Holter in atrial fibrillation patients remains unknown.

METHODS

This study included 228 persistent atrial fibrillation patients who received simultaneous 24-h ABPM and 24-h Holter. The mean 24-h pulse rate and the mean 24-h ventricular rate were calculated, and mVR-mPR was used to reflect the difference between them. The SD of 24-h pulse rate values was calculated as SD-pulse rate. Furthermore, according to the SD-pulse rate, the patients were divided into ≤5, 6-10, 11-15 and >15 bpm subgroups.

RESULTS

For the total population, the mean 24-h pulse rate is positively correlated with the mean 24-h ventricular rate, and the Bland-Altman plot showed quite wide 95% limits. As the SD-pulse rate increased, the 24-h mVR-mPR also increased. The mean 24-h mVR-mPR was 0.5 bpm when SD-pulse rate ≤5, 3.5 bpm when SD-pulse rate of 6-10, 7.6 bpm when SD-pulse rate of 11-15, and 12.5 bpm when SD-pulse rate >15 bpm, respectively. Meanwhile, in the SD-pulse rate 0-10 subgroup, the 95% limits were only from -13.8 to 19.7 bpm, while in the >10 subgroup, these values were from -19.5 to 36.5 bpm.

CONCLUSION

The mean 24-h pulse rate should not be used to represent the true ventricular rate for all atrial fibrillation patients. However, when lower the SD-pulse rate, the mVR-mPR becomes smaller.

Daily Exposure to Air Pollution Particulate Matter Is Associated with Atrial Fibrillation in High-Risk Patients

Several epidemiological studies found an association between acute exposure to fine particulate matter of less than 2.5 μm and 10 μm in aerodynamic diameter (PM_2.5 and PM₁₀) and cardiovascular diseases, ventricular fibrillation incidence and mortality. The effects of pollution on atrial fibrillation (AF) beyond the first several hours of exposure remain controversial. A total of 145 patients with implantable cardioverter-defibrillators (ICDs), cardiac resynchronization therapy defibrillators (ICD-CRT), or pacemakers were enrolled in this multicentric prospective study. Daily levels of PM_2.5 and PM₁₀ were collected from monitoring stations within 20 km of the patient’s residence. A Firth Logistic Regression model was used to evaluate the association between AF and daily exposure to PM_2.5 and PM₁₀. Exposure levels to PM_2.5 and PM₁₀ were moderate, being above the World Health Organization (WHO) PM_2.5 and PM₁₀ thresholds of 25 μg/m³ and 50 μg/m³, respectively, on 26% and 18% of the follow-up days. An association was found between daily levels of PM_2.5 and PM₁₀ and AF (95% confidence intervals (CIs) of 1.34–2.40 and 1.44–4.28, respectively) for an increase of 50 µg/m³ above the WHO threshold. Daily exposure to moderate PM_2.5 and PM₁₀ levels is associated with AF in patients who are not prone to AF.

Can local infiltration of lidocaine reduce the postoperative atrial fibrillation rate in patients undergoing lobectomy for lung cancer?

Background: Postoperative atrial fibrillation (POAF) occurs frequently after lung cancer surgery. Unfortunately, owing to the multifactorial etiology of POAF, no single drug or intervention can prevent POAF in all cases. The effects of local interventions after lung cancer surgery are unknown. This study investigated the effects of local infiltration of an anesthetic (lidocaine) on the post-lobectomy POAF rate.Methods: This non-randomized study included 81 patients who underwent lobectomy for lung cancer. Patients were divided into a lidocaine-infiltration group comprising patients who received lidocaine infiltration around the pulmonary veins and a no-intervention group. Patients were monitored for the development of POAF during hospitalization. Pre- and postoperative demographic and clinical data were analyzed.Results: AF occurred in 3 (7.5%) of 40 patients in the lidocaine-infiltration group and in 10 (24.39%) of 41 patients in the standard surgical resection group. Overall, it was observed that intraoperative lidocaine infiltration resulted in a lower POAF rate (p < .05).Conclusion: Local infiltration of lidocaine around the pulmonary veins in patients undergoing lobectomy for lung cancer was associated with a lower incidence of POAF, which is attributable to the local anesthetic and autonomic effects of lidocaine.

Comparison of CHA2DS2-VASc and C2HEST scores for predicting the incidence of atrial fibrillation among patients with end-stage renal disease

PURPOSE

The authors have studied assessment of CHA2DS2-VASc score versus C2HEST score in atrial fibrillation risk prediction in end-stage renal disease patients.

METHODS

The authors conducted this study by Longitudinal Health Insurance Database 2000. The authors totally enrolled 4,601 end-stage renal disease patients. The predictive capability of atrial fibrillation by using CHA2DS2-VASc and C2HEST score was estimated by area under the receiver operating characteristic curve (AUROC).

RESULTS

The AUROC for CHA2DS2-VASc score in predicting atrial fibrillation events was 0.5786, and AUROC for C2HEST score for atrial fibrillation prediction was 0.5983.

CONCLUSION

Both scores yield almost identical AUROC values implying no difference in predictive power. Further work is warranted to verify the prognostic value of the current scores.

Novel rate control strategy with landiolol in patients with cardiac dysfunction and atrial fibrillation

While patients with acute heart failure often have tachycardia with atrial fibrillation, there have been no established medical tools that control tachycardia safely and definitely. Digoxin has been recommended as a first choice in the former guidelines, but it takes time to affect and has a risk of adverse events particularly for those with chronic kidney disease. Landiolol is a recently innovated ultra‐short‐acting beta‐blocker with 251‐fold β1/β2 selectivity, which was originally indicated only to control peri‐operative supra‐ventricular tachyarrhythmia by 2013 in Japan. We aimed to review how to use landiolol in patients with cardiac dysfunction and tachycardia due to atrial fibrillation. We reviewed recently conducted randomized control trials using landiolol, recently updated guidelines, as well as current practical use of landiolol. Japan landiolol vs. Digoxin (J‐Land) study demonstrated that landiolol was more effective to control tachycardia than digoxin in atrial fibrillation patients with left ventricular dysfunction in 2013. Given the result, the revised Japanese heart failure guideline recommends landiolol for rate control during atrial fibrillation in acute heart failure patients as Class IIa with evidence level B. Currently in Japan, landiolol is used for rate control, even in patients with advanced heart failure receiving continuous infusion of inotropes. The clinical use of landiolol in patients with cardiac dysfunction and tachycardia due to atrial fibrillation is increasing. Further studies are warranted to investigate the implication of faster and safer rate control using landiolol.

CHA2DS2-VASc Score as a Predictor of New-Onset Atrial Fibrillation After Catheter Ablation of Typical Atrial Flutter

Purpose

Cavotricuspid isthmus (CTI) ablation is an effective procedure for typical atrial flutter (AFL), but patients remain at an elevated risk for developing new atrial fibrillation (AF). Currently, there are limited data on the utility of CHA₂DS₂-VASc score to predict new-onset AF after typical AFL ablation. In this study, we assessed whether the CHA₂DS₂-VASc score is a useful predictor of new-onset AF after CTI ablation in typical AFL patients without a prior history of AF.

Methods

This was a retrospective study of 103 typical AFL patients with no prior history of AF, who underwent successful CTI ablation. The endpoint was occurrence of new-onset AF during follow-up.

Results

During a mean follow-up period of 24.6 ± 16.9 months, at least one episode of AF occurred in 33 (32%) patients. Multivariate Cox regression analysis revealed that CHA₂DS₂-VASc score (hazard ratio = 1.736; 95% confidence interval = 1.370–2.201; P < 0.001) was significantly associated with postablation new-onset AF (area under the curve = 0.797). A cutoff value of three stratified these patients into two groups with different incidences of postablation new-onset AF (67.9 vs. 18.7%, P < 0.001).

Conclusion

The CHA₂DS₂-VASc score is a useful tool for the prediction of new-onset AF after ablation of typical AFL. Patients with CHA₂DS₂-VASc score ≥3 are more likely to develop new-onset AF and should be monitored more closely.

Left atrium size and red cell distribution width predict atrial fibrillation progression from paroxysmal or persistent to permanent

Objective: Stratifying patients with paroxysmal or short-term persistent atrial fibrillation (AF) who are at greater risk of developing permanent AF is challenging. Aim of our prospective study was to evaluate association of laboratory parameters (biochemistry and complete blood count (CBC)) together with standard demographic, clinical and echocardiography parameters, with AF progression.Methods: We prospectively recruited 579 patients with AF and divided them into two groups at index hospitalization: paroxysmal or persistent (non-permanent AF), and long-term persistent or permanent AF patients (permanent AF). Clinical, echocardiographic, and relevant CBC parameters were collected. Non-permanent AF patients were selected for follow-up, with a median follow-up time of 21 months. Endpoint was progression to permanent AF.Results: Out of 409 patients with non-permanent AF, 109 (26.6%) progressed within follow-up. In a multivariate Cox regression model only increased left atrium (LA) diameter (HR 2.16, 95% CI 1.20-3.87, p = 0.010), and increased red cell distribution width (RDW; HR 1.19, 95% CI 1.03-1.39, p = 0.022) showed significant independent association with progression. There were 221/409 patients with both LA ≤45 mm and RDW level ≤14.5% who progressed at a rate of only 17.6%, and showed relative risk of AF progression of 0.47 (95% CI 0.34-0.67; p < 0,001).Conclusion: Together with LA size, RDW was independently associated with AF progression. Patients with both LA size ≤45 mm and RDW level ≤14.5% are most probably the best candidates for rhythm control strategies.

Omentin-1 is associated with atrial fibrillation in patients with cardiac valve disease

BACKGROUND

Epicardial adipose tissue (EAT) remodeling and adipocytokines are associated with structural remodeling in atrial fibrillation (AF). However, the role of omentin-1, a novel adipocytokine, in structural remodeling remains unknown.

METHODS

Hematoxylin and eosin (H&E) and Masson's trichrome stains were used to investigate the histology of EAT and right atrial appendages. The expression levels of adipocytokines in these human samples were determined by immunohistochemical assay and western blotting. Models of transforming growth factor (TGF)-β1-induced activation of cardiac fibroblasts (CFs) and TGF-β1-induced endothelial-mesenchymal transition (EndMT) of human umbilical vein endothelial cell (HUVEC) were established to explore roles of omentin-1 in these processes. To determine changes in adipocytokines secretion under hypoxia conditions, adipocytes were treated with 5% O₂ and 95% N₂, and then CFs and HUVECs were co-cultured with the conditioned medium of adipocytes to determine the effects of hypoxia-treated adipocytes on these cells.

RESULTS

Expression of omentin-1 was downregulated in the EAT and right atrial appendages from patients with AF compared to samples from patients without AF, while the TGF-β1 level was upregulated in EAT from patients with AF. EAT from patients with AF exhibited adipocyte hypertrophy and severe interstitial fibrosis. Omentin-1 inhibited TGF-β1-induced CF activation and reversed TGF-β1-induced HUVEC EndMT. Adipocytes treated with hypoxia exhibited downregulation of omentin-1 and partly activated CFs.

CONCLUSIONS

This study demonstrated that omentin-1 was an antifibrotic adipocytokine and was downregulated in patients with AF, which was partly mediated by hypoxia.

Accuracy of implantable loop recorders for detecting atrial tachyarrhythmias after atrial fibrillation catheter ablation

Background

Implantable loop recorders (ILRs) can provide an enhanced possibility to detect atrial fibrillation (AF), but the accuracy, especially the positive predictive value (PPV), is controversial. This study aimed to evaluate the accuracy of ILRs for detecting AF through a comparison with Holter.

Method and results

Thirteen patients who underwent AF ablation were enrolled. ILRs were implanted in all patients, who were scheduled to have Holter monitorings after the procedure. The incidence of AF was compared between the two modalities and analyzed for any correlations. A total of 51 Holters (67,985.5 min) and concomitant ILRs were available for the comparison. The judgment of the presence of AF did not perfectly correlate between the ILR and Holter (Kappa = 0.866, P < 0.001). In the ILR data, the sensitivity of detecting AF on the Holter was 81.6% (95% confidence interval [CI] 0.812–0.820; P < 0.001). The specificity was 99.9% (95% CI 0.998–0.999; P < 0.001). When the ILR detected AF, the PPV was 99.5% (95% CI 0.994–0.995), but the ILR did not detect AF, and the negative predictive value was 94.2% (95% CI 0.941–0.944). A separate analysis of AF/atrial tachycardia (AT) showed that the AT detection rate of the ILR was 2.3%.

Conclusion

The ILR had a low false positive value and high PPV for AF events. However, it was limited in identifying AT.

Sacubitril/valsartan attenuates atrial electrical and structural remodelling in a rabbit model of atrial fibrillation

Atrial structural and electrical remodelling play important roles in atrial fibrillation (AF). Sacubitril/valsartan attenuates cardiac remodelling in heart failure. However, the effect of sacubitril/valsartan on AF is unclear. The aim of this study was to evaluate the effect of sacubitril/valsartan on atrial electrical and structural remodelling in AF and investigate the underlying mechanism of action. Thirty-three rabbits were randomized into sham, RAP, and sac/val groups. HL-1 cells were subjected to control treatment or rapid pacing with or without LBQ657 and valsartan. Echocardiography, atrial electrophysiology, and histological examination were performed. The concentration of Ca²⁺ and expression levels of calcineurin, NFAT, p-NFAT, Cav1.2, collagen Ⅰ and Ⅲ, ANP, BNP, CNP, NT-proBNP, and ST2 in HL-1 cells, and I_caL in left atrial cells, were determined. We observed that compared to that in the sham group, the atrium and right ventricle were enlarged, myocardial fibrosis was markedly higher, AF inducibility was significantly elevated, and atrial effective refractory periods were shortened in the RAP group. These effects were significantly reversed by sacubitril/valsartan. Compared to that in the sham group, collagen Ⅰ and Ⅲ, NT-proBNP, ST2, calcineurin, and NFAT were significantly up-regulated, while p-NFAT and Ca_v1.2 were down-regulated in the RAP group, and sacubitril/valsartan inhibited these changes. Ca²⁺ concentration increased and I_CaL density decreased in in vivo and in vitro AF models, reversed by sacubitril/valsartan. Sacubitril/valsartan attenuates atrial electrical remodelling and ameliorates structure remodelling in AF. This study paves the way for the possibility of clinical use of sacubitril/valsartan in AF patients.

Association Between Use of Warfarin for Atrial Fibrillation and Outcomes Among Patients With End-Stage Renal Disease: A Systematic Review and Meta-analysis

IMPORTANCE

Several studies have examined the role of warfarin in preventing strokes in patients with atrial fibrillation and end-stage renal disease; however, the results remain inconclusive.

OBJECTIVE

To assess recently published studies to examine the outcomes of the use of warfarin among patients with atrial fibrillation and end-stage renal disease.

DATA SOURCES

A literature search was performed using the terms warfarin and atrial fibrillation and end-stage renal disease and warfarin and atrial fibrillation and dialysis in the MEDLINE, Embase, and Google Scholar databases from January 1, 2008, to February 28, 2019.

STUDY SELECTION

The studies included were those with patients with end-stage renal disease and atrial fibrillation who were receiving warfarin and with hazard ratios (HRs) of at least 1 primary outcome. The studies excluded were those with a lack of information on outcomes and unreliable 95% CIs of the results.

DATA EXTRACTION AND SYNTHESIS

The Meta-analysis of Observational Studies in Epidemiology (MOOSE) guidelines were followed in selecting studies. Collected data were also scrutinized for reliable 95% CIs. Finally, studies were examined for perceived biases, their limitations, and the definitions of the outcomes.

MAIN OUTCOMES AND MEASURES

The HRs and 95% CIs were calculated for the incidence of ischemic stroke, hemorrhagic stroke, major bleeding, and mortality among patients receiving anticoagulants and those not receiving anticoagulants.

RESULTS

Study selection yielded 15 studies with a total of 47 480 patients with atrial fibrillation and end-stage renal disease. Of these patients, 10 445 (22.0%) were taking warfarin. With a mean (SD) follow-up period of 2.6 (1.4) years, warfarin use was associated with no significant change for the risk of ischemic stroke (HR, 0.96; 95% CI, 0.82-1.13), with a significantly higher risk of hemorrhagic stroke (HR, 1.49; 95% CI, 1.03-1.94), with no significant difference in the risk of major bleeding (HR, 1.20; 95% CI, 0.99-1.47), and with no change in overall mortality (HR, 0.95; 95% CI, 0.83-1.09).

CONCLUSIONS AND RELEVANCE

In the studies reviewed, warfarin use appears to have been associated with no change in the incidence of ischemic stroke in patients with atrial fibrillation and end-stage renal disease. However, from the studies reviewed, it does appear to be associated with a significantly higher risk of hemorrhagic stroke, with no significant difference in the risk of major bleeding, and with no change in mortality.

Atrial Fibrillation and Surgical Patients with Peripheral Arterial Disease

BACKGROUND

Atrial fibrillation (AF) is the most common cardiac arrhythmia in clinical practice and its prevalence rate significantly increases with age. The prognostic implication of AF in surgical patients with peripheral arterial disease (PAD) has not been analyzed. The aims of this study were to analyze the prevalence of AF among patients operated on with symptomatic PAD, and to determine whether these patients are at a higher risk of death or amputation.

METHODS

We designed a retrospective cohort study, from January 2013 to December 2017, in which we analyzed the medical records of all consecutive patients with symptomatic PAD admitted to our hospital and underwent a vascular procedure. We compared the outcomes of patients with and without AF. All statistically significant demographic variables that underwent a univariate analysis were inserted in the stepwise multivariate model along with AF. A survival analysis was performed to evaluate the factors associated with mortality through a Cox regression model. P-value of 0.05 was considered statistically significant.

RESULTS

Four hundred three patients were admitted in-hospital with symptomatic PAD and they underwent a vascular intervention. The mean follow-up was 2 years. Seventy-six patients (18.8%) had AF. These patients were older (78 ± 9.1 years) than the 327 patients without AF (68 ± 12.37 years) (P < 0.0001), and more likely to undergo emergency surgery (18.42% vs. 7.34%, P = 0.0029). Age and emergency admission were dependent associates of AF. The patients with AF were frequently men (69.7%) with previous hypertension (96% %). The presence of AF was associated with higher rate of all-cause mortality (55.26%, P < 0.0001, hazard ratio 2.24, confidence interval 1.55-3.25), but the multivariate analysis adjusted for risk factors showed that the mortality was only associated with age because these patients were older and with many comorbidities. The majority of this population with AF showed some tissue lesion when they were admitted in-hospital (Rutherford V-VI, AF 80.2%, P = 0.0004), and this fact justified that a 22.36% underwent a major amputation affecting the ischemic lower limb in admission (P = 0.018). During the follow-up the free amputation rate was similar between groups (60.5% AF vs. 78.3% non-AF).

CONCLUSIONS

This study showed the high prevalence of AF in patients with symptomatic PAD that required surgical admission in-hospital. The presence of AF was related with a greater and serious risk of mortality, but this was independently associated to age, because patients with AF were older and frailer. Clearly, this group of patients had a high risk of amputation when they arrived to the hospital and they needed emergency surgery.

Identification of patients with atrial fibrillation: a big data exploratory analysis of the UK Biobank

OBJECTIVE

Atrial fibrillation (AF) is the most common cardiac arrhythmia, with an estimated prevalence of around 1.6% in the adult population. The analysis of the electrocardiogram (ECG) data acquired in the UK Biobank represents an opportunity to screen for AF in a large sub-population in the UK. The main objective of this paper is to assess ten machine-learning methods for automated detection of subjects with AF in the UK Biobank dataset.

APPROACH

Six classical machine-learning methods based on support vector machines are proposed and compared with state-of-the-art techniques (including a deep-learning algorithm), and finally a combination of a classical machine-learning and deep learning approaches. Evaluation is carried out on a subset of the UK Biobank dataset, manually annotated by human experts.

MAIN RESULTS

The combined classical machine-learning and deep learning method achieved an F1 score of 84.8% on the test subset, and a Cohen's kappa coefficient of 0.83, which is similar to the inter-observer agreement of two human experts.

SIGNIFICANCE

The level of performance indicates that the automated detection of AF in patients whose data have been stored in a large database, such as the UK Biobank, is possible. Such automated identification of AF patients would enable further investigations aimed at identifying the different phenotypes associated with AF.

Initial Precipitants and Recurrence of Atrial Fibrillation

BACKGROUND

Atrial fibrillation (AF) may occur after an acute precipitant and subsequently resolve. Management guidelines for AF in these settings are unclear as the risk of recurrent AF and related morbidity is poorly understood. We examined the relations between acute precipitants of AF and long-term recurrence of AF in a clinical setting.

METHODS

From a multi-institutional longitudinal electronic medical record database, we identified patients with newly diagnosed AF between 2000 and 2014. We developed algorithms to identify acute AF precipitants (surgery, sepsis, pneumonia, pneumothorax, respiratory failure, myocardial infarction, thyrotoxicosis, alcohol, pericarditis, pulmonary embolism, and myocarditis). We assessed risks of AF recurrence in individuals with and without a precipitant and the relations between AF recurrence and heart failure, stroke, and mortality.

RESULTS

Among 10 723 patients with newly diagnosed AF (67.9±9.9 years, 41% women), 19% had an acute AF precipitant, the most common of which were cardiac surgery (22%), pneumonia (20%), and noncardiothoracic surgery (15%). The cumulative incidence of AF recurrence at 5 years was 41% among individuals with a precipitant compared with 52% in those without a precipitant (adjusted hazard ratio [HR], 0.75 [95% CI, 0.69-0.81]; P<0.001). The lowest risk of recurrence among those with precipitants occurred with postoperative AF (5-year incidence 32% in cardiac surgery and 39% in noncardiothoracic surgery). Regardless of the presence of an initial precipitant, recurrent AF was associated with increased adjusted risks of heart failure (hazard ratio, 2.74 [95% CI, 2.39-3.15]; P<0.001), stroke (hazard ratio, 1.57 [95% CI, 1.30-1.90]; P<0.001), and mortality (hazard ratio, 2.96 [95% CI, 2.70-3.24]; P<0.001).

CONCLUSIONS

AF after an acute precipitant frequently recurs, although the risk of recurrence is lower than among individuals without an acute precipitant. Recurrence is associated with substantial long-term morbidity and mortality. Future studies should address surveillance and management after newly diagnosed AF in the setting of an acute precipitant.

High-power, Short-duration Radiofrequency Ablation for the Treatment of AF

High-power, short-duration (HPSD) ablation for the treatment of AF is emerging as an alternative to ablation using conventional ablation generator settings characterised by lower power and longer duration. Although the reported potential advantages of HPSD ablation include less tissue oedema and collateral tissue damage, a reduction in procedural time and superior ablation lesion formation, clinical studies of HPSD ablation validating these observations are limited. One of the main challenges for HPSD ablation has been the inability to adequately assess temperature and lesion formation in real time. Novel catheter designs may improve the accuracy of intra-ablation temperature recording and correspondingly may improve the safety profile of HPSD ablation. Clinical studies of HPSD ablation are on-going and interpretation of the data from these and other studies will be required to ascertain the clinical value of HPSD ablation.

Matters of the Heart: Cardiovascular Health in Women Throughout Their Lifetimes

The authors' goal is to review the current recommendations for optimizing cardiovascular health beginning in adolescent years to adulthood, and to expand on the role that pregnancy complications may have as implications for future cardiovascular health. Attention to cardiac health begins in adolescence; however, most young patients are not screened. Pregnancy, with its increased cardiovascular demands and host of antepartum cardiopulmonary complications, may provide a window into future cardiac health. The distinct shift in cardiac risk that occurs once a woman enters menopause is largely ignored in routine screening guidelines.

Prediction of atrial fibrillation using the recurrence complex network of body surface potential mapping signals

OBJECTIVE:

Atrial fibrillation (AF) is the most common type of persistent arrhythmia. Early diagnosis and intervention of AF is essential to avert the further fatality. The technique of noninvasive electrical mapping, especially the body surface potential mapping (BSPM), has a more practical application in the study of predicting AF, when compared with the invasive electrical mapping methods such as the epicardial mapping and interventional catheter mapping. However, the prediction of AF with noninvasive signals has been inadequately studied. Thus, the aim of this paper was to analyze the properties of atrial dynamic system based on the noninvasive BSPM signals (BSPMs), using the recurrence complex network, and consequently to evaluate its role in predicting the recurrence of AF in clinical aspect.

METHOD:

Twelve patients with persistent AF were included in this study. Their preoperative and postoperative BSPMs were recorded. Initially, the preoperative BSPMs were transformed into the recurrence complex network to characterize the complexity property of the atria. Subsequently, the parameters of recurrence ratio (REC), determinism (DET), entropy of the diagonal structure distribution (ENTR), and laminarity (LAM) were calculated. Furthermore, the difference in the parameters in the four regions of the body and the difference obtained from the dominant frequency (DF) method were compared. Finally, the results obtained for the atrial dynamic system complexity from a 12-lead electrocardiogram (ECG) from the BSPMs were discussed.

RESULTS:

Our study revealed that the patients whose REC is greater than an average threshold, and with a lower LAM presented a much higher possibility of AF recurrence, after the AF surgery.

CONCLUSIONS:

The recurrence complex network is a useful and convenient way to evaluate the nonlinear properties of the BSPMs in patients with AF. It has good immunity to the lead position and has a potential role in the understanding of predicting the recurrence of AF.

Association between chymase gene polymorphisms and atrial fibrillation in Chinese Han population

Background

Chymase is the major angiotensin II (Ang II)-forming enzyme in cardiovascular tissue, with an important role in atrial remodeling. This study aimed to examine the association between chymase 1 gene (CMA1) polymorphisms and atrial fibrillation (AF) in a Chinese Han population.

Methods

This case-control study enrolled 126 patients with lone AF and 120 age- and sex-matched healthy controls, all from a Chinese Han population. Five CMA1 polymorphisms were genotyped.

Results

The CMA1 polymorphism rs1800875 (G-1903A) was associated with AF. The frequency of the GG genotype was significantly higher in AF patients compared with controls (p = 0.009). Haplotype analysis further demonstrated an increased risk of AF associated with the rs1800875-G haplotype (Hap8 TGTTG, odds ratio (OR) = 1.668, 95% CI 1.132–2.458, p = 0.009), and a decreased risk for the rs1800875-A haplotype (Hap5 TATTG, OR = 0.178, 95% CI 0.042–0.749, p = 0.008).

Conclusions

CMA1 polymorphisms may be associated with AF, and the rs1800875 GG genotype might be a susceptibility factor for AF in the Chinese Han population.

Burden of Premature Atrial Complexes and Risk of Recurrent Stroke and Death in Patients with Mild to Moderate Ischemic Stroke

BACKGROUND

Premature atrial complexes (PACs) meet increased attention as a potential intermediary between sinus rhythm and atrial fibrillation (AF). Patients with even high numbers of PACs do not fulfill current guidelines for oral anticoagulation treatment though an associated stroke risk is suspected.

OBJECTIVE

We aimed to determine whether a high number of PACs or runs of AF less than 30 seconds in 2-day continuous electrocardiogram (ECG) recording was associated with risk of recurrent ischemic stroke/transient ischemic attack (TIA) or death in a large cohort of patients with acute ischemic stroke or TIA and no prior AF.

METHODS

We performed 48 hours continuous ECG recording within 1 week after ischemic stroke/TIA. PACs were reported as mean number of PACs per hour. Patients were followed in Danish Stroke Registry, Danish Civil Registration System, and Danish National Patient Registry. Cox Regression analysis was used to calculate hazard ratios.

RESULTS

We included 1507 patients with TIA (40%) or ischemic stroke (60%), of which 98.7% had mild to moderate strokes. Mean age was 72.9 (7.8) years, 43.4% were females. Follow-up was 2.3 (1.3) years. Hazard ratio for recurrent stroke/TIA or death did not differ between quartiles of PAC burden, nor did any of the 2 components of this composite endpoint. Nonsustained AF less than 30 seconds was not associated with higher risk of recurrent stroke/TIA or death.

CONCLUSIONS

In a large cohort of patients with recent ischemic stroke or TIA, burden of PACs or nonsustained AF less than 30 seconds were not associated to higher risk of recurrent stroke/TIA or death.

Diagnosis and management of cold urticaria in cryoablation of atrial fibrillation: a case report

Background

Cold-induced urticaria is triggered by exposure to local or environmental cold and manifests as localized or systemic pruritic papules, sometimes accompanied by angio-oedema and anaphylaxis representing a life-threatening condition. Therapy options of atrial fibrillation (AF) include catheter ablation with different energy sources, of which cryoenergy may be superior to other energy sources regarding safety and efficacy.

Case summary

We report the case of a 60-year-old man suffering from symptomatic paroxysmal AF. The patient had a history of cold-induced urticaria without occurrence of systemic reactions to date. After successful pulmonary vein isolation (PVI) using cryoenergy, post-interventional oesophagogastroduodenoscopy and endosonography revealed newly occurred oedema in the middle oesophagus with inclusion of all oesophageal wall layers. Due to missing peri-atrial lesions, activation of cold urticaria during cryoablation rather than procedure-associated alterations was diagnosed. The patient reported no systemic or gastrointestinal symptoms after PVI.

Discussion

We could demonstrate that cold urticaria can manifest as oesophageal angio-oedema in AF patients undergoing cryoablation. Therefore, these patients should be carefully considered for an alternative energy source for PVI or premedication with antihistamines when using cryoenergy.

Recurrent atrial fibrillation/flutter detection after ablation or cardioversion using the AliveCor KardiaMobile device: iHEART results

OBJECTIVE

This study evaluated the impact of daily ECG (electrocardiogram) self-recordings on time to documented recurrent atrial fibrillation (AF) or atrial flutter (AFL) and time to treatment of recurrent arrhythmia in patients undergoing catheter radiofrequency ablation (RFA) or direct current cardioversion (DCCV) for AF/AFL.

BACKGROUND

AF recurrence rates after RFA and DCCV are 20% to 45% and 60% to 80%, respectively. Randomized trials comparing mobile ECG devices to standard of care have not been performed in an AF/AFL population after treatment.

METHODS

Of 262 patients consented, 238 were randomized to either standard of care (123) or to receive the iHEART intervention (115). Patients in the intervention group were provided with and trained to use an AliveCor KardiaMobile ECG monitor, and were instructed to take and transmit daily ECG recordings. Data were collected from transmitted ECG recordings and patients' electronic health records.

RESULTS

In a multivariate Cox model, the likelihood of recurrence detection was greater in the intervention group (hazard ratio = 1.56, 95% confidence interval [CI]: 1.06-2.30, P = .024). Hazard ratios did not differ significantly for RFA and DCCV procedures. Recurrence during the first month after ablation strongly predicted later recurrence (hazard ratio = 4.53, 95% CI: 2.05-10.00, P = .0006). Time from detection to treatment was shorter for the control group (hazard ratio = 0.33, 95% CI: 0.57-2.92, P < .0001).

CONCLUSIONS

The use of mobile ECG self-recording devices allows for earlier detection of AF/AFL recurrence and may empower patients to engage in shared health decision-making.

Uremic Toxins and Atrial Fibrillation: Mechanisms and Therapeutic Implications

Atrial fibrillation (AF) is the most prevalent arrhythmia in the general population. There is a close association between chronic kidney disease (CKD) and AF. In recent years, attention has been focused on the relationship between AF and uremic toxins, including indoxyl sulfate (IS). Several animal studies have shown that IS promotes the development and progression of AF. IS has been shown to cause fibrosis and inflammation in the myocardium and exacerbate AF by causing oxidative stress and reducing antioxidative defense. Administration of AST-120, an absorbent of uremic toxins, decreases uremic toxin-induced AF in rodents. We have recently reported that patients with a higher serum IS level exhibit a higher rate of AF recurrence after catheter ablation, with serum IS being a significant predictor of AF recurrence. In this review, we discuss the possible mechanisms behind the AF-promoting effects of uremic toxins and summarize the reported clinical studies of uremic toxin-induced AF.

Impact of a Multidisciplinary Treatment Pathway for Atrial Fibrillation in the Emergency Department on Hospital Admissions and Length of Stay: Results of a Multi-Center Study

Background

Variability in the management of atrial fibrillation (AF) in the emergency department (ED) leads to avoidable hospital admissions and prolonged length of stay (LOS). In a retrospective single‐center study, a multidisciplinary AF treatment pathway was associated with a reduced hospital admission rate and reduced LOS. To assess the applicability of the AF pathway across institutions, we conducted a 2‐center study.

Methods and Results

We performed a prospective, 2‐stage study at 2 tertiary care hospitals. During the first stage, AF patients in the ED received routine care. During the second stage, AF patients received care according to the AF pathway. The primary study outcome was hospital admission rate. Secondary outcomes included ED LOS and inpatient LOS. We enrolled 104 consecutive patients in each stage. Patients treated using the AF pathway were admitted to the hospital less frequently than patients who received routine care (15% versus 55%; P<0.001). For admitted patients, average hospital LOS was shorter in the AF pathway cohort than in the routine care cohort (64 versus 105 hours, respectively; P=0.01). There was no significant difference in the average ED LOS between AF pathway and routine care cohorts (14 versus 12 hours, respectively; P=0.32).

Conclusions

In this prospective 2‐stage, 2‐center study, utilization of a multidisciplinary AF treatment pathway resulted in a 3.7‐fold reduction in admission rate and a 1.6‐fold reduction in average hospital LOS for admitted patients. Utilization of the AF pathway was not associated with a significant change in ED LOS.

Ligation of Left Atrial Appendage during Off-Pump Coronary Surgery

OBJECTIVE

The main purpose of this article is to evaluate an impact of epicardial ligation of the left atrial appendage (LAA) in patients with atrial fibrillation (AF) undergoing off-pump coronary artery bypass grafting (OPCAB) on the development of ischemic stroke and mortality.

METHODS

From 2009 to 2013, a total of 125 patients (86.4% men, mean age 64 ± 7 years, 95% confidence interval: 61-65 years) received a combined OPCAB and LAA ligation because of coronary artery disease and AF. All the subjects were divided into two groups: group 1 (n = 57)-LAA ligation during OPCAB, group 2 (n = 68) without LAA ligation during OPCAB. Primary endpoints were postoperative incidence of ischemic stroke and mortality.

RESULTS

No difference in the number of ischemic stroke (0 vs. 5.9%) and death (0 vs. 4.4%) in both groups during the hospital period (p > 0.05). Median overall follow-up was 41 (22-61) months: without difference for groups (p > 0.05). During follow-up, there was a difference in the number of ischemic stroke (0 vs. 17.6%, p < 0.001), while there was no difference in mortality in two study groups (5.3 vs. 16.2%, p > 0.05).

CONCLUSION

Epicardial ligation of LAA during OPCAB in patients with AF may reduce the risk of ischemic stroke in long-term follow-up and does not affect the mortality.

Comparative transcriptome analysis to elucidate the therapeutic mechanism of colchicine against atrial fibrillation

In recent years, colchicine has been used to reduce the risk of cardiovascular events; in particular, it has been effectively used for the treatment of atrial fibrillation (AF). We first discovered that colchicine can treat AF in a rat model and that it can reverse the effects of atrial fibrosis. To illustrate the potential therapeutic mechanism of colchicine against AF, we performed comparative transcriptome analyses; our aim was to elucidate the therapeutic effects of colchicine so as to improve treatment and prognoses of AF. Genomics and bioinformatics analyses revealed that the IL-17 signaling pathway, and renin secretion pathway are involved in the mechanism of action of colchicine. Furthermore, there was a significant correlation between overlapping genes in the two groups of differentially expressed genes. The genes encoding Akap4, Pcdha9, Gp2, Cd177, Krt15, Aqp3, Chia, and Bpifb1 were pivotal and possible action sites for the therapeutic mechanisms of colchicine. We conclude that AF involves a multifactorial pathological process. The mechanisms underlying the action of colchicine in the treatment of AF warrant further studies.

Left atrial longitudinal strain by speckle tracking as independent predictor of recurrence after electrical cardioversion in persistent and long standing persistent non-valvular atrial fibrillation

Atrial fibrillation (AF) is the most common arrhythmia in humans. After successful cardioversion, there is a recurrence of 60% due to atrial remodeling, and it has been shown that the global peak atrial longitudinal strain (GPALS) is decreased in these subjects. The aim of this study was to evaluate the predictive value of GPALS for AF recurrence. A prospective cohort of patients with persistent (PnVAF) and long standing persistent non-valvular AF (LSPnVAF) which underwent electrical cardioversion was evaluated with standard echocardiographic variables and GPALS quantification. The primary endpoint was AF recurrence at 6 months. We included PnVAF (n = 50, aged 68.4 ± 10.2 years, female 46%, lasted AF 6 months) and LSPnVAF (n = 81, aged 66.5 ± 13.1 years, female 36%, lasted AF 18 months). At 6 months there were a 68% of recurrence of AF in PnVAF and 53% in LSPnVAF group. GPALS was lower in recurrence 7.8 ± 2.0% versus 21.2 ± 8.9% (p < 0.001) for PnVAF and 7.3 ± 2.7% versus 20.7 ± 7.6% (p < 0.001) in LSPnVAF. GPALS ≤ 10.75% discriminates recurrence at 6 months with a sensitivity of 85%, specificity 99%, PPV 85%, NPV 90%, LR + 8.5 and LR- 0.17. The independent predictors of recurrence in PnVAF were GPALS ≤ 10.75% HR 8.89 [(2.2-35.7), p < 0.01] meanwhile in LSPnVAF were age HR 1.039 [(1.007-1.071), p = 0.01], and GPALS ≤ 10.75% HR 28.1 [(7.2-109.1), p < 0.001]. In subjects with PnVAF and LSPnVAF with successful electrical cardioversion, GPALS ≤ 10.75% predicts arrhythmia recurrence at 6-month follow-up.

A Multicenter Randomized Trial to Evaluate a Chemical-first or Electrical-first Cardioversion Strategy for Patients With Uncomplicated Acute Atrial Fibrillation

BACKGROUND

Emergency department (ED) patients with uncomplicated atrial fibrillation (AF) of less than 48 hours may be safely managed with rhythm control. Although both chemical-first and electrical-first strategies have been advocated, there are no comparative effectiveness data to guide clinicians.

METHODS

At six urban Canadian centers, ED patients ages 18 to 75 with uncomplicated symptomatic AF of less than 48 hours and CHADS₂ score of 0 or 1 were randomized using concealed allocation in a 1:1 ratio to one of the following strategies: 1) chemical cardioversion with procainamide infusion, followed by electrical countershock if unsuccessful; or 2) electrical cardioversion, followed by procainamide infusion if unsuccessful. The primary outcome was the proportion of patients discharged within 4 hours of arrival. Secondary outcomes included ED length-of-stay (LOS); prespecified ED-based adverse events; and 30-day ED revisits, hospitalizations, strokes, deaths, and quality of life (QoL).

RESULTS

Eighty-four patients were analyzed: 41 in the chemical-first group and 43 in the electrical-first group. Groups were balanced in terms of age, sex, vital signs, and CHADS₂ scores. All patients were discharged home, with 83 (99%) in sinus rhythm. In the chemical-first group, 13 of 41 patients (32%) were discharged within 4 hours compared to 29 of 43 patients (67%) in the electrical-first group (p = 0.001). In the chemical-first group, the median ED LOS was 5.1 hours (interquartile range [IQR] = 3.5 to 5.9 hours) compared to 3.5 hours (IQR = 2.4 to 4.6 hours) in the electrical-first group, for a median difference of 1.2 hours (95% confidence interval = 0.4 to 2.0 hours, p < 0.001). No patients experienced stroke or death. All other outcomes, including adverse events, ED revisits, and QoL, were similar.

CONCLUSION

In uncomplicated ED AF patients managed with rhythm control, chemical-first and electrical-first strategies both appear to be successful and well tolerated; however, an electrical-first strategy results in a significantly shorter ED LOS.

A Nurse-led Approach to Improving Cardiac Lifestyle Modification in an Atrial Fibrillation Population

Atrial fibrillation (AF) is a major public health problem and the most common cardiac arrhythmia encountered in clinical practice at this time. AF is associated with numerous symptoms such as palpitations, shortness of breath, and fatigue, which can significantly reduce health-related quality of life and result in serious adverse cardiac outcomes. In light of this, the aim of the present pilot study was to test the feasibility of implementing a mobile health (mHealth) lifestyle intervention titled "Atrial Fibrillation and Cardiac Health: Targeting Improving Outcomes via a Nurse-Led Intervention (ACTION)," with the goal of improving cardiac health measures, AF symptom recognition, and self-management. As part of this study, participants self-identified cardiac health goals at enrollment. The nurse used web-based resources from the American Heart Association (Dallas, TX, USA), which included the Life's Simple 7® My Life Check® assessment, to quantify current lifestyle behavior change needs. Furthermore, on the My AFib Experience™ website (American Heart Association, Dallas, TX, USA), the patient used a symptom tracker tool to capture the date, time, frequency, and type of AF symptoms, and these data were subsequently reviewed by the cardiac nurse. Throughout the six-month intervention period, the cardiac nurse used a motivational interviewing approach to support participants' cardiac health goals. Ultimately, the ACTION intervention was tested in 53 individuals with AF (mean age: 59 ± 11 years; 76% male). Participants were predominantly overweight/obese (79%), had a history of hypertension (62%) or hyperlipidemia (61%), and reported being physically inactive/not preforming any type of regular exercise (52%). The majority (88%) of the participants had one or more Life's Simple 7® measures that could be improved. Most of the participants (98%) liked having a dedicated nurse to work with them on a biweekly basis via the mHealth portal. The most commonly self-reported symptoms were palpitations, fatigue/exercise intolerance, and dyspnea. Seventy percent of the participants had an improvement in their weight and blood pressure as documented within the electronic health record as well as a corresponding improvement in their Life's Simple 7® score at six months. On average, there was a three-pound (1.36-kg) decrease in weight and a 5-mmHg decrease in systolic blood pressure between baseline and at six months. In conclusion, this pilot work provides initial evidence regarding the feasibility of implementing the ACTION intervention and supports testing the ACTION intervention in a larger cohort of AF patients to inform existing AF guidelines and build an evidence base for reducing AF burden through lifestyle modification.

Usefulness of the CHA2DS2-VASc Score to Predict Adverse Outcomes in Acute Coronary Syndrome Patients Without Atrial Fibrillation Undergoing Percutaneous Coronary Intervention

The prognostic value of the CHA₂DS₂-VASc score in acute coronary syndrome (ACS) patients without atrial fibrillation (AF) who underwent percutaneous coronary intervention remains uncertain. We examine the association of the CHA₂DS₂-VASc score and major adverse cardiovascular events (MACE) in this population and compared its risk prediction with 2 other commonly used risk scores (Global Registry of Acute Coronary Events [GRACE] and thrombolysis in myocardial infarction [TIMI]). A total of 3,745 consecutive ACS patients without AF who underwent percutaneous coronary intervention during 2013 to 2017 were classified into 4 groups according to the CHA₂DS₂-VASc score: low (0 to 1), moderate (2 to 3), high (4 to 5), and very high (>5). Incidences of MACE including cardiovascular death, nonfatal myocardial infarction, or stroke in-hospital and during a median follow-up of 33 months were compared among the 4 groups. Receiver-operating characteristic curves were generated to compare CHA₂DS₂-VASc with GRACE and TIMI for risk prediction. The incidences of in-hospital MACE (3.5%, 6.6%, 7.6%, and 9.1%, p <0.001) and mid-term follow-up MACE (4.5%, 7.1%, 13.1%, and 16.1%, p <0.001) were significantly higher as the CHA₂DS₂-VASc score increased. The CHA₂DS₂-VASc score was an independent predictor of subsequent MACE (hazard ratio = 1.31, 95% CI 1.24 to 1.39, p <0.001), and the very high-risk score group showed 3.8-fold increased risk of MACE than the low-risk score group. Receiver-operating characteristic curves showed that the CHA₂DS₂-VASc score was comparable to the GRACE score and to TIMI-STEMI, but, better than the TIMI-NSTEMI/unstable angina pectoris score in terms of predicting MACE. In conclusion, higher CHA₂DS₂-VASc score was independently associated with increased risk of MACE in the ACS patients without AF who underwent PCI.

Relationship Between Obstructive Sleep Apnoea and AF

With the growing obesity epidemic, the global burden of AF and obstructive sleep apnoea (OSA) is increasing at an alarming rate. Obesity, age, male gender, alcohol consumption, smoking and heart failure are common risk factors for both AF and OSA and they are independently associated with adverse cardiovascular outcomes. Weak evidence from observational studies link OSA to the development of AF. Hypoxia/hypercapnia, systemic inflammation and autonomic nervous system modulation are biological mechanisms that link OSA to AF. Patients with OSA have a poor response to catheter ablation of AF and often suffer recurrences. Observational data shows that continuous positive airway pressure is associated with a reduction in AF burden and a better response to catheter ablation of AF. However, prospective randomised studies are needed to confirm the usefulness of continuous positive airway pressure in the treatment of AF in patients with OSA.

Correlation between HCN4 gene polymorphisms and lone atrial fibrillation risk

Background and objective: Atrial electrical remodelling (AER) was significantly associated with atrial fibrillation (AF) development. Polymorphisms in hyperpolarization activated cyclic nucleotide gated potassium channel 4 (HCN4) gene might be correlated with AER. In the present study, we explored the association of HCN4 polymorphisms (rs498005 and rs7164883) with lone AF risk in a Chinese Han population. Methods: In this case-control study, the Sanger sequencing method was utilized to genotype the HCN4 polymorphisms. Relative risk of AF was assessed by the χ² test, and presented by odds ratios (ORs) and corresponding 95% confidence intervals (CIs). Logistic regression analysis was performed for multivariate analysis. The effects of HCN4 polymorphisms on AF clinical features were analyzed by the Mann-Whitney U test and adjusted by the Bonferroni method. Results: C allele of rs498005 was significantly correlated with increased risk of AF (OR = 1.412, 95%CI = 1.012-1.970), and the association still exited after adjustment by age, gender, the status of smoking and drinking, histories of diabetes, hyperlipidaemia and myocardial infarction (adjusted OR = 1.473, 95%CI = 1.043-2.081). G allele of rs7164883 SNP was marginally associated with enhanced AF risk after adjustment by the above clinical parameters (adjusted OR = 1.742, 95%CI = 1.019-2.980). Atrial late potential (ALP), including TP (P wave duration after filtering) and LP₂₀ (the amplitude of superimposed potential in the final 20 ms of P wave) were significantly associated with rs498005 genotype (p < .001). Conclusion: HCN4 rs498005 and rs7164883 polymorphisms are significantly associated with AF risk.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Cost-effectiveness of apixaban for stroke prevention in non-valvular atrial fibrillation in Saudi Arabia

BACKGROUND

Apixaban, an oral anticoagulant for stroke and systemic embolism prevention in non-valvular atrial fibrillation (NVAF), was superior to warfarin in prevention of stroke and systemic embolism, bleeding outcomes and mortality (ARISTOTLE trial), and substantially reduced stroke risk, with no significant increase in major or intracranial bleeding risk versus aspirin (AVERROES trial).

OBJECTIVE

Estimate cost-effectiveness of apixaban versus other anticoagulants for NVAF treatment in Saudi Arabia.

DESIGN

Lifetime Markov model.

SETTING

A published model was adapted from the United Kingdom (UK) to the Saudi Arabia setting.

PATIENTS AND METHODS

The model enabled pairwise comparisons of apixaban against other anticoagulants, aspirin, and aspirin+clopidogrel. Apart from warfarin and aspirin, comparisons were indirect. Subpopulations included vitamin K antagonist (VKA) suitable and unsuitable patients. Medication and physician visit costs were from published lists. A cost ratio (0.533), from comparison of UK and Saudi physician visit costs, was applied to UK model inputs to estimate local event costs. Background life expectancy was from Saudi life tables. Model structure, treatment comparators, patient characteristics, event rates, and utilities were unchanged. Costs and health benefits were discounted by 3.5% annually.

MAIN OUTCOME MEASURE

Incremental cost-effectiveness ratio of cost per quality-adjusted life-year (QALY) gained.

SAMPLE SIZE

Model cohort of 1000 NVAF patients, for VKA suitable and VKA unsuitable populations.

RESULTS

Apixaban was dominant versus warfarin (VKA suitable) and rivaroxaban (VKA suitable and unsuitable). Compared against dabigatran (110mg, 150 mg, 110/150mg), the cost/QALY gained for apixaban was $5166, $11 143, $10 849 (VKA suitable) and $5 157, $14 424, $14 134 (VKA unsuitable), respectively. Cost/QALY for apixaban versus aspirin and aspirin+clopidogrel was $14 805 and $5784 (VKA suitable); and $10 564 and $4203 (VKA unsuitable), respectively. Sensitivity analyses demonstrated consistency of findings across varying inputs.

CONCLUSIONS

Apixaban was found to be cost-effective for stroke prevention among Saudi NVAF patients, when assessed using a US$20 000 willingness-to-pay threshold.

LIMITATIONS

Lack of robust local clinical, cost and utility data for model inputs. Lack of head-to-head clinical trial data for rivaroxaban, dabigatran, and clopidogrel plus aspirin comparators.

CONFLICT OF INTEREST

Study was funded by Pfizer Inc. and Bristol Myers-Squibb. KO, RS, SAK and AAA received salaries from their respective employers, but did not receive direct financial compensation for participation in or authorship of this study.

Prediction of acute coronary syndrome, ischemic stroke, and mortality in patients with heart failure: a comparison of CHA2DS2-VASc and AHEAD scores

PURPOSE

To compare the predictive capacity of the CHA₂DS₂-VASc and AHEAD scores in predicting acute coronary syndrome (ACS), ischemic stroke (IS), and mortality in patients with heart failure (HF).

METHODS

A total of 404,635 patients hospitalized for HF between 2000 and 2011 were recruited from a large national database in Taiwan. The predictive value of both scores was evaluated by analysis of the area under the receiver operating characteristic curve (AUROC), and the difference in their discriminative capacity was assessed using the DeLong test.

RESULTS

The AUROC for the CHA₂DS₂-VASc score was significantly higher than that for the AHEAD score in predicting ACS and IS: 0.53 (95% CI = 0.53-0.54) versus 0.51 (95% CI = 0.51-0.52) for ACS, and 0.57 (95% CI = 0.56-0.57) versus 0.52 (95% CI = 0.51-0.52) for IS, respectively (all DeLong tests p < 0.001). By contrast, for mortality risk, the AUROC was significantly lower for the CHA₂DS₂-VASc score (0.56, 95% CI = 0.55-0.56) than the AHEAD score (0.60, 95% CI = 0.59-0.60; DeLong test p < 0.001).

CONCLUSIONS

The ability of the CHA₂DS₂-VASc score to predict macrovascular complications (ACS and IS) in HF patients was higher than that of AHEAD.

Genetic variants on chromosomes 7p31 and 12p12 are associated with abnormal atrial electrical activation in patients with early-onset lone atrial fibrillation

BACKGROUND

Abnormal P-wave morphology (PWM) has been associated with a history of atrial fibrillation (AF) in earlier studies. Although lone AF is believed to have substantial genetic basis, studies on associations between single nucleotide polymorphisms (SNP) linked to lone AF and PWM have not been reported. We aimed to assess whether SNPs previously associated with lone AF (rs2200733, rs13376333, rs3807989, and rs11047543) are also linked to P-wave abnormalities.

METHODS

Four SNPs were studied in 176 unrelated individuals with early-onset lone AF (age at onset <50 years), median age 38 years (19-63 years), 149 men. Using sinus rhythm ECG, orthogonal PWM was classified as Type 1-positive in leads X and Y and negative in lead Z, Type 2-positive in leads X and Y and biphasic (-/+) in lead Z, Type 3-positive in lead X and biphasic in lead Y (+/-), and the remaining as atypical.

RESULTS

Two SNPs were found to be significantly associated with altered P-wave morphology distribution: rs3807989 near the gene CAV1/CAV2 and rs11047543 near the gene SOX5. Both SNPs were associated with a higher risk of non-Type 1 P-wave morphology (rs3807989: OR = 4.8, 95% CI = 2.3-10.2, p < 0.001; rs11047543: OR = 4.7, 95% CI = 1.1-20.5, p = 0.04). No association was observed for rs2200733 and rs13376333.

CONCLUSION

In this study, the two variants rs3807989 and rs11047543, previously associated with PR interval and lone AF, were associated with altered P-wave morphology distribution in patients with early-onset lone AF. These findings suggest that common genetic variants may modify atrial conduction properties.

Lifestyle of Patients with Atrial Fibrillation Following Self-Management Interventions: a Randomized Clinical Trial

Introduction: Cardiovascular diseases are the most common cause of death in most countries, such as Iran. Cardiac arrhythmias, including Atrial Fibrillation (AF) comprise an important category of these diseases. During recent years, AF has become a serious medical condition. This study aimed to investigate the effect of self-management interventions on the lifestyle of patients with AF. Methods: In this Randomized Clinical Trial study, 88 patients were selected and randomly assigned to intervention and control groups. The intervention group received self-management interventions, including education and telephone follow-ups. The data were collected using a demographic questionnaire and Walker's health-promoting lifestyle profile II, before the intervention and four and twelve weeks after the intervention. The significance level was considered to be 0.05. Results: The results showed a significant increase in the intervention group's lifestyle mean score, four and twelve weeks after the intervention as compared with control group However, this increase was not similar in all the lifestyle dimensions. Conclusion: In conclusion, implementation of self-management interventions could improve the lifestyle of the patients with Atrial Fibrillation. The results can help nurses to conduct self-management interventions into such patients' care plan and prevent many physical, psychological, and social problems that negatively affect patients and their lifestyle.