2011 ACCF/AHA/HRS Focused Update on the Management of Patients With Atrial Fibrillation (Updating the 2006 Guideline)

Ablation Versus Amiodarone for Treatment of Persistent Atrial Fibrillation in Patients With Congestive Heart Failure and an Implanted Device

Background—

Whether catheter ablation (CA) is superior to amiodarone (AMIO) for the treatment of persistent atrial fibrillation (AF) in patients with heart failure is unknown.

Methods and Results—

This was an open-label, randomized, parallel-group, multicenter study. Patients with persistent AF, dual-chamber implantable cardioverter defibrillator or cardiac resynchronization therapy defibrillator, New York Heart Association II to III, and left ventricular ejection fraction <40% within the past 6 months were randomly assigned (1:1 ratio) to undergo CA for AF (group 1, n=102) or receive AMIO (group 2, n=101). Recurrence of AF was the primary end point. All-cause mortality and unplanned hospitalization were the secondary end points. Patients were followed up for a minimum of 24 months. At the end of follow-up, 71 (70%; 95% confidence interval, 60%–78%) patients in group 1 were recurrence free after an average of 1.4±0.6 procedures in comparison with 34 (34%; 95% confidence interval, 25%–44%) in group 2 (log-rank P <0.001). The success rate of CA in the different centers after a single procedure ranged from 29% to 61%. After adjusting for covariates in the multivariable model, AMIO therapy was found to be significantly more likely to fail (hazard ratio, 2.5; 95% confidence interval, 1.5–4.3; P <0.001) than CA. Over the 2-year follow-up, the unplanned hospitalization rate was (32 [31%] in group 1 and 58 [57%] in group 2; P <0.001), showing 45% relative risk reduction (relative risk, 0.55; 95% confidence interval, 0.39–0.76). A significantly lower mortality was observed in CA (8 [8%] versus AMIO (18 [18%]; P =0.037).

Conclusions—

This multicenter randomized study shows that CA of AF is superior to AMIO in achieving freedom from AF at long-term follow-up and reducing unplanned hospitalization and mortality in patients with heart failure and persistent AF.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT00729911.

Analysis of Bipolar Radiofrequency Ablation in Treatment of Atrial Fibrillation Associated with Rheumatic Heart Disease

Background

Among patients with rheumatic heart disease (RHD), 45% to 60% present with atrial fibrillation (AF), which is associated with increased rates of thromboembolism, heart failure, and even death. The bipolar radiofrequency ablation (BRFA) combining with mitral valve procedure has been adopted in patients of AF associated with RHD, but evaluations about its effectiveness are still limited.

Methods

A total of 87 patients with RHD and long persistent AF who had accepted mitral valve replacement concomitant with BRFA were studied. Clinical data were collected to analyze the midterm results of BRFA and evaluate its efficiency. Univariate and multivariate analyses were used to identify the independent factors associated with late AF recurrence.

Results

Sixty-six (75.9%) patients maintained sinus rhythm after a mean follow-up of 13.4 ± 5.2 months. Late AF recurrence had been detected in 21 (24.1%) patients, 11 (12.6%) patients were confirmed to be AF, 8 (9.2%) patients were atrial flutter and 2 (2.3%) patients were junctional rhythm. In Multivariate logistic regression analysis, body mass index (BMI) (OR = 1.756, 95% CI = 1.289–2.391, p = 0.000) and early AF recurrence (OR = 5.479, 95% CI = 1.189–25.254, p = 0.029) were independent predictors of late AF recurrence. In addition, left ventricular ejection fraction (LVEF) and New York Heart Association class showed a greater improvement in patients who maintained sinus rhythm than those who experienced late AF recurrence.

Conclusion

BRFA is an effective technique for the treatment of long persistent AF associated with RHD during mitral valve replacement. The BMI and early AF recurrence are independent predictors for late AF recurrence. Patients with long-term restoration of sinus rhythm experienced a greater improvement of left ventricular function after BRFA.

[New oral anticoagulants for prophylaxis of stroke. Results of an expert conference on practical use in geriatric patients]

Geriatric patients with non-valvular atrial fibrillation (AF) are increasingly being treated with novel oral anticoagulants (NOAC) to prevent ischemic stroke. This article highlights the outcome of an expert meeting on the practical use of NOAC in elderly patients. An interdisciplinary group of experts discussed the current situation of stroke prevention in geriatric patients and its practical management in daily clinical practice. The topic was examined through focused impulse presentations and critical analyses as the basis for the expert consensus. The key issues are summarized in this paper. The European Society of Cardiology (ESC) guidelines from 2012 for the management of patients with non-valvular AF recommend NOAC as the preferred treatment and vitamin K antagonists (VKA) only as an alternative option. Currently, the NOAC factor Xa inhibitors apixaban and rivaroxaban and the thrombin inhibitor dabigatran are more commonly used in clinical practice for patients with AF. Although these drugs have many similarities and are often grouped together it is important to recognize that the pharmacology and dose regimes differ between compounds. Especially n elderly patients NOAC drugs have some advantages compared to VKA, e.g. less drug-drug interactions with concomitant medication and a more favorable risk-benefit ratio mostly driven by the reduction of bleeding. Treatment of anticoagulation in geriatric patients requires weighing the serious risk of stroke against an equally high risk of major bleeding and pharmacoeconomic considerations. Geriatric patients in particular have the greatest benefit from NOAC, which can also be administered in cases of reduced renal function. Regular control of the indications is indispensable, as also for all other medications of the patient. The use of NOAC should certainly not be withheld from geriatric patients who have a clear need for oral anticoagulation.

Sinus Node Dysfunction Is Associated With Higher Symptom Burden and Increased Comorbid Illness: Results From the ORBIT-AF Registry

Background

Patients with sinus node dysfunction (SND) have increased risk of atrial tachyarrhythmias, including atrial fibrillation (AF). To date, treatment patterns and outcomes of patients with SND and AF have not been well described.

Hypothesis

Patients with SND and AF have higher risk of adverse cardiovascular outcomes.

Methods

Sinus node dysfunction was defined clinically, based on treating physician. Treatment patterns were described and logistic regression analysis performed to assess outcomes.

Results

Overall, 1710 (17.7%) out of 9631 patients had SND at enrollment. Patients with SND and AF had increased comorbid medical illnesses, more severe symptoms (European Heart Rhythm Association class IV: 17.5% vs 13.9%; P = 0.0007), and poorer quality of life (median 12‐month Atrial Fibrillation Effect on Quality of Life score: 79.6 vs 85.2; P = 0.0008). There were no differences in AF management strategy between patients with SND and those without (rate control, 69.7% vs 67.7%; rhythm control, 30.0% vs 32.0%; P = 0.11). After adjustment, patients with SND were more likely than those without SND to progress from paroxysmal AF at baseline to persistent or permanent AF at any follow‐up, or persistent AF at baseline to permanent AF at any follow‐up (odds ratio: 1.23, 95% confidence interval: 1.01‐1.49, P = 0.035). However, there was no association between SND and major risk‐adjusted outcomes.

Conclusions

Sinus node dysfunction is present in 1 of 6 patients with AF and is associated with increased comorbidities and higher symptom burden. However, SND is not associated with an increase in major risk‐adjusted outcomes.

Atrial-like cardiomyocytes from human pluripotent stem cells are a robust preclinical model for assessing atrial-selective pharmacology

Drugs targeting atrial-specific ion channels, K_v1.5 or K_ir3.1/3.4, are being developed as new therapeutic strategies for atrial fibrillation. However, current preclinical studies carried out in non-cardiac cell lines or animal models may not accurately represent the physiology of a human cardiomyocyte (CM). In the current study, we tested whether human embryonic stem cell (hESC)-derived atrial CMs could predict atrial selectivity of pharmacological compounds. By modulating retinoic acid signaling during hESC differentiation, we generated atrial-like (hESC-atrial) and ventricular-like (hESC-ventricular) CMs. We found the expression of atrial-specific ion channel genes, KCNA5 (encoding Kv1.5) and KCNJ3 (encoding K_ir 3.1), in hESC-atrial CMs and further demonstrated that these ion channel genes are regulated by COUP-TF transcription factors. Moreover, in response to multiple ion channel blocker, vernakalant, and K_v1.5 blocker, XEN-D0101, hESC-atrial but not hESC-ventricular CMs showed action potential (AP) prolongation due to a reduction in early repolarization. In hESC-atrial CMs, XEN-R0703, a novel K_ir3.1/3.4 blocker restored the AP shortening caused by CCh. Neither CCh nor XEN-R0703 had an effect on hESC-ventricular CMs. In summary, we demonstrate that hESC-atrial CMs are a robust model for pre-clinical testing to assess atrial selectivity of novel antiarrhythmic drugs.

New anthyarrhythmic drugs for atrial fibrillation

Atrial fibrillation (AF) is a common arrhythmia associated with increased mortality and morbidity. Different studies have shown no significant difference between rhythm and rate control strategies in terms of mortality. Moreover, the use of antiarrhythmic drugs is afflicted by cardiac and extracardiac toxicity and related costs of hospitalization. Nevertheless, some patients require a rhythm-control strategy and new anti-AF agents are being sought. Only few novel agents showed promising results in term of efficacy and safety. Dronedarone and vernakalant are two of these compounds, respectively introduced for the chronic and acute rhythm control of AF. This article will review pharmacology and clinical evidence on the use of dronedarone and vernakalant and will mention currently investigated new antiarrhythmic drugs.

Comparison between CHA2DS2-VASc and the new R2CHADS2 and ATRIA scores at predicting thromboembolic event in non-anticoagulated and anticoagulated patients with non-valvular atrial fibrillation

Background

Accurate risk stratification is considered the first and most important step in the management of patients with non-valvular atrial fibrillation (NVAF). We compared the performance of the widely used CHA₂DS₂-VASc and the recently developed R₂CHADS₂ and ATRIA scores, for predicting thromboembolic (TE) event in either non-anticoagulated or anticoagulated patients with NVAF.

Methods

The non-anticoagulated cohort was comprised of 154 patients, whereas 911 patients formed the cohort of patients on vitamin-K-antagonist. The scores were computed using the criteria mentioned in their developmental cohorts. Measures of performance for the risk scores were evaluated at predicting TE event.

Results

In the non-anticoagulated cohort, 9 TE events occurred during 11 ± 2.7 months. CHA₂DS₂-VASc showed significant association with TE occurrence: hazard ratio (HR) = 1.58 (95 % confidence interval [95 % IC] 1.01–2.46), but R₂CHADS₂ and ATRIA did not (HR = 1.23 (95 % CI 0.86–1.77) and 1.20 (95 % CI 0.93–1.56), respectively.

In the anticoagulated cohort, after 10 ± 3 months of follow up, 18 TE events were developed. In that cohort, the three scores showed similar association with TE risk: HR = 1.49 (95 % CI 1.13–1.97), 1.41 (95 % CI 1.13–1.77) and 1.37 (95 % CI 1.12–1.66) for CHA₂DS₂-VASc, R₂CHADS₂ and ATRIA, respectively.

In both cohorts, no TE event occurred in patients classified in the low risk category according to CHA₂DS₂-VASc or R₂CHADS₂.

Conclusions

In this study of NVAF patients, CHA₂DS₂-VASc has better association with TE events than the new R₂CHADS₂ and ATRIA risk scores in the non-anticoagulated cohort. CHA₂DS₂-VASc and R₂CHADS₂ can identify patients at truly low risk regardless of the anticoagulation status.

Towards Low Energy Atrial Defibrillation

A wireless powered implantable atrial defibrillator consisting of a battery driven hand-held radio frequency (RF) power transmitter (ex vivo) and a passive (battery free) implantable power receiver (in vivo) that enables measurement of the intracardiacimpedance (ICI) during internal atrial defibrillation is reported. The architecture is designed to operate in two modes: Cardiac sense mode (power-up, measure the impedance of the cardiac substrate and communicate data to the ex vivo power transmitter) and cardiac shock mode (delivery of a synchronised very low tilt rectilinear electrical shock waveform). An initial prototype was implemented and tested. In low-power (sense) mode, >5 W was delivered across a 2.5 cm air-skin gap to facilitate measurement of the impedance of the cardiac substrate. In high-power (shock) mode, >180 W (delivered as a 12 ms monophasic very-low-tilt-rectilinear (M-VLTR) or as a 12 ms biphasic very-low-tilt-rectilinear (B-VLTR) chronosymmetric (6ms/6ms) amplitude asymmetric (negative phase at 50% magnitude) shock was reliably and repeatedly delivered across the same interface; with >47% DC-to-DC (direct current to direct current) power transfer efficiency at a switching frequency of 185 kHz achieved. In an initial trial of the RF architecture developed, 30 patients with AF were randomised to therapy with an RF generated M-VLTR or B-VLTR shock using a step-up voltage protocol (50–300 V). Mean energy for successful cardioversion was 8.51 J ± 3.16 J. Subsequent analysis revealed that all patients who cardioverted exhibited a significant decrease in ICI between the first and third shocks (5.00 Ω (SD(σ) = 1.62 Ω), p < 0.01) while spectral analysis across frequency also revealed a significant variation in the impedance-amplitude-spectrum-area (IAMSA) within the same patient group (|∆(IAMSA_S1-IAMSA_S3)[1 Hz − 20 kHz] = 20.82 Ω-Hz (SD(σ) = 10.77 Ω-Hz), p < 0.01); both trends being absent in all patients that failed to cardiovert. Efficient transcutaneous power transfer and sensing of ICI during cardioversion are evidenced as key to the advancement of low-energy atrial defibrillation.

Molecular basis of hERG potassium channel blockade by the class Ic antiarrhythmic flecainide

The class Ic antiarrhythmic drug flecainide inhibits KCNH2-encoded "hERG" potassium channels at clinically relevant concentrations. The aim of this study was to elucidate the underlying molecular basis of this action. Patch clamp recordings of hERG current (IhERG) were made from hERG expressing cells at 37°C. Wild-type (WT) IhERG was inhibited with an IC50 of 1.49μM and this was not significantly altered by reversing the direction of K(+) flux or raising external [K(+)]. The use of charged and uncharged flecainide analogues showed that the charged form of the drug accesses the channel from the cell interior to produce block. Promotion of WT IhERG inactivation slowed recovery from inhibition, whilst the N588K and S631A attenuated-inactivation mutants exhibited IC50 values 4-5 fold that of WT IhERG. The use of pore-helix/selectivity filter (T623A, S624A V625A) and S6 helix (G648A, Y652A, F656A) mutations showed <10-fold shifts in IC50 for all but V625A and F656A, which respectively exhibited IC50s 27-fold and 142-fold their WT controls. Docking simulations using a MthK-based homology model suggested an allosteric effect of V625A, since in low energy conformations flecainide lay too low in the pore to interact directly with that residue. On the other hand, the molecule could readily form π-π stacking interactions with aromatic residues and particularly with F656. We conclude that flecainide accesses the hERG channel from the cell interior on channel gating, binding low in the inner cavity, with the S6 F656 residue acting as a principal binding determinant.

Discontinuation/Interruption of Warfarin Therapy in Patients with Nonvalvular Atrial Fibrillation

BACKGROUND

Use of warfarin is standard of care for stroke prevention in patients with atrial fibrillation (AF). However, AF patients experience high rates of warfarin discontinuation/interruption, resulting in increased health risks and health care costs. As such, it is important to study the rates and predictors of warfarin discontinuation/interruption in this population.

OBJECTIVES

To determine (a) rates of warfarin discontinuation and interruption and (b) demographic, clinical, and health care-related factors associated with discontinuation and interruption in patients with nonvalvular AF (NVAF) in the usual clinical practice settings in the United States.

METHODS

This retrospective cohort study used the MarketScan Database and included patients (aged ≥ 18 years) with NVAF who were initiated on warfarin. The study period was January 1, 2008, to June 30, 2012. To be included, patients were required to have at least 2 claims with AF diagnosis separated by ≥ 30 days and ≤ 12 months and at least 1 outpatient claim. Warfarin initiation had to occur within 30 days of the AF diagnosis. Patients also had to have continuous enrollment in prescription drug plans from 6 months prior to warfarin use to at least 12 months after warfarin initiation. Patients were followed for 1 year after warfarin initiation. Persistence was defined as warfarin therapy without a gap ≥ 45 days between the end date of the former prescription and the start date of the current prescription or with international normalized ratio (INR) monitoring at least every 42 days. Interruption was defined as a gap in warfarin therapy ≥ 45 days and ≤ 90 days between the end date of the former prescription and the start date of the current prescription and without INR monitoring at least every 42 days. Discontinuation was defined as greater than 90 days without warfarin therapy between the end date of the former prescription and the start date of the current prescription and without INR monitoring at least every 42 days. Chi-square tests were used to analyze categorical variables, and independent samples t-tests were used for continuous variables. Cox proportional hazards regression model was performed to determine factors associated with warfarin discontinuation/interruption, including demographic (e.g., age, gender); clinical (e.g., comorbidities, CHADS2 score); and health care-related (e.g., hospitalizations or emergency room visits) characteristics. Sensitivity analyses were conducted by varying prescription gaps by 7, 14, and 30 days.

RESULTS

A total of 58,593 patients with NVAF were included. The mean age was approximately 71 years (SD = 12.00) and mean CHADS2 score was 1.66 (SD = 1.23). The majority of patients were male (60%). During 12 months after warfarin initiation, 45% of patients were persistent with warfarin; 12% had interruption without discontinuation; and 43% had discontinuation. The risk of warfarin interruption or discontinuation was significantly greater in patients who were younger than 65 years (HR = 1.22; 95% CI = 1.19-1.25), lived in the West (HR = 1.07; 95% CI = 1.03-1.11), had history of anemia (HR = 1.10; 95% CI = 1.06-1.14), had history of bleeding (HR = 1.10; 95% CI = 1.06-1.14), or had history of hospitalization or emergency room visits (HR = 1.11; 95% CI = 1.08-1.13). The significant factors associated with interruption and discontinuation were similar. In the sensitivity analyses, the significant factors associated with discontinuation/interruption were similar across different prescription gaps.

CONCLUSIONS

In the U.S. clinical practice setting, more than 50% of NVAF patients discontinued or interrupted warfarin within 1 year after initiation. Aged less than  65 years, history of anemia, and history of hospitalization/emergency room visits were associated with increased risk of discontinuation/interruption. Given the high prevalence of warfarin discontinuation/interruption, health care providers should take a more active role in understanding and addressing the reasons behind patient discontinuation/interruption.

An evidence-based review of edoxaban and its role in stroke prevention in patients with nonvalvular atrial fibrillation

Atrial fibrillation is the most common arrhythmia in the elderly. It is responsible for significant morbidity and mortality from cardioembolic complications like stroke. As a result, atrial fibrillation patients are risk-stratified using the CHADS2 or CHA2DS2-VASc scoring systems. Those at intermediate-to-high risk have traditionally been treated with therapeutic anticoagulation with warfarin for stroke prevention. Although effective, warfarin use is fraught with multiple concerns, such as a narrow therapeutic window, drug-drug and drug-food interactions, and excessive bleeding. Novel oral anticoagulant agents have recently become available as viable alternatives for warfarin therapy. Direct thrombin inhibitor dabigatran and factor Xa inhibitors like rivaroxaban and apixaban have already been approved by the US Food and Drug Administration (FDA) for stroke prevention in patients with nonvalvular atrial fibrillation. Edoxaban is the latest oral direct factor Xa inhibitor studied in the largest novel oral anticoagulant trial so far: ENGAGE AF-TIMI 48. Treatment with a 30 mg or 60 mg daily dose of edoxaban was found to be noninferior to dose-adjusted warfarin in reducing the rate of stroke and systemic embolism in patients with nonvalvular atrial fibrillation, with a lower incidence of bleeding complications and cardiovascular deaths. Edoxaban was recently reviewed by an FDA advisory committee and recommended as a stroke-prophylaxis agent. Once approved, it promises to provide another useful alternative to warfarin therapy.

Wenxin Keli versus Sotalol for Paroxysmal Atrial Fibrillation Caused by Hyperthyroidism: A Prospective, Open Label, and Randomized Study

We aimed to compare effectiveness of Wenxin Keli (WK) and sotalol in assisting sinus rhythm (SR) restoration from paroxysmal atrial fibrillation (PAF) caused by hyperthyroidism, as well as in maintaining SR. We randomly prescribed WK (18 g tid) or sotalol (80 mg bid) to 91 or 89 patients. Since it was not ethical not to give patients antiarrhythmia drugs, no control group was set. Antithyroid drugs were given to 90 patients (45 in WK group, 45 in sotalol group); ¹³¹I was given to 90 patients (46 in WK group, 44 in sotalol group). Three months later, SR was obtained in 83/91 or 80/89 cases from WK or sotalol groups (P = 0.762). By another analysis, SR was obtained in 86/90 or 77/90 cases from ¹³¹I or ATD groups (P = 0.022). Then, we randomly assigned the successfully SR-reverted patients into three groups: WK, sotalol, and control (no antiarrhythmia drug was given) groups. After twelve-month follow-up, PAF recurrence happened in 1/54, 2/54, and 9/55 cases, respectively. Log-Rank test showed significant higher PAF recurrent rate in control patients than either treatment (P = 0.06). We demonstrated the same efficacies of WK and sotalol to assist SR reversion from hyperthyroidism-caused PAF. We also showed that either drug could maintain SR in such patients.

2014 Oman Heart Association protocol for the management of acute atrial fibrillation

Although atrial fibrillation (AF) is the most common cardiac arrhythmia, there is variation in practice with regard to the management of acute AF among the hospitals and even within the same hospital in Oman. This variation likely reflects a lack of high-quality evidence. Standard guidelines and textbooks do not offer clear evidence-based direction for physicians to guide the management of acute AF. Particularly controversial is the issue of using rhythm control or rate control. This stimulated Oman Heart Association (OHA) to issue a simplified protocol for the management of acute AF to be applied by the entire cardiac caregivers all over the country. The priorities for acute management of AF include stabilizing the patient's hemodynamic status, symptom control, treatment of the underlying and precipitating cause, and more importantly protecting the brain.

Factors associated with ischemic stroke on therapeutic anticoagulation in patients with nonvalvular atrial fibrillation

PURPOSE

In this study, we investigated the stroke mechanism and the factors associated with ischemic stroke in patients with nonvalvular atrial fibrillation (NVAF) who were on optimal oral anticoagulation with warfarin.

MATERIALS AND METHODS

This was a multicenter case-control study. The cases were consecutive patients with NVAF who developed cerebral infarction or transient ischemic attack (TIA) while on warfarin therapy with an international normalized ratio (INR) ≥2 between January 2007 and December 2011. The controls were patients with NVAF without ischemic stroke who were on warfarin therapy for more than 1 year with a mean INR ≥2 during the same time period. We also determined etiologic mechanisms of stroke in cases.

RESULTS

Among 3569 consecutive patients with cerebral infarction or TIA who had NVAF, 55 (1.5%) patients had INR ≥2 at admission. The most common stroke mechanism was cardioembolism (76.0%). Multivariate analysis demonstrated that smoking and history of previous ischemic stroke were independently associated with cases. High CHADS2 score (≥3) or CHA₂DS₂-VASc score (≥5), in particular, with previous ischemic stroke along with ≥1 point of other components of CHADS₂ score or ≥3 points of other components of CHA₂DS₂-VASc score was a significant predictor for development of ischemic stroke.

CONCLUSION

NVAF patients with high CHADS₂/CHA₂DS₂-VASc scores and a previous ischemic stroke or smoking history are at high risk of stroke despite optimal warfarin treatment. Some other measures to reduce the risk of stroke would be necessary in those specific groups of patients.

Postoperative atrial fibrillation in liver transplantation

Postoperative atrial fibrillation (POAF) is common after major surgeries and is associated with increased morbidity and mortality. POAF after liver transplantation (LT) has not been reported. This study was undertaken to investigate the incidence, impact, and risk factors of POAF in LT patients. After IRB approval, LT between January 2006 and August 2013 at our center were retrospectively reviewed. POAF that occurred within 30 days after LT was included. Patients with and without POAF were compared and independent risk factors were identified by logistic regression. Of 1387 adults LT patients, 102 (7.4%) developed POAF during the study period. POAF was associated with significantly increased mortality, graft failure, acute kidney injury and prolonged hospital stay. Independent risk factors included age, body weight, MELD score, presence of previous history of AF, the vasopressors use prior to LT and pulmonary artery diastolic pressure at the end of LT surgery (odds ratios 2.0-7.2, all p < 0.05). A risk index of POAF was developed and patients with the high-risk index had more than 60% chance of developing POAF. These findings may be used to stratify patients and to guide prophylaxis for POAF in the posttransplant period.

Atrial fibrillation in patients undergoing liver transplantation-a single-center experience

BACKGROUND

As the prevalence of atrial fibrillation rises with age and older patients increasingly receive transplants, the perioperative management of this common arrhythmia and its impact on outcomes in liver transplantation is of relevance.

METHODS

Retrospective review of 757 recipients of liver transplantation from January 2002 through December 2011.

RESULTS

Nineteen recipients (2.5%) had documented pre-transplantation atrial fibrillation. Sixteen patients underwent liver and 3 a combined liver-kidney transplantation. Three patients died within 30 days (84.2% 1-month survival) and another 3 within 1 year of transplantation (68.4% 1-year survival). Compared with patients without atrial fibrillation, the relative risk of death in the atrial fibrillation group was 5.29 at 1 month (P = .0034; 95% confidence interval [CI], 1.73-16.18) and 3.28 at 1 year (P = .0008; 95% CI, 1.63-6.59). Time to extubation and intensive care unit (ICU) and hospital readmissions were not different from the control cohort. Rapid ventricular response requiring treatment occurred in 4 patients during surgery and 7 after surgery, resulting in 3 ICU and 3 hospital readmissions.

CONCLUSIONS

The results suggest that patients with atrial fibrillation may be at increased risk of mortality after liver transplantation. Optimization of medical therapy may decrease ICU and hospital readmission due to rapid ventricular response.

Freedom from atrial fibrillation after cox maze III ablation during follow-up

Background:

Nearly 60% of patients undergoing mitral valve (MV) operations are affected by atrial fibrillation (AF). Cox Maze III ablation is one of the effective ways for restoring sinus rhythm for patients undergoing open heart surgery. The aim of present study was to evaluate efficacy of Maze III ablation procedure for restoring sinus rhythm among patients who had underwent open heart surgery.

Materials and Methods:

During present descriptive-analytic prospective study 114 patients with chronic AF had undergone open heart surgery for their valvular or coronary artery diseases in Educational-Medical centres of Tabriz University of Medical Sciences (Tabriz, Iran) 2006-2012, were included in the study. For all patients Maze III ablation was done. Patients were evaluated by 12 lead electrocardiography (ECG) and 24 hours ambulatory ECG monitoring after 3-6 years (mean 4.8) of follow-up.

Result:

Patients' rhythm before Cox Maze III surgery was chronic AF in all patients. All patients were discharged from operating room with sinus rhythm. During intensive care unit (ICU) hospitalization, rhythm of 34 patients changed to AF and 80 patients had sinus rhythm. Sixteen patients had undergone electrical cardioversion for restoring sinus rhythm which was successful in 12 patients. Ninety-two patients had sinus rhythm when discharged from the hospital. After termination of follow-up, freedom from atrial fibrillation was 51%. Patients with AF during follow-up on surface ECG didn't have episodes of sinus rhythm in their ambulatory monitoring. One patient implanted cardiac pacemaker due to persistent sinus bradycardia.

Conclusion:

Based on the results of this study, Cox Maze III ablation procedure is an effective and safe way for restoring sinus rhythm among patients who are candidate for open heart surgery, while no significant complication was seen among patients.

Who gets stroke prevention? Stroke prevention in atrial fibrillation patients in the inpatient setting

BACKGROUND

Current guidelines strongly recommend antithrombotic therapy, particularly warfarin, for stroke prevention in atrial fibrillation (AF) patients at high risk of stroke. Despite this, use of these medications is far from optimal. The aim of this study was to describe the use of stroke prevention medication in inpatients and identify factors associated with prescription in one local health district in Sydney, Australia.

METHODS

A prospective audit of medical records for patients admitted with an AF diagnosis to five hospitals in the health district and excluding cardiac surgery patients was undertaken. Patients were classified as high or low for stroke risk as well as for risk of bleeding and predictors were identified by logistic regression.

RESULTS

A total of 204 patients were enrolled from July 2012 to April 2013, with a mean age of 75 years (SD 13) and half (50%) were male. Valve disease was present in 17% and 15% received a procedure for their AF (cardioversion/ablation/pulmonary vein isolation). Patients were least likely to be prescribed warfarin/novel oral anticoagulant (NOAC) if they were non-valvular and did not undergo cardioversion/ablation (p=.03), and least likely to be prescribed aspirin if they had no AF procedure (p=.01). In non-valvular patients who did not have cardioversion/ablation the odds of being prescribed warfarin/NOAC were increased by being classified at high risk of stroke (OR 3.1, 95% CI 1.0 -9.5) and decreased if there was a prescription for aspirin (OR .3. 95% CI .1 -.6).

CONCLUSIONS

Overall use of stroke prevention medication indicates that gaps remain in translation of evidence into clinical practice.

Early safety and efficacy of percutaneous left atrial appendage suture ligation: results from the U.S. transcatheter LAA ligation consortium

BACKGROUND

Transcatheter left atrial appendage (LAA) ligation may represent an alternative to oral anticoagulation for stroke prevention in atrial fibrillation.

OBJECTIVES

This study sought to assess the early safety and efficacy of transcatheter ligation of the LAA for stroke prevention in atrial fibrillation.

METHODS

This was a retrospective, multicenter study of consecutive patients undergoing LAA ligation with the Lariat device at 8 U.S. sites. The primary endpoint was procedural success, defined as device success (suture deployment and <5 mm leak by post-procedure transesophageal echocardiography), and no major complication at discharge (death, myocardial infarction, stroke, Bleeding Academic Research Consortium bleeding type 3 or greater, or cardiac surgery). Post-discharge management was per operator discretion.

RESULTS

A total of 154 patients were enrolled. Median CHADS2 score (congestive heart failure, hypertension, age ≥ 75 years, diabetes mellitus, prior stroke, transient ischemic attack, or thromboembolism [doubled]) was 3 (interquartile range: 2 to 4). Device success was 94%, and procedural success was 86%. A major complication occurred in 15 patients (9.7%). There were 14 major bleeds (9.1%), driven by the need for transfusion (4.5%). Significant pericardial effusion occurred in 16 patients (10.4%). Follow-up was available in 134 patients at a median of 112 days (interquartile range: 50 to 270 days): Death, myocardial infarction, or stroke occurred in 4 patients (2.9%). Among 63 patients with acute closure and transesophageal echocardiography follow-up, there were 3 thrombi (4.8%) and 13 (20%) with residual leak.

CONCLUSIONS

In this initial multicenter experience of LAA ligation with the Lariat device, the rate of acute closure was high, but procedural success was limited by bleeding. A prospective randomized trial is required to adequately define clinical efficacy, optimal post-procedure medical therapy, and the effect of operator experience on procedural safety.

Thyroid and the heart

Thyroid hormones modulate every component of the cardiovascular system necessary for normal cardiovascular development and function. When cardiovascular disease is present, thyroid function tests are characteristically indicated to determine if overt thyroid disorders or even subclinical dysfunction exists. As hypothyroidism, hypertension, and cardiovascular disease all increase with advancing age, monitoring of thyroid-stimulating hormone, the most sensitive test for hypothyroidism, is important in this expanding segment of our population. A better understanding of the impact of thyroid hormonal status on cardiovascular physiology will enable health care providers to make decisions about thyroid hormone evaluation and therapy in concert with evaluating and treating hypertension and cardiovascular disease. The goal of this review is to access contemporary understanding of the effects of thyroid hormones on normal cardiovascular function and the potential role of overt and subclinical hypothyroidism and hyperthyroidism in a variety of cardiovascular diseases.

Novel approaches for prevention of stroke related to transcatheter aortic valve implantation

Transcatheter aortic valve implantation (TAVI) has emerged as a therapeutical option in patients with aortic stenosis. The methodology has evolved rapidly throughout the last decade. Nowadays, peri-procedural circulatory support, surgical vascular access, general anesthesia and mechanical ventilation are mainly reserved for selected patients. However, numerous challenges need to be addressed in order to further improved outcome of this distinct cohort: patient selection in general, vascular access strategies, long-term valve performance and paravalvular leakage. Another key issue is the risk of cerebrovascular events related to TAVI. In this article, the authors review the current literature on the risk of cerebrovascular events, the underlying mechanisms, the diagnostic read-outs of cerebral injury and their prognostic value, and ultimately discuss conceivable concepts for prevention of stroke associated with TAVI.

Major bleeding with dabigatran and rivaroxaban in patients with atrial fibrillation: a real-world setting

BACKGROUND

Although the rate of bleeding among patients with atrial fibrillation (AF) taking novel oral anticoagulants in randomized controlled trials is described, the rate of bleeding with "real-world" use is uncertain.

METHODS

We conducted a retrospective electronic medical record interrogation and subsequent chart review among patients within Intermountain Healthcare between October 2010 and November 2012. Patients were included if they had a diagnosis of AF and were receiving either dabigatran or rivaroxaban. Rates of major bleeding were calculated.

RESULTS

Among 2579 patients, 13 (0.5%) experienced major bleeding (95% confidence interval [CI] 0.23-0.77), 5 (0.19%) experienced intracranial hemorrhage (95% CI 0.02-0.36), and 2 (0.08%) experienced fatal bleeding. Of the 13 patients experiencing a major bleed, 8 (61.5%) would have been excluded from the Randomized Evaluation of Long-Term Anticoagulation Therapy (RE-LY) and Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared with Vitamin K Antagonism for prevention of Stroke and Embolism Trial in Atrial Fibrillation (ROCKET AF) clinical trials.

CONCLUSION

We observed a rate of major bleeding similar to that reported in randomized clinical trials among patients with AF prescribed dabigatran or rivaroxaban.

Left ventricular hypertrophy and antiarrhythmic drugs in atrial fibrillation: impact on mortality

BACKGROUND

Despite sparse clinical data, current atrial fibrillation (AF) guidelines favor amiodarone as a drug of choice for patients with left ventricular hypertrophy (LVH).

OBJECTIVE

This study tested the hypothesis that patients with persistent AF and LVH on nonamiodarone antiarrhythmics have higher mortality compared to patients on amiodarone.

METHODS

In an observational cohort analysis of patients who underwent cardioversion for AF, patients with LVH, defined as left ventricular wall thickness ≥1.4 cm, by echocardiogram prior to their first cardioversion, were included; clinical data, including antiarrhythmic drugs and ejection fraction (LVEF), were collected. Mortality, determined via the Social Security Death Index, was analyzed using Kaplan-Meier and Cox proportional hazards models to determine whether antiarrhythmic drugs were associated with higher mortality.

RESULTS

In 3,926 patients, echocardiographic wall thickness was available in 1,399 (age 66.8 ± 11.8 years, 67% male, LVEF 46 ± 15%, septum 1.3 ± 0.4, posterior wall 1.2 ± 0.2 cm), and 537 (38%) had LVH ≥1.4 cm. Among 537 patients with LVH, mean age was 67.5 ± 11.7 years, 76.4% were males, and mean LVEF was 48.3 ± 13.3%. Amiodarone was associated with lower survival (log rank P = 0.001), including after adjusting for age, LVEF, and coronary artery disease (P = 0.023). In propensity-score matched cohorts with LVH treated with no drugs, nonamiodarone antiarrhythmic drugs (non-AADs), or amiodarone (N = 65 each group), there was early lower survival in patients on amiodarone (P = 0.05).

CONCLUSIONS

Patients with persistent AF and LVH on non-AADs do not have higher mortality compared to patients on amiodarone. Importantly, these findings do not support amiodarone as a superior choice in patients with LVH.

Management of Atrial Fibrillation

Atrial fibrillation remains the most prevalent cardiac arrhythmia, and its incidence is increasing as the population ages. Common conditions associated with an increased incidence include advanced age, hypertension, heart failure, and valvular heart disease. Patients with atrial fibrillation may complain of palpitations, fatigue, and decreased exercise tolerance or may be completely asymptomatic. Options for treating patients who experience atrial fibrillation include rate-controlling drugs such as digoxin, β-blockers, and calcium channel blockers or a rhythm-controlling strategy with agents such as sodium channel blockers and potassium channel blockers. Atrial fibrillation increases the risk of stroke due to atrial thrombus formation and embolization. Anticoagulation with the vitamin K antagonist, warfarin, remains the most widely prescribed treatment option to decrease stroke risk. Several other antithrombotic agents have recently become available and offer excellent alternatives to warfarin. Catheter ablation can be undertaken as a nonpharmacologic rhythm control option with varying degrees of success depending on duration of atrial fibrillation and follow-up time from the procedure. This review article further describes the management options for patients presenting with atrial fibrillation.

Evaluation of proper prescribing of cardiac medications at hospital discharge for patients with acute coronary syndromes (ACS) in two Lebanese hospitals

Background

Coronary artery disease (CAD) is the major leading cause of death worldwide. The national practice guidelines from the American College of Cardiology (ACC) and American Heart Association (AHA) promote the use of several medical therapies for secondary prevention for patients with CAD. The purpose of this study was to evaluate whether ACS patients, admitted into two tertiary referral medical centers in Beirut, Lebanon, are discharged on optimal medical therapy based on the current AHA/ACC guidelines.

Methods

We reviewed the medical records of all patients with ACS who were admitted to the coronary care units (CCU) of two hospitals in Beirut, Lebanon between May and August 2012. Discharge prescriptions were reviewed and rating for the appropriateness of discharge cardiac medications was based on the AHA/ACC guidelines. We assessed whether patients were discharged on antiplatelet therapy, β-blockers, angiotensin converting enzymes inhibitors (ACEIs) or angiotensin receptor blockers (ARBs), statins, and nitrates, unless contraindicated or not tolerated. In addition, we assessed whether patients and/or their caregivers were counseled about their disease(s) and discharge medications.

Results

186 patients with a mean age of 63 ± 11.78 years, 70.4% of which were males, were admitted with ACS and were included in the study. Fifty three (28.5%) patients had ST elevation MI (STEMI), 64 (34.4%) had non-ST-elevation myocardial infarction (NSTEMI) and 69 (37.1%) had unstable angina (USA). Sixty two patients (33.3%) were treated with medical therapy and 124 patients (66.7%) underwent percutaneous coronary intervention (PCI).

Among eligible patients, 98.9% were discharged on aspirin, 89.1% on dual antiplatelet therapy (aspirin + thienopyridine or ticagrelor), 90.5% on a β-blocker, 81.9% on an ACEI or ARB, 89.8% on a statin, and 19.4% on nitroglycerin. Overall, 62.9% of the patients received the optimal cardiovascular drug therapy (the combination of dual antiplatelet therapy, a β-blocker, an ACEIs or an ARB, and a statin), 55.1% were counseled on their disease state(s) and drug therapy, and 92.2% and 55.9% were counseled on smoking cessation and life style changes, respectively.

Conclusion

In patients admitted with ACS, discharge cardiac medications are prescribed at suboptimal rates. Education of healthcare providers and implementation of ACS discharge protocols may help improve compliance with ACC/AHA guidelines. In addition, clinicians should be encouraged to provide adequate patient counseling.

Predictors of long-term maintenance of normal sinus rhythm after successful electrical cardioversion

Electrical cardioversion (EC) for atrial fibrillation (AF) is a common procedure performed in an attempt to restore normal sinus rhythm (NSR). Many factors predict long-term maintenance of NSR and the risk of AF recurrence. The duration of AF, cardiac size and function, rheumatic heart disease, significant mitral valve disease, left atrial enlargement, and older age are among the most common recognized factors. A number of interventions can potentially decrease the AF recurrence rate. Identifying and treating reversible causes and the use of antiarrhythmic medications in certain situations can help decrease the risk of AF recurrence. The role of the newer anticoagulants is expanding, and wider application is expected in the near future. We hope that this summary will serve as a guide to physicians and healthcare providers to address the question of who should undergo cardioversion, as there are patients who are most likely to benefit from this procedure and others that will revert back into AF within a short period. To identify who would benefit most from EC and have a reasonable chance of long-term maintenance of NSR, a thorough evaluation of each individual patient should be performed to tailor the best therapy to each individual.

Gastrointestinal ulcers, role of aspirin, and clinical outcomes: pathobiology, diagnosis, and treatment

Peptic ulcer disease is a major cause of morbidity and mortality in the US with more than six million diagnoses annually. Ulcers are reported as the most common cause of hospitalization for upper gastrointestinal (GI) bleeding and are often a clinical concern due to the widespread use of aspirin and nonsteroidal anti-inflammatory drugs, both of which have been shown to induce ulcer formation. The finding that Helicobacter pylori infection (independent of aspirin use) is associated with the development of ulcers led to a more thorough understanding of the causes and pathogenesis of ulcers and an improvement in therapeutic options. However, many patients infected with H. pylori are asymptomatic and remain undiagnosed. Complicating matters is a current lack of understanding of the association between aspirin use and asymptomatic ulcer formation. Low-dose aspirin prescriptions have increased, particularly for cardioprotection. Unfortunately, the GI side effects associated with aspirin therapy continue to be a major complication in both symptomatic and asymptomatic patients. These safety concerns should be important considerations in the decision to use aspirin and warrant further education. The medical community needs to continue to improve awareness of aspirin-induced GI bleeding to better equip physicians and improve care for patients requiring aspirin therapy.

Impact of dronedarone treatment on healthcare resource utilization in patients with atrial fibrillation/flutter

BACKGROUND

The ATHENA (A Placebo-Controlled, Double-Blind, Parallel Arm Trial to Assess the Efficacy of Dronedarone 400 mg bid for the Prevention of Cardiovascular Hospitalization or Death from Any Cause in Patients with Atrial Fibrillation/Atrial Flutter) trial demonstrated a significant reduction (26%) in the rate of first cardiovascular (CV) hospitalization in dronedarone-treated patients with paroxysmal or persistent atrial fibrillation/flutter (AF/AFL). ATHENA was the first trial to demonstrate a CV outcomes benefit, specifically reduced CV hospitalizations, with an antiarrhythmic drug. The objective of this study was to assess the impact of dronedarone treatment on healthcare resource utilization among real-world patients with AF/AFL in United States clinical practice.

METHODS

This retrospective cohort study used claims data from the MarketScan® databases (Truven Health, Durham, NC, USA) to identify patients with ≥2 concurrent de novo pharmacy claims for dronedarone (≥180 days' total supply) between June 2009 and March 2011, and with an AF/AFL diagnosis and no heart failure-related hospitalization during the 12 months preceding the initial (index) dronedarone claim. Annualized inpatient and outpatient resource utilization were compared between the pre-index (baseline) and post-index (follow-up) periods.

RESULTS

In total, 5,656 AF/AFL patients were prescribed dronedarone for ≥6 months and were followed for mean (standard deviation) 11.9 (4.7) months. Reductions in mean numbers of annualized all-cause, CV- and AF-related hospitalizations (~40-45%), and emergency department visits (~30-45%) were realized. These benefits were offset by increases in office visits (~10-30%) and AF-related prescription claims (74%) after dronedarone initiation. The sub-cohort of patients switching to dronedarone from Prior Rhythm-Control therapy (n=2,080) showed similar reductions in hospital and emergency department events.

CONCLUSIONS

This study suggests that dronedarone use in real-world practice, as in the ATHENA trial, results in substantial reductions in hospital admissions, both in first-line and second-line antiarrhythmic treatment settings.

Atrial Fibrillation: Prevalence and Scope of the Problem

Atrial fibrillation is the single most common sustained cardiac dysrhythmia in the United States, and a major cause of hospitalization, stroke, disability, and death. The rapidly increasing prevalence of atrial fibrillation is largely attributable to the aging of the population. Because atrial fibrillation may be intermittent and asymptomatic or minimally symptomatic at onset, its prevalence is difficult to establish. Implanted loop recorders, pacemakers, and defibrillators have enabled precise assessment of the heart rhythm over long periods of time. The incidence of asymptomatic atrial fibrillation is higher than is perceived by patients, and carries with it an increased risk of stoke.

Economic evaluation of rivaroxaban in stroke prevention for patients with atrial fibrillation in Greece

Background

To undertake an economic evaluation of rivaroxaban relative to the standard of care for stroke prevention in patients with non-valvular atrial fibrillation (AF) in Greece.

Methods

An existing Markov model designed to reflect the natural progression of AF patients through different health states, in the course of three month cycles, was adapted to the Greek setting. The analysis was undertaken from a payer perspective. Baseline event rates and efficacy data were obtained from the ROCKET-AF trial for rivaroxaban and vitamin-K-antagonists (VKAs). Utility values for events were based on literature. A treatment-related disutility of 0.05 was applied to the VKA arm. Costs assigned to each health state reflect the year 2013. An incremental cost effectiveness ratio (ICER) was calculated where the outcome was quality-adjusted-life year (QALY) and life-years gained. Probabilistic analysis was undertaken to deal with uncertainty. The horizon of analysis was over patient life time and both cost and outcomes were discounted at 3.5%.

Results

Based on safety-on-treatment data, rivaroxaban was associated with a 0.22 increment in QALYs compared to VKA. The average total lifetime cost of rivaroxaban-treated patients was €239 lower compared to VKA. Rivaroxaban was associated with additional drug acquisition cost (€4,033) and reduced monitoring cost (-€3,929). Therefore, rivaroxaban was a dominant alternative over VKA. Probabilistic analysis revealed that there is a 100% probability of rivaroxaban being cost-effective versus VKA at a willingness to pay threshold of €30,000/QALY gained.

Conclusion

Rivaroxaban may represent for payers a dominant option for the prevention of thromboembolic events in moderate to high risk AF patients in Greece.

Atrial fibrillation and prognosis in patients 80+ years old with chronic heart failure

INTRODUCTION

It is well known that the prevalence of atrial fibrillation (AF) increases with age. The purpose was to evaluate the impact of AF at the 1-year outcome of patients aged 80? who suffered from chronic heart failure (CHF).

MATERIALS AND METHODS

The study included 220 consecutive patients at age 80–92 (mean 82.8 years, 45.5 % men) hospitalized for heart failure. The prospective analysis contains demographic and clinical data, basic laboratory tests with hsTnT and NT-proBNP, 12-lead resting electrocardiogram, echocardiography and coronary angiography results and the number of deaths at the 1-year followup. Patients were analyzed depending on AF in the resting electrocardiogram at hospital entry.

RESULTS

AF was recorded in 52 patients (24 %). The relationship with AF was found for more advanced NYHA class III and IV (p\0.001), higher concentrations of hsCRP (p = 0.0005), hsTnT (p = 0.007) and NT-proBNP (p = 0.0098), higher heart rate in the electrocardiogram (p = 0.000) and longer hospitalization (p = 0.025), older age (p = 0.003) and lower left ventricular ejection fraction (p = 0.006). Annual mortality was 13 % and was higher if AF occurred (17 %). However, there was no association between deaths and AF (p = 0.3297). From the multivariate stepwise analysis, independent risk factors for annual mortality were male gender (OR = 3.432; p = 0.043), left ventricular systolic dimension (OR = 1.871; p = 0.004) and dyslipidemia (OR = 0.252; p = 0.043).

CONCLUSIONS

In the oldest patients aged 80? who suffered from CHF, the incidence of atrial fibrillation and annual mortality was high. The independent variables, which enhanced the risk of death at the 1-year follow-up, were male sex and left ventricular systolic dimension, but not atrial fibrillation.