Comparison of antiarrhythmic drug therapy and radiofrequency catheter ablation in patients with paroxysmal atrial fibrillation: a randomized controlled trial

A novel skeleton based quantification and 3-D volumetric visualization of left atrium fibrosis using late gadolinium enhancement magnetic resonance imaging

This work presents the results of a new tool for 3-D segmentation, quantification and visualization of cardiac left atrium fibrosis, based on late gadolinium enhancement magnetic resonance imaging (LGE-MRI), for stratifying patients with atrial fibrillation (AF) that are candidates for radio-frequency catheter ablation. In this study 10 consecutive patients suffering AF with different grades of atrial fibrosis were considered. LGE-MRI and magnetic resonance angiography (MRA) images were used to detect and quantify fibrosis of the left atrium using a threshold and 2-D skeleton based approach. Quantification and 3-D volumetric views of atrial fibrosis were compared with quantification and 3-D bipolar voltage maps measured with an electro-anatomical mapping (EAM) system, the clinical reference standard technique for atrial substrate characterization. Segmentation and quantification of fibrosis areas proved to be clinically reliable among all different fibrosis stages. The proposed tool obtains discrepancies in fibrosis quantification less than 4% from EAM results and yields accurate 3-D volumetric views of fibrosis of left atrium. The novel 3-D visualization and quantification tool based on LGE-MRI allows detection of cardiac left atrium fibrosis areas. This noninvasive method provides a clinical alternative to EAM systems for quantification and localization of atrial fibrosis.

Curative ablation of atrial fibrillation: comparison between deep sedation and general anesthesia

OBJECTIVE

To compare deep sedation with general anesthesia for curative ablation of atrial fibrillation.

METHODS

We conducted a prospective, randomized study with 32 patients, aged between 18 and 65 years, ASA 2 and 3, BMI d" 30 kg/m2, divided into two groups: deep sedation (G1) and general anesthesia (G2). All patients received intravenous midazolam (0.5 mg / kg). G1 received propofol (1mg/kg) and O2 by facemask, followed by continuous infusion of propofol (25-50mg/kg/min) and remifentanil (0.01-0.05 mg / kg / min). G2 received propofol (2mg/kg) and laryngeal mask with built-in drain tube, followed by continuous infusion of propofol (60-100mg/kg/min) and remifentanil (0.06 to 0.1g/kg/min). We compared heart rate, invasive blood pressure, arterial blood gases, complications and recurrence (outcome) in three months.

RESULTS

G1 patients had arterial blood gas with higher PaCO2 levels and lower pH (p = 0.001) and higher incidence of cough. There was a decrease in Mean Arterial Pressure (MAP) and Heart Rate (HR) in G2. Except cough, complications and recurrence were similar in both groups.

CONCLUSION

Both techniques can be used for the curative ablation of atrial fibrillation. General anesthesia provided smaller respiratory changes and greater immobility of the patient.

Atrial fibrillation

Atrial fibrillation is the most common arrhythmia affecting patients today. Disease prevalence is increasing at an alarming rate worldwide, and is associated with often catastrophic and costly consequences, including heart failure, syncope, dementia, and stroke. Therapies including anticoagulants, anti-arrhythmic medications, devices, and non-pharmacologic procedures in the last 30 years have improved patients' functionality with the disease. Nonetheless, it remains imperative that further research into AF epidemiology, genetics, detection, and treatments continues to push forward rapidly as the worldwide population ages dramatically over the next 20 years.

Identification of left atrial fibrosis with a late-enhancement MR sequence (LE-MR): preliminary results

PURPOSE

This study was done to identify left atrial fibrosis in a group of consecutive patients with atrial fibrillation (AF) candidate for percutaneous radiofrequency catheter ablation (RFCA) by using a late-enhancement magnetic resonance (LE-MR) sequence, and to validate the technique by comparison with electroanatomical mapping (EAM).

MATERIALS AND METHODS

We enrolled 37 patients (29 males; mean age, 61 years) candidate for percutaneous RFCA of AF, who were studied with LE-MR and EAM. To identify left AF we used a three-dimensional LE sequence with cardiac gating and respiratory navigator. The EAM study involved the acquisition of 200 points in the left atrium (LA). The LA was divided into seven segments (pulmonary vein antra, floor, anterior wall, posterior wall-roof). Two blinded radiologists assessed the presence of fibrosis (area of hyperintense signal), reaching a consensus in discordant cases. Inter-observer variability was also evaluated to estimate the reproducibility of the method. We analysed the anatomical agreement between the results obtained with LE-MR imaging and EAM.

RESULTS

Five patients were excluded because of to poor image quality. As for the other 32 patients, inter-observer agreement was good [Cohen's kappa κ = 0.72 with 95 % confidence interval (CI) of 0.55, 0.89]. In the classification of LA segments affected by fibrosis, LE-MR had a sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of 66 % (95 % CI 53.7 %, 77.2 %); 87 % (95 % CI 80.9 %, 91.9 %); 69 % (95 % CI 56.5 %, 80.1 %); 85.5 % (95 % CI 79.1 %, 90.6 %) and 81 % (95 % CU 75.1 %, 85.7 %).

CONCLUSIONS

Despite the small size of the sample studied, the LE-MR sequence proved more useful for excluding the presence of AF than for confirming its existence. Identification of AF prior to RFCA is paramount to select those patients who are truly amenable to the ablation procedure, which is expensive and not entirely free of risks.

Atrial ectopy as a predictor of incident atrial fibrillation: a cohort study

BACKGROUND

Atrial fibrillation (AF) prediction models have unclear clinical utility given the absence of AF prevention therapies and the immutability of many risk factors. Premature atrial contractions (PACs) play a critical role in AF pathogenesis and may be modifiable.

OBJECTIVE

To investigate whether PAC count improves model performance for AF risk.

DESIGN

Prospective cohort study.

SETTING

4 U.S. communities.

PATIENTS

A random subset of 1260 adults without prevalent AF enrolled in the Cardiovascular Health Study between 1989 and 1990.

MEASUREMENTS

The PAC count was quantified by 24-hour electrocardiography. Participants were followed for the diagnosis of incident AF or death. The Framingham AF risk algorithm was used as the comparator prediction model.

RESULTS

In adjusted analyses, doubling the hourly PAC count was associated with a significant increase in AF risk (hazard ratio, 1.17 [95% CI, 1.13 to 1.22]; P < 0.001) and overall mortality (hazard ratio, 1.06 [CI, 1.03 to 1.09]; P < 0.001). Compared with the Framingham model, PAC count alone resulted in similar AF risk discrimination at 5 and 10 years of follow-up and superior risk discrimination at 15 years. The addition of PAC count to the Framingham model resulted in significant 10-year AF risk discrimination improvement (c-statistic, 0.65 vs. 0.72; P < 0.001), net reclassification improvement (23.2% [CI, 12.8% to 33.6%]; P < 0.001), and integrated discrimination improvement (5.6% [CI, 4.2% to 7.0%]; P < 0.001). The specificity for predicting AF at 15 years exceeded 90% for PAC counts more than 32 beats/h.

LIMITATION

This study does not establish a causal link between PACs and AF.

CONCLUSION

The addition of PAC count to a validated AF risk algorithm provides superior AF risk discrimination and significantly improves risk reclassification. Further study is needed to determine whether PAC modification can prospectively reduce AF risk.

PRIMARY FUNDING SOURCE

American Heart Association, Joseph Drown Foundation, and National Institutes of Health.

Improving ablation strategies for the treatment of atrial fibrillation

Atrial fibrillation (AF) is the most common sustained arrhythmia encountered in clinical practice. The contemporary management of AF is centered on symptomatic improvement, as well as reduction in the AF associated morbidity and mortality. For many highly symptomatic patients catheter ablation offers an efficacious means to maintaining sinus rhythm when antiarrhythmic drugs have been ineffective, are contraindicated or cannot be tolerated. Over the past 15 years, catheter ablation has moved from an 'experimental therapy' to the standard of care for the maintenance of sinus rhythm. Unfortunately, while the results of ablation are unequivocally superior to medical therapy, recognized limitations of the contemporary AF ablation procedures have spurred several developments designed to improve the efficacy of the index ablation procedure, while limiting adverse events. The purpose of this review is to discuss the procedural refinements, and technological innovations proposed to outcomes of patients undergoing a percutaneous catheter ablation procedure for AF.

Addressing the controversy of rate-versus-rhythm control in atrial fibrillation

Atrial fibrillation is the most common sustained cardiac arrhythmia and significantly increases patient risk of stroke, cardiomyopathy, and mortality. Rate versus rhythm control as the "best" treatment strategy remains an issue of considerable, ongoing debate. A multitude of clinical trials have compared the 2 strategies and have not shown any benefit of one approach over the other. However, the trials were conducted in specific subgroups of patients and demonstrated low success rates with antiarrhythmic drug (AAD) therapy and a high incidence of adverse AAD effects. Sub-analyses of the trials have confirmed that successful rhythm control with sinus rhythm restoration is associated with a significant reduction in patient mortality. More recently, radiofrequency ablation (RFA) has emerged as a relatively effective procedure for maintaining sinus rhythm compared with use of AADs. Prospective randomized studies have shown good treatment results after the use of RFA, with acceptable risk. Given the limitation of pharmacologic rate versus rhythm control studies, and the promise of RFA, rhythm control should again be reconsidered as the "best" approach for managing many subgroups of patients with atrial fibrillation.

Immediate and medium-term outcomes of cryoballoon-based pulmonary vein isolation in patients with paroxysmal and persistent atrial fibrillation: single-centre experience

BACKGROUND

Pulmonary vein (PV) isolation with cryoballoon is a recently developed technique for the treatment of atrial fibrillation (AF) with acceptable mid-term results in terms of the success and safety. The purpose of our study is to identify the periprocedural complications, mid-term success rates and predictors of recurrence after AF ablation with cryoballoon.

METHOD

A total of 236 patients (54% male, mean age 54.6 ± 10.45 years and 79.6% paroxysmal AF) with symptomatic AF underwent PV isolation with cryoballoon due to failure with ≥1 antiarrhythmic drug previously. Procedural success, complications and follow-up data were defined according to recent guidelines.

RESULTS

Acute procedural success rate was 99.5%. Mean procedural and fluoroscopy times were 72.5 ± 5.3 and 14 ± 3.5 min. At a median of 18 (6-27) months follow-up, 80.8% of paroxysmal AF patients and 50.0% of persistent AF patients were free from AF recurrence. In multivariate regression analysis, body mass index (BMI) (hazard ratio (HR), 1.35; 95% confidence interval (CI), 1.18-2.93, p = 0.001), smoking (HR, 2.12; 95% CI, 1.36-6.67, p < 0.001), non-paroxysmal AF (HR, 1.26; 95% CI, 1.12-2.56, p = 0.024), duration of AF (HR, 1.42; 95% CI, 1.18-2.61, p = 0.015), left atrium (LA) diameter (HR, 2.42; 95% CI, 1.64-5.88, p < 0.001) and early AF recurrence (HR, 4.88; 95% CI, 2.86-35.6, p < 0.001) were independent predictors of AF recurrence following cryoablation.

CONCLUSION

Our results showed that AF ablation with cryoballoon is effective and safe. Non-paroxysmal AF, duration of AF, smoking, BMI, LA diameter and early recurrence were found to be the most powerful predictors and could be helpful to select patients for appropriate therapeutic strategy.

A proposal for a new scoring system in the prediction of catheter ablation outcomes: promising results from the Turkish Cryoablation Registry

BACKGROUND

Although cryoballoon based catheter ablation is an effective therapeutic option in atrial fibrillation (AF), a significant amount of patients failed to remain in sinus rhythm at long term follow-up. Appropriate selection of patients for catheter ablation reduces unnecessary interventions and prevents complications related with catheter ablation. The purpose of our study is to propose a new scoring system in the prediction of recurrence after AF ablation with cryoballoon.

METHOD

A total of 236 patients (54% male, age 54.6 ± 10.45 years and 79.6% paroxysmal) with symptomatic AF underwent an index cryoablation. The first 3 months after AF ablation is defined as blanking period. Predictors of AF recurrence after cryoablation were analyzed with multivariate Cox regression analysis. BASE-AF2 score [acronym stands for Body mass index >28 kg/m(2) (1); Atrial dilatation >40 mm (1); current Smoking (1); Early recurrence (1); duration of AF history >6 years (1) and non-paroxysmal type (1) of AF] is identified by the total number of significant predictors of recurrence in each patient (range=0-6).

RESULTS

At median 20 (range: 12-30) months follow-up, 74.5% of the patients were free from AF recurrence. Of these patients, 64 (27.1%) patients had a BASE-AF2 score of ≥3. Patients with AF recurrence had a higher mean BASE-AF2 score (3.27±0.82 vs. 1.1 ± 0.95, p<0.001) compared to patients without AF recurrence. ROC analysis showed that a BASE-AF2 score of ≥3 well predicted AF recurrence with a sensitivity of 80.8% and a specificity of 91.6% (AUC=0.94; 95% CI: 0.89-0.97, p<0.001). A BASE-AF2 score of ≥3 was found to be an independent predictor of AF recurrence (HR: 3.34, 95% CI: 2.34-4.76, p=0.001).

CONCLUSION

BASE-AF2, which was identified as a new scoring system, has well predicted AF recurrence and could be helpful in selecting appropriate patients for interventional strategy.

Surgical Minimally Invasive Pulmonary Vein Isolation for Lone Atrial Fibrillation

Objective

Minimally invasive surgical pulmonary vein isolation (SMI-PVI) is an emerging therapy for the treatment of symptomatic drug-refractory atrial fibrillation (AF). Nevertheless, the midterm and long-term results of SMI-PVI remain unknown. The aim of this retrospective multicenter study was to report on midterm efficacy and safety of SMI-PVI.

Methods

The study design was retrospective, multicentric, and observational. From July 2005 to November 2011, a total of 86 patients with drug-refractory paroxysmal or persistent AF underwent SMI-PVI in three centers. Patients were eligible for SMI-PVI if they had symptomatic, drug-refractory AF or after failed transcatheter pulmonary vein isolation. Success was defined as absence of AF on 24- or 96-hour Holter monitoring during follow-up, in the absence of antiarrhythmic drugs (AADs).

Results

The mean ± SD age was 54 ± 11 years, and 78% were men. The median AF duration was 30 months (range, 2–203); paroxysmal AF was present in 86% of the patients, persistent in 14%. Fifteen patients (17%) underwent previous transcatheter ablations. After a median follow-up of 24 months (range, 6–78), 72% of all patients were free from atrial arrhythmias without the use of AADs. With AADs, this was 83%. Major perioperative adverse events occurred in 7 patients (8%).

Conclusions

This retrospective multicenter study shows that SMI-PVI is effective at a median follow-up of 24 months for the treatment of mostly paroxysmal drug-refractory AF. Perioperative adverse events do remain a point of caution.

Exploring the Potential Role of Catheter Ablation in Patients with Asymptomatic Atrial Fibrillation: Should We Move away from Symptom Relief?

Although silent atrial fibrillation (AF) accounts for a significant proportion of patients with AF, asymptomatic patients have been excluded from AF ablation trials. This population presents unique challenges to disease management. Recent evidence suggests that patients with asymptomatic AF may have a different risk profile and even worse long-term outcomes compared to patients with symptomatic AF. For the same reasons they might be more prone to side-effects of antiarrhythmic drugs, including pro-arrhythmias. The poor correlation between symptoms and AF demonstrated in several studies should caution physicians against making clinical decisions depending on symptoms. Although current guidelines recommend AF ablation only in patients with symptoms, more attention should be paid to the AF burden and a rhythm control strategy has the potential to improve morbidity and mortality in AF patients. However, limited data exist regarding the use of catheter ablation for asymptomatic AF patients. As ablation techniques have improved, AF ablation has become more widespread and complication rate decreased. As a result, referrals of asymptomatic patients for catheter ablation of AF are on the rise. In this review we discuss the many unresolved questions concerning the role of the ablative approach in asymptomatic patients with AF.

Electrophysiological Evaluation of Thoracoscopic Pulmonary Vein Isolation

Although the majority of patients with atrial fibrillation and an indication for non-pharmacological therapy is treated with catheter ablation, thoracoscopic surgery is an emerging technique that aims at combining the results of the classic Cox Maze operation with a less invasive approach. Recurrences after thoracoscopic surgery have been mainly ascribed to incomplete ablation lines, but literature on electrophysiological confirmation of thoracoscopic pulmonary vein isolation is limited. Currently, surgical confirmation of uni- or bidirectional conduction block may be hampered by insufficient resolution of the mapping material available. Additionally uncertainty remains on the precise lesions sets required, and how to tailor them to individual patients. In hybrid procedures, electrophysiologists and surgeons join forces to combine their expertise and skills which may lead to increased procedural success rates by minimizing the chance of incomplete PV isolation or absence of conduction block across an alternative ablation line. Here we describe techniques for thoracoscopic mapping and present a literature review.

Initial impedance decrease as an indicator of good catheter contact: insights from radiofrequency ablation with force sensing catheters

BACKGROUND

Good catheter-tissue contact force (CF) is critical for transmural and durable lesion formation during radiofrequency (RF) ablation but is difficult to assess in clinical practice. Tissue heating during RF application results in an impedance decrease at the catheter tip.

OBJECTIVE

The purpose of this study was to correlate achieved CF and initial impedance decreases during atrial fibrillation (AF) ablation.

METHODS

We correlated achieved CF and initial impedance decreases in patients undergoing ablation for AF with two novel open-irrigated CF-sensing RF catheters (Biosense Webster SmartTouch, n = 647 RF applications; and Endosense TactiCath, n = 637 RF applications). We then compared those impedance decreases to 691 RF applications with a standard open-irrigated RF catheter (Biosense Webster ThermoCool).

RESULTS

When RF applications with the CF-sensing catheters were analyzed according to an achieved average CF <5 g, 5-10 g, 10-20 g, and >20 g, the initial impedance decreases during ablation were larger with greater CF. Corresponding median values at 20 seconds were 5 Ω (interquartile range [IQR] 2-7), 8 Ω (4-11), 10 Ω (7-16), and 14 Ω (10-19) with the SmartTouch and n/a, 4 Ω (0-10), 8 Ω (5-12), and 13 Ω (8-18) with the TactiCath (P <.001 between categories for both catheters). When RF applications with the SmartTouch (CF-sensing catheter, median achieved CF 12 g) and ThermoCool (standard catheter) were compared, the initial impedance decrease was significantly greater in the CF-sensing group with median decreases of 10 Ω (6-14 Ω) vs 5 Ω (2-10 Ω) at 20 seconds (P <.001 between catheters).

CONCLUSION

The initial impedance decrease during RF applications in AF ablations is larger when greater catheter contact is achieved. Monitoring of the initial impedance decrease is a widely available indicator of catheter contact and may help to improve formation of durable ablation lesions.

Atrial fibrillation and heart failure: beyond the heart rate

PURPOSE OF REVIEW

Atrial fibrillation and heart failure are two of the most prevalent cardiovascular disease conditions. They often coexist and lead to significant morbidity and mortality. Adequate management strategies for this dual epidemic continue to be the subject of many research studies.

RECENT FINDINGS

Recent clinical trials suggest that a rhythm control strategy for atrial fibrillation does not offer a survival advantage over rate control in heart failure patients with reduced systolic function. Rhythm control in these trials was achieved using antiarrhythmic drugs, with evidence of increased mortality associated with certain agents. Catheter ablation is a more effective and increasingly used approach to maintain sinus rhythm in atrial fibrillation patients, with promising results in the heart failure population. Late-gadolinium-enhancement cardiac MRI (LGE-MRI) assessment of atrial fibrosis helps in selecting the better candidates for atrial fibrillation ablation. AV nodal ablation and bi-ventricular pacing remains another viable option. Atrial fibrillation patients with heart failure and preserved systolic function are another group in whom maintenance of sinus rhythm is thought to be advantageous.

SUMMARY

Patients with atrial fibrillation and heart failure are a heterogeneous group and require a personalized treatment approach. Catheter ablation to restore and maintain sinus rhythm is a modality that promises to be advantageous beyond rate control.

Percutaneous recanalization of totally occluded pulmonary veins after pulmonary vein isolation-intermediate-term follow-up

OBJECTIVES

Review mid-term follow-up of percutaneous intervention for post ablation total pulmonary vein occlusion (PVO).

BACKGROUND

Feasibility of percutaneous intervention for PVO has been described, but information remains limited.

METHODS

Patients with total PVO were retrospectively identified from our catheterization database. Medical records, catheterization reports, and outpatient follow-up were reviewed.

RESULTS

Between April 2005 and February 2012, 16 patients were identified with a total of 18 PVOs. Symptoms included hemoptysis in 6/16 (46%), cough in 8/16 (50%), chest pain in 8/16 (50%), dyspnea in 13/16 (81%) with mean NYHA Class of 2.6 ± 0.6. Recanalization was accomplished in 14/18 (78%) veins: 11 treated with balloon dilation and 3 with stents. Median follow-up for 13/14 veins was 13 (0-39) months (one patient with one PVO is awaiting follow-up). Reocclusion occurred in 7/13 (54%) at mean follow-up of 3.6 ± 1.6 months (6/10 post-balloon dilation and 1/3 post-stenting). Despite reocclusion, the reference vessel diameter increased from 4.8 ± 2.4 to 8.5 ± 4.2 mm (P < 0.001) between the first and second catheterization. Re-recanalization and stent placement was accomplished in 5/6 (83%), with one reocclusion not attempted. At latest follow-up 9/13 (69%) recanalized vessels remained patent and percent flow to affected lung quadrant increased from 7.4 ± 3.4% pre-intervention to 14.3 ± 4.2% (P = 0.004). Mean NYHA Class improved to 1.4 ± 0.4 (P < 0.001).

CONCLUSIONS

Recanalization of total PVO can be accomplished with reasonable mid-term patency, improved symptoms, and lung perfusion. Reocclusion is common, but vessel growth is often observed allowing placement of a reasonably sized stent at a second intervention. Staged intervention is often necessary to maintain patency.

Atrial fibrillation in heart failure in the older population

Atrial fibrillation (AF) is an important and often-underrecognized cause of cardiovascular morbidity and mortality. It is an arrhythmia that is commonly seen in the older patient; the median age of patients with AF in early studies was 75 years. Heart failure (HF) is also more frequently seen in the older patient with an approximate doubling of HF prevalence with each decade of life. There is clear interaction between AF and HF, with evidence that HF can lead to AF and AF exacerbates HF. This review focuses on the specific aspect of AF management in elderly patients with HF.

Atrial fibrillation: inflammation in disguise?

Atrial fibrillation is highly prevalent, and affected patients are at an increased risk of a number of complications, including heart failure and thrombo-embolism. Over the past years, there has been increasing interest in the role of inflammatory processes in atrial fibrillation, from the first occurrence of the arrhythmia to dreaded complications such as strokes or peripheral emboli. As the standard drug combination which aims at rate control and anticoagulation only offers partial protection against complications, newer agents are needed to optimize treatment. In this paper, we review recent knowledge regarding the impact of inflammation on the occurrence, recurrence, perpetuation and complications of the arrhythmia, as well as the role of anti-inflammatory therapies in the treatment for the disease.

Cost-effectiveness of catheter ablation for rhythm control of atrial fibrillation

Objective. The objective of this study is to evaluate the cost-effectiveness of catheter ablation for rhythm control compared to antiarrhythmic drug (AAD) therapy in patients with atrial fibrillation (AF) who have previously failed on an AAD. Methods. An economic model was developed to compare (1) catheter ablation and (2) AAD (amiodarone 200 mg/day). At the end of the initial 12 month phase of the model, patients are classified as being in normal sinus rhythm or with AF, based on data from a meta-analysis. In the 5-year Markov phase of the model, patients are at risk of ischemic stroke each 3-month model cycle. Results. The model estimated that, compared to the AAD strategy, ablation had $8,539 higher costs, 0.033 fewer strokes, and 0.144 more QALYS over the 5-year time horizon. The incremental cost per QALY of ablation compared to AAD was estimated to be $59,194. The probability of ablation being cost-effective for willingness to pay thresholds of $50,000 and $100,000 was estimated to be 0.89 and 0.90, respectively. Conclusion. Based on current evidence, pulmonary vein ablation for treatment of AF is cost-effective if decision makers willingness to pay for a QALY is $59,194 or higher.

Improving outcomes in patients with atrial fibrillation: rationale and design of the Early treatment of Atrial fibrillation for Stroke prevention Trial

BACKGROUND

Even on optimal therapy including anticoagulation and rate control, major cardiovascular complications (stroke, cardiovascular death, and acute heart failure) are common in patients with atrial fibrillation (AF). Conceptually, maintenance of sinus rhythm could prevent adverse outcomes related to AF. Rhythm control therapy has been only moderately effective in published trials, and its potential benefit was offset by side effects of repeated interventions.

RATIONALE

Rhythm control therapy applied early after the first diagnosis of AF could preserve atrial structure and function and maintain sinus rhythm more effectively than the current practice of delayed rhythm control (when symptoms persist after otherwise effective rate control). Furthermore, catheter ablation and new antiarrhythmic drugs have enhanced the potential effectiveness and safety of rhythm control therapy. The EAST will test whether an early, modern rhythm control therapy can reduce cardiovascular complications in AF.

DESIGN

The EAST (Early treatment of Atrial fibrillation for Stroke prevention Trial) will randomize approximately 3,000 patients with recent onset AF at risk for stroke (CHA₂DS₂VASc score ≥2) to either guideline-mandated usual care or to usual care plus early rhythm control therapy in a prospective, randomized, open, blinded outcome assessment trial. All patients will be followed up until the end of the trial for the composite primary outcome of cardiovascular death, stroke, worsening of heart failure, and myocardial infarction. Nights spent in hospital will be counted as a coprimary outcome. Usual care will consist of anticoagulation, therapy of underlying heart disease, and rate control as an initial approach. Early rhythm control therapy will consist of usual care plus rhythm control therapy by antiarrhythmic drugs, catheter ablation, and a patient-operated electrocardiographic device to monitor the ongoing rhythm. Key secondary outcomes include cognitive function and quality of life.

CONCLUSION

EAST will determine whether rhythm control therapy, when applied early after the initial diagnosis of AF, can prevent cardiovascular complications associated with AF.

The incidence, pattern, and prognostic value of left ventricular myocardial scar by late gadolinium enhancement in patients with atrial fibrillation

OBJECTIVES

This study sought to identify the frequency, pattern, and prognostic significance of left ventricular (LV) late gadolinium enhancement (LGE) in patients with atrial fibrillation (AF).

BACKGROUND

There are limited data on the presence, pattern, and prognostic significance of LV myocardial fibrosis in patients with AF. LGE during cardiac magnetic resonance imaging is a marker for myocardial fibrosis.

METHODS

A group of 664 consecutive patients without known prior myocardial infarction who were referred for radiofrequency ablation of AF were studied. Cardiac magnetic resonance imaging was requested to assess pulmonary venous anatomy.

RESULTS

Overall, 73% were men, with a mean age of 56 years and a mean LV ejection fraction of 56 ± 10%. LV LGE was found in 88 patients (13%). The endpoint was all-cause mortality, and in this cohort, 68 deaths were observed over a median follow-up period of 42 months. On univariate analysis, age (hazard ratio [HR]: 1.05; 95% confidence interval [CI]: 1.03 to 1.08; chi-square likelihood ratio [LRχ(2)]: 15.2; p = 0.0001), diabetes (HR: 2.39; 95% CI: 1.41 to 4.09; LRχ(2): 10.3; p = 0.001), a history of heart failure (HR: 1.78; 95% CI: 1.09 to 2.91; LRχ(2): 5.37; p = 0.02), left atrial dimension (HR: 1.04; 95% CI: 1.01 to 1.08; LRχ(2): 6.47; p = 0.01), presence of LGE (HR: 5.08; 95% CI: 3.08 to 8.36; LRχ(2): 28.8; p < 0.0001), and LGE extent (HR: 1.15; 95% CI: 1.10 to 1.21; LRχ(2): 35.6; p < 0.0001) provided the strongest associations with mortality. The mortality rate was 8.1% per patient-year in patients with LGE compared with 2.3% patients without LGE. In the best overall multivariate model for mortality, age and the extent of LGE were independent predictors of mortality. Indeed, each 1% increase in the extent of LGE was associated with a 15% increased risk for death.

CONCLUSIONS

In patients with AF, LV LGE is a frequent finding and is a powerful predictor of mortality.

Update in sepsis 2012

Pivotal sepsis clinical trials and preclinical research in 2012 are reviewed. For interventions ranging from synthetic complex starch solutions to recombinant human activated protein C, large multicenter randomized controlled trials generally failed to show benefit and some even demonstrated harm in the intervention group. In smaller innovative clinical trials simple interventions such as external cooling to control fever and biomarker-guided weaning from mechanical ventilation found potential benefit. Biomarkers for sepsis, including multimarker panels, are increasingly showing promise for clinical application. Breakthroughs in basic research in sepsis continue to highlight the complexity of the systemic inflammatory response and its consequences. A series of publications in AJRCCM follow the septic inflammatory response starting from intracellular structures and organelles to mitochondria and the cytoskeleton. Additional publications explore the key leukocyte subsets acting in sepsis, highlighting the underappreciated role of helper T-cell type 2-related pathways. Cellular remnants in the form of microparticles contribute to coagulopathy and further organ dysfunction. As a consequence, we suggest that sepsis may be the paradigm disease or condition requiring personalized care first to discover and validate new therapies and second to increase survival.

Role of preablation neutrophil/lymphocyte ratio on outcomes of cryoballoon-based atrial fibrillation ablation

The neutrophil/lymphocyte ratio (NLR) has recently emerged as better indicator of inflammation and oxidative stress and has been widely studied in several cardiovascular diseases. In the present study, we evaluated the role of the preablation NLR in atrial fibrillation (AF) recurrence after cryoballoon-based catheter ablation. A total of 251 patients (47.8% women, age 54.12 ± 10.9 years, 80.1% with paroxysmal AF) with symptomatic AF underwent cryoablation. At a mean follow-up of 19.0 ± 6.6 months, 60 patients (23.9%) had developed AF recurrence. The patients who developed AF recurrence had had a greater preablation NLR (3.53 ± 0.95 vs 2.65 ± 0.23, p <0.001) and a higher white blood cell count, neutrophil count, and high-sensitivity C-reaction protein levels. On multivariate regression analysis, the preablation NLR (hazard ratio 2.15, 95% confidence interval 1.70 to 2.73, p <0.001), left atrial diameter (hazard ratio 1.09, 95% confidence interval 1.04 to 1.14, p <0.001) and early AF recurrence (hazard ratio 2.99, 95% confidence interval 1.71 to 5.23, p <0.001) were independent predictors of AF recurrence after cryoablation. Using a cutoff level of 3.15, the preablation NLR predicted AF recurrence during follow-up with a sensitivity of 84% and specificity of 75%. Patients with a preablation NLR >3.15 had a 2.5-fold increased risk of developing AF recurrence after cryoablation. In conclusion, an elevated preablation NLR was associated with increased AF recurrence after cryoballoon-based catheter ablation. Our results support the role of a preablation inflammatory environment in the development of AF recurrence after ablation therapy but suggest that other factors are also important.

Antiarrhythmic drugs in atrial fibrillation: do they have a future?

Atrial fibrillation (AF) is a common arrhythmia associated with significant morbidity and mortality. There has been much debate about the relative merits of rate vs rhythm control strategies, and studies to date have failed to show advantage with a rhythm-control strategy using antiarrhythmic drugs (AADs). This is likely because of the inadequacies of our current AADs and the limitations of study designs. However, there is evidence that AADs improve symptoms and quality of life (QOL). Until trials are performed with more appropriate patient selection, and end points and better AADs and strategies for their use, rhythm control should not be abandoned and may continue to be beneficial in selected patients.