Catheter Ablation Versus Antiarrhythmic Drugs for Atrial Fibrillation

Super and Nonresponders to Catheter Ablation for Atrial Fibrillation: A Quality-of-Life Assessment Using Patient Reported Outcomes

[Figure: see text].

Does merged three-dimensional mapping improve contact force and long-term procedure outcome in atrial fibrillation ablation? (MICRO-AF study): a prospective randomized controlled study

Integration of electroanatomical map (EAM) with preacquired three-dimensional (3D) cardiac images provides detailed appreciation of the complex anatomy of the left atrium (LA) and pulmonary vein (PV). High-density (HD) multi-electrode mapping catheters have enabled creating more accurate EAM reflecting real-time volume-rendered LA-PV geometry during atrial fibrillation (AF) ablation. However, no study has compared the outcomes of AF ablation using HD-EAM versus 3D-merged map. We aimed to investigate the procedural and clinical outcomes of AF ablation with HD-EAM (HD-EAM group) versus 3D-merged map (Merge group). One hundred patients (59.5 ± 11.5 years, 53% with paroxysmal AF [PAF]) were randomly assigned (1:1) to HD-EAM or Merged group. HD multi-electrode mapping and contact force (CF)-sensing catheters were used to create virtual LA-PV chamber and to perform wide antral circumferential ablation (WACA), respectively. The two groups showed no significant differences in baseline characteristics and procedural data including ablation time, fluoroscopy time, LA voltage, and CF. PV isolation with a single WACA line was achieved in 21 (42%) and 27 (54%) patients in the Merge and HD-EAM groups, respectively (P = NS). CF was significantly lower in lesions with gap than lesions without gap after a single WACA (7.3 ± 7.3 g vs. 16.0 ± 8.3, respectively, P < 0.001). During the 12-month follow-up, no significant difference in AF recurrence was observed between two groups, irrespective of AF type. In multivariate analysis, non-PAF was an independent risk factor for AF recurrence. Integration of 3D cardiac imaging did not improve procedural and clinical outcomes. HD-EAM provides an accurate real-time LA geometry.

Derivation and Verification of the Relationship between Ablation Index and Baseline Impedance

Objective

To explore the quantitative adjustment of ablation index (AI) under different baseline impedance to achieve similar lesion dimensions.

Methods

(1) Keeping the AIs relatively constant, the lesion dimensions in different baseline impedances were studied. (2) According to Joule's law, Q = I²RT, keeping the current (I) unchanged, the powers corresponding to different baseline impedances can be obtained. Under different baseline impedances and corresponding powers, the swine hearts were ablated for 30 s in simulated human circumstances. The baseline impedances, the lesion dimensions, and AIs were recorded. And the derivation of empirical formula was achieved according to the AIs and baseline impedance values in similar lesions dimension. (3) Basic AI and baseline impedance (AI₀/R₀) were set as 400/120 Ω in the common AI groups and 550/120 Ω in the high AI groups, AI values in different baseline impedances were calculated using the empirical formula, and the corresponding lesion dimensions were measured to verify this formula.

Results

(1) Higher baseline impedances were related to smaller lesion dimensions at similar AIs. (2) The lesion dimensions were roughly the same after modulating the baseline impedance and power to keep the electric current relatively constant. The relationship between AI and R fitted with experimental data is AI = 1.9933R + 203.61 (r = 0.9649), and the formula derived is ΔAI = (AI₀ − 203)/R₀ × ΔR. (3) Under the guidance of the empirical formula, there was no significant difference in lesion dimensions between the standard group and the formula guiding groups when AI₀ = 400, but there was a shrinking tendence when AI > 700.

Conclusion

The lesion depths are negatively correlated with baseline impedance at a certain AI. The relationship between baseline impedance and AI is “ΔAI = (AI₀ − 203)/R₀ × ΔR”. It is verified that when the AI is not too high, the empirical formula can be used to guide the quantitative adjustment of AIs at different baseline impedance, and the lesion depths achieved are roughly the same.

Higher FT4 level within the normal range predicts the outcome of cryoballoon ablation in paroxysmal atrial fibrillation patients without structural heart disease

Background

Accumulated evidence has indicated that a high‐normal FT4 level is an independent risk factor for the clinical progression of AF. However, the association between elevated FT4 concentration within the normal range and AF recurrence after cryoballoon ablation in China is unknown.

Methods

This retrospective and observational study included 453 AF patients who underwent cryoballoon ablation from January 2016 to August 2018. Patients were classified into quartiles based on preprocedural serum FT4 concentration. The clinical characteristics of the patients and the long‐term rate of AF recurrence after ablation were assessed.

Results

After a mean follow‐up period of 17.4 ± 9.0 months, 91 (20.1%) patients suffered from AF recurrence. The AF recurrence rate by FT4 quartile was 17.7%, 19.0%, 21.4%, and 22.3% for participants with FT4 in quartile 1, 2, 3, and 4, respectively (p < .001). On multivariate Cox regression, FT4 concentration (HR: 1.187, 95% CI: 1.093–1.290, p < .001) and left atrial diameter (HR: 1.052, 95% CI: 1.014–1.092, p = .007) were significant predictors of AF recurrence. When stratifying for AF type, the rate of postoperative recurrence was independently increased as FT4 concentration increased in paroxysmal AF, but not in persistent AF (p < .001 in paroxysmal AF and p = .977 in persistent AF).

Conclusion

Higher FT4 level within the normal range predicted the outcome of cryoballoon ablation in Chinese paroxysmal AF patients without structural heart disease.

Katheterablation bei asymptomatischem Vorhofflimmern – Wer profitiert?

Die Katheterablation von paroxysmalem oder persistierendem Vorhofflimmern hat sich in den letzten Jahren als überlegene Therapiebehandlung zur Rhythmusstabilisierung gegenüber Antiarrhythmika etabliert. Allerdings wird diese Behandlung nach den aktuellen Leitlinien nur bei symptomatischen Patienten empfohlen. Ein großer Teil der Vorhofflimmerpatienten bleibt jedoch asymptomatisch. Ältere Studien konnten keinen Vorteil bezüglich der Letalitäts- oder Apoplexreduktion durch Rhythmusstabilisierung nachweisen. Eine aktuelle randomisierte Studie zeigt erstmalig eine Reduktion der kardiovaskulären Ereignisse, aber nicht der Gesamtletalität. Ist nach aktueller Datenlage eine Katheterablation im Falle von asymptomatischen Patienten berechtigt und wer könnte davon profitieren?

Geriatric nutritional risk index as a predictor of arrhythmia recurrence after catheter ablation of atrial fibrillation

BACKGROUND AND AIMS

The nutritional risk of patients who undergo atrial fibrillation (AF) ablation varies. Its impact on the recurrence after ablation is unclear. We sought to evaluate the relationship between the nutritional risk and arrhythmia recurrence in patients who undergo AF ablation.

METHODS AND RESULTS

We enrolled 538 patients (median 67 years, 69.9% male) who underwent their first AF ablation. Their nutritional risk was evaluated using the pre-procedural geriatric nutritional risk index (GNRI), and the patients were classified into two groups: No-nutritional risk (GNRI ≧ 98) and Nutritional risk (GNRI < 98). The primary endpoint was a recurrence of an arrhythmia, and its relationship to the nutritional risk was evaluated. We used propensity-score matching to adjust for differences between patients with a GNRI-based nutritional risk and those without a nutritional risk. A nutritional risk was found in 10.6% of the patients, whereas the remaining 89.4% had no-nutritional risk. During a mean follow-up of 422 days, 91 patients experienced arrhythmia recurrences. The patients with a nutritional risk had a significantly higher arrhythmia recurrence rate both in the entire study cohort (Log-rank p = 0.001) and propensity-matched cohort (Log-rank p = 0.006). In a Cox proportional hazard analysis, the nutritional risk independently predicted arrhythmia recurrences in the entire study cohort (hazard ratio [HR]: 3.91, 95% confidence interval [CI]: 1.84-8.35, p < 0.001) and propensity-matched cohort (HR: 6.49, 95% CI: 1.42-29.8, p = 0.016).

CONCLUSION

A pre-procedural malnutrition risk was significantly associated with increased arrhythmia recurrences in patients who underwent AF ablation.

Newer generation cryoballoon vs. contact force-sensing radiofrequency ablation catheter in the ablation of paroxysmal atrial fibrillation

BACKGROUND

Catheter ablation for atrial fibrillation (AF) has become an effective treatment to control symptoms. The second generation cryoballoon (CB) was designed for more efficient and homogenous freeze. Radiofrequency (RF) ablation catheters using three-dimensional electroanatomical mapping with the use of contact-force radiofrequency (CF RF) technology has achieved good results in several studies.

OBJECTIVES

To compare the efficacy and safety of second-generation CB ablation in contrast to CF RF ablation in the ablation of paroxysmal AF.

METHODS

A total of 81 consecutive patients suffering from paroxysmal AF underwent pulmonary vein isolation (PVI) either by the second generation cryoballoon (n = 44) or a contact force-sensing RF catheter (n = 37). The study was conducted at Ain Shams University Hospitals and Royal Brompton & Harefield NHS trust. Baseline data, procedural data and patient follow up-at 3, 6 and 12 months-were collected and analysed.

RESULTS

The mean age was 53.8 ± 15 years in the CB group and 62.4 ± 12 years in the RF group, females representing 40.9% and 48.6% respectively. The baseline characteristics were comparable, but the CB group had less left atrial diameter and more left ventricular ejection fraction. The CB procedure was shorter (94.4 ± 39.3 vs. 140.8 ± 44.3 min, p < 0.0001), with longer fluoroscopy time (30 vs. 15.1 min, p = 0.047). Procedural complications were comparable between the two groups (CB 4.6%, CF RF 2.7%, p = 0.411). After 1 year, the recurrence rate in the CB group was similar to RF (27.3% vs. 27% respectively, p = 0.980).

CONCLUSION

Second-generation CB ablation of paroxysmal AF has similar efficacy and safety to contact force-sensing RF catheters, with shorter procedure times and more fluoroscopy.

Long-Term Outcomes and Improvements in Quality of Life in Patients with Atrial Fibrillation Treated with Catheter Ablation vs. Antiarrhythmic Drugs

BACKGROUND

Catheter ablation (CA) is a recognized first-line treatment for atrial fibrillation (AF) in selected patients; however, the differences between CA and antiarrhythmic drugs (AADs) in terms of long-term outcomes and quality of life (QoL) have not often been compared.

OBJECTIVES

We performed a meta-analysis of randomized controlled trials (RCTs) to compare long-term outcomes and QoL with CA and AADs in the treatment of AF.

METHODS

We searched the MEDLINE database for English-language RCTs of CA or AADs in AF from 1 January 2005 to 30 October 2019 with no other restrictions. We included studies that reported sample sizes and the long-term outcomes of interest as well as sample size, mean ± standard deviation or 95% confidence intervals (CIs) for QoL outcomes with CA and AADs.

RESULTS

We identified 20 RCTs involving 5425 participants. Compared with patients who received only AADs, patients receiving CA had a significantly decreased risk of all-cause death (relative risk [RR] 0.72; 95% CI 0.58-0.90) and cardiovascular hospitalization (RR 0.85; 95% CI 0.79-0.91). We found a significant increase in the risk of cardiac tamponade (RR 5.86; 95% CI 1.77-19.44) but no difference in the risk of heart failure, stroke or transient ischemic attack, atrial tachycardia, bleeding or hematoma, and pulmonary vein stenosis. For long-term QoL after treatment, both therapies resulted in improved scores on the Medical Outcomes Study 36-Item Short Form Survey (SF-36): weighted mean differences (WMDs) for the physical component score (PCS) were 5.89 for CA and 4.26 for AADs and for the mental component score (MCS) were 7.12 for CA and 5.06 for AADs. At the end of follow-up, groups receiving CA had significantly higher scores in both areas. The change in PCS and MCS between baseline and end of follow-up was also significantly higher in the CA groups: WMD 1.51 for change in PCS and 1.49 for change in MCS. All eight SF-36 subscale scores improved for patients receiving CA, whereas patients receiving AADs recorded no improvement in the general health and bodily pain subscales. At the end of follow-up, CA groups had significantly higher scores than AAD groups in the following subscales: physical functioning, role limitations due to physical health problems, bodily pain, general health, vitality, and role limitations due to emotional problems.

CONCLUSIONS

In the treatment of AF, CA appeared to be superior to AADs, decreasing the risk of all-cause death and cardiovascular hospitalization and improving the long-term QoL of patients with AF. CA was better tolerated and more effective than pharmacological therapy and allowed for improved QoL.

Pulmonary Vein Isolation With Ablation Index via Single Transseptal Crossing: Critical Role of Carina Isolation

AIM

Reconnection of the pulmonary veins (PVs) is the most common reason for the recurrence of atrial fibrillation (AF). The ablation index is a marker of ablation lesion quality that achieves high percentages of first-pass isolation and improved AF ablation results. Most operators use a double transseptal approach with confirmation of PV isolation with a circular mapping catheter. In the present study we aimed to show that an ablation index-guided procedure using a single transseptal approach and ablation catheter only would achieve adequate PV isolation while demonstrating the critical role of the carina in PV isolation.

METHOD

Sixty-six (66) consecutive patients with paroxysmal AF were included. Thirty-four (34) patients underwent wide antral circumferential ablation (WACA-only) and 32 underwent WACA+ (WACA + empiric carina isolation). All procedures were performed via single transseptal approach. Pulmonary vein isolation was confirmed with the use of a circular mapping catheter in both groups.

RESULTS

Compared to WACA-only, WACA+ increased the odds of PV isolation from 65% to 94% (p=0.011). In the WACA-only procedure, ablation of the carina was needed to achieve PV isolation. At the 18-month follow-up (interquartile range 15.2-20.8 months), freedom from AF was 84% for the entire cohort.

CONCLUSIONS

Our study confirmed the high success rate of PV isolation using the ablation index and showed that this can be achieved via a single transseptal crossing. Our study confirmed the role of the carina in PV isolation.

The RACE to the EAST. In pursuit of rhythm control therapy for atrial fibrillation-a dedication to Harry Crijns

The RACE trial was one of the first landmark trials to establish whether restoring and maintaining sinus rhythm could reduce morbidity and mortality in patients with atrial fibrillation (AF). Its neutral outcome shaped clinical decision-making for almost 20 years. However, there were two important treatment-related factors associated with mortality of rhythm control therapy at that time: One was safety of antiarrhythmic drug therapy, and the other one withdrawal of anticoagulation after restoration of sinus rhythm. Both concerns have been overcome, and, moreover, important knowledge considering the importance of time for the treatment of AF has been gained. These insights led to the concept of the EAST-AFNET 4 trial, and after more than two decades in the pursuit of ongoing therapeutic improvement, early rhythm control therapy has demonstrated to reduce a composite of cardiovascular death, stroke, and hospitalization for worsening of HF or acute coronary syndrome, by 21% (first primary outcome, absolute reduction 1.1 per 100 patient-years). For this entire period, Harry Crijns characterized the treatment of AF patients, and contributed decisively to realizing the benefit of rhythm control therapy. It is almost easier to list the clinical trials without Harry's involvement than to list those which he co-designed and led.

Inducibility of atrial fibrillation after catheter ablation predicts recurrences of atrial fibrillation: a meta-analysis

BACKGROUND

Pulmonary vein isolation (PVI) is a component of standard care for patients with symptomatic atrial fibrillation (AF). Procedural inducibility of AF following PVI has been suggested as predictor of AF recurrence but is discussed controversially. This meta-analysis aimed at evaluating the relevance of electrophysiological inducibility of AF following PVI for future AF recurrences.

METHODS

A literature search of MEDLINE and Web of Science was performed until April 2020. Prospective trials of PVI in patients with AF and post-procedural atrial stimulation to test for inducibility of AF as well as adequate follow-up for AF recurrence (defined as AF >10 s to >10 min at follow-up) were included. Odds ratios (ORs) were analyzed using random-effects models.

RESULTS

A total of 11 trials with 1544 patients (follow-up 7-39 months, age 56 ± 6 years, predominantly male 74 ± 6%) were included. Inducibility of AF post-PVI was predictive for AF recurrence during follow-up (OR 2.08; 95% CI 1.25 to 3.46). Prediction for AF recurrence at follow-up was better for patients with paroxysmal AF (OR 4.06; 95% CI 1.39 to 11.91), stimulation in the CS (OR 2.82, 95% CI 1.17 to 6.79). A trend towards higher ORs was seen without the use of isoproterenol (OR 2.43; 95% CI 1.17 to 5.07), as well as few stimulations during induction and a short definition of AF in meta-regression analyses.

CONCLUSIONS

Electrophysiological inducibility of AF following PVI was predictive for future recurrence of AF, in particular in patients with paroxysmal AF, stimulation in only CS and no use of isoproterenol.

The whole term efficacy of different treatments in paroxysmal atrial fibrillation in aging: a meta-analysis of randomized controlled trials

Antiarrhythmic drug therapy (ADT) and catheter ablation (CA) are the main treatments for paroxysmal atrial fibrillation. However, the short- and long-term clinical efficacy of these treatments remains controversial. Our goal is to investigate efficacy and safety of the standardized treatment of elderly patients with paroxysmal atrial fibrillation (PAF). Eight randomized controlled trials on CA and ADT for treating PAF were included. Totally, 1336 patients were included. Studies on CA and ADT for treating PAF that were published between January 2005 and June 2020 in the Cochrane Library, PubMed and EMBASE were screened and identified. Atrial fibrillation-free rates and Short Form (SF-36) health score-related indexes were analyzed. Atrial fibrillation-free rates were similar in the CA and ADT groups [risk ratio (RR) 1.32; 95% confidence interval (CI) 0.96-1.82; P = 0.08] at 3 months. The CA group had a significantly higher atrial fibrillation-free rate at 6 months (RR 1.87; 95% CI 1.38-2.53; P < 0.001), 9 months (RR 2.38; 95% CI 1.43-3.96; P < 0.001), and 12 months (RR 2.21; 95% CI 1.28-3.84; P=0.005). However, there was no significant difference in terms of long-term efficacy at 24 months (RR 1.81; 95% CI 0.97-3.36; P = 0.06). The 12-month QOL physical and mental components (RR 2.41; 95% CI 0.89-3.93; P = 0.002) were significantly higher in CA group. The CA is more effective than ADT in the short-term prognosis. But the long-term prognosis of PAF needs to be verified via randomized controlled trials with longer follow-up durations.

The 4S-AF Scheme (Stroke Risk; Symptoms; Severity of Burden; Substrate): A Novel Approach to In-Depth Characterization (Rather than Classification) of Atrial Fibrillation

Atrial fibrillation (AF) is a complex condition requiring holistic management with multiple treatment decisions about optimal thromboprophylaxis, symptom control (and prevention of AF progression), and identification and management of concomitant cardiovascular risk factors and comorbidity. Sometimes the information needed for treatment decisions is incomplete, as available classifications of AF mostly address a single domain of AF (or patient)-related characteristics. The most widely used classification of AF based on AF episode duration and temporal patterns (that is, the classification to first-diagnosed, paroxysmal, persistent/long-standing persistent, and permanent AF) has contributed to a better understanding of AF prevention and treatment but its limitations and the need for a multidimensional AF classification have been recognized as more complex treatment options became available. We propose a paradigm shift from classification toward a structured characterization of AF, addressing specific domains having treatment and prognostic implications to become a standard in clinical practice, thus aiming to streamline the assessment of AF patients at all health care levels facilitating communication among physicians, treatment decision-making, and optimal risk evaluation and management of AF patients. Specifically, we propose the 4S-AF structured pathophysiology-based characterization (rather than classification) scheme that includes four AF- and patient-related domains-Stroke risk, Symptoms, Severity of AF burden, and Substrate severity-and provide a hypothetical model for the use of 4S-AF characterization scheme to aid treatment decision making concerning the management of patients with AF in clinical practice.

Redefining the Standard for Atrial Fibrillation: A Patient-centric Report

A roundtable discussion with three European clinical experts in AF and one expert patient diagnosed and treated for AF was conducted in London in October 2019. The panel discussed the implications of AF for patients, current patient pathways, what treatment outcomes were relevant for patients and how the recommendations for the management of AF may change in the future, based on the outcomes of recently published and on-going clinical trials. This article summarises the discussion, and draws upon wider sources to detail best practice and optimal patient treatment pathways.

What clinical trials of ablation for atrial fibrillation tell us - and what they do not

Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia in clinical practice. Radiofrequency and cryoballoon catheter ablation are therapeutic options in addition to antiarrhythmic drug therapy for the treatment of AF. Ablation is effective at reducing recurrent atrial arrhythmias and also in the reduction of AF burden. Besides arrhythmia control, improvement in quality of life and clinical outcomes are also desirable goals with AF treatment. Randomized clinical trials have evaluated ablation in several patient populations, including symptomatic patients as first-line or second-line therapy, asymptomatic patients, and patients with heart failure. These trials clarify the durability of ablation in arrhythmia control, clarify quality-of-life improvement, and identify patient populations in whom ablation may be expected to improve clinical outcomes. In this review, we summarize the major clinical trials involving ablation; discuss the strengths, weakness, and clinical implications of these trials; and highlight the knowledge gaps in our current understanding of AF ablation for future clinical studies.

Advanced fully integrated radiofrequency/optical-coherence-tomography irrigated catheter for atrial fibrillation ablation

The inability of current catheter ablation procedures to accurately monitor lesion formation limits their safety and efficacy. An advanced fully integrated radiofrequency (RF)/optical coherence tomography (OCT) ablation catheter is developed, which enables real-time monitoring during ablation. An OCT fiber array is especially designed, developed and integrated into an off-the-shelf irrigated RF ablation catheter. In-vitro experimental studies performed on poultry and ovine hearts demonstrate the ability of the integrated RF/OCT system to provide information on the quality and orientation of catheter/wall contact. Experimental results show that adipose tissue can be accurately identified from normal myocardial tissue with 94% accuracy and lesion formation is monitored with an overall accuracy of 93%. The ability to predict pop events is also demonstrated, with an accuracy of 86%.

Improvement in quality of life and cardiac function after catheter ablation for asymptomatic persistent atrial fibrillation

BACKGROUND

Catheter ablation (CA) for atrial fibrillation (AF) is widely performed. However, the indication for CA in patients with asymptomatic persistent AF is still controversial.

METHODS

Among 259 consecutive patients who were hospitalized for initial CA of AF, a total of 45 patients who had asymptomatic persistent AF were retrospectively analyzed. Quality of life (QOL) before and 1 year after CA was evaluated, and changes in the cardiac function over 5 years after CA were also examined. QOL was assessed using the AF QOL questionnaire (AFQLQ) developed by the Japanese Heart Rhythm Society. In addition, cardiac function was assessed by measuring the plasma B-type natriuretic peptide (BNP) level, left ventricular ejection fraction (LVEF), left atrial diameter (LAD) with transthoracic echocardiogram, and left atrial (LA) volume with computed tomography (CT).

RESULTS

The AFQLQ significantly improved after CA in terms of "symptom frequency" and "activity limits and mental anxiety." The plasma BNP level, LVEF, and LAD significantly improved in the first 3 months after the first CA, with no significant changes thereafter (from 149.0 pg/dL [95% confidence intervals {CI}, 114.5-183.5 pg/dL] to 49.8 pg/dL [95% CI, 26.5-70.1], P < .0001; from 60.8% [95% CI, 58.1%-63.6%] to 65.0% [95% CI, 62.6-67.4], P = .001; and from 41.3 mm [95% CI, 39.7-42.9] to 36.8 [95% CI, 34.5-39.1 mm], P < .0001, respectively). LA volume revealed LA reverse remodeling after CA.

CONCLUSION

Improvement in the QOL and cardiac function after CA of asymptomatic persistent AF was revealed. Asymptomatic persistent AF should be appropriately treated by CA.

Anesthetic Choice for Atrial Fibrillation Ablation: A National Anesthesia Clinical Outcomes Registry Analysis

OBJECTIVE

The authors evaluated the type of anesthesia administered in atrial fibrillation ablation, hypothesizing that monitored anesthesia care is used less frequently than general anesthesia.

DESIGN

A retrospective study.

SETTING

National Anesthesia Clinical Outcomes Registry data, which are multi-institutional from across the United States.

PARTICIPANTS

Adult patients who underwent elective atrial fibrillation ablation between 2013 and 2018.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

National Anesthesia Clinical Outcomes Registry data were evaluated, and covariates were selected a priori within multivariate models to assess for predictors of anesthetic type. A total of 54,321 patients underwent atrial fibrillation ablation; 3,251 (6.0%) received monitored anesthesia care. Patients who received monitored anesthesia care were more likely to be >80 years old (12.4% v 4.9%; p < 0.0001), female (36.1% v 34.3%; p < 0.0001), have American Society of Anesthesiologists physical status >III (17.28% v 10.48%; p < 0.0001), and reside in urban areas (62.23% v 53.37%; p < 0.0001). They received care in the Northeast (17.6% v 10.1%; p < 0.0001) at low-volume centers (median 224 v 284 procedures; p < 0.0001). Multivariate analysis revealed that each five-year increase in age, being female, and having an American Society of Anesthesiologists physical status >III resulted in a 7% (p < 0.0001), 9% (p = 0.032), and 200% (p < 0.0001) increased odds of receiving monitored anesthesia care, respectively. Requiring additional ablation of atria or of a second arrhythmia and residing outside the Northeast resulted in a decreased odds of monitored anesthesia care (adjusted odds ratio 0.24 [p=0.002] and < 0.5 [p < 0.03], respectively). For each 50 cases performed annually at a center, the odds decreased by 5% (p = 0.005).

CONCLUSIONS

General anesthesia is the most common type of anesthesia administered for atrial fibrillation ablation. The type of anesthesia administered, however, varies with patient, procedural, and hospital characteristics.

Prospective Randomized Evaluation of High Power During CLOSE-Guided Pulmonary Vein Isolation: The POWER-AF Study

BACKGROUND

CLOSE-guided atrial fibrillation (AF) ablation is based on contiguous (intertag distance ≤6 mm), optimized (Ablation Index >550 anteriorly and >400 posteriorly) point-by-point radiofrequency lesions. The optimal radiofrequency power remains unknown.

METHODS

The POWER-AF study is a prospective, randomized controlled monocentric study including patients with paroxysmal AF, planned for first CLOSE-guided pulmonary vein isolation using a contact force radiofrequency catheter (Thermocool SmartTouch, Biosense Webster, Inc, Irvine, CA). A total of 100 patients were randomized into 2 groups (1:1). The control group received AF ablation using the standard CLOSE protocol (35 W), whereas in the experimental group, pulmonary vein isolation was performed using high power (45 W). Endoscopic evaluation was performed in patients with intraesophageal temperature rise >38.5 °C.

RESULTS

The resulting sample size was 96 (48+48) patients. In the high power group, shorter procedure time (80 versus 102 minutes, P<0.001), shorter total radiofrequency application time (16 versus 26 minutes, P<0.001), and radiofrequency time per application (26 versus 37 s anteriorly, P<0.001 and 13 versus 17 s posteriorly, P<0.001) were observed. Endoscopic evaluation (performed in 19/48 versus 25/48 patients respectively, P=0.31) showed an ulcerative perforation in a high power group patient (treated by endoscopic stenting and normalization after ≈4 months) and a superficial ulcerative lesion in a control group patient (conservative treatment). Both occurred following excessive Ablation Index applications (up to 460 and 480, respectively) with excessive contact force (30 g on average, with peaks up to 50 g). Six-months AF recurrence was not significantly different (10% in high power versus 8% in control, P=0.74).

CONCLUSIONS

This randomized controlled study shows that a 45 W radiofrequency power CLOSE protocol in patients with paroxysmal AF significantly increases the global procedural efficiency with similar midterm efficacy. However, our study showed a narrower safety margin and a limited increased efficiency at the posterior wall using high power. This advocates against the use of high power in the region neighboring the esophagus.

A novel and simple scoring system for assessing the indication for catheter ablation in patients with atrial fibrillation: The HEAL-AF Score

INTRODUCTION

A scoring system to determine indications for catheter ablation (CA) in atrial fibrillation (AF) is desired.

METHODS AND RESULTS

Among 2898 consecutive patients with AF, CA was performed in 938 (32.4%). A new HEAL-AF score has been developed by six variables, all of which were independently associated with CA by multivariate analysis and for each 1 point was assigned: heart failure ≥ NYHA II, elderly patients (age ≥75 years), asymptomatic AF, long-standing persistent AF, atrial dilation (left atrial diameter ≥ 50 mm), and female sex. Low HEAL-AF score was associated with high incidence of CA performance (52.0% for 0, 36.5% for 1, 15.1% for 2, and 5.6% for ≥ 3) and the predictive capability of this score by AUC of ROC curve was 0.720 (95% CI 0.701-0.739, P < .001). The rates of freedom from AF/AT recurrence were 73.2% in HEAL-AF score 0, 71.0% in 1, 60.0% in 2, and 50.0% in ≥ 3 (log-rank test, P = .004). HEAL-AF score 2 and ≥ 3 were significantly associated with recurrence of atrial tachyarrhythmia as compared with HEAL-AF 0 (HR 1.755, P = .002, and HR 2.211, P = .007, respectively).

CONCLUSIONS

A new HEAL-AF score was associated with patient indication for and the recurrence of atrial tachyarrhythmia after CA in patients with AF. Prescription of CA should be considered carefully in AF patients with HEAL-AF score of 2 and ≥ 3.

Keeping it Simple: Balloon Devices for Atrial Fibrillation Ablation Therapy

Atrial fibrillation is a common disease of increasing prevalence. Catheter ablation has evolved into an established therapeutic option that mainly aims to electrically isolate the pulmonary veins from atrial myocardium. The traditional method comprises point-by-point radiofrequency current ablation guided by electroanatomical mapping and has proven to be effective and safe in experienced hands. However, this approach is technically highly demanding and associated with a long learning curve, limiting its widespread utilization. To address these shortcomings, simplified ablation tools for pulmonary vein isolation are needed. In this context, balloon devices promise to ease the procedure by approaching the entire orifice of a targeted pulmonary vein in a single maneuver. This requires less catheter manipulation in the left atrium and often allows ablation of a large volume of tissue with a single application of ablative energy. Two balloon devices-one using cryoenergy, the other laser energy-have already been established in clinical routine and have demonstrated noninferiority when compared with radiofrequency ablation in large randomized trials. More balloon devices are on the verge of being introduced into clinical practice and bear the potential to expand the interventional electrophysiologist's armamentarium when treating atrial fibrillation. The authors review the use of the established balloon devices available for atrial fibrillation ablation and provide a detailed outlook on upcoming balloon technologies, including 3 different balloons utilizing radiofrequency energy as well as a novel cryoballoon.

Advances in the management of atrial fibrillation with a special focus on non-pharmacological approaches to prevent thromboembolism: a review of current recommendations

Atrial fibrillation (AFIB) is the most common heart rhythm abnormality and is associated with significant morbidity and mortality. While the treatment of AFIB involves strategies of rate with or without rhythm control, it is also essential to strategize appropriate therapies to prevent thromboembolic complications arising from AFIB. Previously, anticoagulation was the main treatment option which exposed patients to higher than usual risk of bleeding. However, with the advent of new technology, novel therapeutic options aimed at surgical or percutaneous exclusion or occlusion of the left atrial appendage in preventing thromboembolic complications from AFIB have evolved. This review evaluates recent advances and therapeutic options in treating AFIB with a special focus on both surgical and percutaneous interventions which can reduce and/or eliminate thromboembolic complications of AFIB.

Magnetic Resonance Imaging-Guided Fibrosis Ablation for the Treatment of Atrial Fibrillation

Background:

Myocardial fibrosis is key for atrial fibrillation maintenance. We aimed to test the efficacy of ablating cardiac magnetic resonance (CMR)-detected atrial fibrosis plus pulmonary vein isolation (PVI).

Methods:

This was an open-label, parallel-group, randomized, controlled trial. Patients with symptomatic drug-refractory atrial fibrillation (paroxysmal and persistent) undergoing first or repeat ablation were randomized in a 1:1 basis to receive PVI plus CMR-guided fibrosis ablation (CMR group) or PVI alone (PVI-alone group). The primary end point was the rate of recurrence (>30 seconds) at 12 months of follow-up using a 12-lead ECG and Holter monitoring at 3, 6, and 12 months. The analysis was conducted by intention-to-treat.

Results:

In total, 155 patients (71% male, age 59±10, CHA 2 DS 2 -VASc 1.3±1.1, 54% paroxysmal atrial fibrillation) were allocated to the PVI-alone group (N=76) or CMR group (N=79). First ablation was performed in 80% and 71% of patients in the PVI-alone and CMR groups, respectively. The mean atrial fibrosis burden was 12% (only ≈50% of patients had fibrosis outside the pulmonary vein area). One hundred percent and 99% of patients received the assigned intervention in the PVI-alone and CMR group, respectively. The primary outcome was achieved in 21 patients (27.6%) in the PVI-alone group and 22 patients (27.8%) in the CMR group (odds ratio: 1.01 [95% CI, 0.50–2.04]; P =0.976). There were no differences in the rate of adverse events (3 in the CMR group and 2 in the PVI-alone group; P =0.68).

Conclusions:

A pragmatic ablation approach targeting CMR-detected atrial fibrosis plus PVI was not more effective than PVI alone in an unselected population undergoing atrial fibrillation ablation with low fibrosis burden.

Registration:

URL: https://www.clinicaltrials.gov . Unique identifier: NCT02698631.

Atrial fibrillation ablation success defined by duration of recurrence on cardiac implantable electronic devices

INTRODUCTION

Ablation for atrial fibrillation (AF) has emerged as an effective method of rhythm control. This exploratory analysis aimed to determine how various measures of recurrence would influence the definition of treatment success.

METHODS

Using an electronic health record data set from January 2007 to June 2019 linked with Medtronic cardiac implantable electronic device (CIED) data, patients who underwent a first AF ablation procedure following CIED implantation were identified. Data were analyzed for recurrence of AF stratified by varying definitions of successful ablation. The performance of various simulated external AF monitoring strategies was assessed.

RESULTS

A total of 665 patients were analyzed including 248 with paroxysmal AF (mean age: 66.2 ± 9.3 years, 73.0% male) and 417 patients with persistent AF (mean age: 67.3 ± 9.0 years, 73.6% male). Among patients with paroxysmal AF, survival free from recurrence at 1 year ranged from 28.2% to 72.1% (>6 min and >23 h thresholds, respectively) with an overall median percentage of time in AF reduction of 99.6%. Among patients with persistent AF, survival free from recurrence at 1 year ranged from 24.9% to 60.0% (>6 min and 7 consecutive days > 23 h thresholds, respectively) with an overall median percentage of time in AF reduction of 99.3%. A single 7-day monitoring strategy had a sensitivity of less than 50% for detecting AF greater than 6 min in patients with paroxysmal and persistent AF.

CONCLUSION

In this real-world data set of AF patients with CIEDs undergoing catheter ablation, treatment success varied substantially with different definitions of minimally required AF duration and is significantly impacted by the method of recurrence detection.

Catheter ablation for atrial fibrillation: current indications and evolving technologies

Catheter ablation for atrial fibrillation (AF) has emerged as an important rhythm-control strategy and is by far the most common cardiac ablation procedure performed worldwide. Current guidelines recommend the procedure in symptomatic patients with paroxysmal or persistent AF who are refractory or intolerant to antiarrhythmic drugs. The procedure might also be considered as a first-line approach in selected asymptomatic patients. Data from large registries indicate that AF ablation might reduce mortality and the risk of heart failure and stroke, but evidence from randomized controlled trials is mixed. Pulmonary vein isolation using point-by-point radiofrequency or with the cryoballoon remains the cornerstone technique in AF ablation. Additional atrial ablation can be performed in patients with persistent AF, but its benefits are largely unproven. Technological advances in the past decade have focused on achieving durable vein isolation, reducing procedure duration and improving safety. Numerous exciting new technologies are in various stages of development. In this Review, we discuss the relevant data to support the recommended and evolving indications for catheter ablation of AF, describe the different ablation techniques, and highlight the latest advances in technology that aim to improve its safety and efficacy. We also discuss lifestyle modification strategies to improve ablation outcomes.

Assessing myocardial circumferential strain using cardiovascular magnetic resonance after magnetic resonance-conditional cardiac resynchronization therapy

Nondrug therapy for arrhythmia patients had been developed dramatically until recent years. Cardiac resynchronization therapy (CRT), a nondrug therapy for arrhythmia, is especially utilized for the treatment of left ventricular (LV) severe heart failure caused by cardiac dyssynchrony. Prolonged QRS duration (≧130 ms) is strongly used as a CRT indication criterion, but QRS is not the direct clinical index of mechanical contraction delay of the LV myocardium. Therefore, identifying the presence of dyssynchrony by diagnostic imaging is necessary. Echocardiography is widely used for the assessment of dyssynchrony as a standard diagnostic imaging. Several studies have addressed the efficacy of cardiovascular magnetic resonance feature tracking (CMR-FT) in the diagnosis of dyssynchrony for arrythmia patients. In addition, cardiac implantable electronic devices (CIEDs) were not available to examine CMR until recent years; however, new MR-conditional CIEDs have become available for use before and after CRT. Recently, diagnostic imaging using CMR-FT has been attracting attention for the assessment of dyssynchrony. However, a strong metal artifact caused by CIEDs may make the analysis difficult after CRT implantation. Strain analysis using short-axis (SA) cine CMR overcame this issue of artifact by enabling slice selection by avoiding artifact. Moreover, circumferential strain has superiority over other strain methods with respect to sensitivity, and we focused on these advantages. This case illustrates that circumferential strain with CMR-FT using SA cine CMR is useful in the assessment of improvement of myocardial motion after CRT and can provide useful additional information with imaging to determine the responders of CRT.

Regional differences in the effects of the ablation index and interlesion distance on acute electrical reconnections after pulmonary vein isolation

BACKGROUND

In pulmonary vein isolation, the regional differences in the ablation index (AI) and interlesion distance (ILD) remain unclear. This study aimed to evaluate the association between the AI, ILD, and other relevant indices with pulmonary vein reconnections (PVRs) during the surgical intervention with a focus on the heterogeneous regional variability through a retrospective analysis.

METHODS

We divided the wide area circumferential ablation (WACA) region into 12 segments in 32 consecutive patients, which resulted in a 384 segment analysis to evaluate the association of the minimum AI (AI min) and maximum ILD (ILD max) with acute PVRs, which were defined as spontaneous PVRs or dormant conduction after adenosine triphosphate administration.

RESULTS

Acute PVRs were observed in 48 (13%) segments and 40 (63%) WACA regions. The AI min was significantly lower and ILD max greater in segments with PVRs than in those without (372 vs 403 au and 6.5 vs 5.7 mm, respectively). PVRs were more frequent in the left posterior segments, adjacent to the esophagus, than in other segments (23% vs 10%, respectively). Notably, ILD max was significantly greater in the left posterior segments with acute PVRs with AI min < 297 (median; 6.5 vs 5.1 mm); a similar finding was not observed when with AI min ≥ 297.

CONCLUSION

Smaller ILD may prevent acute PVRs when the AI min is low in the left posterior segments.

Early recurrence after pulmonary vein isolation is associated with inferior long-term outcomes: Insights from a retrospective cohort study

AIMS

The aim of this retrospective cohort study was to assess the influence of early recurrence (ER) after pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (AF) on long-term outcomes and to identify clinical variables associated with ER.

METHODS

We retrospectively collected clinical and procedural data from 1285 patients with paroxysmal AF who underwent PVI from 2011 to 2016. Kaplan-Meier, receiver operating characteristic (ROC) curve, logistic and Cox regression analyses were performed to analyze the influence of ER on long-term outcomes.

RESULTS

ER was observed in 13% of patients. Kaplan-Meier analyses showed significantly different outcomes in 1285 patients with and without ER (49% vs 74%, log rank P < .01) and in 286 patients in the subgroup that underwent reablation (44% vs 79%, log rank P < .01). The hazard ratio (HR) of ER was 1.7 within 48 hours (5% of patients), 2.7 within 1 month (5%), 3.0 within 2 months (2%), and 6.4 within 3 months (1%) for late recurrence (LR), P < .01. ROC analysis (area under the curve [AUC] = 0.79) resulted in 70.3% sensitivity and 74.2% specificity for a 14-day blanking period, and 53.1% sensitivity and 85.5% specificity for a 30-day blanking period. Female patients (odds ratio [OR] 1.69, P < .01) and those with diabetes (OR 1.95, P = .01) were at higher risk for ER.

CONCLUSIONS

ER is observed in a substantial number of patients with paroxysmal AF after PVI and has a continuous direct effect on LR according to the timing of ER. Randomized trials are required to assess the safety and effects of reablations in a shortened blanking period on long-term outcomes.

Impact of the Temporal Relationship Between Atrial Fibrillation and Heart Failure on Prognosis After Ablation

BACKGROUND

The purpose of this study was to elucidate the effect of the temporal relationship between atrial fibrillation (AF) and heart failure (HF) on clinical outcomes after catheter ablation.Methods and Results:We included 129 consecutive patients with AF and HF who underwent catheter ablation in hospital from December 2014 to September 2017. The patients were divided into 2 groups based on the temporal relationship between AF and HF. Group 1 consisted of 42 patients with AF following HF while Group 2 consisted of 87 patients with AF preceding HF or those who developed both of them simultaneously at the timing of first visit to a doctor. The primary endpoint was a composite of death and hospitalization due to HF during a 2-year follow-up. AF recurrence was more common in Group 1 (45% vs. 23%; hazard ratio [HR], 2.49; 95% confidence interval [CI], 1.25-4.94; P=0.009). Death and HF hospitalization were more frequent in Group 1 (19 [45%], 6 [7%] patients, respectively, P<0.0001). After adjustment for several covariates, patients in Group 1 were independently associated with poorer outcomes after AF ablation (HR, 8.66; 95% CI, 2.942-5.5; P<0.0001).

CONCLUSIONS

Adverse clinical outcomes of death, HF hospitalization and AF recurrence were more frequent in patients with AF following HF than in those with AF preceding HF.

Does Catheter Ablation Lower the Long-Term Risk of Stroke and Mortality in Patients with Atrial Fibrillation? A Concise Review of the Current State of Knowledge

Atrial fibrillation (AF) is the most common cardiac arrhythmia worldwide and carries a significant risk of morbidity and mortality. Multiple trials have highlighted the benefit of catheter ablation over medical therapy in restoring sinus rhythm and improving quality of life. Whether it reduces long-term risk of stroke and mortality is still unclear.

We performed a literature search using the PubMed database to review the current state of knowledge regarding the long-term outcomes of stroke and mortality in ablated patients compared to patients who receive medical therapy. Our review mainly consisted of recent randomized controlled trials and large observational studies. 

Results from large observational studies show that catheter ablation significantly reduces the risk of stroke in high-risk patients and mortality compared to medical therapy. However, randomized controlled trials have only demonstrated a mortality benefit in patients with comorbid systolic heart failure. In patients with paroxysmal AF, ablation therapy significantly limits the progression to persistent AF and has a higher efficacy in restoring sinus rhythm. Maintenance of sinus rhythm is the most important factor associated with lower long term risk of stroke and mortality.

Large randomized controlled trials similar to the Catheter Ablation Versus Anti-arrhythmic Drug Therapy for Atrial Fibrillation (CABANA) trial are still needed to clarify whether catheter ablation is superior over medical therapy in improving the long-term outcomes of stroke and mortality.

Physical activity and atrial tachyarrhythmia recurrence in atrial fibrillation patients after catheter ablation

BACKGROUND

The association between physical activity (PA) and atrial tachyarrhythmia (AT) recurrence after ablation for atrial fibrillation (AF) remains unclear.

METHODS

We consecutively enrolled 496 patients treated with AF ablation therapy in Beijing Anzhen Hospital. After excluding six patients with valvular heart disease, seven patients with congenital heart disease, 33 patients lost to follow-up, and 14 patients who did not provide PA level during follow-ups, 436 patients had their PA level assessed by the International Physical Activity Questionnaire-Short Form before ablation and each time of follow-up. The association between PA level (measured at the time closest to AT recurrence, or the end of 12-month follow-up if no AT recurrence), as well as active PA during follow-up, and postablation AT recurrence was tested by multivariate logistic regression.

RESULTS

Of the enrolled patients, 134 (30.7%) patients experienced AT recurrence in the first 12 months postablation. Compared to patients with low PA, patients with moderate or high PA had a lower risk of AT recurrence (odds ratio [OR] = .44; 95% confidence interval [CI], .25-.80; P = .01 for patients with moderate PA; and OR = .43 [95% CI, .21-.85], P = .02 for patients with high PA). Compared to patients without active PA, patients with active PA had a lower risk of AT recurrence (OR = .44 [95% CI, .27-.70], P < .01).

CONCLUSIONS

Moderate and high PA are associated with a lower risk of AT recurrence after AF ablation. Active PA during follow-up is also associated with a significantly lower risk of AT recurrence in the postablation AF population.

Emerging Technologies for Pulmonary Vein Isolation

Atrial fibrillation is the most common sustained cardiac arrhythmia and is associated with considerable morbidity and mortality. Electrically isolating the pulmonary veins from the left atrium by catheter ablation is superior to antiarrhythmic drug therapy for maintaining sinus rhythm, but its success varies depending on multiple factors, including arrhythmic burden. Although procedural outcomes have improved over the years, further gains are limited by a seemingly zero-sum relationship between effectiveness and safety, which is largely a product of the available technologies. Current energies used to create contiguous, transmural, and durable atrial lesions can result in serious complications if they reach the esophagus or phrenic nerve, for instance—structures that can be adjacent to the atrial myocardium, often within millimeters of the energy source. Consequently, high rates of pulmonary vein-left atrium reconnections are consistently seen in clinical studies and in clinical practice as operators appropriately forgo ablation effectiveness to protect patients from harm. However, as ablative technologies evolve to circumvent this stalemate, safer, and more effective pulmonary vein isolation seems increasingly realistic. Furthermore, the innovative nature of these technologies raises the prospect of markedly improved procedural efficiency, which could increase patient comfort, reduce operator occupational injuries, and enhance the use of health resources—all of which are increasingly important considerations particularly as the demand for catheter ablation for atrial fibrillation continues to rise. We herein review 3 promising candidate ablation technologies with the potential to revolutionize the management of patients with atrial fibrillation: electroporation (pulsed-field ablation), expandable lattice-tip radiofrequency ablation/electroporation, and ultra-low temperature cryoablation.

The Cryoballoon vs Irrigated Radiofrequency Catheter Ablation (CIRCA-DOSE) Study Results in Context

The Cryoballoon vs Irrigated Radiofrequency Catheter Ablation: Double Short vs Standard Exposure Duration (CIRCA-DOSE) study was a multicentre, randomised, single-blinded trial that compared contact-force radiofrequency ablation and two different regimens of cryoballoon ablation. All patients received an implantable cardiac monitor for the purpose of continuous rhythm monitoring, with all arrhythmia events undergoing independent adjudication by a committee blinded to treatment allocation. The study demonstrated there were no significant differences between contact-force radiofrequency ablation and cryoballoon ablation with respect to recurrence of any atrial tachyarrhythmia, symptomatic atrial tachyarrhythmia, asymptomatic AF, symptomatic AF or AF burden. While the results of the CIRCA-DOSE study are reviewed here, this article focuses on considerations around the design of the study and places the observed outcomes in context.

Meta-Analysis of Catheter Ablation versus Medical Therapy in Patients with Atrial Fibrillation Without Heart Failure

Introduction

Catheter ablation has shown to reduce mortality in patient with atrial fibrillation (AF) and heart failure (HF) with reduced ejection fraction. Its effect on mortality in patients without HF has not been well elucidated.

Methods

Thirteen randomized controlled trials encompassing 3856 patients were selected using PubMed, Embase and the CENTRAL till April 2019. Estimates were reported as random effects risk ratio (RR) with 95% confidence intervals (CI).

Results

Compared with medical therapy, catheter ablation did not reduce the risk of all-cause mortality (RR, 0.86, 95% CI, 0.62-1.19, P=0.36; I2=0), stroke (RR, 0.55, 95% CI, 0.18-1.66, P=0.29; I2=0), need for cardioversion (RR, 0.84, 95% CI, 0.66-1.08, P=0.17; I2=0) or pacemaker (RR, 0.59, 95% CI, 0.34-1.01, P=0.06; I2=0). However, ablation reduced the RR of cardiac hospitalization (0.37, 95% CI, 0.18-0.77, P=0.01; I2=86), and recurrent atrial arrhythmia (0.46, 95% CI, 0.35-0.60, P<0.001; I2=87). There were non-significant differences among treatment groups with respect to major bleeding (RR, 1.89, 95% CI, 0.59-6.08, P=0.29; I2=15), and pulmonary vein stenosis (RR, 3.00, 95% CI, 0.83-10.87, P=0.09; I2=0), but had significantly higher rates of pericardial tamponade (RR, 4.46, 95 % CI, 1.70-11.72, P<0.001; I2=0).

Conclusions

Catheter ablation did not improve survival compared with medical therapy in patients with AF without HF. Catheter ablation reduced cardiac hospitalization and recurrent atrial arrhythmia at the expense of pericardial tamponade.

Clinical outcomes of adjunctive posterior wall isolation in persistent atrial fibrillation: A meta-analysis

BACKGROUND

Pulmonary vein isolation (PVI) is the cornerstone of atrial fibrillation (AF) ablation but the recurrence rate remains relatively high in persistent patients with AF. Therefore, posterior wall isolation (PWI) in addition to PVI has been proposed to increase freedom from AF.

OBJECTIVE

To evaluate the success of adjunctive PWI in persistent AF.

METHODS

We searched electronic database using specific terms. The primary outcomes are recurrence rate of AF and recurrence of atrial arrhythmias. The secondary outcomes were atrial flutter/tachycardia (AFL/AT), procedure time, fluoroscopy time, and procedure related complications. Estimated risk ratios (RRs) and 95% confidence intervals (CIs) were evaluated.

RESULTS

Six studies were included (1334 patients with persistent AF). Adjunctive PWI resulted in a significant reduction in the recurrence rate of AF compared with patients who had PVI only (19.8% vs 29.1%; RR, 0.64; 95% CI, 0.42-0.97; P < .04; I²  = 76%). There was a significant reduction in the recurrence rate of all atrial arrhythmia (30.8% vs 41.1%; RR, 0.75; 95% CI, 0.60-0.94; P < .01; I²  = 60%). Compared with PVI only, adjunctive PWI did not increase the rate of AFL or AT (11.6% vs 13.9%; RR, 0.85; 95% CI, 0.54-1.32; P < .46; I²  = 47%) or the rate of procedure related complications (4.6% vs 3.6%; RR, 1.25; 95% CI, 0.72-2.17; P < .44; I²  = 0%).

CONCLUSION

In patients with persistent AF, adjunctive PWI was associated with decreased recurrence of AF and atrial arrhythmias compared with PVI alone without an increased risk of AFL or AT or procedure related complications.

Cryoballoon ablation for pulmonary vein isolation

Over the past 20 years, multiple studies have demonstrated the superiority of percutaneous catheter-based pulmonary vein isolation (PVI) in the management of atrial fibrillation (AF). Unfortunately, the results of catheter ablation can be limited by arrhythmia recurrence, which is often a result of a failure to achieve durable lesions around the pulmonary vein ostia. In response, significant efforts have been directed toward developing technologies to achieve safer and more durable PVI, including the development of dedicated catheters capable of achieving PVI with a single ablation lesion (eg, the Arctic Front Cryoballoon; Medtronic CryoCath, Pointe-Claire, Canada). The purpose of this review is to discuss the contemporary role of cryoballoon ablation in the invasive management of AF, with a focus on the characteristics that differentiate cryoballoon from radiofrequency ablation.

Health-Related Quality of Life in Patients With Atrial Fibrillation Treated With Catheter Ablation or Antiarrhythmic Drug Therapy: A Systematic Review and Meta-analysis

Background

Catheter ablation (CA) is performed in patients with atrial fibrillation (AF) to reduce symptoms and improve health-related quality of life (HRQL).

Methods

This systematic review and meta-analysis of randomized controlled trials (RCTs) evaluated CA of any energy modality compared with antiarrhythmic drugs (AADs) using inverse-variance random-effects models. We searched for RCTs reporting HRQL and AF-related symptoms at 3, 6, 12, 24, 48, and 60 months after treatment as well as the number of repeat ablations.

Results

Of 15,878 records, we included 13 RCTs of CA vs AADs for the analyses of HRQL, 7 RCTs for the analyses of AF-related symptoms, and 13 RCTs for the number of repeat ablations. For the HRQL analyses at 3 months, there were significant increases in both the Physical Component Summary score (3 months' standardized mean difference = 0.58 [0.39-0.78]; P < 0.00001, I ² = 6%, 3 trials, n = 443) and the Mental Component Summary score (3 months' standardized mean difference = 0.57 [0.37-0.77]; P < 0.00001, I ² = 0%, 3 trials, n = 443), favouring CA over AADs. These differences were sustained at 12 months but not >24 months after randomization. Similar results were seen for AF-related symptoms. The number of repeat ablations and success rates after procedure varied considerably across trials.

Conclusions

Evidence from few trials suggests that CA improves physical and mental health and AF-related symptoms in the short term, but these benefits decrease with time. More trials, reporting both HRQL and AF-related symptoms, at consistent time points are needed to assess the effectiveness of CA for the treatment of AF.

Positioning an ECG electrode to the dorsal side can record higher amplitude of CMAPs during cryoballoon ablation

PURPOSE

Phrenic nerve injury (PNI) is one of the important complications during cryoballoon (CB) ablation. Recording diaphragmatic compound motor action potentials (CMAPs) during CB ablation can predict PNI. CMAP monitoring may be inaccurate when CMAP amplitudes are low. We examined the effect of positioning an electrocardiography (ECG) electrode at the dorsal side.

METHODS

We retrospectively analyzed the cases of 197 consecutive patients who underwent CB ablation for pulmonary vein isolation (PVI) (April 2016 to December 2018) at our institution. CMAP amplitudes were monitored using two recording methods just before cryoapplication. (a) Conventional method: right-arm ECG electrode positioned 5 cm above the xiphoid on the ventral side; left-arm ECG electrode positioned along the costal margin. (b) Our original method: right-arm electrode positioned 5 cm above the xiphoid on the dorsal side; left-arm electrode positioned along the costal margin.

RESULTS

The CMAP amplitude during right phrenic nerve pacing was significantly higher at the dorsal side than the ventral side (0.80 ± 0.31 mV vs 0.66 ± 0.29 mV, P < .01). Similarly, the CMAP amplitude during left phrenic nerve pacing was significantly higher at the dorsal side than the ventral side (0.92 ± 0.39 mV, 0.73 ± 0.37 mV, P < .01). PNI occurred in six patients (3.0%); three patients experienced transient PNI, another three patients experienced persistent PNI, and none developed permanent PNI.

CONCLUSIONS

CMAP amplitudes were significantly high at the dorsal side compared to the ventral side. Monitoring phrenic nerve function using an ECG electrode at the dorsal side is a simple and easy procedure.

Opposite effect of ablation on early/late-phase thromboembolic incidence in patients with atrial fibrillation: A meta-analysis on more than 100 000 individuals

Background

Atrial fibrillation (AF) is an important risk factor for thromboembolic events, for which catheter ablation represents an effective therapy for rhythm control. Intuitively, ablation may reduce the incidence of thromboembolism, but data is quite limited.

Hypothesis

Catheter ablation was associated with the fewer risk of thromboembolism compared with nonablation in patients with AF.

Methods

A systematic search was performed in PubMed, EMBASE, the Web of Science, and the Cochrane Library from inception to September 2019. Random‐effects model was used to estimate the risk ratios (RR) for the thromboembolic events between the ablation and nonablation groups.

Results

Twenty‐five studies (12 randomized controlled trials and 13 observational studies) with 104 687 participants were included. Pooled analysis suggested that ablation was associated with a 35% lower risk of total thromboembolic events compared to nonablation group (RR = 0.65; 95% CI, 0.51‐0.82; P = .0003). When separated into early‐phase (<30 days) and late‐phase (>30 days) events, ablation was associated with an increased early‐phase thromboembolism (RR = 1.96; 95% CI, 1.35‐2.83; P = .0004) but a decreased late‐phase thromboembolism (RR = 0.75; 95% CI, 0.63‐0.90; P = .002). Subgroup analysis according to different study types found similar results were found in observation studies, but not in RCT studies because the sample size was too small to be conclusive.

Conclusions

In patients with AF, catheter ablation was associated with a fewer risk of overall and late‐phase thromboembolism in comparison with nonablation. However, over the early postoperative period, catheter ablation was associated with the double higher risk of thromboembolic events.

Impact of atrial fibrillation catheter ablation on mortality, stroke, and heart failure hospitalizations: A meta-analysis

BACKGROUND

The impact of atrial fibrillation catheter ablation (AFCA) on hard clinical endpoints remains controversial.

OBJECTIVE

Our aim was to conduct a random-effect model meta-analysis on efficacy data from high-quality large matched database/registry studies and randomized clinical trials. We compared long-term all-cause mortality, stroke, and hospitalization for heart failure in patients undergoing AFCA vs patients treated with medical therapy alone (rhythm and/or rate control medications) in a general AF population.

METHODS AND RESULTS

PubMed/MEDLINE and Embase databases were screened and a total of nine studies were selected (one randomized clinical trial-CABANA-and eight large matched population studies). A total of 241 372 patients (27 711 in the ablation group, 213 661 in the nonablation group) were included. After a median follow-up of 3.5 years, AFCA decreased the risk of mortality (hazard ratio [HR], 0.62; 95% confidence interval [CI], 0.54-0.72; I² = 54%; number needed to treat [NNT] = 28), stroke (HR, 0.63; 95% CI, 0.56-0.70; I²  = 23%; NNT = 59) and hospitalization for heart failure (HR, 0.64; 95% CI, 0.51-0.80; I²  = 28%; NNT = 33) compared with AF patients treated with medical therapy alone.

CONCLUSION

Based on the currently available efficacy and effectiveness evidence, AFCA significantly reduces the risk of death, stroke, and hospitalization compared with medical therapy alone.

Investigation of proper home blood pressure with atrial fibrillation recurrence in patients undergoing radiofrequency catheter ablation

BACKGROUND

Hypertension is an important target for interventions to improve ablation outcome in atrial fibrillation (AF) patients. No studies to date have determined the blood pressure level at which AF is less likely to recur in patients without hypertension.

METHODS

A total of 503 AF patients undergoing radiofrequency catheter ablation (RFCA) (mean age, 59.6±9.6 years; 319 males [63.4%]) were identified for the study cohort and analysis. Patients received a pocket diary to record their home blood pressure (HBP) before RFCA and routine 48-hour Holter-ECGs to evaluate AF recurrence after RFCA.

RESULTS

A total of 383 (76.1%) patients were free of AF recurrence one year after RFCA. Blood pressure (BP), including systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and pulse pressure (PP), had different effects on AF recurrence one year after RFCA. A χ2 test showed that when SBP was <110 mmHg, it was associated with a lower AF recurrence in patients with hypertension (P=0.029). AF recurrence decreased (P=0.002) when SBP increased from <110 mmHg to >130 mmHg in patients without hypertension. Regression analysis indicated a significant linear correlation between BP and LAD in all patients.

CONCLUSIONS

SBP should be strictly maintained at 110 mmHg after RFCA to minimize AF recurrence in patients with hypertension. Low SBP might be a risk factor for AF recurrence among patients without hypertension.

Intermediate term outcome after electrogram guided segmental ostial pulmonary vein isolation using an 8 mm tip catheter for paroxysmal atrial fibrillation

Introduction

Pulmonary vein isolation (PVI) is the most widely used procedure for ablation in patients with paroxysmal atrial fibrillation (AF). Not withstanding recent advancements in this field, including sophisticated three-dimensional (3D) based imaging and advanced ablation catheters with contact force technology, many patients and healthcare systems in developing countries will not afford such an expensive therapeutic procedure. There are no data from India analyzing the efficacy of PVI for PAF using conventional mapping and ablation. In this article, we have summarized the intermediate term outcome following PVI in patients with PAF using electrogram-based mapping and a 8 mm tip ablation catheter.

Method

A total of 42 consecutive patients who underwent PVI for symptomatic PAF not controlled with at least one antiarrhythmic drug were studied in a tertiary care institute from March 2011 to June 2018. Patients with rheumatic AF were excluded. The pulmonary vein (PV) anatomy was assessed by pulmonary angiography during the ablation procedure. Using conventional electrophysiologic mapping, a variable curve Lasso catheter placed in the PVs was used to guide the earliest site of breakthrough. The segmental ostial PVI was performed using a 8 mm tip radiofrequency (RF) ablation catheter. Elimination of all PV ostial potentials and complete entrance block into the PV were considered indicative of complete electrical isolation. Follow-up visits were scheduled at one, three, and six months after the procedure, and every six months thereafter. History, symptom review, clinical examination, and 12-lead ECG were performed at each follow-up.

Results

At pre-discharge, 34 patients (81%) were in sinus rhythm, while eight patients (19%) continued to have atrial fibrillation. The age of the study population was 51.5 ± 11.7 yrs. The mean follow-up duration was 44 ± 21 months (range 6–84 months). The number of PVs isolated included one (five patients, 11.9%), two (20 patients, 47.6%), three (12 patients, 28.6%), and four (five patients, 11.9%). In 42 patients, a total of 101 PVs were isolated. The right superior PV (RSPV) was isolated in 37 patients, the left superior PV (LSPV) was isolated in 39 patients, the left inferior PV (LIPV) was isolated in 14 patients, and the right inferior PV (RIPV) was isolated in six patients. The procedure duration was 125 ± 29 min and the fluoroscopy time was 47 ± 13 min. The number of patients who remained in sinus rhythm at 1, 6, 12, and 24 months were 34 (81%), 32 (76%), 30 (71%), and 26 (62%), respectively. Two patients of these underwent repeat PVI, which was successful, and they had freedom from AF episodes. Complications were rare. One patient had a minor pericardial effusion, and one patient had transient sinus pauses, which were conservatively managed.

Conclusion

Conventional RF ablation using PV potential-based mapping and ablation with 8 mm tip catheters is safe for patients with PAF. The intermediate term outcome is satisfactory and cost-effective in our setting with limited resources.

Elongation of the high right atrium to coronary sinus conduction time predicts the recurrence of atrial fibrillation after radiofrequency catheter ablation

BACKGROUND

The impact of intra-atrial conduction delay on the recurrence of atrial tachyarrhythmia after radio frequency catheter ablation (RFCA) has not been fully elucidated.

METHODS

We retrospectively analyzed 155 AF patients who were sinus rhythm at the start of RFCA. The conduction time from the onset of the earliest atrial electrogram at the high right atrium (HRA) to the end of the latest electrogram at the coronary sinus (CS) during sinus rhythm was defined as HRA-CS conduction time. Pulmonary vein isolation (PVI) was performed followed by linear roof lesion and complex fractionated atrial electrogram (CFAE) ablation until AF termination. We evaluated atrial tachyarrhythmia recurrence 12 months after RFCA.

RESULTS

The follow-up data were available for 148 patients. The recurrence of atrial tachyarrhythmia was noted in 28 (18.9%) patients. Atrial tachyarrhythmia recurrence patients had longer HRA-CS conduction times (151.3 ± 22.1 ms vs 160.1 ± 32.6 ms, p = .017). The patients were divided into the long or short HRA-CS conduction time group. The Kaplan-Meier analysis revealed that the long HRA-CS conduction time group held a higher risk of atrial tachyarrhythmia recurrence (log-rank test, p = .019). The multivariable Cox hazard analysis revealed that a long HRA-CS conduction time was a significant risk factor for the recurrence of atrial tachyarrhythmia, despite a long AF duration, persistent AF, and larger left atrial diameter (LAD) were not statistically significant.

CONCLUSIONS

The HRA-CS conduction time was the primary influencing factor that predicted the recurrence of atrial tachyarrhythmia after catheter ablation.

Impedance drop predicts acute electrical reconnection of the pulmonary vein-left atrium after pulmonary vein isolation using short-duration high-power exposure

PURPOSE

To determine the efficacy and identify the relevant factors for durable lesion creation in pulmonary vein isolation (PVI) using a high-power short-duration (HPSD) strategy.

METHODS

Thirty-two consecutive patients who underwent PVI using HPSD (50 W) (HP group: HP-G) were compared with 32 controls using normal power (25-40 W) (conventional group: C-G). The segments were divided into 12 segments per group; thus, there were 768 segments for analysis. Radiofrequency (RF) ablation (RFA) was mainly performed under guidance with a unipolar electrogram at the distal tip of the ablation catheter in both groups. The high-power strategy reduced radiofrequency energy (P < 0.0001), RFA time (P < 0.0001), acute pulmonary vein reconnection (PVR) segments (P = 0.02), and several three-dimensional-mapping-related indices except for minimum impedance drop (Imp-min).

RESULTS

There was a significant difference only in Imp-min between the subjects with acute PVR and those without in the HP-G (P = 0.002). Multivariate analysis revealed Imp-min to be the only independent predictor of the absence of PVR after adjusting for maximum inter-lesion distance and minimum ablation index (odds ratio [OR] 1.22, 95% confidence interval [CI] 1.07-1.39, P = 0.001). In the region-specific analysis, this was attenuated in posterior segments, where the HP strategy independently predicted the absence of PVR (OR 2.80 [95% CI 1.32-6.30], P = 0.007).

CONCLUSION

The HPSD strategy reduced RF time, RF energy, and three-dimensional mapping-related indices but also improved the acute outcome. The HP strategy may be a sophisticated strategy under guidance with the impedance drop rather than the ablation index.