Pulmonary Vein Stenosis After Atrial Fibrillation Ablation: Insights From the ADVICE Trial.

BACKGROUND: Pulmonary vein (PV) stenosis is a complication of atrial fibrillation (AF) ablation. The incidence of PV stenosis after routine post-ablation imaging remains unclear and is limited to single-centre studies. Our objective was to determine the incidence and predictors of PV stenosis following circumferential radiofrequency ablation in the multicentre Adenosine Following Pulmonary Vein Isolation to Target Dormant Conduction Elimination (ADVICE) trial. METHODS: Patients with symptomatic AF underwent circumferential radiofrequency ablation in one of 13 trial centres. Computed tomographic (CTA) or magnetic resonance (MRA) angiography was performed before ablation and 90 days after ablation. Two blinded reviewers measured PV diameters and areas. PVs with stenosis were classified as severe (> 70%), moderate (50%-70%), or mild (< 50%). Predictors of PV stenosis were identified by means of multivariable logistic regression. RESULTS: A total of 197 patients (median age 59.5 years, 29.4% women) were included in this substudy. PV stenosis was identified in 41 patients (20.8%) and 47 (8.2%) of 573 ablated PVs. PV stenosis was classified as mild in 42 PVs (7.3%) and moderate in 5 PVs (0.9%). No PVs had severe stenosis. Both cross-sectional area and diameter yielded similar classifications for severity of PV stenosis. Diabetes was associated with a statistically significant increased risk of PV stenosis (OR 4.91, 95% CI 1.45-16.66). CONCLUSIONS: In the first systematic multicentre evaluation of post-ablation PV stenosis, no patient acquired severe PV stenosis. Although the results are encouraging for the safety of AF ablation, 20.8% of patients had mild or moderate PV stenosis, in which the long-term effects are unknown.

Cost-effectiveness and screening performance of ECG handheld machine in a population screening programme: The Belgian Heart Rhythm Week screening programme.

AIMS: Overall, 40% of patients with atrial fibrillation are asymptomatic. The usefulness and cost-effectiveness of atrial fibrillation screening programmes are debated. We evaluated whether an atrial fibrillation screening programme with a handheld electrocardiogram (ECG) machine in a population-wide cohort has a high screening yield and is cost-effective. METHODS: We used a Markov-model based modelling analysis on 1000 hypothetical individuals who matched the Belgian Heart Rhythm Week screening programme. Subgroup analyses of subjects ≥65 and ≥75 years old were performed. Screening was performed with one-lead ECG handheld machine Omron® HeartScan HCG-801. RESULTS: In both overall population and subgroups, the use of the screening procedure diagnosed a consistently higher number of diagnosed atrial fibrillation than not screening. In the base-case scenario, the screening procedure resulted in 106.6 more atrial fibrillation patient-years, resulting in three fewer strokes, 10 more life years and five more quality-adjusted life years (QALYs). The number needed-to-screen (NNS) to avoid one stroke was 361. In subjects ≥65 years old, we found 80.8 more atrial fibrillation patient-years, resulting in three fewer strokes, four more life-years and five more QALYs. The NNS to avoid one stroke was 354. Similar results were obtained in subjects ≥75 years old, with a NNS to avoid one stroke of 371. In the overall population, the incremental cost-effectiveness ratio for any gained QALY showed that the screening procedure was cost-effective in all groups. CONCLUSIONS: In a population-wide screening cohort, the use of a handheld ECG machine to identify subjects with newly diagnosed atrial fibrillation was cost-effective in the general population, as well as in subjects ≥65 and subjects ≥75 years old.

Cerebrovascular disease, associated risk factors and antithrombotic therapy in a population screening cohort: Insights from the Belgian Heart Rhythm Week programme.

Background Cerebrovascular disease confers a major healthcare burden worldwide and is a major cause of death and disability. Several well-established risk factors, such as atrial fibrillation (AF), are associated with cerebrovascular disease and antithrombotic therapy reduces risk. Design This study was a subgroup analysis from the Belgian Heart Rhythm Week, a nationwide AF awareness programme. Methods We studied subjects screened between 2012 and 2014 with available data on clinical risk factors and antithrombotic treatment. Results Of the 38,034 subjects eligible for this analysis, 1513 (4.0%) reported a positive clinical history for cerebrovascular disease. Logistic regression analysis found that age, hypertension, diabetes mellitus, history of vascular disease, history of heart failure and history of AF (all p < 0.001) were independently associated with cerebrovascular disease. Among subjects with history of cerebrovascular disease and AF, 1.7% were taking oral anticoagulant drugs only, while both oral anticoagulant drugs and aspirin were used in 61.5% of subjects, aspirin in 4.3% of patients and no antithrombotic therapy in 32.5% of subjects. Among those subjects without AF, the corresponding figures were 0.8, 9.5, 2.0 and 87.6%, respectively. Conclusions The prevalence of cerebrovascular disease in this contemporary population screening project was higher than that reported in the general population and was associated with the major known stroke risk factors. Sub-optimal antithrombotic therapy management was evident, with a low use of oral anticoagulant drugs among patients with AF and a low use of aspirin among subjects without AF.

A population screening programme for atrial fibrillation: a report from the Belgian Heart Rhythm Week screening programme.

AIMS: Despite the increased prevalence of atrial fibrillation (AF), data for the implementation of nationwide screening programmes are limited. The aim of this national screening study was to increase nationwide awareness about AF and stroke risk, to determine the prevalence of AF in Belgian general population using an ECG handheld machine and its feasibility to identify new AF cases. METHODS AND RESULTS: We analysed data obtained from 5 years of the 'Belgian Heart Rhythm Week' screening programme. All subjects were screened using a one-lead ECG handheld machine. Among 65 747 subjects screened, AF was recorded in 911, with an overall prevalence of 1.4% [95% confidence interval (CI) 1.2-1.6%]. High thrombo-embolic risk, as assessed by CHA2DS2-VASc score ≥2, was recorded in 69% of AF subjects. In subjects with high thrombo-embolic risk, only 5.4% were treated with oral anticoagulant (OAC) and 5.8% were treated with OAC and antiplatelet drugs. Among recorded AF cases, the use of the ECG handheld machine allowed identification of 603 new AF patients (1.1%, 95% CI 0.9-1.3%). Factors associated with incident AF were chronic heart failure (P < 0.001), age (P < 0.001), diabetes mellitus (P < 0.001), previous stroke (P < 0.001), vascular disease (P < 0.001), and male sex (P < 0.001). CONCLUSION: In this Belgian national screening programme, prevalence of AF was 1.4%. The use of an ECG handheld machine is feasible to identify a significant number of new AF cases, most with a high thrombo-embolic risk. Given the low OAC use recorded, greater efforts in AF detection and treatment are urgently needed to reduce the burden of stroke associated with this common arrhythmia.

Adenosine-guided pulmonary vein isolation for the treatment of paroxysmal atrial fibrillation: an international, multicentre, randomised superiority trial.

BACKGROUND: Catheter ablation is increasingly used to manage atrial fibrillation, but arrhythmia recurrences are common. Adenosine might identify pulmonary veins at risk of reconnection by unmasking dormant conduction, and thereby guide additional ablation to improve arrhythmia-free survival. We assessed whether adenosine-guided pulmonary vein isolation could prevent arrhythmia recurrence in patients undergoing radiofrequency catheter ablation for paroxysmal atrial fibrillation. METHODS: We did this randomised trial at 18 hospitals in Australia, Europe, and North America. We enrolled patients aged older than 18 years who had had at least three symptomatic atrial fibrillation episodes in the past 6 months, and for whom treatment with an antiarrhythmic drug failed. After pulmonary vein isolation, intravenous adenosine was administered. If dormant conduction was present, patients were randomly assigned (1:1) to additional adenosine-guided ablation to abolish dormant conduction or to no further ablation. If no dormant conduction was revealed, randomly selected patients were included in a registry. Patients were masked to treatment allocation and outcomes were assessed by a masked adjudicating committee. Patients were followed up for 1 year. The primary outcome was time to symptomatic atrial tachyarrhythmia after a single procedure in the intention-to-treat population. The trial is registered with ClinicalTrials.gov, number NCT01058980. FINDINGS: Adenosine unmasked dormant pulmonary vein conduction in 284 (53%) of 534 patients. 102 (69·4%) of 147 patients with additional adenosine-guided ablation were free from symptomatic atrial tachyarrhythmia compared with 58 (42·3%) of 137 patients with no further ablation, corresponding to an absolute risk reduction of 27·1% (95% CI 15·9-38·2; p<0·0001) and a hazard ratio of 0·44 (95% CI 0·31-0·64; p<0·0001). Of 115 patients without dormant pulmonary vein conduction, 64 (55·7%) remained free from symptomatic atrial tachyarrhythmia (p=0·0191 vs dormant conduction with no further ablation). Occurrences of serious adverse events were similar in each group. One death (massive stroke) was deemed probably related to ablation in a patient included in the registry. INTERPRETATION: Adenosine testing to identify and target dormant pulmonary vein conduction during catheter ablation of atrial fibrillation is a safe and highly effective strategy to improve arrhythmia-free survival in patients with paroxysmal atrial fibrillation. This approach should be considered for incorporation into routine clinical practice. FUNDING: Canadian Institutes of Health Research, St Jude Medical, Biosense-Webster, and M Lachapelle (Montreal Heart Institute Foundation).

Low contact force and force-time integral predict early recovery and dormant conduction revealed by adenosine after pulmonary vein isolation.

AIM: After pulmonary vein isolation (PVI), dormant conduction (DC) is present in at least one vein in a substantial number of patients. The present study seeks to determine whether there is a relationship between poor contact forces (CF) and the presence of DC after PVI. METHODS AND RESULTS: This prospective, operator-blinded, non-randomized dual-centre trial enrolled 34 consecutive patients with paroxysmal atrial fibrillation who were candidates for PVI. Radiofrequency (RF) energy was delivered by using an irrigated-tip force-sensing ablation catheter (Tacticath, St Jude Medical) at pre-defined target power. The operators were blinded to the CF data at all times. A total of 1476 RF applications were delivered in 743 pre-defined PV segments. For each application, the precise location of the catheter was registered and the following data were extracted from the Tacisys unit: application duration, minimum contact force, maximum contact force, average contact force (CF), and force-time integral (FTI). Sixty minutes after PVI, spontaneous early recovery (ER) of the left atrium (LA) to PV conduction was evaluated. In the absence of ER, the presence of a DC was evaluated by using intravenous adenosine (ATP). In the 34 patients recruited (23 males; mean age: 62 ± 9 years), all PVs were successfully isolated. At the end of the 60 min waiting period, 22 patients demonstrated at least one spontaneous ER or DC under ATP. The mean CF and FTI per PV segment differed significantly among the different veins but the sites of ER and DC were evenly distributed. However, both the minimum, the first and the mean CF and FTI per PV segment were significantly lower in the PV segments presenting either ER or DC as compared with those without ER or DC (mean CF: 4.9 ± 4.8 vs. 12.2 ± 1.65 g and mean FTI: 297 ± 291 vs. 860 ± 81 g s, P < 0.001 for both). Using multivariate analysis, both the mean CF and the FTI per lesion remained significantly associated with the risk of ER or DC. Moreover, a CF < 5 g per PV segment predicted ER+ and DC+ with a sensitivity of 71% and specificity of 82%. In contrast, ER and DC were very unlikely if RF application was performed with a mean CF > 10 g (negative predictive value: 98.7%). CONCLUSION: Both a low CF and a low FTI are associated with the ER of the PVI and DC after PVI.

Risk scores and geriatric profile: can they really help us in anticoagulation decision making among older patients suffering from atrial fibrillation?

OBJECTIVES: Anticoagulation for the prevention of cardio-embolism is most frequently indicated but largely underused in frail older patients with atrial fibrillation (AF). This study aimed at identifying characteristics associated with anticoagulation underuse. METHODS: A cross-sectional study of consecutive geriatric patients aged ≥75 years, with AF and clear anticoagulation indication (CHADS2 [Congestive heart failure, Hypertension, Age >75, Diabetes mellitus, and prior Stroke or transient ischemic attack] ≥2) upon hospital admission. All patients benefited from a comprehensive geriatric assessment. Their risks of stroke and bleeding were predicted using CHADS2 and HEMORR2HAGES (Hepatic or renal disease, Ethanol abuse, Malignancy, Older (age >75 years), Reduced platelet count or function, Rebleed risk, Hypertension (uncontrolled), Anemia, Genetic factors, Excessive fall risk, and Stroke) scores, respectively. RESULTS: Anticoagulation underuse was observed in 384 (50%) of 773 geriatric patients with AF (median age 85 years; female 57%, cognitive disorder 33%, nursing home 20%). No geriatric characteristic was found to be associated with anticoagulation underuse. Conversely, anticoagulation underuse was markedly increased in the patients treated with aspirin (odds ratio [OR] [95% confidence interval]: 5.3 [3.8; 7.5]). Other independent predictors of anticoagulation underuse were ethanol abuse (OR: 4.0 [1.4; 13.3]) and age ≥90 years (OR: 2.0 [1.2; 3.4]). Anticoagulation underuse was not inferior in patients with a lower bleeding risk and/or a higher stroke risk and underuse was surprisingly not inferior either in the AF patients who had previously had a stroke. CONCLUSION: Half of this geriatric population did not receive any anticoagulation despite a clear indication, regardless of their individual bleeding or stroke risks. Aspirin use is the main characteristic associated with anticoagulation underuse.

Use of electroanatomic voltage mapping to guide lead implantation in young adults with congenital heart disease.

Lead implantation in young adults with congenital heart disease is often problematic due to the reduction in the number of surgical access routes and consequent scar tissue formation related to previous surgery. In such a situation, anatomic and electromagnetic voltage mapping of the heart may be useful to find the optimal implantation site for sensing and pacing activities.

Intravenous adenosine to predict conduction recurrence in cavotricuspid isthmus early after ablation of typical atrial flutter: myth or reality?

INTRODUCTION: Early recovery of conduction (ER) after cavotricuspid isthmus (CTI) ablation for typical atrial flutter (AFl) occurs in approximately 10% of the patients. If not recognized, ER might lead to AFl recurrences. In this study, we hypothesized that intravenous adenosine (iADO) can be used to predict ER in the CTI immediately after RF ablation and distinguish functional block from the complete destruction of the CTI myocardium. METHODS: We prospectively included 68 consecutive patients (age: 65 ± 14 years; male: 78%) referred in our centers for AFl ablation. Immediately after bidirectional isthmus block validation, a bolus of iADO was given during continuous pacing from the proximal coronary sinus. Patients with functional block revealed under iADO (iADO+) and those without (iADO-) were subsequently observed for a 30-minute waiting period (ER-) or until sustained recovery of the conduction through the CTI (ER+). RESULTS: Seven patients presented a persistent recovery (ER+, 10.3%, mean time to recovery: 14 ± 9 minutes). None of them presented even a transient resumption of conduction under iADO (iADO+: 0). With univariate analysis, we identified a heavy patient weight (>95 kg) as a predictor of ER (sensitivity: 71%). CONCLUSIONS: Adenosine does not predict early recovery in the CTI after linear ablation for atrial flutter. We found that a patient weight over 95 kg predicted early recovery of conduction through the CTI with a sensitivity of 71%.

Adenosine following pulmonary vein isolation to target dormant conduction elimination (ADVICE): methods and rationale.

BACKGROUND: Pulmonary vein (PV) isolation (PVI) has emerged as an effective therapy for paroxysmal atrial fibrillation (AF). However, AF recurs in up to 50% of patients, generally because of recovery of PV conduction. Adenosine given during the initial procedure may reveal dormant PV conduction, thereby identifying the need for additional ablation, leading to improved outcomes. The Adenosine Following Pulmonary Vein Isolation to Target Dormant Conduction Elimination (ADVICE) study is a prospective multicentre randomized trial assessing the impact of adenosine-guided PVI in preventing AF recurrences. METHODS: Patients undergoing a first PVI procedure for paroxysmal AF will be recruited. After standard PVI is completed, all patients will receive intravenous adenosine in an attempt to unmask dormant conduction. If dormant conduction is elicited, patients will be randomized to no further ablation (control group) or additional adenosine-guided ablation until dormant conduction is abolished. If no dormant conduction is revealed, randomly selected patients will be followed in a registry. The primary outcome is time to first documented symptomatic AF recurrence. Assuming that dormant conduction is present in 50% of patients post PVI and symptomatic AF recurs in 45% of controls, 244 patients with dormant conduction will be required to obtain > 90% power to detect a difference of 20%. Thus, a total of 488 patients will be enrolled and followed for 12 months. CONCLUSION: The ADVICE trial will assess whether a PVI strategy incorporating elimination of dormant conduction unmasked by intravenous adenosine will decrease the rate of recurrent symptomatic AF compared with standard PVI.

Fever as a precipitant of idiopathic ventricular fibrillation in patients with normal hearts.

INTRODUCTION: Ventricular fibrillation (VF) is the main mechanism of sudden cardiac death. The clinical precipitants of sudden cardiac death due to idiopathic VF are poorly characterized. Emerging evidence implicates triggers originating predominantly from the distal Purkinje arborization and the right ventricular outflow tract. METHODS AND RESULTS: We report three patients without structural heart disease or repolarization abnormalities in whom a febrile illness was the only concurrent disease associated with unexpected sudden cardiac death due to VF storm. An automated defibrillator was implanted in all three patients. In one patient with persistent recurrent VF episodes, mapping demonstrated the origin of these triggers was from the Purkinje arborization of the anterior wall of the right ventricle. Ablation at a site of earliest activation during ectopy, where pace mapping was concordant and Purkinje potential preceded the onset of ventriculogram, resulted in suppression of all arrhythmias. After follow-up of 22, 9, and 18 months in the three patients, no ventricular arrhythmias have been recorded. CONCLUSION: We present a series of patients in whom an apparently benign febrile illness was associated with malignant ventricular arrhythmias in the absence of cardiac disease or other factors known to precipitate sudden cardiac death. Physicians should be aware of this possible phenomenon in cases of febrile illness associated with syncope.

Pulmonary vein disconnection using the LocaLisa three-dimensional nonfluoroscopic catheter imaging system.

INTRODUCTION: Catheter ablation for atrial fibrillation (AF) is associated with prolonged fluoroscopy times. We prospectively evaluated the use of the LocaLisa three-dimensional nonfluoroscopic catheter imaging system with the aim of reducing fluoroscopy times during pulmonary vein (PV) disconnection. METHODS AND RESULTS: Fifty-two patients with AF (47 men and 5 women, mean age 53 +/- 9 years) underwent disconnection of all four PVs guided by a circumferential mapping catheter. The LocaLisa navigation system was used for real-time three-dimensional nonfluoroscopic imaging of the circumferential mapping catheter and ablation catheter electrodes in 26 patients. Procedural parameters were compared with those of a control group consisting of 26 patients in whom only standard fluoroscopy was used. PV disconnection was performed similarly in both groups by circumferential ablation around the ostia, with the endpoint of disconnecting left atrium to PV breakthroughs. The cumulative duration of radiofrequency (RF) energy delivery, procedural time, and fluoroscopy time required for PV disconnection were compared. Successful disconnection was achieved in all PVs, without acute complications. There was no significant difference in cumulative RF energy delivery: 34.8 +/- 11.4 minutes for the nonfluoroscopic imaging group versus 38.2 +/- 10.5 minutes for the control group. The fluoroscopy time required for disconnection of all four PVs was significantly lower in the LocaLisa group than in the control group: 8.4 +/- 4.3 minutes versus 23.7 +/- 9.7 minutes (P < 0.0001). There also was a significant difference in the mean time taken for PV disconnection: 46.5 +/- 12.0 minutes for the nonfluoroscopic imaging group versus 66.3 +/- 18.9 minutes for the control group (P < 0.0001). CONCLUSION: By allowing continuous three-dimensional monitoring of ablation and mapping catheter position and orientation, the LocaLisa nonfluoroscopic imaging system significantly reduces fluoroscopy and PV disconnection times.

Mapping and ablation of ventricular fibrillation associated with long-QT and Brugada syndromes.

BACKGROUND: The long-QT and Brugada syndromes are important substrates of malignant ventricular arrhythmia. The feasibility of mapping and ablation of ventricular arrhythmias in these conditions has not been reported. METHODS AND RESULTS: Seven patients (4 men; age, 38+/-7 years; 4 with long-QT and 3 with Brugada syndrome) with episodes of ventricular fibrillation or polymorphic ventricular tachycardia and frequent isolated or repetitive premature beats were studied. These premature beats were observed to trigger ventricular arrhythmias and were localized by mapping the earliest endocardial activity. In 4 patients, premature beats originated from the peripheral right (1 Brugada) or left (3 long-QT) Purkinje conducting system and were associated with variable Purkinje-to-muscle conduction times (30 to 110 ms). In the remaining 3 patients, premature beats originated from the right ventricular outflow tract, being 25 to 40 ms ahead of the QRS. The accuracy of mapping was confirmed by acute elimination of premature beats after 12+/-6 minutes of radiofrequency applications. During a follow-up of 17+/-17 months using ambulatory monitoring and defibrillator memory interrogation, no patients had recurrence of symptomatic ventricular arrhythmia but 1 had persistent premature beats. CONCLUSIONS: Triggers from the Purkinje arborization or the right ventricular outflow tract have a crucial role in initiating ventricular fibrillation associated with the long-QT and Brugada syndromes. These can be eliminated by focal radiofrequency ablation.

Radiation exposure during radiofrequency catheter ablation for atrial fibrillation.

RF catheter ablation of paroxysmal atrial fibrillation (PAF) is associated with prolonged fluoroscopy. The procedural duration and fluoroscopic exposure to patients and medical staff were recorded and compared among 43 ablation procedures for PAF, 20 for common atrial flutter, and 16 for accessory pathways. Patient radiation exposure was measured by dosimeters placed over the xyphoid, while that of physicians and nurses was measured by dosimeters placed outside and inside the lead apron. The mean fluoroscopy time was 57 +/- 30 minutes for PAF, 20 +/- 10 minutes for common flutter, and 22 +/- 21 minutes for accessory pathway ablation. The patient median radiation exposure was 1110 microSv for PAF, compared with 500 microSv for common flutter and 560 microSv for accessory pathway ablation (P < 0.01). The median radiation exposure to physician and nurse inside the lead apron were, respectively, 2 microSv and 3 microSv for PAF, 1 microSv and 2 microSv for common flutter, and < 0.5 microSv and 3 microSv for accessory pathway ablations. RF catheter ablation for PAF was associated with prolonged fluoroscopy times and a twofold higher radiation exposure to the patient and physician compared with other ablation procedures. Assuming 300 procedures/year, radiation exposure to the medical staff was below the upper recommended annual dose limit.

Ablation therapy for atrial fibrillation (AF): past, present and future.

Atrial fibrillation, the most common arrhythmia, is frequently disabling and drug resistant. Non-pharmacological approaches including surgery and catheter-based ablation have been developed for the most symptomatic patients. These new treatment strategies have dramatically increased our knowledge of the pathophysiology of this arrhythmia but most importantly demonstrated that atrial fibrillation is curable. These approaches are far from being perfect but good enough to be offered in routine practice to selected patients in experienced centers. The importance of pulmonary veins in the initiation of AF has clearly been demonstrated and their role in maintaining AF is likely. Most of the curative approaches are therefore based on their isolation. Future technical improvements based on presently applied concepts are likely to widen the indications for ablation therapy of AF.