Marco Scaglione

Does the left atrial appendage morphology correlate with the risk of stroke in patients with atrial fibrillation?: results from a multicenter study.

OBJECTIVES This study investigated the left atrial appendage (LAA) by computed tomography (CT) and magnetic resonance imaging (MRI) to categorize different LAA morphologies and to correlate the morphology with the history of stroke/transient ischemic attack (TIA). BACKGROUND LAA represents one of the major sources of cardiac thrombus formation responsible for TIA/stroke in patients with atrial fibrillation (AF). METHODS We studied 932 patients with drug-refractory AF who were planning to undergo catheter ablation. All patients underwent cardiac CT or MRI of the LAA and were screened for history of TIA/stroke. Four different morphologies were used to categorize LAA: Cactus, Chicken Wing, Windsock, and Cauliflower. RESULTS CT scans of 499 patients and MRI scans of 433 patients were analyzed (age 59 ± 10 years, 79% were male, and 14% had CHADS(2) [Congestive heart failure, hypertension, Age >75, Diabetes mellitus, and prior stroke or transient ischemic attack] score ≥2). The distribution of different LAA morphologies was Cactus (278 [30%]), Chicken Wing (451 [48%]), Windsock (179 [19%]), and Cauliflower (24 [3%]). Of the 932 patients, 78 (8%) had a history of ischemic stroke or TIA. The prevalence of pre-procedure stroke/TIA in Cactus, Chicken Wing, Windsock, and Cauliflower morphologies was 12%, 4%, 10%, and 18%, respectively (p = 0.003). After controlling for CHADS2 score, gender, and AF types in a multivariable logistic model, Chicken Wing morphology was found to be 79% less likely to have a stroke/TIA history (odd ratio: 0.21, 95% confidence interval: 0.05 to 0.91, p = 0.036). In a separate multivariate model, we entered Chicken Wing as the reference group and assessed the likelihood of stroke in other groups in relation to reference. Compared with chicken wing, cactus was 4.08 times (p = 0.046), Windsock was 4.5 times (p = 0.038), and Cauliflower was 8.0 times (p = 0.056) more likely to have had a stroke/TIA. CONCLUSIONS Patients with Chicken Wing LAA morphology are less likely to have an embolic event even after controlling for comorbidities and CHADS2 score. If confirmed, these results could have a relevant impact on the anticoagulation management of patients with a low-intermediate risk for stroke/TIA.

Radiofrequency catheter ablation of atrial fibrillation: A cause of silent thromboembolism? Magnetic resonance imaging assessment of cerebral thromboembolism in patients undergoing ablation of atrial fibrillation

Background— Radiofrequency left atrial catheter ablation has become a routine procedure for treatment of atrial fibrillation. The aim of this study was to assess with preprocedural and postprocedural cerebral magnetic resonance imaging the thromboembolic risk, either silent or clinically manifest, in the context of atrial fibrillation ablation. The secondary end point was the identification of clinical or procedural parameters that correlate with cerebral embolism. Methods and Results— A total of 232 consecutive patients with paroxysmal or persistent atrial fibrillation who were candidates for radiofrequency left atrial catheter ablation were included in the study. Pulmonary vein isolation or pulmonary vein isolation plus linear lesions plus atrial defragmentation with the use of irrigated-tip ablation catheters was performed. All of the patients underwent preprocedural and postablation cerebral magnetic resonance imaging. A periprocedural symptomatic cerebrovascular accident occurred in 1 patient (0.4%). Postprocedural cerebral magnetic resonance imaging was positive for new embolic lesions in 33 patients (14%). No clinical parameters such as age, hypertension, diabetes mellitus, previous history of stroke, type of atrial fibrillation, and preablation antithrombotic treatment showed significant correlation with ischemic cerebral embolism. Procedural parameters such as activated clotting time value and, in particular, electric or pharmacological cardioversion to sinus rhythm correlated with an increased incidence of cerebral embolism. Cardioversion was also associated with an increased risk of 2.75 (95% confidence interval, 1.29 to 5.89; P=0.009). Conclusions— Radiofrequency left atrial catheter ablation carries a low risk of symptomatic cerebral ischemia but is associated with a substantial risk of silent cerebral ischemia detected on magnetic resonance imaging. Independent risk factors for cerebral thromboembolism are the level of activated clotting time and, in particular, the electric or pharmacological cardioversion to sinus rhythm during the procedure.

Incidence of Silent Cerebral Thromboembolic Lesions After Atrial Fibrillation Ablation May Change According to Technology Used: Comparison of Irrigated Radiofrequency, Multipolar Nonirrigated Catheter and Cryoballoon

AF Ablation Technologies and Silent Cerebral Ischemic Lesions. Introduction: Silent cerebral ischemic lesions have recently emerged as the most frequent complications after pulmonary vein isolation (PVI). To reduce thromboembolic complications, new types of catheters and energy source have been introduced in clinical practice. The study purpose is to compare the incidence of new silent cerebral ischemic events in patients with paroxysmal atrial fibrillation (PAF) undergoing PVI with different ablation technologies.

Long-Term Clinical Results of 2 Different Ablation Strategies in Patients With Paroxysmal and Persistent Atrial Fibrillation

Background—Data regarding the long-term efficacy of atrial fibrillation (AF) ablation are still lacking. Methods and Results—Two hundred four consecutive patients symptomatic for paroxysmal or persistent/permanent AF were randomly assigned to 2 different ablation schemes: pulmonary vein isolation (PVI) and PVI plus left linear lesions (LL). Primary end point was to assess the maintenance of sinus rhythm (SR) after procedures 1 and 2 in the absence of antiarrhythmic drugs in a long-term follow-up of at least 3 years. Paroxysmal AF—With a single procedure at 12-month follow-up, 46% of patients treated with PVI maintained SR, whereas at 3-year follow-up, 29% were in SR; using the “PVI plus LL” at the 12-month follow-up, 57% of patients were in SR, whereas at the 3-year follow-up, 53% remained in SR. After a second procedure, the long-term overall success rate without antiarrhythmic drugs was 62% with PVI and 85% with PVI plus LL. Persistent/Permanent AF—With a single procedure at the 12-month follow-up, 27% of patients treated with PVI were in SR, whereas at the 3-year follow-up, 19% maintained SR; using the PVI plus LL with a single procedure at the 12-month follow-up 45% of patients were in SR, whereas at the 3-year follow-up, 41% remained in SR. After a second procedure, the long-term overall success rate without antiarrhythmic drugs was 39% with PVI and 75% with PVI plus LL. Conclusions—A long-term follow-up of AF ablation shows that short-term results cannot be considered permanent because AF recurrences are still present after the first year especially in patients who have had “PVI” strategy. PVI isolation plus LL is superior to the PVI strategy in maintaining SR without antiarrhythmic drugs after procedures 1 and 2 both in paroxysmal and persistent AF.

Prevalence of silent cerebral ischemia in paroxysmal and persistent atrial fibrillation and correlation with cognitive function.

OBJECTIVES The aim of this study was to compare the prevalence of silent cerebral ischemia (SCI) and cognitive performance in patients with paroxysmal and persistent atrial fibrillation (AF) and controls in sinus rhythm. BACKGROUND Large registries have reported a similar risk for symptomatic stroke in both paroxysmal and persistent AF. The relationship among paroxysmal and persistent AF, SCI, and cognitive impairment has remained uncharted. METHODS Two hundred seventy subjects were enrolled: 180 patients with AF (50% paroxysmal and 50% persistent) and 90 controls. All subjects underwent clinical assessment, neurological examination, cerebral magnetic resonance, and the Repeatable Battery for the Assessment of Neuropsychological Status. RESULTS At least 1 area of SCI was present in 80 patients (89%) with paroxysmal AF, 83 (92%) with persistent AF (paroxysmal vs. persistent, p = 0.59), and 41 (46%) controls (paroxysmal vs. controls and persistent vs. controls, p < 0.01). The number of areas of SCI per subject was higher in patients with persistent AF than in those with paroxysmal AF (41.1 ± 28.0 vs. 33.2 ± 22.8, p = 0.04), with controls reporting lower figures (12.0 ± 26.7, p < 0.01 for both). Cognitive performance was significantly worse in patients with persistent and paroxysmal AF than in controls (Repeatable Battery for the Assessment of Neuropsychological Status scores 82.9 ± 11.5, 86.2 ± 13.8, and 92.4 ± 15.4 points, respectively, p < 0.01). CONCLUSIONS Patients with paroxysmal and persistent AF had a higher prevalence and number of areas of SCI per patient than controls and worse cognitive performance than subjects in sinus rhythm.

Ablation of atrial fibrillation: does the addition of three-dimensional magnetic resonance imaging of the left atrium to electroanatomic mapping improve the clinical outcome?A randomized comparison of Carto-Merge vs. Carto-XP three-dimensional mapping ablation in patients with paroxysmal and persistent atrial fibrillation

AIMS To compare in a randomized and prospective fashion the outcome of atrial fibrillation (AF) ablation either after one procedure or after two procedures using the Carto-XP vs. the Carto-Merge mapping system in two different AF populations. METHODS AND RESULTS Two hundred and ninety-nine patients with paroxysmal and persistent AF were enrolled in the study. One hundred and fifty patients with paroxysmal or persistent AF were randomly assigned to the Carto-Merge group and 149 patients to the Carto-XP group. The Carto-Merge patients underwent magnetic resonance imaging (MRI) of left atrium (LA) the day before the ablation. The ablation scheme included electrical disconnection of the pulmonary veins plus linear lesions. In the Carto-Merge patients, the three-dimensional MRI of the LA reconstruction merged with the electroanatomical map, and in the Carto-XP patients, the electroanatomical map guided the procedure. Considering the overall population with paroxysmal AF, 54% maintained sinus rhythm (SR), whereas in the persistent AF population, SR was present in 43% of the patients at the 12-month follow-up. In patients with paroxysmal AF, 52% in the Carto-XP group and 55% in the Carto-Merge group maintained SR without drugs. Procedure durations and exposure to X-ray in the Carto-XP group were 94.6 +/- 17.5 and 40.4 +/- 13.5 min, respectively. In the Carto-Merge group, duration and X-ray exposure were 89 +/- 41.6 and 22.1 +/- 11.4 min, respectively. Considering the patients with persistent AF at the12-month follow-up, 44% in the Carto-XP group and 42% in the Carto-Merge group maintained SR without drugs. Procedure durations and X-ray exposure in the Carto-XP group were 102.9 +/- 22.9 and 58 +/- 8.7 min, respectively. In the Carto-Merge group, both duration and X-ray exposure were 114.4 +/- 50.9 and 28.8 +/- 14.3 min, respectively. CONCLUSION Image integration using Carto-Merge in patients undergoing catheter ablation for paroxysmal and persistent AF does not significantly improve the clinical outcome, but shortens the X-ray exposure.

Limited posterior left atrial cryoablation in patients with chronic atrial fibrillation undergoing valvular heart surgery

OBJECTIVES We sought to evaluate whether a limited surgical cryoablation of the posterior region of the left atrium was safe and effective in the cure of atrial fibrillation (AF) in patients with associated valvular heart disease. BACKGROUND Extensive surgical ablation of AF is a complex and risky procedure. The posterior region of the left atrium seems to be important in the initiation and maintenance of AF. METHODS In 32 patients with chronic AF who underwent heart valve surgery, linear cryolesions connecting the four pulmonary veins and the posterior mitral annulus were performed. Eighteen patients with AF who underwent valvular surgery but refused cryoablation were considered as the control group. RESULTS Sinus rhythm (SR) was restored in 25 (78%) of 32 patients immediately after the operation. The cryoablation procedure required 20 +/- 4 min. There were no intraoperative and perioperative complications. During the hospital period, one patient died of septicemia. Thirty-one patients reached a minimum of nine months of follow-up. Two deaths occurred but were unrelated to the procedure. Twenty (69%) of 29 patients remained in SR with cryoablation alone, and 26 (90%) of 29 patients with cryoablation, drugs and radiofrequency ablation. Three (10%) of 29 patients remained in chronic AF. Right and left atrial contractility was evident in 24 (92%) of 26 patients in SR. In control group, two deaths occurred, and SR was present in only four (25%) of 16 patients. CONCLUSIONS Linear cryoablation with lesions connecting the four pulmonary veins and the mitral annulus is effective in restoration and maintenance of SR in patients with heart valve disease and chronic AF. Limited left atrial cryoablation may represent a valid alternative to the maze procedure, reducing myocardial ischemic time and risk of bleeding.

Efficacy of catheter ablation for atrial fibrillation in hypertrophic cardiomyopathy: impact of age, atrial remodelling, and disease progression

AIMS In patients with hypertrophic cardiomyopathy (HCM) and atrial fibrillation (AF), radiofrequency catheter ablation (RFCA) represents a promising option. However, the predictors of RFCA efficacy remain largely unknown. We assessed the outcome of a multicentre HCM cohort following RFCA for symptomatic AF refractory to medical therapy. METHODS AND RESULTS Sixty-one patients (age 54 +/- 13 years; time from AF onset 5.7 +/- 5.5 years) with paroxysmal (n = 35; 57%), recent persistent (n = 15; 25%), or long-standing persistent AF (n = 11; 18%) were enrolled. A scheme with pulmonary vein isolation plus linear lesions was employed. Of the 61 patients, 32 (52%) required redo procedures. Antiarrhythmic therapy was maintained in 22 (54%). At the end of a 29 +/- 16 months follow-up, 41 patients (67%) were in sinus rhythm, including 17 of the 19 patients aged < or = 50 years, with marked improvement in New York Heart Association (NYHA) functional class (1.2 +/- 0.5 vs. 1.9 +/- 0.7 at baseline; P < 0.001). In the remaining 20 patients (33%), with AF recurrence, there was less marked, but still significant, improvement following RFCA (NYHA class 1.8 +/- 0.7 vs. 2.3 +/- 0.7 at baseline; P = 0.002). Independent predictors of AF recurrence were increased left atrium volume [hazard ratio (HR) per unit increase 1.009, 95% confidence interval (CI) 1.001-1.018; P = 0.037] and NYHA functional class (HR 2.24, 95% CI 1.16-4.35; P = 0.016). Among 11 genotyped HCM patients (6 with MYBPC3, 2 with MYH7, 1 with MYL2 and 2 with multiple mutations), RFCA success rate was comparable with that of the overall cohort (n = 8; 73%). CONCLUSION RFCA was successful in restoring long-term sinus rhythm and improving symptomatic status in most HCM patients with refractory AF, including the subset with proven sarcomere gene mutations, although redo procedures were often necessary. Younger HCM patients with small atrial size and mild symptoms proved to be the best RFCA candidates, likely due to lesser degrees of atrial remodelling.

Catheter ablation of permanent junctional reciprocating tachycardia with radiofrequency current

OBJECTIVES This study evaluated accessory pathway location, its relation to retrograde P wave polarity on the surface electrocardiogram and radiofrequency ablation efficacy and safety in a large group of patients with permanent junctional reciprocating tachycardia. BACKGROUND Permanent junctional reciprocating tachycardia is an uncommon form of reciprocating tachycardia, almost incessant from infancy and usually refractory to drug therapy. It is characterized by RP > PR interval and usually by negative P waves in leads II, III, aVF and V4 to V6. Retrograde conduction occurs through an accessory pathway with slow and decremental properties. Although this accessory pathway has been classically located in the posteroseptal zone, other locations have been recently reported. METHODS The study included 32 patients (20 men, 12 women, mean [+/- SD] age 29 +/- 15 years) with a diagnosis of permanent junctional reciprocating tachycardia confirmed at electrophysiologic study. Seven patients had depressed left ventricular function. Radiofrequency energy was applied at the site of the earliest retrograde atrial activation during tachycardia. RESULTS There were 33 accessory pathways. The site of the earliest retrograde atrial activation was posteroseptal in 25 patients (76%), midseptal in 4 (12%), right posterior in 1 (3%), right lateral in 1 (3%), left posterior in 1 (3%) and left lateral in 1 (3%). Thirty pathways were ablated with a right approach; in 11 patients with posteroseptal pathway the ablation was performed through the coronary sinus. Three pathways were ablated with a left approach. Positive retrograde P wave in lead I suggested that ablation could be performed from the right side; if negative, it did not exclude ablation from this approach. All the accessory pathways were successfully ablated, with a median of 3 and a mean of 5.6 +/- 5 radiofrequency applications of 70 +/- 26 s in duration. In two patients with the accessory pathway in the midseptal zone, a transient second- and third-degree atrioventricular block, respectively, was observed after ablation. At a mean follow-up of 18 +/- 12 months, 31 patients (97%) are asymptomatic without antiarrhythmic therapy (95% confidence interval [CI] 84% to 99%). Recurrences were observed in four patients (13%) (95% CI 4% to 29%), three of whom had the accessory pathway ablated successfully at a second session. All patients with depressed left ventricular function showed a marked improvement after successful ablation. CONCLUSIONS In our experience, most of the patients with permanent junctional reciprocating tachycardia had posteroseptal pathways; all these pathways were ablated from the right side. P wave configuration may be helpful in suggesting the approach to the site of ablation. Catheter ablation using radiofrequency energy is an effective therapy for permanent junctional reciprocating tachycardia.

Different patterns of atrial activation in idiopathic atrial fibrillation: simultaneous multisite atrial mapping in patients with paroxysmal and chronic atrial fibrillation

OBJECTIVES We aimed to evaluate: 1) the behavior of electrical activity simultaneously in different atrial regions during atrial fibrillation (AF); 2) the difference of atrial activation between paroxysmal and chronic AF; 3) the atrial refractoriness dispersion; and 4) the correlation between the effective refractory periods (ERPs) and the FF intervals. BACKGROUND Little data exist on the electrophysiologic characteristics of the different atrial regions in patients with AF. A more detailed knowledge of the electrical activity during AF may provide further insights to improve treatment of AF. METHODS Right and left atria were extensively mapped in 30 patients with idiopathic AF (18 paroxysmal and 12 chronic). In different atrial locations, we analyzed 1) the FF interval duration; and 2) the grade of organization and, in case of organized electrical activity, the direction of atrial activation. Furthermore, in patients with paroxysmal AF, we determined the atrial ERP, evaluated the ERP dispersion and assessed the presence of a correlation between the ERPs and the FF intervals. RESULTS In patients with chronic AF, we observed a shortening of the FF intervals and a greater prevalence of disorganized activity in all the atrial sites examined. In patients with paroxysmal AF, a significant dispersion of refractoriness was observed. The right lateral wall showed longer FF intervals and more organized atrial activity and, unexpectedly, the shortest mean ERPs. In contrast, the septal area showed shorter FF intervals, greater disorganization and the longest mean ERPs. CONCLUSIONS Electrical activity during AF showed a significant spatial inhomogeneity, which was more evident in patients with paroxysmal AF. The mean FF intervals did not correlate with the mean ERPs.