D. Caponi

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

AIMSnTo 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.nnnMETHODS AND RESULTSnTwo 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.nnnCONCLUSIONnImage 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.

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

AIMSnIn 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.nnnMETHODS AND RESULTSnSixty-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%).nnnCONCLUSIONnRFCA 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.

Visualization of multiple catheters with electroanatomical mapping reduces X-ray exposure during atrial fibrillation ablation

AIMSnAtrial fibrillation (AF) ablation still requires long procedural time and high radiation exposure with its related risk for the patient and the operators. This study was designed to compare three different approaches of AF ablation to verify the hypothesis that image integration with electroanatomic mapping allows minimal use of fluoroscopy. Therefore, we evaluated the procedure and fluoroscopy times of ablation using three imaging modalities: conventional fluoroscopy, image integration electroanatomic mapping, and a new electroanatomic mapping system that provides visualization of multiple catheters.nnnMETHODS AND RESULTSnOne hundred and twenty patients with symptomatic refractory AF were enrolled in the study. Patients were randomly assigned to fluoroscopy alone (Group A, 40 patients), electroanatomic integration (Cartomerge®, Group B, 40 patients), and electroanatomic integration plus catheters visualization (Carto® 3 System, Group C, 40 patients) guided procedures. The ablation procedure aimed at isolating the pulmonary veins and creating lesion lines at the left atrial roof and left isthmus. Procedure and fluoroscopy parameters were recorded in all patients. Total procedure time and skin to catheter positioning time did not significantly differ between the groups. Total fluoroscopy time was statistically different between all three groups (Group A, 1809″±500″; Group B, 948″±341″; Group C, 228″±140″; P<0.001). A significant difference was noted in ablation fluoroscopy time between all groups (P<0.001), mainly due to shortened fluoroscopy time in Group B (734″±315″) and Group C (021″±031″) when compared with Group A (1607″±504″).nnnCONCLUSIONnImage integration and, to a larger extent, visualization of multiple catheters allowed a minimal use of fluoroscopy in transcatheter AF ablation.

Very long-term results of electroanatomic-guided radiofrequency ablation of atrial arrhythmias in patients with surgically corrected atrial septal defect

AIMSnAtrial tachycardias are common after repair of atrial septal defect (ASD). Although ablation has shown promising results in the short and mid-term follow-up, little data regarding the very long-term success exist. Our aim was to assess very long-term follow-up in patients who have undergone electroanatomic-guided radiofrequency (RF) ablation of late-onset atrial arrhythmias after ASD surgery.nnnMETHODS AND RESULTSnForty-six consecutive patients with surgically repaired ASD were referred for atrial tachycardia ablation. Electrophysiological (EP) study and ablation procedure with the aid of an electroanatomic mapping (EAM) system were performed. Mean age was 49 ± 13 years (females 61%). The presenting arrhythmias were typical atrial flutter (48%), atypical atrial flutter (35%), and atrial tachycardia (17%). In 41% of patients, atrial fibrillation was also present. The EP study showed a right atrial macroreentrant circuit in all the patients. In 12 of 46 (26%), the circuit was localized in the cavo-tricuspid isthmus, whereas in the remaining 34 patients (74%) was atriotomy-dependent. Acute success was 100%. Clinical arrhythmia recurred in 24% of the patients. Nine patients underwent a second and two a third ablation procedure, reaching an overall efficacy of 87% (40 of 46) at a mean follow-up of 7.3 ± 3.8 years since the last procedure. With antiarrhythmic drugs the success rate increased to 96% (44 of 46). No complications occurred.nnnCONCLUSIONnIn patients with surgically corrected ASD, EAM-guided RF ablation of late-onset macroreentrant atrial arrhythmias demonstrated a high success rate in a very long-term follow-up. Therefore, RF ablation could be considered early in the management of late-onset macroreentrant atrial tachycardias.

Relationship of ECG findings to phenotypic expression in patients with hypertrophic cardiomyopathy: A cardiac magnetic resonance study ☆

BACKGROUNDnThe 12-lead electrocardiogram (ECG) is considered an essential screening tool for hypertrophic cardiomyopathy (HCM). A vast array of ECG abnormalities has been described in HCM, although their relationship to left ventricle (LV) morphology and degree of hypertrophy appears elusive. Aim of this study was to assess the relationship of ECG patterns with the HCM phenotype assessed according to the novel opportunities offered by cardiac magnetic imaging (CMR).nnnMETHODSnCMR and 12-lead ECG were performed in 257 HCM patients. Severity of ECG abnormalities was defined by the sum of 9 criteria: abnormal cardiac rhythm, QRS duration ≥ 100 ms, Romhilt-Estes score ≥ 5, fascicular block (LAHB) and/or bundle-branch block (LBBB or RBBB), ST-T abnormalities, ST-T segment elevation ≥ 0.2 mV, prolonged QTc interval, pathological Q waves, absence of normal Q wave. Four ECG groups were identified: normal (0 criteria); mildly abnormal (1-3 criteria); moderately abnormal (4-6 criteria); markedly abnormal (7-9 criteria).nnnRESULTSnThere was a direct relationship between severity of ECG abnormalities and HCM phenotype. LV mass index was normal in most patients with normal ECG and progressively increased with each class of ECG score, from 70.9 ± 18.6g/m(2) in patients with normal ECG to 107.1 ± 55.1g/m(2) among those with markedly abnormal ECG (p=<0.0001). Likewise, the prevalence and extent of late gadolinium enhancement (LGE) increased significantly with the ECG score, from 37% in patients with normal ECG to 93% in patients with markedly abnormal ECG (overall p=0.0012). A normal ECG had a negative predictive accuracy of 96% for markedly increased LV mass (>91 g/m(2) for men and >69 g/m(2) for women), and of 100% for maximum LV thickness ≥ 30 mm.nnnCONCLUSIONSnIn a large HCM cohort, the number and severity of ECG abnormalities were directly related to phenotypic expression as revealed by CMR. Although false negative ECG findings remain a challenge in population screenings for HCM, a normal ECG proved effective in ruling out severe LV hypertrophy, suggesting potential implications for long-term follow-up of HCM patients and family members. A simple score for quantification of ECG abnormalities in HCM patients is proposed.

Incidence of cerebral thromboembolic events during long-term follow-up in patients treated with transcatheter ablation for atrial fibrillation.

AIMSnNet clinical benefit of long-term oral anticoagulation therapy (OAT) continuation after successful atrial fibrillation (AF) ablation is still controversial. To evaluate long-term thromboembolic (TE) and haemorrhagic events incidence according to OAT strategy used after AF transcatheter ablation.nnnMETHODS AND RESULTSnThree months after AF ablation, OAT was discontinued in patients with CHADS2 ≤ 1 if no recurrences were documented, while OAT was maintained in patients with CHADS2 ≥ 2 regardless of AF recurrences. CHA2DS2VASc and HAS-BLED scores have been retrospectively evaluated. Seven hundred and sixty-six patients were followed for a median of 60.5 months. Six (6/267 = 2.2%) and five (5/499 = 1%) TE events occurred in the ON and the OFF-OAT patients, respectively (P = 0.145), all in concomitance with the AF recurrence. CHADS2 and CHA2DS2VASc ≥ 2 were associated with high TE incidence (P = 0.047 and P = 0.020). Among patients with a CHADS2 score of 0 or 1, a CHA2DS2VASc score ≥ 2 was predictive of TE events (P = 0.014). Overall, the incidence of the TE events in patients with CHA2DS2VASc ≥ 2 was 0.6 per 100 patient-years whereas seven haemorrhagic events occurred, all of them in the ON-OAT patients (7/267 = 2.6%).nnnCONCLUSIONnPatients with AF undergoing transcatheter ablation have a lower incidence of TE events as compared with the general AF population, regardless of OAT maintenance. The unpredictable risk of AF recurrence, mandate the routine use of the CHADS2, CHA2DS2VASc, and HAS-BLED scores to guide clinical decision regarding OAT management in this peculiar setting of patients. The potential protective role of rhythm control strategy in the TE events needs to be confirmed by future large randomized trials.

Very Long-Term Results of Surgical and Transcatheter Ablation of Long-Standing Persistent Atrial Fibrillation

BACKGROUNDnNew hybrid approaches for atrial fibrillation (AF) ablation, combining surgical and percutaneous procedures, are emerging to enhance the long-term success rate of these 2 procedures severally considered. Recent guidelines underline the need for long-term follow-up to really assess the efficacy of AF ablation.nnnMETHODSnFrom 2000 to 2002, 33 patients with long-standing persistent AF and valvular heart disease underwent valve surgery and cryoablation (pulmonary veins isolation and mitral isthmus and roof line lesions). The surgically created ablation scheme was validated with electroanatomic mapping and percutaneous radiofrequency ablation was performed in case of lesion incompleteness.nnnRESULTSnIn 19 of 33 patients (58%) the electroanatomic mapping showed a complete lesion scheme, which increased to 79% (26 of 33) with the addition of radiofrequency ablation. At the mean follow-up of 10.7 ± 3.1 years, 73% (24 of 33) of patients were in sinus rhythm (SR),xa0whereas 27% had permanent AF. At the end of follow-up 81% of patients with a complete lesion scheme were in SR, while 43% with an incomplete one maintained SR (pxa0= 0.048).nnnCONCLUSIONSnIn patients with long-standing persistent AF and valvular heart disease, the hybrid approach with surgical cryoablation consisting of pulmonary veins isolation and left atrial linear lesions combined with transcatheter radiofrequency ablation was highly effective in maintaining SR for a very long-term follow-up. Electrophysiological evaluation, to validate the transmurality of the surgical lesions and to complete the lesion scheme applying radiofrequency energy, improved the long-term efficacy.

Zero-Fluoroscopy Ablation of Accessory Pathways in Children and Adolescents: CARTO3 Electroanatomic Mapping Combined with RF and Cryoenergy.

Fluoroscopic catheter ablation of cardiac arrhythmias in pediatric patients exposes the patients to the potential risk of radiation considering the sensitivity of this population and its longer life expectancy. We evaluated the feasibility, safety, and efficacy of accessory pathway (AP) ablation guided by CARTO3 electroanatomic mapping (EAM) system with both cryoenergy and radiofrequency (RF) energy in order to avoid x‐ray exposure in pediatric patients.

Optimization of Resynchronization Therapy by Intracardiac Ventricular Impedance

Cardiac resynchronization through biventricular pacing has proved to be an effective therapy in patients with severe heart failure (HF) with interventricular conduction disorders [1-7]. Nevertheless, about 25% of selected HF patients do not respond to synchronous biventricular pacing. The optimization of therapy in terms of pacing site(s) and interventricular delay is still under discussion.

Present Role and Future Perspectives of Radiofrequency Ablation of Atrial Fibrillation

Transcatheter ablation of atrial fibrillation has been recently developed and is part now of the armamentarium in the treatment of atrial fibrillation. The ablation of atrial fibrillation started out from the experience of the surgical maze procedure, which showed very encouraging results but at a high price because it required open chest surgery. In the following years the attempt has been made to produce similar results using transcatheter ablation. Different approaches have been used: linear lesions mimicking the surgical maze operation, linear lesions in the right or left atrium using different schemes, or a sequential approach ablating first in the right and then in the left atrium.