Evaluation of myocardial injury induced by different ablation approaches in atrial fibrillation patients

Funding Acknowledgements

Type of funding sources: None.

Background

To evaluate myocardial injury in Atrial Fibrillation (AF) patients undergoing High Power Short Duration radiofrequency (HPSD) and visually guided Laser Balloon Ablation (LBA).

Methods and results

In this single center registry we prospectively enrolled 40 patients (67% male), mean age 63±9, with paroxysmal or persistent AF (see table I). The ablation target has been the pulmonary vein isolation (PVI) with LBA and wide area circumferential ablation (WACA) with HPSD.

6 and 18 hours post-procedure samples of high sensitive cardiac troponin I (cTnI) were collected.

The results show not significant differences in target population and no significant differences in high sensitive cardiac troponin I (cTnI pg/ml) levels at 6h (HPSD cTnI =806±496 pg/ml vs laser cTnI = 664±339 pg/ml p=0.17) and 18 hours after ablation (HPSD cTnI =833±540 pg/ml vs laser cTnI = 1081±962 pg/ml p=0.07).

Conclusion

These results indicate that myocardial injury induced by HPSD and LBA at 6 and 18 hours after procedure are similar targeting WACA and PVI respectively. This registry is ongoing to evaluate freedom from AF at 12 months follow up.

Gender differences in arrhythmias and psychological discomfort management

Funding Acknowledgements

Type of funding sources: None.

Background

Palpitations and/or syncope are common in patients with psychoneurological disorders [1]. Arrhythmias may be associated to psychological discomfort as well [2]. Psychiatrics, epidemiology and commonplace agree that gender may lead to difference in symptom perception, and management [3-4]

Purpose

To investigate the abovementioned association we realized a retrospective multicentric registry including, after definite instrumental diagnosis, patients with previous mental disorder diagnosis, referring to arrhythmology ambulatories.

Results

64 pts (48 F, 75%), mean age 54±18y, were enrolled in 7 centers. Psychiatric diagnoses were: anxiety-depression disorder (N=50), panic attack (N=5), behavioural disorder (N=4), epilepsy (N=3), psychosis (N=1), diagnosed in 83% by General Practitioners and in 14% by Psychiatrists. 55 pts (86%) were on drug therapy: benzodiazepines (67%), SSRI (22%), neuroleptics (3%), antidepressants (2%), and natural products (5%). Among these, 89% reported no symptoms relief. 57 pts complained palpitations, 17 extrasystoles and 19 reported syncope. EPS study was performed in 48%, 24 h Holter ECG in 28%, and LR implantation in 5% of patients. We diagnosed AF (N=11), typical AFL (N=4), AT (N=8), AVNRT (N=16), AVRT (N=4), PAC (N=1), PVC (N=10), AV block (N=4), VT (N=3) and unspecified SVT (N=3). 44 pts underwent ablation. 62 pts (96,8) experienced strong symptoms reduction or resolution, and 42 psychiatric drugs withdrawal. One pt underwent PMK implantation.

Conclusions

In our series of cardiac symptoms ascribed to psychiatric disorders, women markedly prevailed. Psychologic discomfort could be caused by arrhythmias, as resolved or dramatically ameliorated by diagnosis and treatment. Further investigation in Psychiatric context is warranted.

P1020Persistent AF patients with limited areas of low voltage have a similar benefit from pulmonary vein isolation as compared to paroxysmal AF patients: insight from the SMOP study

Background

Pulmonary vein isolation (PVI) performed with radio-frequency catheter ablation (CA) is an effective therapy for atrial fibrillation (AF). However previous data have suggested that PVI is less effective in persistent (PER) vs. paroxysmal (PAR) AF. Atrial fibrosis and scar, indeed, are an important substrate involved in persistent AF, and some author correlate them to an increased rate of recurrences after CA. For this reason several adjunctive ablation strategies have been suggested for invasive treatment in PER AF pts. However, there is a lack of evidence on their effectivness in current literature.

Objective

the aim of our study was to assess the rate of AF recurrences in PAR and PER AF patients after a first pulmonary vein isolation (IVP) procedure, and their relationship with low voltage areas of the left atrium assessed by means of high density mapping performed before CA.

Methods

we analyzed 214 patients of the SMOP-AF study (Substrate Mapping as Outcome Predictor in Atrial Fibrillation Ablation), a prospective multi-centric registry enrolling patients with both PAR and PER AF undergoing a first radio-frequency CA procedure aimed to obtain permanent PVI . High-density mapping was performed in sinus rhythm using the CARTO system before PVI. Areas with less than 0,5 mV on mapping were defined as low voltage zone (LVZ); LVZ was indexed on the atrial area. Comparisons were made by cross-tables and Chi-square test or Student T test.

Results

Patients with PER AF (n = 44, 21%) were older (63 ± 9 vs 58 ± 10 yrs, p = 0.01), but notably with no difference in LVEF and atrial dimensions as compared to pts with PAR AF. In addition no statistical difference was observed in procedural variables, except for a greater LVZ area on atrial mapping (8 ± 18 % vs. 5 ± 15 %, p = 0.04) and a longer p wave duration (115 ± 21 msec vs. 103 ± 18 msec, p = 0.01) in pts with PER AF. The incidence of recurrence in the overall population was 15.3% at 3 months and 13.7% from 3 to 12 months: there was no statistical difference in success-rate between PER and PAR pts (respectively 79,5% vs 86% p value = 0.315 in blanking period and 85,3% vs 86,5% p value = 0.8 at 3-12 months follow-up). No statistical difference was observed for ablation variables (number of lesion, contact force, force time integral) in pts with vs. without recurrences.

Conclusion

Our study showed that pulmonary vein isolation alone seems to be as effective in paroxismal and persistent AF patients with low degree of left atrial fibrosis. Our data call into question the idea that PVI alone is not effective in PER AF. High density mapping of the LA could help to identify a subset of PER AF patients with a limited extension of low voltage areas (i.e around 10% of the overall LA surface) that could benefit from PVI without adjunctive ablation strategies. Our data needs to be confirmed in a longer follow-up.

P1896Single-procedure success-rate of pulmonary vein isolation using point-by-point tagging lesions algorithm based on contact force technology: preliminary results of the multicentric SMOP study

Background

Pulmonary veins isolation (PVI)is an effective therapy for atrial fibrillation (AF), recommended by current guidelines. However, recurrences after first radio-frequency (RF) catheter ablation (CA) are still high. PV reconnection could be due to ineffective transmural lesions; automated ablation lesion tags (the VisiTag algorithm) based on predefined parameters of catheter stability and contact force (CF) have been developed to allow the detection of ineffective ablation lesion, nevertheless there is a lack of multicenter studies exploring this technology.

Objective

the aim of our study was to assess the rate of recurrence after a first PVI procedure in a large, multicentric Italian population and to explore the efficacy of Visitag algorithm (CARTO 3) used to guide RF ablation of AF.

Methods

we analyzed 214 patients of the SMOP-AF study (Substrate Mapping as Outcome Predictor in Atrial Fibrillation Ablation), a prospective multi-centric study enrolling patients with paroxysmal and persistent AF undergoing a first PVI procedure after an high-density mapping during sinus rhythm. During the procedure, ablation was guided by an automated annotation system in which tag based on predefined parameters were displayed real-time in each lesion site on the electroanatomical map. Visitag settings for the catheter position stability were a 2,5 mm distance limit for at least 7 sec and a minimum CF of 5 g over 30% of the ablation and a FTI>400 g*s. Where available (n=106, 49.5%), Ablation Index (AI), which also incorporates information on delivered RF power, was used instead of FTI to guide RF ablation with a threshold range of 400–550 for anterior/roof and 330–420 for posterior/inferior segments. Minimum and mean contact force, time and power values for each RF-lesion were recorded while both FTI and AI values were calculated automatically by the CARTO system. Comparison between groups were made by cross-tables, Mann-Whitney or Student T test as appropriated.

Results

the mean age of the enrolled population was 59±9 years, left ventricular ejection fraction was 59±9%. AF was paroxysmal in 89.7%, persistent in 10.3% of the patients and refractory to at least one anti-arrhythmic drug in 86.4% of the population. At 3 months follow-up 85% of the patients were free from AF recurrences and the success rate increased to 90.8% at 3–6 months, and 86.3% at 3–12 months follow-up. The mean ablation time was shorter in AI-guided vs. FTI-guided procedures (31±9 vs 46±29 min; p<0.001). There was a trend toward a reduction in AF recurrences when AI vs. FTI was used, both at 6 and 12 months (respectively 5,4% vs 13.6%; p 0.06 and 9.6% vs 18.5%; p 0.08).

Conclusion

PVI isolation using dedicated algorithms developed to guide the effectiveness of RFCA leads to a very high success-rate after a single procedure. The use of AI, which integrates contact force information with delivered power, reduces the procedural time and increases the overall success-rate

P1037Relationship between left atrium low voltage areas and atrial fibrillation radiofrequency ablation success-rate: preliminary results of the SMOP study

Background

radio frequency catheter ablation (CA) is an effective therapy for atrial fibrillation (AF). Some authors have described a potential relationship between the presence of areas of fibrosis in the left atrium (LA) and the success of CA, nevertheless there is a lack of multicenter studies in this field.

Objective

the aim of our study was to assess the relationship between the of presence of low voltage areas of the LA detected during subtrate mapping at the time of the procedure and recurrences of AF after CA.

Methods

we analyzed 214 patients of the SMOP-AF (Substrate Mapping as Outcome Predictor in Atrial Fibrillation Ablation), a prospective multi-centric study enrolling patients with both paroxysmal and persistent AF undergoing a first radio-frequency CA procedure. High-density mapping was performed in sinus rhythm using the CARTO system before performing pulmonary vein isolation. Areas with less than 0,5 mV on mapping were defined as low voltage zone (LVZ), while between 0,5 mV and 1,5 mV intermediate voltage zone (IVZ). IVZ and LVZ were expressed as a percentage of the LA surface. Comparisons were made by Pearson correlation, cross-tables and Chi-square test or Student T test.

Results

the mean age of the enrolled population was 59±9 years, left ventricular ejection fraction was 59±9%, 86.4% of the pts had tested at least one anti-arrhythmic drug. Persistent atrial fibrillation was present in 10.3% of patients. The rate of documented AF recurrence at 3 months was 15,3% (n=29). There was a statistical significant correlation between the presence of IVZ and the rate of recurrences at 3 months (r=0.16, p value 0.03). Patients with IVZ greater than 4% of the left atrium surface showed a higher risk of recurrences (19.5% vs. 8,7%, p value 0.04). No statistical difference was observed in other procedural variables (number of lesions, contact force, force-time integral) among patients with or without recurrences.

Conclusion

Our study showed a relationship between CA short-term success rate and the presence of areas of intermediate voltage zone detected with high-density substrate mapping at the time of the procedure. The presence of areas of intermediate voltage zone greater than 4% of the LA determines a 2.5 folds increased risk of short-term recurrence. Our data needs to be confirmed in a longer follow-up.