The very high-power short-duration (vHPSD) temperature-controlled ablation (vHPSD) improves the efficiency of pulmonary vein isolation (PVI) procedures. We evaluated the procedural and 12-months outcomes in atrial fibrillation (AF) patients undergoing PVI by means of vHPSD ablation. In patients with AF or atrial tachyarrythmia (AT) recurrence undergoing a redo procedure the durability of the PVI was investigated.Consecutive paroxysmal/persistent AF patients undergoing PVI with the vHPSD ablation strategy (90 W, for 4 s) were enrolled. The rate of PVI, first-pass isolation, acute reconnection, and procedural complications were evaluated. Follow-up examinations and EKG were scheduled at 3,6, and 12 months. In case of AF/AT recurrence, patients underwent a redo procedure.Overall, 163 AF patients (29 persistent and 134 paroxysmal) were enrolled. The PVI was reached in 100% of patients (88% at the first pass). The rate of acute reconnection was 2%. The radiofrequency, fluoroscopy and procedural times were respectively 5.5 ± 1 min, 9 ± 1 min and 75 ± 20 min. No death, tamponade nor steam pops occurred; however, 5 patients had vascular complications. The 12-months freedom from AF/AT recurrence was 86% in both paroxysmal and persistent patients. Overall, 9 patients underwent a redo procedure, and in 4 all veins were still isolated, whereas in 5 pulmonary vein reconnections were found. The PVI durability was 78%. No overt clinical complications were observed in the follow-up.The vHPSD ablation represents an effective and safe ablation strategy to achieve PVI. The 12-months follow-up showed high freedom from AF/AT recurrence and a good safety profile.
Radiofrequency catheter ablation of the cavotricuspid isthmus is the standard treatment for patients suffering from typical atrial flutter. The aim of this study was to test the feasibility of tissue thickness and lesion transmurality measurement by a novel dielectric system. This was a retrospective multicentric non-randomized open-label, single-arm study. The atrial wall thickness was significantly higher close to the tricuspid annulus than close to the inferior vena cava and a trend towards a progressive decrease of atrial wall thickness was observed moving the mapping catheter from the tricuspid valve to the inferior vena cava. The possibility to visualize the tissue thickness could modify the way to deliver radiofrequency energy, allowing a tailored approach in cardiac ablation procedures.
Abstract Funding Acknowledgements Type of funding sources: None. Background An early and comprehensive rhythm-control therapy emerges as a need to treat AF in an effective way and to improve the ablation outcomes, in terms of arrhythmia-free survival. Purpose We aimed to investigate the importance of timing of ablation in preventing AF recurrences. Methods 153 consecutive patients (pts) undergoing AF ablation from the CHARISMA registry at 8 Italian centres were included. Ablations were guided by a novel radiofrequency ablation catheter with local impedance (LI)-sensing capability through a dedicated algorithm (DirectSense, Boston Scientific). Pts were grouped as early treated (ET) if the procedure was performed within 1 year after the first AF episode and as delayed treated (DT) if admitted for ablation after more than 1 year. The ablation endpoint was PVI as assessed by entrance and exit block. Post-ablation follow-up was scheduled at 3, 6 and 12 months. AF and atrial tachycardia (AT) recurrences were considered as long-term endpoint. Results Of the 153 pts enrolled (69.9% male, 59 ± 10 years, 61.4% paroxysmal AF, 38.6% persistent AF), 123 (80.4%) met Class I indications, 23 (15%) Class IIa indications and 7 (4.6%) Class IIb indications according to current ESC AF guidelines. The mean time to ablation procedure from the first AF episode was 1034 ± 1483 days. Eighty pts (52.3%) were included in ET group, whereas 73 pts (47.7%) in DT group. No differences were found between AF type in terms of ablation strategy (53.3% of the cases -52 out 94- were classified as ET for paroxysmal AF vs 47.5% of the cases -28 out 59- were ET for persistent AF, p = 0.4346). At the end of the procedures, all PVs had been successfully isolated in all study pts. During a mean follow-up of 366 ± 130 days, 18 pts (11.8%) suffered an AF/AT recurrence after the 90-day blanking period. Recurrences occurred mostly in the DT group compared to the ET one (13 out 73 -17.8%- vs 5 out 80 -6.3%-, p = 0.042) and the time to AT/AF recurrence was longer in the ET group (HR = 0.2876, 95%CI: 0.1029 to 0.8038; p = 0.0181). On multivariate logistic analysis adjusted for baseline confounders, only hypertension (HR = 4.66, 95%CI: 1.5 to 14.48, p = 0.0081) was independently associated with recurrences. An early rhythm-control therapy was associated with a low risk of recurrences beyond the hypertension risk factor, ranging from 2% (no hypertension and an ET ablation therapy) to 30.3% (with hypertension and a DT procedure) (Figure 1). Conclusion A LI-guided ablation strategy for PVI proved to be safe and effective and resulted in a very high recurrence-free rate. An early rhythm-control therapy in the absence of common risk factors was associated with the lowest rate of recurrences. Abstract Figure. AT/AF Recurrence
Abstract Funding Acknowledgements Type of funding sources: None. Background Very high-power short-duration (vHPSD) temperature-controlled radiofrequency ablation minimizes conductive heating and increase resistive heating, achieving uniform and transmural lesion while reducing the risk of collateral tissue damages. The shape of the vHPSD lesion, wider and shallower than standard radiofrequency, raises some concerns during atrial flutter ablation (AFL). Purpose We evaluated the feasibility, efficacy and safety of the vHPSD ablation of the cavotricuspid isthmus (CTI) in patients presenting with typical AFL. Methods Sixty-one consecutive patients, with typical AFL, underwent CTI ablation using the QDot Micro catheter and vHPSD (90 w for 4 s). Patients were followed-up by means of visits and ECG in the outpatient clinic 1, 6 and 12 months after the procedure and later on with telephone interviews or by 24-h Holter monitoring in case of symptoms. Results Acute CTI bidirectional block was achieved in all patients (91% of first-pass block) with a mean fluoroscopy time of 114±29 s and a mean procedure time of 37±9 min. Two steam pops were observed. Two patients had groin hematoma, no further complications were observed. During a mean follow-up of 14±7 months, two (3.2%) patient had typical AFL recurrence, and four (6.5%) patients had an atrial fibrillation recurrence. Conclusions The vHPSD ablation represents an effective and safe ablation strategy to achieve bidirectional block for the treatment of typical AFL.
Abstract Background Isthmus-dependent right atrial flutter is the most frequently encountered atrial flutter in clinical practice (80–90% of atrial flutters). Purpose The aim of our study was to assess as first experience the feasibility and safety of radiofrequency catheter ablation (RFCA) of cavo-tricuspid isthmus (CTI) guided by KODEX-EPD imaging system in patients presenting with typical atrial flutter (AFL). Methods 16 consecutive patients (mean age 68,46±7,8 years, 80% males) with diagnosis of AFL underwent RFCA guided by KODEX-EPD imaging system. In 15 patients the analysis performed during tachycardia showed a counter-clockwise activation. In 1 patient no tachycardia could be induced and the ablation was performed in sinus rhythm with fixed pacing from the coronary sinus. The KODEX-EPD imaging system was also used to guide ablation and to confirm persistent bidirectional block after ablation. Results Mean procedural time was 37,6±8,2 min, mean radiofrequency ablation time was 7,8±3,4 min, and mean fluoroscopy time was 2,1±1,2 min. All procedures were acutely successful with interruption of AFL during RFCA along the inferior CTI in 15 patients and achievement of the bidirectional conduction block in 16 patients proven by atrial pacing medial and lateral to the ablation line. There were no major procedural and 30-day complications. Over a mean follow-up of 18 months, we observed no recurrence of arrhythmia and no complications. Conclusions Our study shows that RFCA for AFL using the KODEX-EPD imaging system is feasible, safe, and effective. Funding Acknowledgement Type of funding sources: None.
