BACKGROUND: Catheter ablation (CA) technology development reflects the need to improve the effectiveness of atrial fibrillation (AF) treatment. Recently, the DiamondTemp Ablation (DTA) RF generator software was updated with a more responsive power ramp. METHODS: DIAMOND FASTR-AF was a prospective, single-arm, multicenter trial. This study sought to characterize the performance of the updated DTA system for the treatment of patients with drug-refractory paroxysmal and persistent AF (PAF and PsAF). The primary effectiveness endpoint was freedom from atrial arrhythmia recurrence following a 90-day blanking period through 12 months, and the primary safety endpoint was a composite of serious adverse events. RESULTS: In total, 60 subjects (34 PAF and 26 PsAF) underwent CA at three centers. Patients were 71.7% male, (age 63.9 ± 10.2 years, with an AF diagnosis duration 3.1 ± 3.9 years and left atrial size 4.4 ± 0.8 cm). Pulmonary vein isolation-only ablation strategy was performed in 34 (56.7%) subjects. The procedural characteristics show a procedure time 90.8 ± 31.6 min, total RF time 14.7 ± 7.7 min, ablation duration 10.7 ± 3.6 s, and fluid infusion 284.7 ± 111.5 ml. The serious adverse event rate was 8.3% (5/60), 3 pulmonary edema and 2 extended hospitalizations. Freedom from atrial arrhythmia recurrence was achieved in 67.6% of subjects by 12 months. CONCLUSIONS: The updated DTA system demonstrated long-term safety and effectiveness through 12 months of post-ablation follow-up for patients with atrial fibrillation. Additionally, procedures were demonstrated to be highly efficient with short procedure times and low levels of fluid infusion. TRIAL REGISTRATION: Sponsored by Medtronic, Inc.; FASTR-AF ClinicalTrials.gov; NCT03626649.

• Keywords
• Atrial fibrillation, Catheter ablation, DiamondTemp, Radiofrequency,
• MeSH
• Atrial Fibrillation * surgery   MeSH
• Catheter Ablation * methods   MeSH
• Middle Aged MeSH
• Humans MeSH
• Prospective Studies MeSH
• Recurrence MeSH
• Aged MeSH
• Temperature MeSH
• Pulmonary Veins * surgery   MeSH
• Treatment Outcome MeSH
• Check Tag
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Multicenter Study MeSH

• Keywords
• Ablation, Anticoagulation, Arrhythmia, Atrial fibrillation, Atrial flutter, Atrial tachycardia, Catheter ablation, Stroke, Surgical ablation,
• MeSH
• Atrial Fibrillation diagnosis   physiopathology   surgery   MeSH
• Catheter Ablation adverse effects   standards   MeSH
• Consensus MeSH
• Cryosurgery adverse effects   standards   MeSH
• Humans MeSH
• Risk Factors MeSH
• Cardiac Catheterization adverse effects   standards   MeSH
• Treatment Outcome MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Review MeSH
• Practice Guideline MeSH

• Keywords
• Ablation, Anticoagulation, Arrhythmia, Atrial fibrillation, Atrial flutter, Atrial tachycardia, Catheter ablation, Stroke, Surgical ablation,
• MeSH
• Atrial Fibrillation diagnosis   physiopathology   surgery   MeSH
• Catheter Ablation adverse effects   standards   MeSH
• Consensus MeSH
• Cryosurgery adverse effects   standards   MeSH
• Humans MeSH
• Risk Factors MeSH
• Cardiac Catheterization adverse effects   standards   MeSH
• Treatment Outcome MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Review MeSH
• Practice Guideline MeSH

• Keywords
• Ablation, Anticoagulation, Arrhythmia, Atrial fibrillation, Atrial flutter, Atrial tachycardia, Catheter ablation, Stroke, Surgical ablation,
• MeSH
• Ablation Techniques standards   MeSH
• Atrial Fibrillation surgery   MeSH
• Cardiology * MeSH
• Catheter Ablation standards   MeSH
• Consensus Development Conferences as Topic * MeSH
• Humans MeSH
• Heart Conduction System surgery   MeSH
• Societies, Medical * MeSH
• Check Tag
• Humans MeSH
• Publication type
• News MeSH

• Keywords
• Ablation, Anticoagulation, Arrhythmia, Atrial fibrillation, Atrial flutter, Atrial tachycardia, Catheter ablation, Stroke, Surgical ablation,
• MeSH
• Atrial Fibrillation diagnosis   physiopathology   surgery   MeSH
• Cardiac Surgical Procedures standards   MeSH
• Catheter Ablation standards   MeSH
• Consensus MeSH
• Humans MeSH
• Risk Factors MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH

• Keywords
• AAD, antiarrhythmic drug, AF, atrial fibrillation, AFL, atrial flutter, Ablation, Anticoagulation, Arrhythmia, Atrial fibrillation, Atrial flutter, Atrial tachycardia, CB, cryoballoon, CFAE, complex fractionated atrial electrogram, Catheter ablation, LA, left atrial, LAA, left atrial appendage, LGE, late gadolinium-enhanced, LOE, level of evidence, MRI, magnetic resonance imaging, OAC, oral anticoagulation, RF, radiofrequency, Stroke, Surgical ablation,
• Publication type
• Journal Article MeSH

AIMS: A challenge of pulmonary vein isolation (PVI) in catheter ablation for paroxysmal atrial fibrillation (PAF) is electrical reconnection of the PV. EFFICAS I showed correlation between contact force (CF) parameters and PV durable isolation but no prospective evaluation was made. EFFICAS II was a multicentre study to prospectively assess the impact of CF guidance for an effective reduction of PVI gaps. METHODS AND RESULTS: Pulmonary vein isolation using a radiofrequency (RF) ablation catheter with an integrated force sensor (TactiCath™) was performed in patients with PAF. Operators were provided EFFICAS I-based CF guidelines [target 20 g, range 10-30 g, minimum 400 g s force-time integral (FTI)]. Conduction gaps were assessed by remapping of PVs after 3 months, and gap rate was compared with EFFICAS I outcome. At follow up, 24 patients had 85% of PVs remaining isolated, compared with 72% in EFFICAS I (P = 0.037) in which CF guidelines were not used. The remaining 15% of gaps correlated to the number of catheter moves at creating the PVI line, quantified as Continuity Index. For PV lines with contiguous lesions and low catheter moves, durable isolation was 81% in EFFICAS I and 98% in EFFICAS II (P = 0.005). At index procedure, the number of lesions was reduced by 15% in EFFICAS II vs. EFFICAS I. CONCLUSION: The use of CF with the above guidelines and contiguous deployment of RF lesions in EFFICAS II study resulted in more durable PVI in catheter ablation of PAF.

• Keywords
• Atrial fibrillation, Catheter ablation, Conduction gaps, Contact force, Pulmonary vein isolation,
• MeSH
• Equipment Failure Analysis MeSH
• Surgery, Computer-Assisted instrumentation   methods   MeSH
• Equipment Design MeSH
• Adult MeSH
• Atrial Fibrillation diagnosis   surgery   MeSH
• Catheter Ablation instrumentation   methods   MeSH
• Humans MeSH
• Body Surface Potential Mapping instrumentation   methods   MeSH
• Stress, Mechanical MeSH
• Transducers, Pressure MeSH
• Heart Conduction System surgery   MeSH
• Pulmonary Veins surgery   MeSH
• Treatment Outcome MeSH
• Check Tag
• Adult MeSH
• Humans MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Controlled Clinical Trial MeSH
• Multicenter Study MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• Europe MeSH

The efficacy of catheter ablation of atrial fibrillation (AF) remains limited. Increase of success would require more durable lesions without increased risk of complications, such as of steam pop and cardiac perforation. Recently, novel technologies have been developed to estimate real-time catheter-tissue contact force (CF). This paper reviews three available tools for assessment of CF and data on experimental or clinical experience. Experimental data with open-irrigated catheter showed that lesion size was greater with applications of lower power (like 30 W) and greater CF (e.g. 30 to 40 g) than vice versa with high power and low CF. Impedance drop in the first 5 seconds was significantly correlated to catheter CF. Perforation was achieved more rapidly with the ablation catheter in a sheath despite the same CF because the sheath prevents catheter buckling. Clinical experience confirmed poor relationship between CF and either unipolar amplitude, bipolar amplitude, or impedance. Within the left atrium, the most common high CF site was found at the anterior/rightward LA roof, directly beneath the ascending aorta (confirmed by merging the CT image and map). Importantly, several studies showed that the use of CF leads to shorter procedure with less fluoroscopy time and less RF applications. CF assessment was also found to be associated with higher proportion of durable lesions. Finally, pilot studies showed that CF measurement could be associated with better clinical efficacy AF ablation.

• Keywords
• Atrial Fibrillation, Catheter Ablation, Contact Force, Pulmonary Vein Isolation,
• Publication type
• Journal Article MeSH
• Review MeSH