Efficacy Comparison of High and Very High Power Short Duration Pulmonary Vein Isolation
Condition: Atrial Fibrillation
MeSH terms: Atrial Fibrillation
Study type: Interventional

Summary: 
      Objective: To evaluate the long-term durability of PVI performed with 90W and 50W (QDot
      catheter).

      Primary hypothesis: Pulmonary vein isolation performed with 90W (QMODE+) and inter-tag
      distance <5 mm is non-inferior to pulmonary vein isolation performed with 50W guided by
      ablation index (QMODE) and inter-tag distance <5 mm.

      Study Design: 40 patients will be randomized in a 1:1 ratio to 50W and 90W PVI.

      Study procedures: Initial PVI will be performed via femoral access and double transseptal
      puncture guided by fluoroscopy and pressure monitoring. If necessary intracardiac
      echocardiography (ICE) will be used for the transseptal puncture. A fast anatomical left
      atrial map will be created with a multipolar mapping catheter; then, point-by-point PVI will
      be performed with QDot catheter with 50W or 90W according to randomization. Three months
      after the initial procedure, patients will undergo a repeated high density left atrial
      mapping with PentaRay or OctaRay catheter to evaluate the durability of the PVI. Exact gap
      numbers and locations will be registered. If necessary, reablation of the pulmonary veins
      (rePVI) will be performed.

      Inclusion criteria: Symptomatic paroxysmal/persistent AF, >18 years, willingness to sign
      informed consent form.

      Exclusion criteria: Long-standing persistent AF, active malignancy, contraindication for
      anticoagulant therapy, life expectancy <1 year, valvular AF, hyperthyroidism.

      Endpoints: At repeat procedure, a high density left atrial map will be created with PentaRay
      or if available OctaRay catheter to evaluate the durability of the PVI. Primary endpoint will
      be pulmonary vein reconnection.
    

Detailed description: 
      1. Background

           Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia in adults. Its
           prevalence increases with age, affecting 3/100 people, and its incidence is also
           correlated with age, affecting 30/100,000 people per year. Its clinical significance
           stems from common complications (stroke, heart failure) and concomitant higher
           mortality.

           The most effective treatment method of atrial fibrillation is catheter ablation, which
           seeks to maintain sinus rhythm. Isolation of the triggering pulmonary veins (PVI) from
           the left atrium is the cornerstone of AF ablation. PVI has undergone significant
           technical development over the past decade; however, the chances of arrhythmia
           recurrence and the occurrence of procedural complications are not negligible.

           Experiments have shown that lesions with a larger surface diameter but less depth
           develop during HPSD ablation; the higher the energy is, the shallower and wider the
           lesions are. These lesion properties make it easier to create a solid line from the
           ablation points, while the shallower lesion causes less damage to the surrounding
           tissues. The latest application of HPSD technology is the so-called "very high power
           short duration" (vHPSD) ablation when we apply 90W power. No data are available on
           long-term efficacy or safety comparing ablation with HPSD vs. vHPSD.

        2. Objective: To evaluate the durability of radiofrequency PVI performed with 90W (QMODE
           plus) and 50W (QMODE) with the QDot catheter.

        3. Primary hypothesis: Pulmonary vein isolation performed with 90W (QMODE+) and inter-tag
           distance <5 mm is non-inferior to pulmonary vein isolation performed with 50W guided by
           ablation index (QMODE) and inter-tag distance <5 mm.

        4. Study Design: Single-center, prospective, randomized study. Patients will be randomly
           assigned in a 1:1 ratio to HPSD (50W) and vHPSD (90W) PVI.

        5. Research period Planned research period from the second quarter of 2022 for a maximum of
           1 year.

        6. Study subjects

           • Planned number of included subjects: 40.

        7. Study procedures:

             -  Initial PVI will be performed via femoral access after double transseptal puncture
                guided by fluoroscopy and pressure monitoring. If necessary ICE will be used for
                the transseptal puncture. A fast anatomical left atrial map will be created with a
                multipolar mapping catheter; then, point-by-point PVI will be performed with QDot
                catheter with 50W or 90W according to randomization. After creating the isolation
                circle, the presence or absence of first-pass isolation will be assessed by
                multipolar catheters. If PVI is not complete at this point, it will be completed to
                reach complete isolation of all veins. After that, a 20 minutes waiting period will
                be the next step to evaluate presence or absence of acute reconnection of the PV-s.
                In case of acute reconnection, touch-up applications will be delivered to complete
                the PVI.

             -  Three months after the initial procedure, patients will undergo a repeated high
                density left atrial mapping with PentaRay or, if available OctaRay catheter to
                evaluate the durability of the PVI. Exact gap numbers and locations will be
                registered (based on the 16 segment PV model). If necessary, rePVI will be
                performed.

        8. Statistical analysis Continuous variables are expressed as mean and standard deviation,
           or median and interquartile ranges, depending on the normal of non-normal distribution.
           Categorical variables are expressed in numbers and percentages. Continuous variables are
           compared by parametric or non-parametric tests, depending on the distribution, while
           categorical variables are compared by Chi-square test or Fisher's exact test. The
           predictive value of different ablation techniques in outcome is planned to be analyzed
           by logistic regression. A two-tailed p-value of <0.05 will be considered statistically
           significant. Statistical analyses will be performed using IBM SPSS 25 (Apache Software
           Foundation, USA) and GraphPad Prism 7.1 (GraphPad Softwares Inc., USA) software
           products.

        9. Data management All study patient data is entered into Semmelweis University's
           electronic database (accessible only from Semmelweis University's network) in a coded
           and unique manner, with a unique identifier, to which project staff has a
           password-protected, defined level of access. Each person involved in the study is given
           a unique identification code, and the data stored in the database is linked to that
           unique identifier. Thus, a data set will be incomprehensible and unusable for an
           external (unauthorized) user. The data belonging to the unique identification code, with
           which the patient's identity can be clearly indicated (name, place and date of birth,
           clinical reference number, identification number, identity card number, etc.) are not
           available from the database and are stored separately from it. Access to personal data
           is restricted to institutional leaders and program professional leaders.

       10. Personal and material requirements The personal and material requirements of the
           research are available at the Heart and Vascular Center of Semmelweis University. The
           personal requirements are given by the staff of the Electrophysiological Laboratory, and
           the material conditions are provided by the equipment of the same laboratory.

       11. Ethics approval

      An ethics approval was obtained from the Hungarian National Public Health Center (No.
      8119-2/2022/EÜIG).
    

Intervention name(s): QDot Micro Catheter
Intervention type(s): Device
Intervention description(s): Atrial fibrillation radiofrequency ablation with 90W or 50W energy setting.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: atrial fibrillation; catheter ablation; high-power, short-duration; pulmonary vein isolation; durability