Intracardiac CrYoablation for AtrioVentricular Nodal Reentrant Tachycardia

• Freezor Xtra Cryoablation Catheter (Device): Freezor® Xtra Cardiac CryoAblation applied for cryoablation of the conducting tissues of the heart in the treatment of patients with atrioventricular nodal reentrant tachycardia using an endocardial approach.

Primary outcomes

• Chronic Effectiveness (Through 6 Months) of the Freezor Xtra Catheter for the Treatment of AVNRT Using an Endocardial Approach. [6 months]: Subjects must have met both of the following acute and chronic conditions to be considered a chronic effectiveness (treatment) success: * Acute Success: The inability to induce more than one echo beat by the same pacing maneuvers that induced AVNRT before cryoablation (with drug provocation if required for induction before cryoablation) at the conclusion of the study cryoablation procedure assessment. * Chronic Success: Lack of documented recurrence of clinical AVNRT during the 6-month follow-up period after the study cryoablation procedure.
• Chronic Safety (Through 6 Months) of the Freezor Xtra Catheter When Used for the Treatment of AVNRT Using an Endocardial Approach. [6 Months]: Subjects who had at least one safety event during or after their cryoablation procedure or through 6 months of follow-up are considered a primary (chronic) safety failure. A safety event is defined as the occurrence of any adverse event that is adjudicated by the AE Adjudication Committee as being serious and study ablation procedure-related and/or Freezor Xtra Catheter related that: 1) Resulted in death, 2) Resulted in a life-threatening illness or injury, 3) Resulted in permanent impairment of a body function or permanent damage to a body structure, 4) Necessitated significant intervention, such as major surgery or even intravenous medical therapy (e.g., vasopressors), to prevent permanent impairment of a body function or permanent damage to a body structure, or 5) Required in-patient hospitalization or a prolongation of an existing hospital stay.

Secondary outcomes

• Chronic Effectiveness (Through 6 Months) of the Freezor Xtra Catheter for the Treatment of AVNRT in Subjects Who Achieved Acute Procedural Success. [6 Months]: If there was no documented evidence of AVNRT recurrence in the post-procedure 6-month follow-up period, the subject is counted as a chronic effectiveness success. The AE Adjudication Committee adjudication of AVNRT recurrence is used to classify subjects for this endpoint.

Sex: All, ages: 18 Years to any

Pre-Electrophysiology Study Inclusion Criteria:

* Supraventricular tachycardia (SVT) compatible with atrioventricular nodal reentrant tachycardia (AVNRT), documented by ECG, TTM, Holter or event monitor

Pre-Electrophysiology Study Exclusion Criteria:

* History of sustained (≥30 seconds) of ventricular tachycardia
* Atrial tachycardia or other arrhythmia that could be confused with AVNRT
* Reversible cause of SVT
* History of previous AVNRT ablation
* Therapy with amiodarone within last 90 days
* Unstable angina/myocardial infarction/open heart surgery in past 60 days
* New York Heart Association (NYHA) Classification III or IV currently or within the past 90 days
* Implantable cardiac rhythm device
* Atrioventricular block (first degree (PR interval ≥ 220ms), second degree, or third degree) or left bundle branch block
* Stroke or transient ischemic attack within the past 180 days
* Life expectancy less than 12 months
* Female known to be pregnant
* Unable/unwilling to give informed consent
* Unable/unwilling to comply with follow-up visits and study requirements
* Less than 18 years of age
* Active systemic infection
* Cryoglobulinemia
* Other conditions where the manipulation of the catheter would be unsafe (for example, intracardiac mural thrombus)
* Participating in a concurrent clinical study that may confound the results of this study

Post-Electrophysiology Study Inclusion Criteria:

* Subject must have one electrophysiology study documented inducible sustained (greater than or equal to 15 seconds) supraventricular tachycardia that is classified as AVNRT.

Post-Electrophysiology Study Exclusion Criteria:

* Presence of a second inducible arrhythmia that could be confused with AVNRT during follow-up or will likely result in ablation within the next 6 months
* Presence of inducible sustained ventricular tachycardia or fibrillation
* Presence of an accessory pathway
* Presence of abnormal conduction or refractoriness parameters of the atrioventricular conduction system.
* Indication for a pacemaker, defibrillator or cardiac resynchronization therapy (CRT)

Participant flow

Outcome results

• Chronic Effectiveness (Through 6 Months) of the Freezor Xtra Catheter for the Treatment of AVNRT Using an Endocardial Approach. (Primary), Count of participants, Participants: mITT Set 368 (p <0.0001)
• Chronic Safety (Through 6 Months) of the Freezor Xtra Catheter When Used for the Treatment of AVNRT Using an Endocardial Approach. (Primary), Count of participants, Participants: mITT Set 4 (p <0.0001)
• Chronic Effectiveness (Through 6 Months) of the Freezor Xtra Catheter for the Treatment of AVNRT in Subjects Who Achieved Acute Procedural Success. (Secondary), Count of participants, Participants: mITT Subjects With Acute Procedural Success 368 (p <0.0001)

Adverse events

Time frame: Adverse events were collected for each subject from the time of their enrollment through the visit cut-off date for the primary endpoint analyses (September 18, 2015).

Serious adverse events by term

Other adverse events by term

134 more terms not shown.

• Results publication: Wells P, Dubuc M, Klein GJ, Dan D, Roux JF, Lockwood E, Sturmer M, Dunbar D, Novak P, Rao A, Peterson BJ, Kueffer F, Ellenbogen KA; ICY-AVNRT Investigators. Intracardiac ablation for atrioventricular nodal reentry tachycardia using a 6 mm distal electrode cryoablation catheter: Prospective, multicenter, North American study (ICY-AVNRT STUDY). J Cardiovasc Electrophysiol. 2018 Jan;29(1):167-176. doi: 10.1111/jce.13367. Epub 2017 Nov 10. PMID 29044787

• Peter Wells, M.D., Principal investigator, Baylor Univ Medical Ctr Dallas, TX.