Safety and Effectiveness of the Sphere-9™ Catheter and Affera™ Ablation System for the Treatment of Ventricular Tachycardia (Sphere VT)

Safety and Effectiveness of the Sphere-9™ Catheter and Affera™ Ablation System for the Treatment of Ventricular Tachycardia

Sphere VT is a prospective, multi-center, single-arm, unblinded pivotal clinical study. Adult subjects with recurrent, sustained, monomorphic ventricular tachycardia (MMVT) due to prior myocardial infarction (MI) will be enrolled and treated with the Sphere-9 Catheter and Affera Ablation System.

Study Overview

• Status: Not yet recruiting
• Conditions: Ventricular Tachycardia
• Intervention / Treatment: Device: Sphere-9 Catheter with the Affera Mapping and Ablation System

• Study Type: Interventional
• Enrollment (Estimated): 260
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Josh Treadway; Phone Number: 817-412-0608; Email: josh.b.treadway@medtronic.com
• Study Contact Backup: Name: Analyn Jackson; Phone Number: 214-697-9894; Email: analyn.u.jackson@medtronic.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Prior myocardial infarction (MI).
2. At least one episode of sustained (continuous for >30 seconds or requiring ICD intervention for termination) monomorphic ventricular tachycardia within the 6 months prior to enrollment.
3. Recurrence of sustained ventricular tachycardia despite Class I or III antiarrhythmic drug therapy or ICD intervention.
4. Implanted with an implantable cardiac defibrillator (ICD) or CRT-D for at least 2 months prior to the ablation procedure.
5. Age 18 through 85 years old.
6. Willing and able to provide informed consent.
7. Willing and able to comply with all pre-, post-, and follow-up testing requirements.

Exclusion Criteria:

1. Incessant VT necessitating hemodynamic support prior to the ablation procedure.
2. Unstable polymorphic VT or ventricular fibrillation (VF).
3. Idiopathic VT or VT of non-ischemic cardiomyopathy.
4. VT secondary to electrolyte imbalance, active thyroid disease, or any other reversible or non-cardiac cause (e.g., drug-induced arrhythmia).
5. VT or VF thought to be from channelopathies.
6. More than two prior VT ablations at any time, more than one prior VT ablation within 12 months prior to the ablation procedure, or any VT ablation within 4 weeks prior to the ablation procedure.
7. Sarcoidosis.
8. Hypertrophic cardiomyopathy, except when due to an apical aneurysm.
9. Unstable angina.
10. Active myocardial ischemia.
11. Type 1 myocardial infarction within 2 months (60 days) prior to the ablation procedure.
12. Any percutaneous coronary intervention performed in a setting of unstable angina or acute MI (STEMI or non-STEMI) within 2 months (60 days) prior to the ablation procedure. Note: elective PCI performed during elective angiogram would be excluded only if occurring within 30 days prior to the ablation procedure.
13. Any cardiac surgery within 2 months (60 days) prior to the ablation procedure. Note: ICD lead implant/replacement falls under this exclusion, but ICD generator-only replacement does not.
14. Left ventricular ejection fraction (LVEF) <15%.
15. NYHA Class IV heart failure.
16. Decompensated heart failure.
17. Extravascular ICD (EV-ICD) or subcutaneous ICD (S-ICD)
18. Currently receiving support, or anticipated to receive support prior to the index ablation procedure, via extracorporeal membrane oxygenation (ECMO).
19. Circulatory/ventricular assist device (VAD; surgical or percutaneous) implanted, planned or required for the procedure.
20. Severe aortic or mitral stenosis, or severe aortic or mitral regurgitation.
21. Presence of prosthetic valve in the aortic or mitral valve.
22. Patients with advanced COPD (on home oxygen).
23. Presence of intracardiac tumor or other abnormality that precludes vascular access, catheter introduction, or manipulation.
24. Thromboembolic event (stroke or transient ischemic attack) within 6 months (180 days) prior to the index ablation procedure or with neurologic deficit.
25. Left atrium (LA) or left ventricle (LV) intracardiac thrombus on imaging.
26. Severe bleeding, clotting or thrombotic disorder, or thrombocytopenia (defined as platelet count <80,000).
27. Contraindication to anticoagulation.
28. End-stage renal disease (requiring dialysis).
29. Acute illness, active infection, or sepsis.
30. Life expectancy less than 12 months.
31. Any woman known to be pregnant or breastfeeding, or any woman of childbearing potential who is not on a reliable form of birth regulation method or abstinence.
32. Body mass index >45 kg/m2.
33. Known ongoing drug or alcohol dependency.
34. Current or anticipated participation in any other ongoing study of a drug, device, or biologic during the duration of the study not pre-approved by the Sponsor.
35. Vulnerable subjects (such as a prisoner, handicapped or mentally disabled person, or person under tutelage or guardianship).
36. Any other condition that, in the opinion of the investigator, would preclude enrollment in this study or compliance with follow-up requirements or would pose a significant hazard to the subject if an ablation procedure were performed.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Ventricular tachycardia catheter ablation; Ablation using the Sphere-9 Catheter with the Affera Mapping and Ablation System	Device: Sphere-9 Catheter with the Affera Mapping and Ablation System; Adult subjects with ventricular tachycardia will be enrolled and undergo ablation with the Sphere-9 Catheter with the Affera Mapping and Ablation System.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Primary Safety	A pre-defined list of device- or procedure-related SAEs, as adjudicated by the Clinical Events Committee (CEC), occurring within 7 days after the index ablation procedure (or within 3 months after the index ablation procedure for any esophago-pericardial fistula/esophageal perforation) will be considered a primary safety event.	As applicable, within 7 days or 3 months after the index ablation procedure
Primary Effectiveness	Freedom from recurrence of sustained monomorphic VT (MMVT) in the absence of new or increased dose of Class I or III antiarrhythmic drugs (AAD) through 6 months after the index ablation procedure.	Through 6 months after the index ablation procedure

Collaborators and Investigators

• Sponsor: Medtronic Cardiac Ablation Solutions
• Investigators: Principal Investigator: Vivek Reddy, MD, Icahn School of Medicine at Mount Sinai; Principal Investigator: Pasquale Santangeli, MD, The Cleveland Clinic

Study record dates

Study Major Dates

• Study Start (Estimated): June 1, 2026
• Primary Completion (Estimated): March 1, 2028
• Study Completion (Estimated): September 1, 2028

Study Registration Dates

• First Submitted: May 7, 2026
• First Submitted That Met QC Criteria: May 7, 2026
• First Posted (Actual): May 14, 2026

Study Record Updates

• Last Update Posted (Actual): May 14, 2026
• Last Update Submitted That Met QC Criteria: May 7, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Pathologic Processes; Cardiovascular Diseases; Heart Diseases; Ventricular tachycardia; Ischemic heart disease; Ischemic cardiomyopathy; Arrhythmias, Cardiac; Patient with Implantable Cardioverter Defibrillator (ICD); Recurrent sustained scar-related monomorphic ventricular tachycardia
• Additional Relevant MeSH Terms: Cardiac Conduction System Disease; Vascular Diseases; Tachycardia; Pathological Conditions, Signs and Symptoms; Cardiovascular Diseases; Heart Diseases; Pathologic Processes; Myocardial Ischemia; Tachycardia, Ventricular; Arrhythmias, Cardiac
• Other Study ID Numbers: Sphere VT

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes