Adagio Ventricular Ablation Tech Performs Well In Clinical Trial

Ventricular tachycardia (VT) is a life-threatening ventricular rhythm disturbance. Although it can be treated medically, VT often is very resistant to drugs and results in many hospitalizations and ICD shocks. A new generation of easier and safer ablation tools for VT have been under development by a small medical device maker. Recently presented pivotal clinical trial results for the adagio Medical vCLAS catheter and ultra-low temperature cryoablation (ULTC) technology will change how VT is managed and how electrophysiologists practice and result in improved patient quality of life for many patients with VT.

Pivotal Clinical Trial Results

The results from the FULCRUM-VT trial recently presented at the 2026 Heart Rhythm Society (HRS) Scientific Sessions confirm that the vCLAS catheter from small medical device maker Adagio Medical is transitioning from a promising concept to a potential clinical standard for VT ablation. The ULTC technology used in the vCLAS allows for relatively easy creation of very large lesions within the ventricles, making it particularly well suited for the large number of patients with structural heart disease and a variety of different arrhythmias. The acute results of non-inducibility of VT from targeted ablation sites in 98% of 100 patients followed on average of six months after the procedure are very important but the follow-up results are more telling of the long-term potential of the technology.

Why It Matters

VT is a potentially life-threatening arrhythmia that is difficult to treat medically and is often characterized by recurrences of episodes of arrhythmia resulting in hospitalizations. Simple ablation for VT is not commonly performed due to technical difficulties associated with VT ablation and low success rate for long-term freedom from VT recurrences within 1 year after VT ablation. Creation of lesions that are often inadequate in ablation for VT, in addition, procedures for VT ablation are often long and require specialized skills, in addition to technical expertise, advanced equipment, and experience, ablation for VT also often requires adjunctive maneuvers for optimal success. These maneuvers can pose additional risks to the patient.

In addition to the high temperature produced by the vCLAS catheter using ultra-low temperature cryoablation (ULTC) technology to create large, deeply tapered lesions in the ventricle, other advantages of the technology include facilitating an ablation procedure of less complexity and reduced duration. By allowing the catheter to remain in a stable location within the endocardium, many additional maneuvers are often obviated to achieve adequate lesions in a variety of underlying cardiac diseases (e.g. ischemic heart disease vs. non-ischemic heart disease with cardiomyopathy).

What the research says

The results of the FULCRUM-VT trial are very impressive. The technology used in the vCLAS catheter delivers very consistent results in all types of structural heart disease and thus is a major step forward in the ablation of VT. For many years, ablation technologies have been more effective in the treatment of patients with ischemic heart disease than in those with non-ischemic heart disease. Indeed, the results of most radiofrequency ablation studies for VT are significantly better in the ischemic patient. However, the results from the FULCRUM-VT trial using the ULTC technology in the vCLAS system are consistent in all types of structural heart disease and thus can be used to treat all types of VT in all types of structural heart disease without the need for different tools for different diseases.

The major adverse events (MAE’s) for the vCLAS device in the FULCRUM-VT trial occurred in 2.4% of patients and were not related to the use of saline irrigation (a common cause of fluid overload in heart failure patients) or nitroglycerin (a common maneuver used to prevent coronary artery spasm during radiofrequency ablation). The ability of the vCLAS system to function without these maneuvers simplifies the electrophysiology cockpit or workspace, decreases the operator’s cognitive load as well as the patient’s physical stress.

Most importantly for the patient though, 84% of the patients in the trial were free from ICD shocks at the 6 month follow up. And of the 72% of patients that were on amiodarone pre-operatively, 72% were able to come off of it completely or on partial dose at follow up. Simple numbers, but these numbers can translate into a dramatic improvement in a patient’s quality of life. So, while these data are from a small number of patients in a clinical trial, and the follow-up is only 6 months, the results are certainly very promising and support further investigation with a view to hopefully bringing this technology to the patient population as quickly as possible. Adagio are expecting FDA premarket approval in the near future.

Healthsystems Implications

There is value to the clinician, hospital, health system and payer to a strategy that decreases VT episodes, ICD shocks, and amiodarone doses. Each of these events can lead to subsequent episodes of heart failure. The value to the clinician is to prevent untoward effects of antiarrhythmic medications. To the hospital, there is value in decreasing episodes of emergency care. To the health system, there is value in decreasing subsequent hospitalizations for heart failure and other arrhythmic illnesses. To the payer, there is value in decreasing costs associated with hospitalizations for heart failure and other arrhythmic illnesses as well as for emergency care.

Who It Affects

Patients

Patients with structural heart disease are the subjects of the study. They can suffer from ischemic heart disease due to prior heart attacks, or they can suffer from non-ischemic cardiomyopathy. Often, these patients are already equipped with an ICDs and experience shocks on an intermittent basis that is very bad for quality of life and results in poor outcomes. In addition to ICD shocks, these patients are also on long-term antiarrhythmic medications that have very serious side effects. Thus, reducing the frequency of ICD shocks and the need for antiarrhythmic medications would be of great value to these patients.

Clinicians

Ablation of ventricular arrhythmias can be more challenging than ablation of atrial fibrillation due in part to the more complex anatomy of the ventricles. The vCLAS system can be used to create the necessary lesions within the confines of the ventricles in order to treat VT. Furthermore, the vCLAS system has the potential to simplify many of the step of the procedure while maintaining safety of critical structures including the coronary arteries and the cardiac conduction system. This could allow for safe and effective VT ablation to be performed in a greater number of centers and by a greater number of electrophysiologists.

Hospitals, Healthsystems, and Payers

Hospitals, healthsystems, and payers will also need to develop strategies to facilitate introduction of the vCLAS system into clinical practice. Factors that typically influence the adoption of novel technologies such as vCLAS include cost of the technology as well as training required to safely and proficiently use the technology. Also, development of strategies to secure reimbursement as well as selling the technology to hospital leadership on the basis of expected decreased spending for readmissions as well as for subsequent complications of heart failure will be required. Finally, the roles of regulators and of various clinical guideline writing committees will also need to be defined, especially as more long-term follow-up is accumulated and the technology is incorporated into various clinical pathways and into the quality metrics used to measure the treatment of various heart rhythm disorders.

What Changes

• Operators may gain a more streamlined VT ablation workflow. The new cryo-based catheter is designed for stable contact and controlled lesion depth, which could cut procedure steps and reduce the need for adjunctive measures that increase complexity.
• Patients could experience fewer ICD shocks and less dependence on long-term toxic medications. Early results show meaningful reductions in both, which matters for quality of life and for avoiding drug-related complications.
• Program-level implications include potential shifts in referral patterns and access. If the technology proves reproducible across centers, more hospitals — including some that currently refer complex VT cases elsewhere — might offer ablation, improving patient access to definitive therapy.
• But adoption will confront trade-offs. Early clinical success needs long-term confirmation. Payers will want evidence of durable benefit before widening coverage. And some VT substrates that sit on the outer surface of the heart may still require epicardial strategies that this endocardial-only approach cannot address.

The Work Ahead

Acutely, the success rate in the trial was extremely high. In the intermediate follow-up there is an extremely positive safety signal. Perhaps, most importantly, for a disease as heterogeneous as VT, the results for both ischemic and non-ischemic patients are comparable and can be treated with similar strategies.

While the early clinical data show successful ablation of VT using the Pulsar Axiom system in a variety of patient populations with a variety of different VTs, medium-term follow-up is required to assess whether the early success with ablation of VT is maintained in the long term. It is known that VT can recur many years after successful ablation and that the early clinical experience with any new technology can be very different from the broader clinical experience post trial. Therefore, as with any new technology, there is a need for training and proctoring to ensure safe and effective use in the clinical setting.

Lack of irrigation and pharmacological adjuvants, in addition to other technical aspects, could affect the formation of lesions as well as the impact on surrounding tissue. These are factors that need to be considered in order to compare the results of the currently approved device for VT ablation with other approved energy sources for cardiac ablation, such as radiofrequency ablation and the more recently introduced pulsed field ablation technologies. Information on these aspects will be necessary in order to assess the comparative effectiveness of new technologies.

Regulatory and Reimbursement Pathways

The next step for a new device for ablation of ventricular arrhythmias will be the formal approval process from the regulatory bodies for the use of this new device in the clinical treatment of patients with VT. Following formal approval, the new device will then progress through the process of reimbursement for the cost of the device for use in the treatment of VT by the hospitals, healthsystems and insurance companies. Often this process of formal approval and subsequent reimbursement will take many years during which time the new device will be available in only the few specialized centers where it is performed by experienced clinicians.

Referrals

For clinicians, there is also the possibility that they would refer patients for earlier intervention with ablation when using a tool that would make the procedure safe and easily reproducible. Given the fact that VT can be quite tolerable to many patients, and in the presence of many new drugs for the condition with many side effects, the perception of burden of ablation, and uncertainty regarding the benefit, has caused many to not recommend earlier intervention with ablation for patients with VT. This could change in the presence of a tool that would result in successful ablation.

Future Application

A further consideration of VT and its treatment is the impact that shocks from an ICD as well as side effects from antiarrhythmic medications can have on a patient’s quality of life. By potentially decreasing the number of shocks as well as the number of hospitalizations for patients with VT, this new technology will allow patients to return to work, travel, and even get a good night’s sleep thus enhancing their quality of life.

On the plus side, there will likely be additional data generated by this technology, including follow-up of trial patients and analysis of its use in broader clinical settings. In addition to conducting clinical trials, the technology will also likely be used by centers of excellence worldwide to treat VT patients, and become a tool that other physicians can learn to use as part of their clinical practice. There will also be additional studies conducted that directly compare the use of this technology for VT ablation with that of other currently used energy sources for creating lesions in the heart to treat arrhythmias. These studies will provide additional insights on the merits and demerits of different techniques.

And so there you have it, a major emerging problem and desperately needed medical technologies to treat this very serious and potentially life-threatening heart rhythm disorder. We are cautiously optimistic with the initial results from this as yet untested device for VT ablation. We will look for additional data in the long term follow-up of the patients in this trial as well as in the upcoming single and multi-center registries around the world. Hopefully, such information will lead to a definitive head-to-head comparison with existing technologies and techniques for the ablation of VT. In the meantime, a pragmatic approaches will be best for this technology as it finds its place in the armamentarium of clinical tools for treating VT. And, to our patients with drug-refractory VT, there are indeed emerging options for the management of your life-threatening arrhythmias and we are hopeful that these technologies will provide the kind of management that you so desperately need.

References

1. https://www.massdevice.com/adagio-ventricular-ablation-tech-hrs-2026/
2. https://us.adagiomedical.com/clinical-evidence-studies
3. https://clinicaltrials.gov/study/NCT05675865