Largest Real-World Study of Wearable Defibrillators Confirms Strong Effectiveness and Safety Performance of Kestra’s ASSURE Device

News | Published: Monday, November 10, 2025

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Kestra Medical Technologies, Ltd., a wearable medical device and digital healthcare company, announced the primary results from the ASSURE® WCD Clinical Evaluation Post-Approval Study (ACE-PAS), presented as a Late-Breaking Science session at the American Heart Association (AHA) Scientific Sessions 2025 in New Orleans, LA. ACE-PAS, the largest prospective real-world study of wearable defibrillators (WCDs) to date, confirmed the strong safety and effectiveness of the ASSURE WCD in clinical practice.

A recorded panel discussion featuring ACE-PAS investigators and other leading clinical experts, hosted by MedAxiom, offers perspective on the study’s design, outcomes and implications for patient care. The full discussion can be viewed here.

“ACE-PAS delivers robust, real-world evidence on how the ASSURE WCD performs in routine care and provides contemporary data describing the risk of life-threatening ventricular tachycardia and fibrillation in diverse populations with reduced cardiac function,” said Jeanne E. Poole, MD, professor of Medicine at the University of Washington and Principal Investigator. “Life-threatening arrhythmias can occur early in patients with low ejection fraction who have recently experienced a myocardial infarction, undergone coronary revascularization, or have been newly diagnosed with heart failure. These patients may have significant recovery of heart function during a waiting period of one to six months, such that a permanently implanted defibrillator is not indicated. The ASSURE WCD should be considered to protect patients at elevated risk of sudden cardiac death during this vulnerable time.”

The study enrolled 21,612 patients across the U.S. Key findings demonstrate consistent safety, effectiveness and adherence in real-world use:

• Proven Effectiveness: The primary effectiveness endpoint was achieved, with 100% successful conversion for ventricular tachycardia and fibrillation (VT/VF) events, surpassing the prespecified performance goal.
• Validated Safety: The study met its primary safety endpoint, with an inappropriate-shock rate of 0.0065 per patient-month, below the prespecified benchmark and confirming a strong safety profile.
• Minimal False Alarms: 94% of patients experienced no false positive shock alarms, ensuring confidence and comfort during wear.
• Critical Protection: 2.6% of patients experienced at least one life-threating VT/VF event within only a few months, highlighting the importance of protection in this vulnerable population.
• Clinically Actionable Insight: The WCD detected additional arrhythmias enabling timely intervention.
• High Compliance: Patients wore the device for a median of more than 23 hours per day, and one-third continued use beyond 90 days – highlighting its practicality in real-world care.

“These results reinforce the critical role wearable device therapy can play in protecting patients during periods of elevated risk,” said Brian Webster, president and chief executive officer of Kestra Medical Technologies. “As the largest and most contemporary study of its kind, ACE-PAS provides compelling evidence that may help inform future updates to clinical guidelines – particularly around how we identify and protect patients at early risk of sudden cardiac death. By pairing proven performance with connected, data-driven insight, Kestra is redefining what’s possible in wearable protection and advancing evidence-based innovation.”

The ACE-PAS results represent a significant step forward in understanding and managing sudden cardiac arrest risk. Additional analyses from the study will be shared in forthcoming scientific forums.

About ACE-PAS

The ASSURE WCD Clinical Evaluation Post Approval Study (ACE-PAS) is a prospective, multicenter registry evaluating the use, safety, and effectiveness of the ASSURE Wearable Cardioverter Defibrillator in the prevention of sudden cardiac death. The study enrolled 21,612 patients from November 2021 through July 2025 across the U.S. Primary endpoints were overall VT/VF shock conversion and inappropriate-shock rate.

About Kestra

Kestra Medical Technologies, Ltd. is a commercial-stage wearable medical device and digital healthcare company focused on transforming patient outcomes in cardiovascular disease using monitoring and therapeutic intervention technologies that are intuitive, intelligent, and connected. For more information, please visit www.kestramedical.com.

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