Dr. Robert Kowal, Vice President at Medtronic Shares Insights on a New Clinical Study on Micra AV Leadless Pacing Performance

Shots:

Robert spoke about the publication of the new study in the Heart Rhythm Journal about the Micra AV leadless pacemaker and how it is an effective therapy for patients with atrioventricular (AV) block
Robert talked about the study design and the key findings from the study evaluating Medtronic’s Micra AV device
The interview gives an understanding of Medtronic’s vision to bring innovative treatment options to meet the needs of patients and physicians

Smriti: Highlight the functioning of Medtronic’s Micra AV device. How will this system prove to be a better treatment option for patients with AV block?

Robert Kowal: Micra™ AV has several internal atrial sensing algorithms which detect cardiac movement, allowing the device to adjust pacing in the ventricle to coordinate with the atrium, providing “AV synchronous” pacing therapy to patients with AV block. Previous treatment options consisted of transvenous pacemakers with leads. While those treatments are useful, patients with Micra™ AV will benefit from a faster recovery time and fewer potential complications as there is no device pocket or leads with Micra™ AV.

Smriti: Give our readers some insight into the study design along with the key findings of the study evaluating the effectiveness of the Micra AV system.

Robert Kowal:

Study Design:

The Accel AV study, and Optimize sub-study, is the first, prospective, multi-center performance study of the AV synchrony (the sequence in which the atria and the ventricles of the heart contract) features of the Micra™ AV pacemaker.
A total of 152 patients were included in the overall study, of which 54 were in complete heart block at their 1-month follow-up visit
The aim was to test the synchrony between the atria and ventricles in the patients in greatest need of AV synchrony, so researchers followed the 54 patients with complete AV block who were being paced >90% of the time through three months post-implant. In this cohort, the study analyzed over 4.6 million cardiac cycles.
Of the 54 patients, 23 patients received further optimization of programming at 10 months post-procedure.

Key Findings:

Results of the Accel AV study showed Micra™ AV maintained its expected performance over time without the need to change to a pacemaker with leads. Stated simply, patients went about their daily lives and received the synchronous pacing that improved the symptoms that drove them to needing a pacemaker.
This data validates earlier Micra™ studies (Marvel and Marvel21) which assessed the feasibility of using accelerometer-based atrial sensing algorithms to detect atrial signals without the need for a lead in the atrium itself.
The Optimize sub-study of 20 patients determined that optimizing the programming can provide an even higher rate of ambulatory AV synchrony (during activities of daily living).
- Another 10.5% improvement can be gained, bringing the average ambulatory AV synchrony to 82.6%.
- The 10.5% ambulatory AV synchrony improvement was most pronounced at sinus rates of 80-110 bpm.

The Accel AV/Optimize study is an important milestone in leadless, synchronous cardiac pacing evidence as it adds to the body of evidence showing that single chamber, leadless pacing helps improve the quality of life for patients with AV block, especially when programming is optimized.

Smriti: Give our readers a comparative overview of the leadless dual-chamber pacing device vs. the conventional dual-chamber pacing device.

Robert Kowal: While traditional, dual-chamber transvenous pacing systems work well, leadless pacing provides some additional benefits. These include

Reduced complications – 63% fewer major complications than traditional pacemakers – such as infection, hematoma, and erosion seen with a pocket, or fractures, insulation breaches, venous thrombosis, and obstruction, or tricuspid regurgitation from leads. Additionally, leadless pacemakers see a significant reduction in the rate of reintervention and risk for chronic complications through two years, relative to transvenous-VVI pacemakers
Enhanced patient experience – no chest scar, no bump or visible reminder of having a pacemaker because it’s implanted inside the heart, it responds to patients’ activity levels by automatically adjusting therapy, a faster procedure, and shorter recovery times with fewer post-implant activity restrictions.

Smriti: Please give us a brief detail about the changes or advancements done on the Micra AV device over the past several years.

Robert Kowal: The Micra™ AV leadless pacemaker was first approved in the U.S. in 2020 and has since been launched in more than 60 countries. The Micra™ AV device looks like the original Micra™ VR device which was approved by the FDA in 2016 and is the size of a vitamin. It has all the same benefits as Micra™ VR, plus internal atrial sensing algorithms which detect cardiac movement, allowing the device to adjust pacing in the ventricle to coordinate with the atrium, providing “AV synchronous” pacing therapy.

Smriti: How has the publication in the Heart Rhythm Journal contributed to raising awareness of the Micra AV device to help patients and doctors learn more about the device?

Robert Kowal: Heart Rhythm is the official Journal of the Heart Rhythm Society and the Cardiac Electrophysiology Society, reaching physicians and other healthcare professionals specializing in electrophysiology. This article supports the body of evidence on the effectiveness of leadless pacing and may help more implanters learn about the advantages of Micra™ AV leadless pacing, as well as programming adjustments they can make to the device’s pacing algorithms to help improve the health of patients.

Smriti: Are there any other products being developed under your product pipeline dedicated toward the treatment of Cardiological diseases or other indications?

Robert Kowal: Through the years, Medtronic has led innovation to meet the needs of patients and physicians – just as our founder Earl Bakken did when he created the first wearable pacemaker in 1957. Medtronic launched the first leadless pacemaker, Micra™ VR, six years ago, and our Micra™ AV two years ago. We are committed to continuing this innovation to help serve more pacing patients and ultimately help alleviate pain, restore health, and extend lives.

Source: UCSF Benioff Children’s Hospital

About the Author:

Dr. Robert Kowal is the Vice President & general manager of the Cardiac Pacing Therapies (CPT) business within the Cardiac Rhythm Management (CRM) operating unit. Dr. Kowal received his undergraduate degree at Yale University and his MD and Ph.D. degrees from UT Southwestern Medical Center, completing his graduate work in molecule genetics. He completed an internal medicine internship and residency as well as a cardiovascular disease fellowship at Brigham and Women’s Hospital.