Leadless cardiac pacemakers have rightfully earned the title of being a disruptive innovation in the health tech industry. Traditionally, Transvenous Cardiac Pacing (TVP) were implanted under the skin of the chest and connected to the heart using wire leads, but leadless pacemakers have changed the game entirely. These are implanted directly into the heart without the need for leads, remote generators, or skin incisions.
However, leadless pacemakers are only limited to a single chamber as of now. Patients who require dual-chamber pacemakers are, therefore, not eligible for this technology.
Currently, there are two leadless pacemakers in the market: the Micra TPS (Medtronic plc., Dublin, Ireland) and the Aveir VR(Abbott Vascular, Santa Clara, CA, USA). Various scientific publications show that the Micra TPS paces the heart just as well as the traditional transvenous pacemakers but it has a “50% lower overall complication rate” over a “2-year period”.
While the Aveir VR portrays benefits as promising as the Micra TPS, there doesn’t seem to be enough scientific evidence yet demonstrate its safety and efficacy as compared to the Micra TPS.
| Device | Transvenous Pacemakers (TVPs) | Aveir VR | Micra TPS |
|---|---|---|---|
| Type | Generator with wire lead | Leadless | Leadless |
| Size | Medium | Small | Smallest |
| One, or both heart chamber pacing? | One, or both | One only, but under investigation for both | One only |
| Procedure | Incision on upper chest | Inserted through a vein | Inserted through a vein |
| Typical Procedure Duration | 1 to 2 hrs | 30 mins | 30 mins |
| Ideal Candidate | Patients with heart rate below normal, irregular heartbeat, extreme palpitations, abnormally fast heart rate, and atrial fibrillation. | Patients with heart rate below normal, Normal heart rhythm with rare episodes of “atrio-ventricular” electrical conduction block, artial fibrillation | Patients with irregular heart rhythms, heart rate below normal, Paroxysmal or permanent high-grade “atrio-ventricular” conduction block. |
| Anesthesia Required for procedure? | Yes | No | No |
| Outpatient or Inpatient? | Inpatient | Outpatient | Outpatient |
| Can it defibrillate also? | Yes | No | No |
| Invasiveness | Moderate | Minimal | Minimal |
| Recovery Period | 4 to 6 weeks | 1 week | 1 week |
| Complication Risk | High | Low | Low |
| Complications | Infections, lead fracture, insulation problems, skin erosion, keloid formation, chest scars, generator bulge, and blood clots. | Valve damage, cardiac perforation, AV block, pericarditis (accumulation of cardiac fluid), Valve damage or malfunction, increased defibrillator threshold, sepsis, and endocarditis. | Cardiac perforation, pacemaker syndrome, Atrio-ventricular conduction block, kidney dysfunction, pericarditis (accumulation of fluid around the heart), valve damage, increased defibrillator threshold, sepsis, and endocarditis. |
| Battery life | 6-10 years | 10+ years | 8 – 13 years |
| Electromagnetic Interference | High | Minimal | Minimal |
| Device Retrieval | Difficult (high-risk procedure) | Easy | Difficult |
Your cardiologist just broke the news to you: you need a pacemaker. What are your options?
You may already know that a pacemaker is an implantable electronic device that helps control the heartbeat. You might also know implantation of a pacemaker involves a surgical procedure.
But do you know the latest types of pacemakers available in the market and which would work best for you, keeping in mind the relevant factors and risks associated with your condition?
It’s okay if you don’t. We’re here to guide you through the essential information to know about pacemakers – primarily the breakthrough, leadless ones.
1. Micra® Transcatheter Pacing System (TPS)
A good way to introduce this pacemaker would be to mention that it is the world’s smallest single chamber pacemaker. The Micra TPS, developed by Medtronic, operates like a conventional pacemaker, generating electrical impulses that enable the heart to contract.
However, unlike a conventional pacemaker, the Micra TPS is leadless. While conventional pacemakers are surgically placed underneath the chest with leads that connect to the heart, the Micra TPS is inserted through a vein in the upper thigh and advanced into the right ventricle via a catheter. Once implanted in the heart successfully, the catheter is removed.
Given its size and minimally invasive approach, it leaves no sign of a medical device implanted underneath the skin, so patients don’t have to be reminded of their health condition constantly. It is also self-contained within the heart, which eliminates the risk of potential complications due to the chest incision or the wire leads from a conventional pacemaker.
The Micra TPS devices are made for patients:
- Who need a single chamber pacemaker.
- With cardiac arrhythmia, which means having an irregular heartbeat.
- With bradycardia, which is defined as having a heart rate of fewer than 60 beats per minute.
- With paroxysmal or permanent high-grade AV block and chronic atrial fibrillation. AV block is a condition in which electrical signals between the chambers of the heart are impaired.
For whom dual-chamber pacing is considered difficult, risky, or not effective.
Its purpose is two-fold: Sensing, which involves monitoring the heart’s natural electrical activity and only delivering a pacing pulse when needed, and Pacing, which involves sending electrical impulses to the heart when the rhythm is slow or interrupted.
The Micra TPS was originally approved by the FDA in 2016 so it has a long enough “track record” for doctors and researchers to evaluate what it can and cannot do. The newest version was approved in January 2020 in order to better treat patients with atrio-ventricular conduction block.
While this newest Micra TPS is a step forward, it remains disadvantaged in another element: the ability to provide cardiac defibrillation, which is the use of electrical current to help your heart return to a normal rhythm when faced by potentially fatal abnormal heart rhythm.
2. Aveir VR
Aveir VR by Abbott (formerly St. Jude Medical) is the other single-chamber, leadless pacemaker available in the market. It follows the same procedure as the Micra TPS, being implanted via a catheter in the right ventricle typically through a vein in the upper thigh.
The Aveir VR is a modified version of the Nanostim LP system, which was manufactured by St. Jude Medical. The Nanostim was withdrawn from premarket testing in October 2016 due to premature battery failure. A study showed that of 1423 Nanostim implantations globally, 34% of batteries failed, with no associated patient injury.
Smaller than the size of a standard AAA battery, the Aveir VR Leadless System was granted FDA approval on March 31, 2022. It is intended for patients with
- Bradycardia (a heart rate that is too slow)
- Normal sinus rhythm with only rare episodes of AV block (also called a heart block)
- Chronic atrial fibrillation (irregular/rapid heartbeat)
- Severe physical disability
A key plus point of the Aveir VR is its ability to be easily retrieved when the device needs to be replaced or if therapy needs to be changed.
Traditional Pacemakers
We now know that there are two leadless pacemakers in the industry; Micra TPS and Aveir VR. Other than these, you’ll find the traditional pacemakers that are implanted in the chest surgically and connected to the heart with wire leads.
Traditional pacemakers do have advantages over the newer leadless pacemakers. Specifically, they can treat a broader range of disorders as they can be single-chambered (usually the right ventricle), dual-chambered (two leads connecting to the right atrium and right ventricle), or a biventricular pacemaker (three leads connected to the right atrium and both ventricles).
The Battle of the Pacemakers
Traditional pacemakers require caution with airport security detectors, MRI, diathermy, and high-voltage or radar machinery. Patients might also be required to take antibiotic medication to prevent infections caused by the lead inside the heart.
Leadless pacemakers make it okay to safely go through airport security and MRI scans under patient eligibility requirements. However, it is recommended to keep magnet-containing items at least 6 inches away from implanted pacemakers, which applies to both traditional and leadless devices.
A primary advantage of leadless pacemakers is the elimination of several complications associated with the leads attached to transvenous pacemakers: pocket infections, lead dislodgement, and lead fracture.
One research study compared the incidence of complications and good short-term electrical performance in Micra leadless pacemakers and traditional wire lead pacemakers, revealing that 90% of leadless pacemakers have acceptable pacing thresholds at one year and are also associated with 51% lower risk of complications.
Ngo et al. 2021(2)
Leadless pacemakers are also associated with a better quality of life. Another research study concluded that the Micra leadless pacemaker is better accepted by patients and supports a better quality of life when compared to traditional wire lead pacemakers.
Palmisano et al. 2021(5)
In terms of battery, the Micra TPS battery offers estimated average longevity of between 8 and 13 years, while the Aveir VR shows battery longevity of about 10.3 years.
The Aveir VR may also allow patients the ability to expand to a true dual chamber pacemaker if needed. Further research is currently underway to examine this.
Frequently Asked Questions
What is the success rate of leadless pacemaker?
Micra VR was successfully implanted in 99.1% of the 1817 patients included in the Micra PAR, with a 1-year major complication rate of 2.7% (63% lower than patients with TV-PM) and low and stable thresholds through 12 months.
Who is a candidate for a leadless pacemaker?
Leadless pacemakers are ideal for patients who require pacing mostly from the bottom chamber of the heart. The majority of these people have permanent atrial fibrillation and a healthy heart pump.
How long can you live with leadless pacemaker?
A leadless pacemaker’s battery life can last up to ten years or more.
How long is recovery from leadless pacemaker?
After 1-2 days, you can begin physical activity, but avoid severe activity, such as exercise, for 1 week after the treatment. For 7 days, avoid taking a bath, using a Jacuzzi, or swimming.
How easy is it to dislodge pacemaker leads?
The rate of dislodgement of atrial pacing leads is ∼3%.
Let’s Wrap it Up
To conclude, it’s no secret that leadless pacemakers have definitely taken the world by storm. However, it cannot be ignored that as of now, pacemakers such as Micra TPS and Aveir VR are limited to single-chamber procedures (Aveir VR’s dual chamber expandability needs more trials) and cannot be recommended to all patients in need of pacemakers. Aveir VR reviews have highlighted the potential of this technology, although further comparative studies with Micra pacemaker reviews are awaited.
It should also be noted that further data from trials is needed to support the widespread adoption of these devices in clinical practice. (Ngo, L, Nour, D, Denman, RA, Walters, TE, Haqqani, HM, Woodman, RJ, and Ranasinghe, I. Safety and Efficacy of Leadless Pacemakers: A Systematic Review and Meta-Analysis. J Am Heart Assoc. 2021;10(13):e019212.) The Aveir vs Micra debate continues to evolve as more evidence emerges from ongoing trials and clinical reviews.
That being said, leadless pacemakers offer a myriad of potential benefits, including no visible signs of scarring and a significantly lower risk of complications. If your cardiologist is advising you to have a pacemaker implanted, we highly recommend that you ask if a leadless pacemaker is right for you. At the time of this publication, the scientific evidence leans toward Micra TPS being a safer, tried-and-tested option for leadless pacemakers, as supported by Aveir VR reviews and Micra pacemaker reviews.
Selected References
- Ngo, L, Nour, D, Denman, RA, Walters, TE, Haqqani, HM, Woodman, RJ, and Ranasinghe, I. Safety and Efficacy of Leadless Pacemakers: A Systematic Review and Meta-Analysis. J Am Heart Assoc. 2021;10(13):e019212.
- Zucchelli, G, Tolve, S, Barletta, V, Di Cori, A, Parollo, M, De Lucia, R, Della Tommasina, V, Giannotti Santoro, M, et al. Comparison between leadless and transvenous single-chamber pacemaker therapy in a referral centre for lead extraction. J Interv Card Electrophysiol. 2021;61(2):395-404
- Martinez-Sande, JL, Garcia-Seara, J, Gonzalez-Melchor, L, Rodriguez-Mañero, M, Baluja, A, Fernandez-Lopez, XA, and Gonzalez Juanatey, JR. Conventional single-chamber pacemakers versus transcatheter pacing systems in a “real world” cohort of patients: A comparative prospective single-center study. Indian Pacing and Electrophysiology Journal. 2021;21(2):89-94.
- Palmisano, P, Guido, A, Panico, V, Chiuri, MD, Chiarillo, MV, Sergi, C, Ponzetta, MA, Zaccaria, M, et al. Leadless pacemaker versus transvenous single-chamber pacemaker therapy: peri-procedural aspects, utilization of medical resources and patient acceptance. Expert Review of Medical Devices. 2021;18(5):483-491.
- Dar, T, Akella, K, Murtaza, G, Sharma, S, Afzal, MR, Gopinathannair, R, Augostini, R, Hummel, J, et al. Comparison of the safety and efficacy of Nanostim and Micra transcatheter leadless pacemaker (LP) extractions: a multicenter experience. J Interv Card Electrophysiol. 2020;57(1):133-140.
- El-Chami, MF, Bockstedt, L, Longacre, C, Higuera, L, Stromberg, K, Crossley, G, Kowal, RC, and Piccini, JP. Leadless vs. transvenous single-chamber ventricular pacing in the Micra CED study: 2-year follow-up. Eur Heart J. 2022;43(12):1207-1215.
- Piccini, JP, Stromberg, K, Jackson, KP, Laager, V, Duray, GZ, El-Chami, M, Ellis, CR, Hummel, J, et al. Long-term outcomes in leadless Micra Transcatheter pacemakers with elevated thresholds at implantation: Results from the Micra Transcatheter Pacing System Global Clinical Trial. Heart Rhythm. 2017;14(5):685-691.
- Piccini, JP, El-Chami, M, Wherry, K, Crossley, GH, Kowal, RC, Stromberg, K, Longacre, C, Hinnenthal, J, et al. Contemporaneous Comparison of Outcomes Among Patients Implanted With a Leadless vs Transvenous Single-Chamber Ventricular Pacemaker. JAMA Cardiol. 2021;6(10):1187-1195.
- Sattar, Y, Ullah, W, Roomi, S, Rauf, H, Mukhtar, M, Ahmad, A, Ali, Z, Abedin, MS, et al. Complications of leadless vs conventional (lead) artificial pacemakers – a retrospective review. J Community Hosp Intern Med Perspect. 2020;10(4):328-333.
