In the rapidly evolving landscape of cardiovascular medicine, Renal Denervation (RDN) has emerged as a revolutionary approach.
In November 2023, the FDA approved 2 new RDN therapies: Paradise by Recor Medical and Symplicity Spyral by Medtronic.
These groundbreaking developments offer a paradigm shift in the management of resistant hypertension, especially when it is extremely difficult to achieve blood pressure control through conventional means, such as lifestyle modifications and various drug therapies.
But what is resistant hypertension, and why does it require renal denervation?
Hypertension vs Resistant Hypertension
Normal blood pressure is generally around 120/80 mm Hg. Hypertension, commonly known as blood pressure, occurs when these values consistently exceed the normal range, potentially damaging the arteries, heart, brain, kidneys, and other organs.
It is often referred to as the “silent killer” because it typically does not exhibit noticeable symptoms, yet it poses a significant risk for serious health complications.
Resistant hypertension occurs when individuals find it challenging to achieve blood pressure control through conventional means, such as lifestyle modifications and multiple antihypertensive medications.
This condition poses a heightened risk for cardiovascular events, including heart attacks, strokes, and kidney problems. Hence, to reduce the risk of CVDs, regular diagnosis using advanced tools like the Wellnest 12L ECG Machine and modern therapies such as Renal Denervation for treatment is needed to improve the health and quality of life of individuals with resistant blood pressure.
Understanding Renal Denervation
Renal Denervation is an innovative and minimally invasive procedure designed to treat resistant hypertension, especially when the high blood pressure remains elevated despite the use of three or more antihypertensive medications at optimal doses, including a diuretic.
How RDN Works
In individuals with resistant hypertension, the sympathetic nervous system is overactive, contributing to elevated blood pressure. Renal Denervation aims to disrupt this process by selectively ablating or disabling the sympathetic nerves in the renal arteries.
RDN explicitly targets the sympathetic nervous system, which plays a crucial role in regulating blood pressure by releasing norepinephrine, a neurotransmitter that signals the arteries to be narrow.
During the RDN procedure, a catheter is threaded through the blood vessels to reach the renal arteries. Once in position, the catheter delivers either radiofrequency energy or ultrasound waves to the targeted nerves surrounding the arteries. This process effectively reduces the hyperactivity of the sympathetic nerves, leading to a decrease in blood pressure.
Latest research in Renal Denervation
The Paradise by Recor Medical
How does Paradise renal denervation work?
In this groundbreaking system, a transducer is situated within a balloon, delivering a circumferential energy ring. This transducer is safeguarded by a water-cooling system that circulates through the balloon, ensuring protection for the arterial wall.
The ultrasound energy is administered in 7-second bursts to each main renal artery, typically involving two or three treatments for each artery, resulting in an average total ablation time of approximately 40 seconds.
The Paradise system has demonstrated substantial reductions in blood pressure across three pivotal sham-controlled trials: RADIANCE II, RADIANCE-HTN SOLO, and RADIANCE-HTN TRIO.
Dr. Ajay Kirtane, MD, director of Interventional Cardiovascular Care and a regular participant in the study, reported a drop in blood pressure of around 5 to 10 mm Hg from baseline within 1 to 2 months post-procedure.
He also stressed that the procedure is not expected to necessitate a repeat in the same patient, underscoring the goal of achieving a lasting and substantial benefit with a single intervention.
He further added that with a follow-up extending to 3 to 5 years, the data suggests a durable reduction in blood pressure, making repeat procedures unnecessary and reinforcing the concept of obtaining a lasting benefit from a single intervention.
The Symplicity Spyral by Medtronic
How does Symplicity Spyral work?
The Symplicity Spyral system utilizes a catheter featuring an electrode pattern arranged in a helical configuration, enabling simultaneous or individual ablation in all four quadrants.
Radiofrequency energy is independently delivered to the main renal artery, accessory arteries, and branch vessels, maximizing the denervation achieved. Each ablation session persists for approximately 45 to 60 seconds, with an average total ablation time recorded at around 15 minutes during clinical trials.
Symplicity Spyral Trial Results
The Symplicity Spyral system underwent evaluation in two significant trials. The HTN-OFF trial, involving hypertensive patients whose medications were discontinued, demonstrated a notable reduction in blood pressure compared to the sham-control group.
However, the SPYRAL HTN-ON study, where patients continued their blood pressure medications, did not validate the substantial reduction observed in 24-hour ambulatory blood pressure monitoring at the 6-month mark, as noted in the pilot study. The reason for this has been widely attributed to the higher use of medication by participants in the sham group.
Patient Selection Criteria for Renal Denervation: Navigating the Path to Precision Treatment
Precision in patient selection is paramount for the success of Renal Denervation. Dr. Kirtane from the Paradise study emphasizes that lifestyle modifications and medications should remain the first-line interventions for hypertension.
However, Renal Denervation comes into play for patients with resistant hypertension, a group defined by uncontrolled blood pressure despite lifestyle changes and multiple antihypertensive medications.
Dr. Fisher, who has been involved in both trials, further expands on the diverse pool of eligible patients, incorporating those unwilling to take multiple medications due to difficulties or adverse effects.
The approval indication, intentionally broad, encompasses individuals with resistant hypertension, a population estimated at 5% to 10%, and those unable to tolerate multiple antihypertensive medications. This inclusivity widens the scope of Renal Denervation, making it a potential game-changer for a significant subset of hypertensive patients.
Challenges and Considerations: Navigating the Road Ahead
As with any transformative medical intervention, challenges and considerations accompany the adoption of Renal Denervation. Dr. Kirtane echoes concerns about reimbursement, anticipating a potential impediment initially.
Dr. George Bakris, MD, a prominent figure in hypertension research, also underscores the challenge of determining who will undergo the procedure, noting that business decisions intertwined with payer considerations will play a pivotal role.
However, the designation of both devices as breakthrough technologies, with rigorous post-marketing studies, offers a glimmer of hope as patients can currently access the procedure through these studies, providing a bridge until more widespread reimbursement is established.
Safety Considerations and Future Prospects: Towards a Safer Tomorrow
While efficacy is paramount, safety considerations are equally crucial. Dr. Fisher emphasizes the need for a careful risk-benefit analysis, ensuring that the benefits of Renal Denervation outweigh potential risks.
To assess them, the post-marketing studies will provide a more comprehensive understanding of the safety profile, contributing to refining the procedure and its application.
Looking towards the future, Renal Denervation holds promise not only as a standalone intervention but also as part of a holistic approach to hypertension management.
Integration with emerging technologies like Wellnest ECG Solutions, personalized medicine, and advancements in procedural techniques may further enhance the safety and efficacy of Renal Denervation, paving the way for its seamless inclusion in the cardiovascular armamentarium.
Conclusion: Renal Denervation as a Beacon of Hope
In conclusion, Renal Denervation stands as a beacon of hope in the realm of hypertension management. The approval of Paradise and Symplicity Spyral systems marks a significant leap forward, bringing us to the cusp of a new era in cardiovascular medicine. As the medical community treads cautiously into this uncharted territory, Renal Denervation stands poised as a promising addition to the arsenal of hypertension management strategies.