Initial Data Presented From SPYRAL HTN-ON MED Study of Medtronic's Symplicity Spyral Renal Denervation System
June 1, 2018—Medtronic recently announced first-ever data from the SPYRAL HTN-ON MED study. Initial study results found statistically significant and clinically important blood pressure reductions in hypertensive patients prescribed antihypertension medications treated with the company's Symplicity Spyral renal denervation (RDN) system with no major adverse safety events out to 6 months.
The data were presented as a Late-Breaking Trial at the 2018 EuroPCR annual meeting held May 22–25 in Paris, France. The findings were published online simultaneously by David E. Kandzari, MD, et al in The Lancet.
Medtronic reported that at 6 months, patients randomized to the RDN procedure experienced an average 9-mm Hg drop in 24-hour mean systolic ambulatory blood pressure, resulting in a 7.4-mm Hg difference compared with patients in the sham control arm (P= .005). For RDN patients, 24-hour mean diastolic ambulatory blood pressure also declined by 6 mm Hg, which is 4.1 mm Hg lower than the sham control arm (P= .029).
The investigators found that average office systolic blood pressure in patients in the RDN arm declined by 9.4 mm Hg, which is a 6.8-mm Hg difference from the sham control arm (P= .021), and the office diastolic blood pressure declined by 5.2 mm Hg, a 3.5-mm Hg difference from the sham control arm (P= .048).
Additional analysis of the cyclical hourly changes in blood pressure demonstrated that the blood pressure–lowering effects of RDN were distributed throughout the day and, importantly, throughout the nighttime period when blood pressure control is even more critical because of higher risks of adverse events like heart attack and stroke caused by hypertension.
Patients in the SPYRAL HTN-ON MED study were prescribed a stable regimen of up to three antihypertensive medications, including diuretics, calcium channel blockers, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, or beta blockers. Similar to recent studies of uncontrolled hypertension, drug testing indicated that adherence to prescribed antihypertensive medication was inadequate, with approximately 60% of patients found to be taking medications as prescribed. Medication adherence remains a challenge in controlling hypertension in patients resulting in intermittent blood pressure control that can lead to an increased risk for cardiovascular events.
The company advised that the global SPYRAL HTN clinical program—composed of the ON MED and OFF MED trials—has now moved into its final pivotal phase. The clinical program utilizes the Medtronic next-generation RDN technology, composed of the flexible, 6-F guide catheter–compatible Symplicity Spyral multielectrode RDN catheter and Symplicity G3 RDN RF radiofrequency generator. The Symplicity Spyral system is an investigational device in the United States and Japan.
Dr. Kandzari, the study's Coprincipal Investigator, commented in the company's announcement, “Data from the SPYRAL HTN-ON MED study is important for the clinical community and for patients with hypertension as it represents a typical scenario of managing uncontrolled hypertension patients, prescribed up to three blood pressure medications. With these new results, mirroring those of the parallel SPYRAL HTN-OFF MED trial, we have convincing evidence at 6 months showing the continued safety and efficacy of RDN in both the presence and absence of blood pressure medication.”
Raymond Townsend, MD, Coprincipal Investigator in the trial, added, “We are encouraged by these data showing the procedure may enable a blood pressure lowering effect 24 hours a day. RDN is essentially ‘always on’ even when the effect of medications may be subsiding between doses. These data also show that treatment with RDN in the main renal artery and branches with the Spyral system can help reduce blood pressure.”