Medical device industry giant Medtronic (NYSE:MDT) this week offered a 1st look at results from its global Symplicity registry of renal denervation patients, finding that treatment with the company’s Symplicity system appears safe as well as effective in real-world patients.
The Symplicity registry, which Medtronic calls the largest patient cohort in renal denervation to date, aims to verify procedure safety of the Simplicity system. In 6-month data from the 617 patients with follow-up information available, there were no major complications or serious adverse events connected with delivery of radio frequency energy to the renal artery, Medtronic said.
Among the 617 patients, 9% showed irregularity in the renal vessels on angiography due to the application of radiofrequency energy to the vessel walls, but none of the irregularities interfered with blood flow and "all are believed to have resolved shortly after the procedure," according to a press release. A total of 2 patients experienced vascular complications at the access site immediately following the procedure.
Although safety was the primary endpoint, the registry found additional evidence to support the efficacy of renal denervation in treating patients with drug-resistant hypertension. According to Medtronic:
Patients with systolic blood pressure (SBP) of ³180 mm Hg and diastolic blood pressure (DBP) of ³100 mm Hg had an average office blood pressure reduction of -30/-16 mm Hg (n=17) [SBP p<0.0002; DBP p<0.0008] from baseline at 6 months. Patients with a SBP ³160 mm Hg (or ³150 mm Hg in patients with diabetes) (n=114) had an average office blood pressure reduction of -18/-9 mm Hg) [p<.0001]; average blood pressure reduction for these patients who also had ambulatory blood pressure* measurement (n=30) was -11/-4 mm Hg [SBP p<.0001; DBP p<0.256] from baseline.
"These data speak strongly to the safety and efficacy of the renal denervation procedure with the Symplicity system; it is encouraging to see these positive results in a real-world setting," interventional cardiologist Dr. Felix Mahfoud of the University Hospital Homburg in Saar, Germany, said on behalf of the company. "The significant reductions in blood pressure seen in these patients could substantially reduce cardiovascular risk, as we know that in middle age even a 2 mm Hg decrease in systolic blood pressure can lead to a decrease risk of death from stroke by 10 percent and lower risk of death from ischemic heart disease or other vascular cause by 7 percent."
The Symplicity registry is the 1st of its kind to analyze real-world use of renal denervation in an uncontrolled setting and a large and diverse patient population. In total the registry will enroll more than 5,000 patients from at least 200 treatments centers, with planned follow-up out to 5 years.
These registry findings will be the topic of discussion at an oral session at the EuroPCR conference in Paris later this week.
Cutting procedure times in half
In a separate release also issued during the EuroPCR conference in Paris, Medtronic touted early results from a feasibility study of its next-generation Symplicity Spyral multi-electrode denervation catheter, saying that the device helped cut procedure times by more than half in a small sample of 29 patients.
The Spyral, which features 4 RF delivery electrodes to the Flex catheter’s 1, demonstrated a mean procedure time of 21 minutes compared with 54 minutes with Medtronic’s Symplicity Flex single-electrode catheter, which was the subject of the company’s Symplicity HTN-2 clinical trial.
Researcher reported no safety concerns with the Spyral technology and the device produced reductions in blood pressure at 1 month consistent with the Flex single-electrode catheter, according to Medtronic. The 29 reported patients received treatment with the Spyral catheter with a 100% acute success rate in accessing the vessels and delivering radiofrequency therapy. There were 3 procedural events observed during the study – 2 pseudo-aneurysms and 1 closure site complication, which were not related to the RF energy delivery, Medtronic reported.
The Simplicity Spyral study will enroll about 50 patients in Australia and New Zealand, with primary endpoints of acute procedure safety and primary effectiveness endpoints observing office blood pressure from baseline at 6 months.
Continued success with renal denervation
Finally, Medtronic also posted new results from its Simplicity HTN-2 long-term study, posting continued benefits from renal denervation at 30 months following treatment.
In March the medical device giant released 2-year clinical data showing that 40 patients who received the Symplicity treatment "sustained a significant drop in blood pressure," with no device-related serious adverse events, no late vascular complications and no significant decline in kidney function.
The latest 30-month results show sustained benefits in reducing blood pressure in the 37 reported patients with information included in the analysis, with a 35 mm Hg reduction in systolic BP and a 13 mm Hg reduction in diastolic BP, TheHeart.org reported. Heart rate was down from 74 beats per minute at baseline to 69, although there was no reported increase in blood-pressure reducing medications.
