Results from the SYMPLICITY HTN-3 Study Presented at TCT and Published Simultaneously in The Lancet
BOSTON – September 18, 2022 – Long-term results from the first and largest randomized, sham-controlled clinical trial of renal denervation (RDN) for uncontrolled hypertension (HTN) show that the procedure could lower blood pressure (BP) in patients with resistant hypertension over three years.
Longer-term follow-up findings from SYMPLICITY HTN-3 were reported today at TCT 2022, the 34th annual scientific symposium of the Cardiovascular Research Foundation (CRF). TCT is the world’s premier educational meeting specializing in interventional cardiovascular medicine.
In the primary report of the SYMPLICITY HTN-3 trial, at six months, RDN was found to be safe but did not show any significant incremental blood pressure lowering benefit compared with a sham procedure. The present analysis reports long-term blood pressure changes in both initially treated RDN patients as well as in a composite control group consisting of sham-treated patients as well as sham-treated patients who crossed over to RDN after six months (but using blinded, pre-crossover data as the control).
Eligible patients had an office systolic blood pressure (OSBP) ≥160 mmHg and 24-hour ambulatory systolic blood pressure (ASBP) ≥135 mmHg. In addition, they were on stable, maximum tolerated doses of three or more antihypertension (AH) drugs. A total of 535 patients at 88 sites in the United States were randomized 2:1 to RDN using the Symplicity Flex catheter (n=364) or sham control (n=171). Unblinding occurred after six months, and eligible control patients could crossover to RDN. For the 101 patients who crossed over and received RDN, their most recent blinded pre-crossover BP measurement and medication data were used as controls. Treatment differences were adjusted for baseline BP.
At 12 months, RDN patients had significantly greater OSBP reductions compared with sham control after crossover imputation (-18.9 mmHg vs -6.3 mmHg, p<0.0001, respectively). In addition, the number of AH drugs were similar between patients in the RDN and control groups (4.7±1.4 vs. 4.7±0.9, p=0.22). The OSBP reductions continued each year following the procedure, and at 36 months, the reduction in BP following RDN was -26.4 mmHg compared with -5.7 mmHg for the control group (p<0.0001). Similar results were observed in other measures of blood pressure (office diastolic BP, 24 hour systolic and diastolic BP).
Researchers also compared the SYMPLICITY HTN-3 results to the SPYRAL HTN-ON MED trial results. The SYMPLICTY HTN-3 trial used a first-generation catheter with one electrode which only treated the main renal artery. SPYRAL HTN-ON MED utilized a second-generation catheter with four electrodes which circumferentially treated the main renal artery and branches. The mean number of ablations for SPYRAL HTN-ON MED was 45.9 ±13.7 compared with 11.2±2.8 for SYMPLICITY HTN-3. Comparison of BP in RDN patients between the two trials shows that patients in SPYRAL HTN-ON MED had similar long-term BP reductions through three years [OSBP: -28.5 mm Hg versus -25.2 mmHg (p=0.50) and 24 Hour SBP: -22.1 mmHg versus -15, mmHg (p=0.06)].”
“Long-term follow up from the SYMPLICITY HTN-3 trial showed that renal denervation is safe, and no late-emerging complications were found,” said Deepak L. Bhatt, MD, MPH, Executive Director of Interventional Cardiovascular Programs at Brigham and Women’s Hospital Heart & Vascular Center and Professor of Medicine at Harvard Medical School. “In addition, significant reductions were seen in office and 24-hour blood pressure after three years, independent of medications. These findings indicate that durable blood pressure reductions with radio-frequency renal denervation in combination with maximal medical therapy can be safely achieved.”
The study was funded by Medtronic. Dr. Bhatt received research funding from Medtronic paid to Brigham and Women’s Hospital for his role as the co-Principal Investigator of SYMPLICITY HTN-3.
About CRF and TCT
The Cardiovascular Research Foundation (CRF) is one of the world’s leading nonprofit organizations specializing in interventional cardiology innovation, research, and education. CRF is dedicated to helping doctors improve survival and quality of life for people suffering from heart and vascular disease. For over 30 years, CRF has helped accelerate medical breakthroughs and educated doctors on the latest treatments for heart disease. CRF’s centers of excellence include the CRF Skirball Center for Innovation, CRF Clinical Trials Center, CRF Center for Education, CRF Digital, TCTMD, and Structural Heart: The Journal of the Heart Team.
Transcatheter Cardiovascular Therapeutics (TCT) is the annual scientific symposium of CRF and the premier educational meeting specializing in interventional cardiovascular medicine. Now in its 34th year, TCT features major medical research breakthroughs and gathers leading researchers and clinicians from around the world to present and discuss the latest evidence-based research in the field.
For more information, visit www.crf.org and www.tctconference.com.