Effectiveness of Radiofrequency Renal Denervation in the United States: Six-Month Primary End Point Results From the SPYRAL AFFIRM Study

BACKGROUND: Radiofrequency renal denervation (RDN) is a guideline-recommended therapy for uncontrolled hypertension. SPYRAL AFFIRM is a single-arm, postapproval study assessing the efficacy and safety of radiofrequency RDN using the Symplicity Spyral catheter. We report the 6-month primary end point results in the SPYRAL AFFIRM US population. METHODS: Enrolled patients had an office systolic/diastolic blood pressure (BP) ≥140/90 mm Hg and a home systolic BP ≥135 mm Hg. Patients with type 1 diabetes, poorly controlled type 2 diabetes (HbA1c >8.0%), or an estimated glomerular filtration rate <45 mL/min per 1.73 m 2 were excluded. The primary end point was the 6-month change in office systolic BP from baseline compared with a prespecified performance goal (−6.0 mm Hg). RESULTS: Among 594 patients treated in the AFFIRM study from 73 US clinical sites, baseline clinical characteristics included: mean (±SD) age, 57±12 years; female, 45%; African American, 27%; Hispanic, 11%; type 2 diabetes, 19%; and mean estimated glomerular filtration rate, 79±20 mL/min per 1.73m 2 . Baseline systolic/diastolic office, home, and 24-hour ambulatory BP (mm Hg) were 169±21/106±13, 158±17/101±13, and 151±18/96±13, respectively. Patients were prescribed an average of 3.6±2.0 antihypertensive medications at baseline that remained unchanged through 6 months. Six months after RDN, the change in systolic BP (mm Hg) was −18.2±22.0, −9.4±13.8, and −9.7±16.8 for office, home, and 24-hour ambulatory measures, respectively ( P <0.001 compared with baseline). Adverse clinical events through 6 months were uncommon. CONCLUSIONS: In this US postapproval study, the primary end point was met with significant BP reductions following radiofrequency RDN consistent across different measures. In a broader patient population with uncontrolled hypertension, these results reaffirm the safety and efficacy of radiofrequency RDN. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT05198674.