Blood pressure and renal function changes in patients with severe chronic kidney disease undergoing radiofrequency renal denervation: 12 months outcomes from the Global SYMPLICITY Registry DEFINE
Authors: Schlaich M , Mahfoud F , Narkiewicz K , Ruilope L M , Williams B , Mancia G , Sharif F , Ribichini F L , Fahy M , Boehm M 
Published: October 2024

Abstract

Background
Radiofrequency renal denervation (RF RDN) lowers blood pressure (BP) in patients with uncontrolled hypertension (HTN). The impact of renal function on safety and efficacy of RDN is unknown.

Purpose
To assess BP and renal function in patients with HTN following RDN.

Methods
All patients treated with RF RDN (n=3332) from the observational Global SYMPLICITY Registry Denervation Findings in Real World (GSR DEFINE) were included. Patients were categorized into CKD stages by the corresponding estimated glomerular filtration rate (eGFR; mL/min/1.73m2): &lt;45 (CKD stage 3b and higher; n=339), 45-59 (CKD stage 3a; n=467), ≥60 (CKD stage 2 and lower; n=2334). BP (office, 24h ambulatory BP), eGFR changes from baseline through 12 months were compared between groups. Comparisons between groups were made after adjusting for baseline BP and change in number of antihypertensive drug classes from baseline.

Results
At baseline, office systolic SBP (OSBP) in eGFR groups &lt;45, 45-59, and ≥60 ml/min/1.73 m2 was: 164±25, 163±26 and 165±25 mmHg, respectively (p=0.083). 24-h ambulatory systolic BP (ASBP) was: 156±19, 153±20 and 154±19 mmHg, respectively (p=0.082). Mean eGFR was: 32.5±11.2, 53.6±4.4, and 86.8±18.6 ml/min/1.73 m2, respectively.
A total of 1.1% of patients were on dialysis. Patients in eGFR group &lt;45 ml/min/1.73 m2 were significantly older, had higher rates of ischemic heart disease, heart failure, diabetes, on more antihypertensive drug classes compared to higher eGFR groups. Patients were on 5.0±1.3, 4.6±1.3, and 4.5±1.4 antihypertensive drugs in eGFR &lt;45, 45-59 and ≥60 ml/min/1.73 m2 groups, respectively (p&lt;0.001). At 12 months, all had significant OSBP drop from baseline within the different eGFR groups (p&lt;0.001). OSBP changed by -10.8±27.8, -10.5±25.9 and -14.7±26.6 mmHg in eGFR &lt;45, 45-59 and ≥60 ml/min/1.73 m2 groups, respectively (adjusted p=0.095; Figure 1A). Similarly at 12 months, all patients had significant ASBP reductions from baseline across the eGFR groups (p&lt;0.01). ASBP changed by -5.2±18.0, -6.9±18.8, and -8.5±18.8 mmHg in eGFR &lt;45, 45-59 and ≥60 ml/min/1.73 m2 subgroups, respectively (adjusted p=0.16).
At 12 months, eGFR did not significantly change from baseline in eGFR &lt;45 and 45-59 ml/min/1.73 m2 groups (Figure 1B): 0.1±14.6 (p=0.92) and -0.6±12.8 ml/min/1.73 m2 (p=0.45), respectively. Estimated GFR changed from baseline by -5.6±15.5 ml/min/1.73 m2 in eGFR ≥60 ml/min/1.73 m2 group (p&lt;0.001). Between group differences in eGFR changes were statistically significant (adjusted p&lt;0.001), but by a numerically small difference. The no. of antihypertensive drug classes changed by -0.2±1.3, -0.1±1.0 and -0.1±1.0 in eGFR &lt;45 and 45-59 ml/min/1.73 m2 groups, respectively.

Conclusion
Patients with uncontrolled HTN with different CKD severity including those with eGFR &lt;45 ml/min/1.73 m2 had significant SBP reductions from baseline through 12 months, whilst renal function was preserved.Figure 1