Results of a randomized controlled pilot trial of intravascular renal denervation for management of treatment-resistant hypertension

Figures & data

Table 1. Characteristics of participants.

Characteristic	Control	Renal denervation
Number in treatment group	9	6
Number with characteristic (%)
Women	5 (55.6)	3 (50.0)
Smoking	1 (11.1)	4 (66.7)
Drinking alcohol	5 (55.6)	5 (83.3)
Serum cholesterol ≥200 mg/dL	4 (44.4)	4 (66.7)
Diabetes mellitus	3 (33.3)	0
Antihypertensive medication
Angiotensin receptor blocker	9 (100)	6 (100)
β-blocker	7 (77.8)	4 (66.7)
Calcium-channel blocker	8 (88.9)	6 (100)
Any diuretic	7 (77.8)	6 (100)
Thiazide/thiazide-like diuretic	5 (55.6)	4 (66.7)
Loop diuretic	1 (11.1)	1 (16.7)
Aldosterone antagonist	5 (55.6)	5 (83.3)
Mean characteristic ± SD
Age, years	47.9 ± 8.8	48.4 ± 10.8
Body mass index, kg/m^2	31.0 ± 4.9	29.3 ± 4.5
Blood glucose, mg/dL	105.3 ± 27.7	105.3 ± 25.7
Serum cholesterol, mg/dL	191.6 ± 38.0	212.3 ± 46.3
Serum sodium, mmol/L	138.8 ± 5.1	140.3 ± 1.4
Serum potassium, mmol/L	4.29 ± 0.50	4.07 ± 0.30
Serum creatinine, mg/dL	1.00 ± 0.32	0.87 ± 0.22
eGFR, mL/min/1.73 m^2	80.1 ± 23.9	93.5 ± 12.4
Kidney length, cm	11.2 ± 1.5	11.6 ± 1.2
Median (interquartile range)
History of hypertension, years	9.5 (4.0–15.5)	10.5 (10.0–16.0)
N° antihypertensive drugs	4.0 (3.0–5.0)	4.0 (3.0–5.0)
Morisky adherence score	7.0 (6.8–7.0)	7.5 (7.0–8.0)

eGFR is the glomerular filtration rate estimate from serum creatinine by the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations. No patient was taking angiotensin-converting enzyme inhibitors. Kidney length is the average of both kidneys measured by ultrasound. None of the between-group differences were significant.

Table 2. Baseline-adjusted changes in blood pressure 6 months after randomization.

	Systolic blood pressure			Diastolic blood pressure
Blood pressure, mm Hg	Control (n = 9)	Renal denervation (n = 6)	P	Control (n = 9)	Renal denervation (n = 6)	P
Office
Baseline	158.6 ± 25.5	173.4 ± 30.0		95.4 ± 14.5	107.4 ± 19.6
6 Months	166.1 ± 16.1	161.5 ± 34.5		97.6 ± 17.9	99.2 ± 23.4
Change	7.6 (–10.2 to 25.3)	–11.9 (–30.4 to 6.6)	0.088	2.2 (–10.0 to 14.4)	–8.2 (–17.6 to 1.1)	.088
24-h
Baseline	157.6 ± 20.7	161.3 ± 15.2		95.4 ± 9.6	100.9 ± 9.4
6 Months	158.2 ± 17.0	139.7 ± 23.0*		95.6 ± 12.7	88.1 ± 12.6*
Change	0.7 (–12.0 to 13.4)	–21.7 (–33.4 to –9.9)	0.018	0.3 (–8.8 to 9.4)	–12.8 (–23.1 to –2.4)	.049
Daytime
Baseline	162.0 ± 17.2	167.2 ± 14.5		100.1 ± 8.7	105.6 ± 11.9
6 Months	162.7 ± 17.4	153.4 ± 30.2		99.5 ± 13.5	98.5 ± 14.6
Change	0.8 (–14.8 to 16.4)	–13.8 (–38.3 to 10.7)	0.22	–0.6 (–10.2 to 9.0)	–7.1 (–21.6 to 7.5)	.33
Nighttime
Baseline	147.1 ± 27.0	149.6 ± 20.7		86.2 ± 14.2	91.7 ± 12.2
6 Months	148.5 ± 19.3	118.1 ± 17.5*		87.1 ± 11.5	70.5 ± 8.6*
Change	1.4 (–10.5 to 13.2)	–31.5 (–54.4 to –8.7)	0.008	0.9 (–7.7 to 9.4)	–21.1 (–34.9 to –7.3)	.008

An asterisks indicates a within group P-value of <0.05.Values are mean ± SD. P-values derived by Wilcoxon rank-sum test refer to the between-group difference in the baseline adjusted blood pressure change.

Table 3. Baseline-adjusted differences in ECG measurements.

Characteristic	Control	Renal denervation	P
Number in treatment group	9	6
Cornell mV
Baseline	1.71 ± 0.66	2.49 ± 0.54
6 Months	2.04 ± 0.59	1.89 ± 0.67
Change	0.33 (0.11 to 0.55)	–0.60(–1.25 to 0.06)	.002
Siegel voltage, mV
Baseline	13.3 ± 3.0	16.7 ± 1.2
6 Months	13.5 ± 3.6	14.0 ± 1.0
Change	+0.20 (–0.90 to 1.3)	–2.7 (–4.5 to -0.87)	.005
Cornell index, mV × ms
Baseline	215 ± 67	283 ± 82
6 Months	244 ± 41	229 ± 88
Change	29 (–9 to 67)	–55 (–126 to 17)	.036
Siegel voltage index, mV ± ms
Baseline	1276 ± 396	1619 ± 173
6 Months	1332 ± 400	1400 ± 215
Change	55 (–84 to 194)	–219 (–501 to 62)	.036

Values are mean ± SD. P-values derived by Wilcoxon rank-sum test refer to the between-group difference in the baseline-adjusted ECG changes.

Figure 1. Change (Δ) in office systolic blood pressure (A) and 24-h ambulatory systolic blood pressure (B) from baseline to the 6-months follow-up in individual patients randomized to control (n = 9) or renal denervation (RDN; n = 6). SBP indicates systolic blood pressure.

Figure 2. Time course of the change (Δ) in office systolic blood pressure (A), 24-h ambulatory systolic blood pressure (B) and adherence (C) from baseline until the 6-month follow-up. Adherence was expressed as the change in percentage of prescribed drugs detectable in urine. P-values were obtained from a mixed model assessing the within-group changes in blood pressure and adherence over follow-up time.