Twenty-Four-Hour Blood Pressure Monitoring to Predict and Assess Impact of Renal Denervation. The DENERHTN Study (Renal Denervation for Hypertension)

Literature - Gosse P, Cremer A, Pereira H, et al. - Hypertension. 2017;69: published online ahead of print

Background

Renal denervation on top of a standardized stepped-care antihypertensive treatment (SSAHT), significantly reduced daytime, night-time, and 24-hour ambulatory systolic blood pressure (SBP), compared with SSAHT alone, in patients with well-defined resistant hypertension (RH). This finding of the DENERHTN trial (Renal Denervation for Hypertension trial) was confirmed by ambulatory blood pressure monitoring (ABPM) [1]. The use of ABPM for the evaluation of the blood pressure effect by renal denervation contributes to the elimination of observer bias and placebo effect, and allows investigating the effects of renal denervationon a 24-hours basis, and on indices of blood pressure variability [2].

In this predefined analysis, the ABPM results were evaluated in detail, especially those of blood pressure and heart rate (HR) variability, and it was assessed whether ABPM can help predicting blood pressure response to renal denervation.

Main results

• From baseline to 6 months, the mean decreases in daytime, night-time and 24-hour ambulatory SBP were significantly greater in the renal denervation group compared with the control group, with a mean baseline-adjusted difference of approximately −6.0 mmHg.
• The smoothness index was significantly greater in the renal denervation group (1.4±1.2) compared with the control group (0.9±0.6, P=0.02), whereas there were no significant differences in regard to the standard deviations of SBP, diastolic blood pressure and HR, ambulatory arterial stiffness index or the proportion of non-dipper patients.
• The number of responders was significantly higher in the renal denervation group (44.5%) than in the control group (20.8%, P=0.01).
• In univariate analysis, 5 baseline variables were significantly different between responders and non-responders: treatment group, average 24-hour-, daytime-, and night-time SBP and night-time standard deviation of SBP (SDSBP) calculated on wide or narrow periods.
• The number of patients with isolated systolic hypertension did not differ significantly between responders (25%) and non-responders (37%).
• In the stepwise discriminant analysis, baseline average night-time SBP, night-time SDSBP and the treatment group remained significant predictors of daytime SBP response. When analysis was restricted to the renal denervation group, only average night-time SBP and night-time SDSBP remained significantly associated to responders (P=0.005).
• In the receiver operating characteristic (ROC) curves to predict responders according to baseline night-time SBP, night-time SDSBP values and L score in the renal denervationgroup, the area under the curve (AUC) was 0.65 (95% CI: 0.486–0.816; P=0.07) for baseline average night-time SBP and 0.72 (95% CI: 0.565–0.874; P=0.005) for baseline night-time SDSBP.
• For baseline average night-time SBP, a cut-off of 136 mmHg offers the best compromise between sensitivity (75%) and specificity (54%) to predict responders.
• For night-time SDSBP, a cut-off of 12 mmHg offers the best compromise between sensitivity (55%) and specificity (83%) to predict responders.
• When combined together, the 2 cut-off points allow adequate classification of 70% of patients who underwent renal denervationin responder and non-responder groups. The AUC for the L score was 0.76 (95% CI: 0.615–0.900; P<0.001).

Conclusion

Editorial comment

References

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