Predictors of response to renal denervation for resistant arterial hypertension: a single center experience.

BACKGROUND: Renal denervation (RDN) has been shown to reduce blood pressure in patients with resistant arterial hypertension (RAH). We aimed to investigate predictors for response to RDN.
METHODS: Patients suffering from RAH underwent RDN after exclusion of secondary causes of hypertension. Ambulatory blood pressure measurement (ABPM) for 24 h was performed at baseline, 6 and 12 months after RDN. Response was defined as a at least 5 mmHg 24 h SBP drop at 6 months. A linear regression model was used to analyze an association between baseline variables and response to RDN.
RESULTS: In total, 45.6% of patients were responders to RDN. In those, there was a significant reduction in ABPM values at 6 and 12 months (12 months: 24 h SBP: -17.2 ± 9.0 mmHg, P < 0.01; 24 h DBP: -9.0 ± 11.6 mmHg, P < 0.01). Per 10 mmHg increase in baseline 24 h SBP, there was a 5.5 mmHg 24 h SBP reduction at 6 months. Per kg/m increase in BMI, 24 h SBP increased by 0.7 mmHg at 6 months. Per increment in antihypertensive drugs used at baseline, there was a 2.7 mmHg 24 h SBP reduction at 6 months.
CONCLUSION: Out of a wide range of baseline variables, elevated systolic ABPM values, BMI and the number of antihypertensive drugs used were associated with response. One has to consider the Hawthorne effect, the regression to the mean phenomenon, the actual effect of sympathetic denervation and the interaction of therapy modification when interpreting data from RDN registries without a control arm.