Skin sodium content as a predictor of blood pressure response to renal denervation

Objective: In patients with treatment resistant hypertension (TRH), renal denervation (RDN) emerged as an adjacent therapeutic option. It has been detected that patients with TRH have elevated Sodium (Na) content in muscle and skin. This analysis aimed at evaluating whether tissue Na content predicts blood pressure (BP) response after RDN. Design and method: Radiofrequency device based endovascular RDN was performed in 53 patients with uncontrolled TRH (office BP> = 140/90 mmHg and diagnosis confirmed by 24-h ambulatory BP monitoring) in our certified RDN center. Office and 24-h ambuatory BP were measured at baseline and after 6 months. To assess tissue Na content 23 Na-MRI was performed at baseline prior to RDN. We splitted the study cohort based on the median systolic 24-h ambulatory BP reduction after 6 months into responders and non-responders and compared tissue Na content and baseline characteristics between these groups. The study was registered at http://www.clinicaltrials.gov (NCT01687725). Results: 53 patients were followed up for at least 6 months. Office systolic and diastolic BP were reduced by -12.9±21.1 mmHg and -7.7±12.5 mmHg and 24-h ambulatory systolic and diastolic BP were reduced by -8.6±14.0 mmHg and -4.7±9.5 mmHg after 6 months. Responder could be characterized as patients with low tissue sodium content in skin, more female patients, patients with aldosteron-antagonists, high baseline 24-h night-time heart rate and high LDL-cholesterol (see table, only p<0.10 are shown). This results remained significant after adjustment for baseline 24-h SBP. Similar results were obtained if the two groups were created based on the median of 24-h day-time and night-time BP reduction after 6 months. Conclusions: We identified Na in skin, sex, 24-h night-time heart rate, aldosterone antagonists and LDL-cholesterol as predictors of the systolic BP response. We conclude that 23 Na-MRI may assist to select patients with uncontrolled TRH who will have a clinically meaningful BP reduction following RDN treatment.