#4540 LONG-TERM OUTCOMES AFTER RENAL DENERVATION: A FOLLOW-UP OF 5 YEARS
Authors: Roxo Maria Inês , Carnevale Andreia , Calça Ana Rita , Martins Ana Rita , Gonçalves Pedro , Almeida Manuel , Gaspar Augusta , Branco Patricia 
Published: June 2023

Abstract

Background and Aims
Arterial hypertension is a significant cause of cardiovascular morbimortality worldwide. Adequate blood pressure control constitutes a crucial tool to prevent the enduring end-organ damage inflicted by hypertension and, consequently, its high burden of disease. Resistant hypertension may be particularly challenging to address: in this field, denervation of the renal sympathetic nerves is developing as a promising despite controversial therapy. Our goal was to study long-term outcomes in a cohort of patients with resistant hypertension submitted to renal denervation.

Method
We conducted a retrospective, single-centre study amongst patients with resistant hypertension who underwent renal denervation between July 2011 and July 2022. All patients routinely underwent blood and urine testing, 24-hour ambulatory blood pressure monitoring (ABPM) and echocardiographic evaluation every 6 to 12 months after the procedure. We collected several demographic, clinical and laboratory variables, and analysed outcomes at 5 years of follow-up using SPSS software.

Results
78 patients were submitted to renal denervation in our centre, 53% of which (n = 41) were male. There were no reported complications related to the procedure. At 5 years of follow-up, there were different types of responders. In ABPM, 61% of the patients showed a decrease in mean systolic blood pressure (SBP), with a median reduction of 16 mmHg (IQR 16.5). In 46% of patients, there was a reduction in albumin/creatinine ratio (ACR), with a median decrease of 17.63 mg/g (IQR 120.67). Before renal denervation, 30 patients (38.5%) had an ACR above 30 mg/g, while after 5 years the number of patients with ACR in this range was 21 (26.9%). In echocardiographic evaluation, 70% of the patients evidenced a decrease in left ventricular mass index (LVMI) with a median reduction of 20 g/m2 (IQR 41). These results are summarised in Figure 1. In total, 70% of the patients were considered responders to renal denervation, either through a reduction in mean SBP in ABPM, in LVMI, in ACR or simultaneously in all three variables. Additionally, the reduction in mean SBP in ABPM, LVMI and ACR proved to be independent variables, both in Spearman tests and binary logistic linear regression (nonsignificant p-values). 77% of the patients were prescribed less antihypertensive drugs after follow-up, with a median reduction of 2 drugs (IQR 2).

Conclusion
Our study identified a significant percentage of responders to renal denervation, evidenced by an improvement in one or more variables associated with blood pressure control and hypertension-mediated end-organ damage, without any safety issues to report. It is also important to emphasize that the observed reduction in ACR and LVMI was independent of the reduction in SBP. This finding suggests that renal denervation might have a direct effect on albuminuria and left ventricular hypertrophy, instead of solely as an indirect result of the control of blood pressure. Hence, while further studies are necessary to support this evidence, the results nevertheless raise hope for the therapeutic potential of renal denervation in patients with resistant hypertension.