BLOOD PRESSURE RESPONDERS TO RENAL DENERVATION BASED ON A NEW DEFINITION

Abstract

Objective: Identifying predictors of blood pressure (BP) response to renal denervation (RDN) is an unmet need for patient selection. Any antihypertensive intervention follows the law of the inital value, which means that the baseline BP predicts the BP change, a phenomenon known as Wilder‘s Principle (European Heart Journal, 2015, 36, 576-579). Thus, any observed change in BP after renal denervation is the sum of the change in BP depending on the baseline BP and the specific BP reduction related to RDN. Based on this concept, we propose a new definition of BP responders. Design and method: In our center, a total of 127 patients with uncontrolled hypertension underwent RDN and 24h ambulatory BP was measured at baseline, 6- and 12 months after the procedure. According to the Wilder's principle, the decrease in the 24h ambulatory systolic BP (SBP) was related to the baseline 24h SBP (p=<0.001, r=-0.466, y=69.28–0.52∗x). Subsequently, we calculated the predicated decrease in 24h SBP and subtracted this from the the observed decrease in 24h SBP, thereby getting the specific or residual effect of SBP decrease. According to this RDN specific change of 24h SBP, the study cohort was divided into tertials: RDN responders, neutral responders and non-responders. Results: Our study population with mean of age of 59 years consisted of 74% males and 55% with type 2 Diabetes (T2D). The RDN specific (residual) 24-hour ambulatory blood pressure decreased by -14.4/-8.8mHg (responder group), 1.4/0.4mmHg (neutral group) und 15.7/8.5 mmHg (non-responder group) twelve months after RDN (see table). According to our new definition of BP-responders to RDN, the RDN responder group was characterized only by lower number of antihypertensive medication (p=0.002), low BMI (p<0.001), and the absence of T2D (p=0.013). Conclusions: We propose a new definition of responders to RDN, separating the BP- changes related to the baseline BP from those related to the reduction of the sympathetic nerve activity after RDN. Following this approach, we identified low BMI, less antihypertensive medication and absence of T2D as positive predictors for BP response to renal denervation.