HIGHER BASELINE SYSTOLIC BLOOD PRESSURE IS ASSOCIATED WITH GREATER BLOOD PRESSURE REDUCTIONS FOLLOWING RADIOFREQUENCY RENAL DENERVATION IN A POOLED COHORT OF OVER 3900 PATIENTS

Abstract

Objective: Uncontrolled hypertension (HTN) is the leading global risk factor for cardiovascular disease, and higher systolic blood pressure (SBP) increases this risk. Radiofrequency renal denervation (RF RDN) has been shown to reduce BP effectively in patients with uncontrolled HTN. We investigated the relationship between increasing baseline SBP and its change after RF RDN. Design and method: Patients undergoing RF RDN (N=3974) were pooled from global clinical trials in patients on antihypertensive drugs: SPYRAL First-In-Man, SYMPLICITY HTN-3, HTN-Japan, SPYRAL HTN ON-MED, and the Global SYMPLICITY Registry DEFINE. Office and 24-h ambulatory SBP at baseline and 6 months after RF RDN were evaluated. Linear regression analysis was performed to evaluate the correlation between baseline and SBP change after 6 months (SBP change=intercept+slope∗baseline SBP). Results: The baseline SBP for office and 24-h ambulatory BP were 167±24mmHg and 154±18mmHg, respectively. Patients were prescribed 4.4±1.5 antihypertensive drugs at baseline. After 6 months, prescribed antihypertensive drugs decreased to 4.3±1.5 (p<0.0001). In both office and 24-h ambulatory SBP, baseline SBP correlation with SBP change after 6 months was statistically significant; every 1mmHg increase in baseline office SBP was associated with a 0.59mmHg (r2=0.30; p<0.001) reduction in SBP, and every 1mmHg increase in baseline 24-h ambulatory SBP was associated with a 0.45mmHg (r2=0.19; p<0.001) reduction in SBP at 6 months. According to this linear regression, a baseline office SBP of 160mmHg, 170mmHg and 180mmHg were associated with 6 months office SBP reduction by -9.2mmHg, -15.1mmHg and -21.0mmHg, respectively (Figure). Reductions in SBP of this magnitude have previously been shown to correspond with substantial reductions in the risk of cardiovascular events. Conclusions: A continuous and inverse relationship was observed between baseline SBP and 6 months SBP change in patients with uncontrolled HTN undergoing RF RDN. Higher baseline SBP led to a greater reduction in SBP and may derive greater benefit from an RDN procedure. These findings may help clinicians and patients in their shared decision making regarding their BP management. However, this is a retrospective analysis which needs further prospective validation.