Effect of renal denervation in attenuating the stress of morning surge in blood pressure: post-hoc analysis from the SPYRAL HTN-ON MED trial

Abstract

Catheter-based renal denervation (RDN) reduces blood pressure (BP) throughout the 24-h period, as reported in several randomized sham-controlled trials. Reduction of BP in the early morning hours is especially important due to increased cardiovascular risks during that time. In this report, we examine the impact of RDN on systolic BP (SBP) and diastolic BP (DBP) during the critical morning surge period in a post-hoc analysis of patients in the SPYRAL HTN-ON MED trial. Ambulatory BP measurements were collected at baseline and 6months for treatment and control patient groups over 24-h periods. Average morning BP surge is the difference between average morning BP and average nighttime BP, and the morning surge slope reflects the rate of change of BP from nighttime to morning. Mean morning DBP surge slopes were significantly lower for RDN vs. control groups at 6months (1.1 vs. 3.6mmHg/h; p = 0.029). In the RDN group, morning DBP surge slopes were significantly lower at 6months compared to baseline (1.1 vs. 4.1mmHg/h; p = 0.006). Similar patterns were observed for mean morning SBP surge slope but did not reach statistical significance. This decrease in the morning DBP surge slope, an index of the sympathetically-mediated morning BP surge, thus indicates a drop in late morning BP relative to early morning/nocturnal BP in the RDN group. Thus, RDN appears effective in attenuating the slope of morning surge in DBP that might indicate possible benefits in a high-risk hypertensive population. https://www.clinicaltrials.gov (NCT02439775), registered May 12, 2015.