Abstract 9590: Early Blood Lowering Effects of Renal Sympathetic Denervation
Introduction and Hypothesis Hypertension is a major global health problem. Renal sympathetic hyperactivity has been identified as a major contributor to the complex pathophysiology of hypertension. Catheter-based renal sympathetic denervation (RDN) has been shown to significantly reduce blood pressure (BP) in patients with severe hypertension. According to Symplicity HTN-1 and -2 trials it is known that the BP lowering effect will take about 1 to 6 month to develop. However, there is little information available on the immediate BP lowering effects of RDN. Our study carefully investigated early BP response to RDN in a cohort of patients with resistant hypertension (systolic BP >150 mm Hg on >3 antihypertensive drugs).
Methods and Results Our study enrolled 28 consecutive patients (mean age 65 years, 48% women, 47% diabetic). Baseline values included a mean of 5.7 antihypertensive medications. A 24h Holter BP monitoring was recorded in every patient 24h before and after RDN. BP readings were then averaged according to daytime (7:00am-22:00pm), night (22:00pm-7:00am) and 24 hours intervals (figure 1). In treated patients mean averaged systolic BP was reduced by 15.3±3.34 mmHg (p<0.001) during the first 24 hours. Systolic BP reduction appeared to be much higher at daytime (17.5±3.59 mmHG; p<0.001) compared to night (9.6±3.88 mmHg; p<0.021) which might indicate the role of sympathetic activity at daytime. A concordant effect on diastolic BP was observed: 6.9±1.72 mmHg (p<0.001). Heart rate was not affected at the early time points (1.64±1.62; p=0.319). The missing changes in heart rate may indicate the absence of inpatient stress factors that could have influenced BP.
Conclusion In patients with resistant hypertension, catheter-based renal sympathetic denervation results in an immediate substantial reduction of systolic and diastolic BP. The relationship between the immediate and long-term BP lowering effect of RDN-therapy remains to be investigated.
- © 2011 by American Heart Association, Inc.