Nighttime blood pressure reductions after radiofrequency renal denervation through 24 months in patients with uncontrolled hypertension: pooled analysis from the SPYRAL HTN trials

Abstract Introduction Studies have shown that elevated nighttime and early morning systolic blood pressure (SBP) are associated with the highest risk for cardiovascular (CV) events. Radiofrequency renal denervation (RF RDN) is an interventional therapy to reduce BP in patients with uncontrolled hypertension (HTN). Although sustained, durable reductions in office and 24-h ambulatory systolic BP (SBP) after RDN have been observed, whether the therapy produces similar, durable nighttime and early morning SBP reductions requires further evaluation. Objective To assess whether RF RDN significantly reduces nighttime SBP through long-term follow-up, in addition to other times of the day. Methods We pooled data from patients with uncontrolled HTN undergoing RF RDN using the latest-generation Symplicity SpyralTM multi-electrode catheter from the published SPYRAL HTN-OFF and -ON MED clinical trials. Office and 24-h ambulatory SBP were evaluated from baseline through 24 months. We also assessed BP changes during specific, diurnal time ranges including nighttime (1am-6am), early morning (7am-9am), and daytime (9am-9pm). The number of antihypertensive drugs and drug burden (determined by number of classes and prescribed dosage) from urine and plasma drug testing were tabulated from baseline through 24 months. Results Outcomes from 388 patients undergoing RF RDN were pooled for this analysis. Patients were on average 54±10yrs old, 26.8% female, mean BMI was 31.3±6.0, 45.1% with >10yrs diagnosis of hypertension, 7.7% with type 2 diabetes, 9.8% with obstructive sleep apnea, 47.7% with a history of smoking. The baseline nighttime SBP was 139±11mmHg, morning SBP was 154±15mmHg, and daytime SBP was 156±9mmHg. At baseline, 92.5% of patients had nocturnal hypertension (BP ≥120/70 mmHg) and took 1.0±1.2 antihypertensive drugs. 12 months after RF RDN, 30.6% of patients no longer had nocturnal hypertension (p<0.0001). The mean nighttime SBP change at 12 months was -10.8±15.4mmHg, morning changed was -12.8±20.4mmHg, and daytime changed was -12.2±13.6mmHg (Figure). The mean 24-h ambulatory SBP change at 12 months was -11.9±12.4mmHg, and the office SBP change was -17.7±15.4mmHg . Patients took 1.8±1.1 antihypertensive drugs at 12 months. Results from 24 months, not currently available, will also be presented for the first time. Conclusions In this pooled cohort of RDN patients with uncontrolled hypertension, nocturnal hypertension was highly prevalent. Clinically meaningful reductions at 12 months throughout the 24-hr circadian cycle, including at nighttime and early morning SBP, are consistent with the "always on" effect of RDN. Results from 24 months will also be presented for the first time at ESC. As an adjunctive therapy to pharmacotherapy, RDN may help to reduce CV risk by lowering nighttime and morning SBP.