Impact of Antihypertensive Medication Changes After Renal Denervation Among Different Patient Groups: SPYRAL HTN-ON MED

Abstract

Background: The SPYRAL HTN-ON MED (Global Clinical Study of Renal Denervation With the Symplicity Spyral Multi-electrode Renal Denervation System in Patients With Uncontrolled Hypertension in the Absence of Antihypertensive Medications)trial showed significant office and nighttime systolic blood pressure (BP) reductions in patients with hypertension following renal denervation (RDN) compared with sham-control patients, despite similar 24-hour BP reductions. We compared antihypertensive medication and BP changes among prespecified subpopulations.

Methods: The multicenter, randomized, sham-controlled, blinded SPYRAL HTN-ON MED trial (n=337) evaluated BP changes after RDN compared with a sham procedure in patients with hypertension prescribed 1 to 3 antihypertensive drugs. Most patients (n=187; 54%) were enrolled outside the United States, while 156 (46%) US patients were enrolled, including 60 (18%) Black Americans.

Results: Changes in detected antihypertensive drugs were similar between RDN and sham group patients in the outside US cohort, while drug increases were significantly more common in the US sham group compared with the RDN group. Patients from outside the United States showed significant reductions in office and 24-hour mean systolic BP at 6 months compared with the sham group, whereas BP changes were similar between RDN and sham in the US cohort. Within the US patient cohort, Black Americans in the sham control group had significant increases in medication burden from baseline through 6 months (P=0.003) but not in the RDN group (P=0.44).

Conclusions: Patients enrolled outside the United States had minimal antihypertensive medication changes between treatment groups and had significant office and 24-hour BP reductions compared with the sham group. Increased antihypertensive drug burden in the US sham cohort, especially among Black Americans, may have diluted the treatment effect in the combined trial population.

Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02439775.

Keywords: Black or African American; antihypertensive agents; blood pressure; hypertension; renal denervation.

Figure 1.

Twenty-four-hour systolic blood pressure (SBP) and office SBP forest plots of prespecified subgroups. BMI indicates body mass index; BP, blood pressure; and RDN, renal denervation.

Figure 2.

Medication burden change from baseline to 6 months based on medication testing comparing renal denervation (RDN) and sham control groups in US patients and patients outside the United States as well as Black Americans and non-Black Americans. P values use the Mantel-Haenszel test for linear trend. Reported changes detected by blood and urine testing are based on the medication number, dosage, and class of antihypertensive medications.

Figure 3.

Changes in prescribed medication burden from baseline to 6 months in renal denervation (RDN) and sham control groups among Black Americans, non-Black Americans, and patients outside the United States.

Figure 4.

Reduction in mean 24-hour ambulatory and office systolic blood pressure (SBP) at 6 months for renal denervation (RDN) and sham control groups among Black Americans, non-Black Americans, and patients outside the United States.

Figure 5.

Change in office systolic blood pressure (BP) from baseline up to 6 months in select subgroups of renal denervation and sham control patients Mean office systolic blood pressure changes are depicted through 6 months in Black American patients (A), non-Black American patients (B), and patients outside the United States (C) in renal denervation (blue) and sham control groups (red). Error bars represent SE.