Renal vascular calcification and response to renal nerve denervation in resistant hypertension

Abstract

Renal sympathetic nerve denervation (RDN) is accepted as a treatment option for patients with resistant hypertension. However, results on decline in ambulatory blood pressure (BP) measurement (ABPM) are conflicting. The high rate of nonresponders may be related to increased systemic vascular stiffness rather than sympathetic overdrive. A single center, prospective registry including 26 patients with treatment resistant hypertension who underwent RDN at the Isala Hospital in the Netherlands. Renal perivascular calcium scores were obtained from noncontrast computed tomography scans. Patients were divided into 3 groups based on their calcium scores (group I: low 0-50, group II: intermediate 50-1000, and group III: high >1000). The primary end point was change in 24-hour ABPM at 6 months follow-up post-RDN compared to baseline. Seven patients had low calcium scores (group I), 13 patients intermediate (group II), and 6 patients had high calcium scores (group III). The groups differed significantly at baseline in age and baseline diastolic 24-hour ABPM. At 6-month follow-up, no difference in 24-hour systolic ABPM response was observed between the 3 groups; a systolic ABPM decline of respectively -9 ± 12, -6 ± 12, -12 ± 10 mm Hg was found. Also the decline in diastolic ambulatory and office systolic and diastolic BP was not significantly different between the 3 groups at follow-up. Our preliminary data showed that the extent of renal perivascular calcification is not associated with the ABPM response to RDN in patients with resistant hypertension.

Figure 1

Renal perivascular calcium score assessment. cm = centimeters.

Figure 2

Computed tomography-angiography reconstruction of the renal arteries and part of the aorta of 3 patients with respectively a low (A), intermediate (B), or high calcium score (C). The ambulatory blood pressure measurements response for these patients 6 months post-RDN was respectively: −17 mmHg (A), −25 mmHg (B), and −13 mmHg (C).

Figure 3

Flowchart. Inclusion of our study population.

Figure 4

Ambulatory blood pressure response at 6 months of follow-up post-RDN in 3 patient groups based on their calcium scores (I: low, II: intermediate, and III: high).

Figure 5

Office blood pressure response at 6 months of follow-up post-RDN in 3 patient groups based on their calcium scores (I: low, II: intermediate, and III: high).