Effect of Catheter-Based Renal Denervation on Morning and Nocturnal Blood Pressure: Insights From SYMPLICITY HTN-3 and SYMPLICITY HTN-Japan

Abstract

High nighttime and early morning blood pressure (BP) have been associated with greater risk for cardiovascular events than high clinic or daytime BP. BP is typically highest in the rising hours, when morning activities typically begin. We examined the effect of renal denervation on morning (6:00-8:59 AM), daytime (9:00 AM-8:59 PM), and nighttime (1:00-5:59 AM) ambulatory BP. Patient data from 2 prospective, randomized controlled trials of patients with treatment-resistant, uncontrolled hypertension, one conducted in a US population (Renal Denervation in Patients With Uncontrolled Hypertension [SYMPLICITY HTN-3]) and the other in a Japanese population (SYMPLICITY HTN-Japan [HTN-Japan]), were analyzed. Patients in SYMPLICITY HTN-3 and HTN-Japan were prescribed a similar number of baseline antihypertensive medications (5.2±1.4 versus 4.9±1.6, P=0.28), but the classes prescribed and changes in prescription varied by study. Among patients treated with renal denervation, although the number of ablation treatments were similar in both studies (11.2±2.8 versus 11.5±1.9, P=0.55), patients in SYMPLICITY HTN-3 were less likely to receive at least 1 four-quadrant ablation treatment (25% versus 82%, P<0.001). In SYMPLICITY HTN-3, compared with controls (n=159), patients treated with renal denervation (n=325) experienced a significantly greater change in morning (-7.3±19.8 mm Hg, P<0.001) and nighttime (-6.1±18.2 versus -1.6±19.7 mm Hg, P=0.02) but not daytime systolic BP (-7.2±16.2 versus -6.4±18.6 mm Hg, P=0.67). This same trend was observed in the pooled analysis with HTN-Japan. Reduction of BP during these high-risk periods might provide cardiovascular protection in drug-resistant hypertensive patients, although this will need to be proved in future randomized trials.

Clinical trial registration: URL: www.clinicaltrials.gov; Unique identifiers: NCT01418261 (SYMPLICITY HTN-3) and NCT01644604 (HTN-Japan).

Keywords: SYMPLICITY; ambulatory blood pressure monitoring; blood pressure; denervation; hypertension.