Physicians' Academy for Cardiovascular Education

Novel endovascular baroreflex-amplifying implant lowers BP in therapy-resistant hypertension

Endovascular baroreflex amplification for resistant hypertension: a safety and proof-of-principle clinical study

Spiering W, Williams B, Van der Heyden J, et al., CALM-FIM_EUR investigators - Lancet. 2017 Sep 1. doi: 10.1016/S0140-6736(17)32337-1


Resistant hypertension, defined as uncontrolled blood pressure (BP) despite treatment with three or more drugs including a diuretic, and the associated increased CV and renal complication risk, occurs in about 10% of all treated hypertensive patients. Devices have been developed to treat resistant hypertension, but none has thus far been adopted for routine care [1].

Stimulation of the carotid baroreflex pathway, thereby amplifying the signal sensed by the carotid baroreceptors, results in inhibition of sympathetic outflow, and consequently a decrease in BP [2]. As a less invasive alternative to implantable pulse generators that stimulate the carotid baroreceptors [3], the MobiusHD device has been developed, an endovascular implant that reshapes the carotid sinus. It yields in increased wall strain in the carotid sinus, which is sensed as increased pressure by the baroreceptors. The baroreceptors then respond by inhibiting sympathetic outflow and reducing BP [4]. In an acute study in dogs, the MobiusHD device induced a more pronounced increase in carotid sinus nerve activity than a standard carotid stent and BP was lowered by around 50/30 mmHg for up to 6 hours. Long-term efficacy could not be assessed in the canine model.

This CALM-FIM_EUR study is a prospective first-in-human open-label study to assess the safety and efficacy of the MobiusHD in 30 patients with resistant hypertension who underwent carotid angiography (mean office SBP >160 mmHg, mean ambulatory SBP >130 mmHg for at least 30 days despite >80% treatment adherence to at least three antihypertensive drugs). The primary endpoint was the incidence of serious adverse events, including unanticipated adverse device effects at 6 months.

Main results


This first-in-man study of a novel endovascular baroreflex amplification device resulted in clinically important reductions in office and 24hrs ambulatory BP with acceptable safety, in patients with resistant hypertension. Most patients needed fewer medications after 6 months of follow-up.

This study has limitations inherent to a small, non-blinded set up, thus the safety profile and efficacy of the Mobius HD needs to be studied further in larger studies with longer follow-up.


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Find this article online at The Lancet