WASHINGTON – A new device may be the best opportunity yet to achieve sustained blood pressure control in individuals aged 60 years and older, according to Paul Sobotka, MD, Chief Scientific Officer at ROX Medical, the maker of the device.
The experimental device is an arteriovenous coupler that provides an anastomosis between artery and vein to lower arterial volume and reduce blood pressure due to a structural cause. The device has already performed well in initial clinical studies, including a controlled, open-label trial, he reported at CRT 2017 sponsored by the Cardiovascular Research Institute at Washington Hospital Center.
Dr. Paul Sobotka
While neurohormonally driven elevations drive increases in diastolic and systolic blood pressures in younger patients, aortic stiffness and loss of vascular elasticity characterize the structurally driven hypertension of older patients, he said. While diuretics can lower arterial volume to achieve reductions in structurally related systolic hypertension, large doses are typically required to have meaningful results and are likely to be accompanied by unacceptable side effects in a large proportion of patients, he said.
“Somewhere between the age of 50 and 60 years, the majority of hypertensive patients will no longer be principally responsive to drugs acting on neurohormonal pathways or to renal denervation strategies.” In the elderly, cardiovascular risk is largely driven by hypertension principally related to the loss of aortic elasticity, which does not respond to most antihypertensive drugs.
The investigational arteriovenous coupler being developed by ROX Medical is intended to lower systolic blood pressure by reducing vascular resistance and therefore arterial volume. The coupler can be placed during cardiac catheterization, does not require sedation, takes about 1 hour to insert, and can be removed if necessary.
In a randomized, open-label study (Lancet. 2015 Apr;385:1634-41), mean systolic blood pressure was reduced by 26.9 mmHg on average in the 44 patients who received the arteriovenous coupler (P less than .001 vs. baseline) and by 3.7 mmHg (P = .31 vs. baseline) in the 39 patients who were maintained on antihypertensive medication, said Dr. Sobotka, who was a coauthor on this and several other clinical studies testing the efficacy and safety of the coupler. Systolic blood pressure falls almost immediately after the device is positioned, and blood pressure control has been sustained for up to 2 years of follow-up so far.
The procedure has been effective in patients resistant to antihypertensive medications and in those who have failed renal denervation, he said.
“The most significant adverse event observed has been venous stenosis related to turbulence, which occurs within in the first 12 months” after device placement, Dr. Sobotka reported. He said that venous stenting has resolved the problem in all affected patients. “Adverse events beyond that have been trivial.”