And speaking of adherence, a key feature of SPYRAL HTN-ON MED was that the trial incorporated periodic drug adherence monitoring using both urine and blood testing. The results, Dr. Kandzari said, were eye opening: At any given time, roughly 40% of patients in both study arms were nonadherent to their antihypertensive medications. Moreover, nonadherence was dynamic: It was not predictable for any single patient at any time point.
This 40% nonadherence rate was surprisingly high given that participants in SPYRAL HTN-ON MED were volunteers eager to participate in a non–drug treatment study and were informed up front that they would be undergoing adherence testing.
As in RADIANCE-HTN SOLO, no safety issues arose during follow-up in SPYRAL HTN-ON MED. The results were published simultaneously with Dr. Kandzari’s presentation (Lancet 2018 May 23; doi: 10.1016/S0140-6736[18]30951-6).
One difference between the two technologies is that, unlike the ReCor Paradise ultrasound catheter, which ablates in the main renal arteries, the Medtronic radiofrequency device is placed in the side branches.