I've read the whole study (at least I think so
), so here is some additional information.
This minimally invasive procedure, which would likely be performed by interventional radiologists and/or interventional cardiologists, consists of several (4-6) 2 minute applications of RF energy to the renal artery nerves. It is simple, safe and the kidney function is not affected.
Blood pressure reductions were achieved as early as 1 month after the ablation. Not all people in the study responded. 83% had sustained reductions in blood pressure of >10mmHg, while 17% did not. The reason for the non-responsiveness could have been an inadequately performed ablation, or non-involvement of the renal sympathetic activation in these individuals' hypertension.
Now comes the part we were wondering about. Medications were stable over the course of the trial (what do they mean, stable???
) with three people requiring a reduction in blood pressure medication when they developed symptomatic hypotension, as their blood pressure normalized, and nine requiring increased medication. The trial had 50 participants in all, 5 of which were not treated. The blood pressure of people not receiving the ablation treatment continued to rise and they are included in these stats.
Interestingly, ambulatory blood pressure monitoring showed that people who were non-dippers
before the procedure became dippers
after the RF ablation. The others quickly returned to their normal nightime blood pressure variations (decreases).
There are plans to investigate this procedure in the setting of chronic kidney disease and systolic heart failure. This procedure could eventually have applications in people with less severe forms of hypertension. A randomized trial is next.