Reply to the letter “Renal denervation: The potential causes of non-response”

Abstract

I thank Dr Liu for his letter [1] and appreciate the interest he demonstrates on the case report on the effects of monolateral renal denervation on sympathetic nerve traffic, clinic and 24-hour ambulatory blood pressure in a patient with true resistant hypertension [2]. The letter by Dr Liu poses a number of questions and it allows one to provide additional information on the case report that space constraints prevented to add in the original paper. As recommended by current European Guidelines on hypertension as well as by the most recent international Expert Consensus Statement on renal denervation [3,4], our patient before undergoing the renal denervation procedure was carefully screened for ruling out any secondary nature of his high blood pressure state. All the instrumental and laboratory tests performed excluded a hypertensive state of secondary nature. Similarly, as already mentioned in the case report publication [2], adherence to treatment was also accurately checked before the procedure, in order to rule out the possibility that a poor patient's adherence to drug treatment was responsible for the clinical state. Adherence to treatment was also carefully checked during the follow-up after the procedure. These evaluations allowed one to exclude any change in the dosage and/or number and type of antihypertensive drugs taken by the patient. Finally, we would like to emphasize that at present the number of ablation points is not a strictly fixed variable (although 6 is recommended as routine procedure), and that this number depends on many variables, including the length of the renal artery as a main factor. I would like, however, to emphasize that, as stated in our case report, the reason of failure of the ablation in one renal artery was the damage of the guide catheter and not the vascular injury. In summary, mentioning again the recommendations of the European Guidelines document [3] and the latest Expert Consensus Statement [4], which I have contributed to in writing, I would like to emphasize that bilateral renal denervation is the goal standard to try to obtain a blood pressure reduction in true resistant hypertension, the monolateral approach not guaranteeing a sympathetic deactivation and thus a blood pressure reduction.