One of the highlights of the Tuesday sessions of the Society for Interventional Radiology (SIR) was the very lively Hot Topics debate. This session featured teams of two interventionists arguing for or against current topics of interest. One of the big recent developments in the industry is Medtronics' $1 billion acquisition of Ardian for their renal denervation technology. This has generated some buzz both through industry and clinicians, leaving many wondering about the future role of renal artery stenting and angioplasty in the face of this emerging denervation technology.
Right off the bat, Dr. Tim Murphy conceded the negative trial data from the STAR and ASTRAL trials. However he also did stress the well known criticisms surrounding both trials. Dr. Murphy further pointed out that there would be cases where denervation would not be indicated and where blood pressure controlling drugs are ineffective, thereby keeping a role for renal stenting.
On the other hand, Dr. Mark Sapoval argued for leaving renal stenting behind and embracing denervation, as well as focus on better medical management. He stressed that renal stenting has shown no benefit over medical management by any measure in trials, but comes with complications such as vessel perforation and hemorrhage. Furthermore denervation has shown a decrease in blood pressure, one of the key end points in therapy. Hope from future trials for stenting, such as CORAL is lukewarm and not expected to change perception. The new tool, renal denervation, for patients with no stenosis or other cause of secondary hypertension, is the answer.
Dr. Thomas Soh replied by arguing that the debate is moot because both treatment options, denervation and stenting, are non-competitive and complementary. He said that if the indications and contraindications for both were such that the indications for one were the contraindications for the other, and vice versa, suggesting a possible lack of complete overlap in terms of eligible patient populations.
Dr. Alan Matsumoto noted however, that less than 5% of hypertension was due to renal artery stenosis. Hypertension treatment therefore, would be better treated with denervation. He further argued that the current trials for renal artery stenting were poorly designed and haven't even determined the right type of patients to treat, so the evidence is weak. Dr. Matsumoto ended his rebuttal stating that interventional radiologists needed to adapt their treatment for hypertension or be left behind.
Overall, the judging panel narrowly agreed that there would still be a continued role for renal artery stenting and angioplasty. Although denervation is not expected to completely eliminate renal stenting, procedural growth will continue to fall due to lack of clinical safety and efficacy, as well as the relative uncertainty as to which patients would truly benefit from the procedure.