The results of a really interesting clinical trial were reported at the annual meeting of the American College of Cardiology and simultaneously published online before print by the New England Journal of Medicine.
The trial, SIMPLICITY-HTN3, was designed to test the efficacy of renal artery denervation by radiofrequency ablation in the treatment of medication resistant hypertension. For those of you unfamiliar with the technique, it utilizes catheters similar to those used in intra-cardiac ablations by cardiac electrophysiologists. In this case, the ablation catheters are positioned in the renal arteries, and deliver radiofrequency energy through the arterial wall to the nexus of nerves in the surrounding tissue. In early reports of the technique, this “catheter based sympathectomy” led to stunning reductions in systolic blood pressure, and cardiologists were jumping on the bandwagon to do the procedure.
Cooler heads prevailed, and the recent trial was designed to address several methodologic limitations of the earlier reports. For me, the most interesting difference was the inclusion of a blinded control group, which was “treated” with a sham procedure. The sham included insertion of catheters into the renal arteries, along with renal artery angiography, but no ablation. The patients were all sedated, and the duration of the procedures was adjusted so that neither the patient nor family members could tell what had been done. The effectiveness of the blinding efforts was confirmed with patient questionnaires.
The results? No significant difference in the blood pressure at 6 months between the ablation and the control groups:
Here’s the really interesting part. There was no difference, not because the ablation failed to lower blood pressure, but because the sham procedure lowered blood pressure just as much as the “real” intervention. Once again we are reminded of the power of patients’ believing that they had undergone a therapeutic procedure.
I believe that tapping in to the strength of patients’ beliefs is one of the “unmeasurable” things that separate great doctors from technically proficient ones. Great doctors develop a therapeutic bond, characterized by mutual respect and trust. That trust leads to faith in the prescribed course of action, which leads to better results. Every “medicine-man” or shaman knew that to be the case. We should remember it too.
What do you think?
Ira S. Nash, MD, FACP, is the senior vice president and executive director of the North Shore-LIJ Medical Group, and a professor of Cardiology and Population Health at Hofstra North Shore-LIJ School of Medicine. He is Board Certified in Internal Medicine and Cardiovascular Diseases and was in the private practice of cardiology before joining the full-time faculty of Massachusetts General Hospital. He then held a number of senior positions at Mount Sinai Medical Center prior to joining North Shore-LIJ. He is married with two daughters and enjoys cars, reading biographies and histories, and following his favorite baseball team, the New York Yankees, when not practicing medicine. This post originally appeared at his blog, Ausculation.