MUNICH – Renal denervation remains investigational in the United States, where a large clinical trial testing its safety and efficacy is now in progress.
But in Europe, Australia, and elsewhere, renal denervation – an intravascular procedure that zaps the sympathetic innervation in a patient’s renal arteries with a few pulses of radiofrequency energy – is rapidly becoming the big new thing for treating patients with drug-resistant hypertension since marketing of a denervation catheter began in April 2010.
As of last spring, Medtronic, the company that sells the only renal denervation (RD) catheter currently commercially available, estimated that the 5,000th patient had been treated by RD, although Dr. Michael Böhm, who oversees what might be the most active RD program in the world, recently put his estimate upwards of 10,000 patients treated worldwide. Among the smaller number of closely followed patients included in this experience with reported outcomes data, perhaps 300-500 patients, the results have been striking: A drop in office blood pressure on the order of 28/10 mm Hg in patients who began treatment with pressures in the 180/100 mm Hg ballpark (despite treatment with as many as six antihypertensive drugs), that has been durable over follow-up as long as 36 months, with response rates among patients that rise over time and run over 90% once patients are followed longer than a year, and uniform reports of good safety during 6-36 months’ follow-up, with no evidence of impaired renal function or arterial sclerosis over time or other untoward effects.
And now emerging in new reports, both recently published and presented at the meeting in August, are hints of several effects beyond simple blood pressure reduction that hold promise for expanding the application of RD beyond just antihypertensive treatment and broadening the recognized benefits of this treatment.
RD "is a transformative area for treating hypertension, and now heart failure" and other disorders, commented Dr. Adrian Brady, a cardiologist and hypertension specialist in Glasgow, Scotland.
More Than Just Blood Pressure
Among the newest findings was a report on a small, controlled study with 43 normotensive patients with New York Heart Association class III or IV heart failure that showed RD could significantly raise left ventricular ejection fraction, reduce left ventricular end-systolic and end-diastolic volume index, and cut serum levels of brain natriuretic peptide during 12 months of follow-up. RD had these positive effects on surrogate markers of heart failure severity without causing hypotension or other adverse effects, and the treatment also cut the rate of heart failure hospitalizations over 12 months by more than half, although the study wasn’t powered to examine this end point, reported Dr. Milos Táborský, a cardiologist at Olomouc University Hospital in the Czech Republic.