February 9th, 2015
Selections from Richard Lehman’s Literature Review: February 9th
CardioExchange is pleased to reprint this selection from Dr. Richard Lehman’s weekly journal review blog at BMJ.com. Selected summaries are relevant to our audience, but we encourage members to engage with the entire blog.
NEJM 5 Feb 2015 Vol 372
Efficacy of a Device to Narrow the Coronary Sinus in Refractory Angina (pg. 519): Refractory angina seems to be common in cardiac clinics but not in primary care. When all the drugs have failed, and revascularization is not an option, device makers like to get inventive. The latest gizmo is an hour-glass shaped expandable metal object which sits at the portal of the coronary arteries and “creates a focal narrowing and increases pressure in the coronary sinus, thus redistributing blood into ischemic myocardium.” My inclination is to say “Yeah, right,” but these things do seem to work, somehow or other. “The device was also associated with improvement of at least one Canadian Cardiovascular Society angina class in 71% of the patients in the treatment group (37 of 52 patients), as compared with 42% of those in the control group (22 of 52) (P=0.003).” The control was a sham procedure.
Lancet 7 Feb 2015 Vol 385
Optimum and Stepped Care Standardized Antihypertensive Treatment With or Without Renal Denervation for Resistant Hypertension (OL): In the course of my clinical working life, I had as little to do with drug companies as possible, and nothing whatever to do with device manufacturers. It came as a jaw-dropping surprise to me when Medtronic decided to let its full data on a commercial product be analysed by two independent teams. I was at Yale University when it happened and I got some trickle-down money from that project, so I must declare an interest. The other thing that impressed me about Medtronic was that it performed a sham-controlled trial on the Symplicity renal denervation device which it had bought from another company on the back of a massively successful open-label trial in so-called resistant hypertension. The Symplicity-2 trial, using a sham procedure as control, failed to meet its prespecified end-point, and rather than make excuses, Medtronic accepted that it should not be promoted thereafter. Now along comes another open-label trial comparing the Symplicity device with stepped drug treatment, paid for by the French government: and Symplicity wins by 6mm Hg.
Bizarrely, the accompanying editorial in effect criticizes Medtronic for not pushing its own product, pointing out various flaws in the Symplicity-2 trial and alleging “an important question is whether a sham procedure is ethical and practical in patients with resistant hypertension often accompanied by other comorbidities, leaving these patients at high risk of cardiovascular and renal disease progression and potentially adding to treatment costs.” What nonsense. We have no idea what these devices do for long term outcomes and sham-controlled trials are the only ethical way to find out.