February 11th, 2013
Selections from Richard Lehman’s Literature Review: February 11th
CardioExchange is pleased to reprint selections 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.
JAMA 6 Feb 2013 Vol 309
Effect of Ramipril on Walking Times and Quality of Life Among Patients With PAD and Intermittent Claudication (pg. 453): Stone the crows, a great little study from Oz that will change your practice at a stroke. They recruited 212 patients with intermittent claudication who had never had invasive treatment—which immediately made me realise the study couldn’t have been done in America, where at the first twinge of calf pain you get a stent or balloon stuck down your femoral artery. No, these were mostly fine specimens of Australian manhood, mean age 65, getting pains below the level of their shorts if they walked too far, despite the fact that one third of them had never smoked and all of them had normal blood pressure. One half of them were randomized to a well-known drug and after six months they found they could walk four minutes longer before they had to stop. The wonder drug? Ramipril 10mg. This is the kind of trial that makes nobody millions of dollars, but which we should all be doing in our fields of interest. It took just three interested hospitals in Southern Australia.
NEJM 7 Feb 2013 Vol 368
Genetic Associations with Valvular Calcification and Aortic Stenosis (pg. 503): And now back to the Northern Hemisphere where the big boys live. This study was done in over 30 centres across North America and Europe, and in Iceland, which is somewhere between. Compared with the little fishing boats the Australians used to bring in their useful catch, this looks like an imperial Navy, with battle cruisers and aircraft carriers in full steam. What do they sail forth to capture for the benefit of mankind? “One SNP in the lipoprotein(a) (LPA) locus (rs10455872) reached genomewide significance for the presence of aortic-valve calcification (odds ratio per allele, 2.05; P=9.0×10−10), a finding that was replicated in additional white European, African-American, and Hispanic-American cohorts (P<0.05 for all comparisons). Genetically determined Lp(a) levels, as predicted by LPA genotype, were also associated with aortic-valve calcification, supporting a causal role for Lp(a).” Genomic true believers will argue that this is a real step forward, because it is another piece of evidence that this lipoprotein fraction is implicated in valvular calcification. I leave this for you to decide.
Rivaroxaban for Thromboprophylaxis in Acutely Ill Medical Patients (pg. 513): If you are a major medical journal with a business model that involves large payments for reprints from pharmaceutical companies, then you are bound to love the two wars that ensure your income stream—the Stent Wars (see this week’s Lancet) and the Clotbusting Wars. Given the number of competing products and possible study designs, these two wars alone could go on forever, boring and confusing clinicians and filling the coffers of the NEJM and the Lancet throughout eternity. Rule One for selling reprints is that you make the conclusion of the Abstract as favourable as possible, because this is all that most clinicians read:
“In acutely ill medical patients, rivaroxaban was noninferior to enoxaparin for standard-duration thromboprophylaxis. Extended-duration rivaroxaban reduced the risk of venous thromboembolism. Rivaroxaban was associated with an increased risk of bleeding.” And for your further information: “The study was designed and supervised by the steering committee and was sponsored by Bayer HealthCare Pharmaceuticals and Janssen Research and Development. The members of the steering committee signed confidentiality agreements with the study sponsors. The data were collected and analyzed by the sponsors. All the authors had full access to the data and analyses and contributed to the writing of the manuscript. Editorial assistance was provided by Chameleon Communications.” But even the best chameleon cannot disguise the fact that that rivaroxaban is more than twice as likely as enoxaparin to cause a bleed requiring two or more units of blood by day 10, and similarly by day 35. So an honest Abstract conclusion might read: “In acutely ill medical patients, compared with rivaroxaban, enoxaparin provides equal protection from thromboembolism and is considerably safer.” And the editor of this journal was telling us a few weeks ago that we should not mistrust the reporting of industry trials.
Lancet 9 Feb 2013 Vol 381
Paclitaxel-Eluting Balloons, Paclitaxel-Eluting Stents, and Balloon Angioplasty in Patients with Restenosis After Implantation of a Drug-Eluting Stent (pg. 461): Not that all non-pharma trials are much better. I utterly fail to understand why this one is published in a leading journal, because it has no endpoints of clinical significance but simply measured the angiographic effect of a paclitaxel eluting balloon as opposed to a non-eluting balloon or a paclitaxel eluting stent in patients who had restenosis after drug-eluting stent implantation. Having some paclitaxel around – whether from the balloon or the stent – seemed to improve the coronary diameters measured 6 months later. “Frequency of death, myocardial infarction, or target lesion thrombosis did not differ between groups.” So?
Acute Pneumonia and the CV System (pg. 496): “Pneumonia tends to affect individuals who are also at high cardiovascular risk. Results of recent studies show that about a quarter of adults admitted to hospital with pneumonia develop a major acute cardiac complication during their hospital stay, which is associated with a 60% increase in short-term mortality.” Golly, somebody has finally twigged that the heart and the lungs are joined up to each other and live in this space called the chest, or thorax. This could have major implications. We could start thinking of providing services for elderly breathless patients rather than making them wander from chest physicians to cardiologists and back again: we could tackle the problem of the post-hospital syndrome by attending to the cardiovascular risks of chest infections and the right ventricular contribution to heart failure; we could even ask patients what their main problems are and whether they are sufficiently addressed to make them feel safe at home. But all this requires a level of genius far beyond the reach of any known health service.
BMJ 9 Feb 2013 Vol 346
Dietary Linoleic Acid for Secondary Prevention of CHD and Death: Evaluation of Recovered Data from the Sydney Diet Heart Study and Updated Meta-Analysis: The BMJ was lucky to scoop this paper based on retrieved follow-up data from the Sydney Diet Heart Study (1966-73) which recruited men who had had coronary events and successfully lowered their cholesterol by substituting safflower oil for animal fat. This raised mortality by a third over five years. Beware omega 6 linoleic acid which abounds in safflower oil and constitutes more than 50% of sunflower, cottonseed, corn and soy oils. Stick to healthy butter, lard, goose fat and olive oil, as civilised people have done through the centuries.