April 8th, 2013
Selections from Richard Lehman’s Literature Review: April 8th
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 3 Apr 2013 Vol 309
A New Era of Open Science Through Data Sharing (pg. 1355): With the runaway success of the Alltrials petition, it may seem as if everyone in the world has now agreed on the need to share every bit of data relating to every medical device and product used on millions of patients every day. In reality, this is going to be a very slow process, involving hard work over many years. Nobody is more aware of this than Joe Ross and Harlan Krumholz, whose YODA project is pioneering the methodology needed to do the job properly, in a way that few others have even considered attempting. The imperative to do this work is absolute, and is beautifully set out by them in this Viewpoint article. But the editor of JAMA, Howard Bauchner, announced in Oxford that he is planning to sit on the fence about Alltrials a while longer, consulting his editorial board in a few months’ time. In the meantime we can look forward to a piece on the “unintended consequences” of data disclosure by Robert Califf some time soon.
NEJM 4 Apr 2013 Vol 368
Primary Prevention of CVD with a Mediterranean Diet (pg. 1279): The most important event in England in 1950 (apart from my birth) was the publication of a slim volume called A Book of Mediterranean Food by Mrs Elizabeth David. In this book the British public, then thin and pale from ten years of food rationing, caught a vision of unlimited delicious sun raised produce, simple to cook and heavenly to eat. Unfortunately it never found its way into my parental home. The chapters of Mediterranean Food dealt with: soups; eggs and luncheon dishes; fish; meat; substantial dishes; poultry and game; vegetables; cold food and salads; sweets; jams, chutneys and preserves; and sauces. Growing up as the child of immigrant benefit scroungers living on national assistance, I rarely saw any of these. I have tried to catch up ever since, and suggest that you do the same.
As for what is called a Mediterranean diet by American researchers, I have no strong views. This seems to be the same as Elizabeth David’s diet, but with many of the nice things omitted. Compared with a standard low-fat diet, the PREDIMED diet achieved a reduction in cardiovascular events of about 30% over a median of 4.8 years, at which point the trial was stopped.
Effect of Platelet Inhibition with Cangrelor during PCI on Ischemic Events (pg. 1303): All the time I’ve been writing these reviews, drug companies have been trying to come up with new platelet inhibitors to break into the immense market dominated by aspirin and clopidogrel. Intravenous cangrelor was compared with an oral dose of clopidogrel (which could be 300mg or 600mg) in this study of 11,145 patients undergoing percutaneous coronary intervention for a variety of reasons. And cangrelor definitely won, with a small but statistically significant reduction in the composite end-point (an absolute reduction of 1.2% in immediate thrombotic events or death). Overall, there was a 0.6% difference in stent thrombosis.
Atherosclerosis Across 4000 Years of Human History (pg. 1211): We sometimes hear it claimed that the so-called Mediterranean diet is good for you because it represents the historical ideal for human beings; arterial atheroma is our fault because we no longer follow this lost Edenic model. In reality, humans throughout their history have eaten a huge range of food, both as hunter-gatherers and as agricultural pastoralists – and whatever they have eaten, they have always developed some gunk in their arteries as they grew older. This wonderful study of atherosclerosis in mummies from around the world only goes back about 4,000 years, but the message is clear. The mean age of the bodies was just 36 years, but probable or definite atherosclerosis was noted in 47 (34%) of 137 mummies and in all four geographical populations: 29 (38%) of 76 ancient Egyptians, 13 (25%) of 51 ancient Peruvians, two (40%) of five Ancestral Puebloans, and three (60%) of five Unangan hunter gatherers (p=NS). Eat whelks. Or elks. Or nuts, or grains. Butter, olive oil or seal blubber. Beer. Mealy worms, peaches, samphire and locusts. Wine. Goats, mammoths, aurochs, whales, snails and anchovies. All these are good for you and bad for you.
BMJ 6 Apr 2013 Vol 346
CV events After Clarithromycin use in Lower Respiratory Tract Infections: About fifteen years ago, there was a lot of interest in the possibility that long term macrolide antibiotics might prevent coronary events by killing off Chlamydia pneumonia in arterial plaque. The ACES trial, published in 2005, finished off that hypothesis, and now the argument has turned full circle in a study which finds a higher rate of cardiovascular events in patients given clarithromycin in hospital for community-acquired pneumonia or infective exacerbations of COPD. The harmful cardiovascular effect of the macrolides seems very persistent in this and other studies, and takes some explaining. The drugs of greatest risk seem to be erythromycin and clarithromycin.
Ann Intern Med 2 Apr 2013 Vol 158
Discontinuation of Statins in Routine Care Settings (pg. 526): Once you have started taking a statin, is there ever any good reason to stop? I can’t think of any, except for intolerable side effects which do not respond to a change of agent. Yet more than half of this cohort of patients started on statins by doctors affiliated to the Massachusetts Hospital or Brigham & Women’s stopped their medication at some point. Fortunately this study found that contrary to widespread belief, “most patients who are rechallenged can tolerate statins long-term. This suggests that many of the statin-related events may have other causes, are tolerable, or may be specific to individual statins rather than the entire drug class.” The paper is behind a paywall, but the guide for patients is not.