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18 Feb 2013

Selections from Richard Lehman’s Literature Review: February 18th

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  13 Feb 2013  Vol 309

Relationship Between Hospital Readmission and Mortality Rates for Patients Hospitalized With Acute MI, HF, or Pneumonia (pg. 587): Speaking of hypothesis generation, here’s a little brain teaser: if you look at risk-adjusted hospital figures for death and readmission for the commonest medical conditions – myocardial infarction, heart failure and pneumonia – would you expect to find a correlation between the two? And which way would it go? Would hospitals where more patients die have fewer readmissions? Or would they have more, because they are so bad at managing acute illness?

Well, don’t spend too long over this, because this immense study of outcomes in over 4,500 American hospitals shows that there is no correlation between risk-standardised mortality and risk-standardised readmission in these conditions, with the possible exception of some grades of heart failure. You may recollect the BMJ editorial a couple of weeks ago from the chief investigator of this study, Harlan Krumholz: nothing is straightforward when trying to assess the quality of hospitals, even using such apparently robust data. A timely lesson, as the NHS goes tipping the barrel in search of rotten apples.

Lancet  16 Feb 2013  Vol 381

Effects of Body Size and Hypertension Treatments on CV Event Rates (pg. 537): Most doctors are very uncomfortable with the fact that people over 65 who are overweight or obese live longer than those who are of “normal” weight. Not only does this run counter to the deep puritanism of medical culture, but it also flies in the face of logic, because such people are much more likely to have diabetes, heart failure and hypertension.

And yet obese people with hypertension have the best outcomes, in trial after trial. And if you give them thiazide diuretics and so increase their insulin resistance, they do even better. And if they get heart failure, they will greatly outlive their thinner peers. Here is an analysis of the ACCOMPLISH trial – don’t even try to remember which one that was – which clearly shows that thiazide treatment gives better outcomes in hypertensive fat people.

By all that’s holy in mechanistic reasoning, this should not be true, and it is all too much for the authors of the accompanying editorial. They list their objections and state:” Therefore, we reject the conclusion of Weber and colleagues that diuretic-based regimens are a reasonable choice in obese patients. On the contrary, we surmise that thiazide diuretics are contraindicated in obesity, relatively speaking.” So surmise trumps evidence? I don’t think so.

BMJ   16 Feb 2013  Vol 346

Long-Term Calcium Intake and Rates of All-Cause and CV Mortality: Less is more applies to calcium intake in older women. Many osteoporosis-fixated “women’s health experts” have recommended high calcium intake for decades, well in excess of anything that is plausibly available from dietary sources. But this mammography cohort study from Sweden followed up 39,000 women for 19 years and found that high calcium intake – over 1400mg daily as judged purely from two dietary assessments – is associated with a 40% increase in all-cause mortality and a doubling of death from ischaemic heart disease. “Harmless” chalk as sold by thousands of health supplement vendors should hereafter carry a health warning.