June 2nd, 2014
Selections from Richard Lehman’s Literature Review: June 2nd
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.
JAMA 28 May 2014 Vol 311
Durability of Class I ACC/AHA Clinical Practice Guideline Recommendations (pg. 2092): What would be your collective noun for a gathering of cardiologists? A Pontificate? An Oligarchy? A Pride? Few professional groups are so given to proclaiming their authority, especially when they can back it with evidence. But evidence changes, and this — fortunately — is sometimes reflected in the declarations of authority. In this study, the authors sought to characterize variations in the durability of class I (“procedure/treatment should be performed/administered”) American College of Cardiology/American Heart Association (ACC/AHA) guideline recommendations. Of 619 index recommendations, 495 (80.0%) were retained in the subsequent guideline version, 57 (9.2%) were downgraded or reversed, and 67 (10.8%) were omitted.
Lancet 31 May 2014 Vol 383
Efficacy and Safety of Nebivolol and Valsartan as Fixed-Dose Combination in Hypertension (pg. 1889): The Lancet doesn’t seek to disguise the large contribution to its income that comes from sales of reprints to industry. But it would be nice if it could find some other business model. Here is the report of a trial funded by Forest Laboratories, one of whose employees designed the study, analysed data, and revised the manuscript. The eight week duration of the study was no doubt a factor in getting ethical approval to compare a fixed dose drug combination with placebo for newly diagnosed, uncomplicated high blood pressure. The drugs in the combination were nebivolol and valsartan. Believe it or not, they lowered blood pressure. So now (look, it says so in this paper from the Lancet) we can use the Forest combination as first line for newly diagnosed hypertension, instead of the cheaper and more rational alternatives.
Blood Pressure and Incidence of Twelve Cardiovascular Diseases (pg. 1899): So what is this thing called “hypertension”? I got interested in this question about 20 years ago, especially in the context of progression to heart failure without systolic dysfunction, which unfortunately gets little space in this article. Putting behind the eight week trial just mentioned, we can pore over data here describing the lifetime course of this bundle of risk factors—made up of diastolic BP, systolic BP, pulse pressure, and BP variance, plus the effects of treatments. I’m afraid there is no way of summarising this wealth of information, except to quote the authors themselves: “The widely held assumptions that blood pressure has strong associations with the occurrence of all cardiovascular diseases across a wide age range, and that diastolic and systolic associations are concordant, are not supported by the findings of this high-resolution study. Despite modern treatments, the lifetime burden of hypertension is substantial. These findings emphasise the need for new blood pressure-lowering strategies, and will help to inform the design of randomised trials to assess them.”
Hypertension Management in England (pg. 1912): English general practice is doing well at controlling high blood pressure. Call it hypertension if you will, but it is just a subset of cardiovascular risk factors, according to age, specific variables, and everything else that’s dealt with in the preceding paper. And individuals should make their own treatment choices for themselves, taking into account all their other risk factors, but that is still well into the future. This study looked at the years between 1994 and 2011 in samplings which included BP measurement. There has been a steady rise in the detection of high blood pressure (defined as >140/90) and in the effectiveness of treatment, without any evidence of a sudden change after 2004, when payment by results (QOF) was introduced. And I am pleased to note that only 37% of people who fall within this overtight definition have their BP brought below those levels: this probably represents a good balance between the benefits and harms of treatment.