March 24th, 2014
Selections from Richard Lehman’s Literature Review: March 24th
Richard Lehman, BM, BCh, MRCGP
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 Intern Med
Nonleg Venous Thrombosis in Critically Ill Adults (OL): Almost all the deep venous thromboses we see in normal practice are in the legs, but in critically ill adults, nonleg venous thrombosis is not rare, despite the use of thromboprophylaxis. It is a particular risk in cancer patients. I might not have singled out this Australasian ICU study for comment, but I could not resist the title of the accompanying commentary piece “Upper Extremity Deep Vein Thrombosis: A Call to Arms.”
JAMA 19 Mar 2014 Vol 311
Age-Adjusted D-Dimer Cutoff Levels to Rule Out Pulmonary Embolism (pg. 1117): In the previous item, we encountered the new adjective “nonleg.” In this one, which is also about venous thromboembolism, we encounter “nonhigh.” It applied to the pre-test probability of a pulmonary embolism in a cohort of nonyoung European patients. The test, as you might expect, is D-dimer, and the rule, as you may already know, is to take the age of the patient and multiply it by ten to get the cut-off which excludes PE in patients with a low pre-test probability. So if you are 63, your cut-off is 630 μcg/L, and under that your risk of having a PE goes from nonhigh to practically nonexistent. This study was carried out at 19 centres in Belgium, France, the Netherlands, and Switzerland and confirmed this simple principle. Nonbad.
Factor Xa Inhibitors vs Warfarin for Preventing Stroke and Thromboembolism in Patients With Atrial Fibrillation (pg. 1150): Last week, an array of medical luminaries contributed to a Lancet paper extolling the merits of novel fixed-dose oral anticoagulants over warfarin in atrial fibrillation. I didn’t mention that many had ties with the manufacturers of these agents because that almost goes without saying. Here is a JAMA Clinical Evidence Synopsis on much the same topic—though it covers Factor Xa inhibitors only—by two authors who have only one slight industry connection between them. It reaches the same conclusion.
Lancet 22 Mar 2014 Vol 383
Association Between Change in Daily Ambulatory Activity and CV Events in People with Impaired Glucose Tolerance (pg. 1059): Two of the great truths of medicine are that levels of blood sugar are observationally related to cardiovascular risk, and that levels of physical activity, by contrast, are associated with decreased cardiovascular risk. Factor the two together and what do you find? “In individuals at high cardiovascular risk with impaired glucose tolerance, both baseline levels of daily ambulatory activity and change in ambulatory activity display a graded inverse association with the subsequent risk of a cardiovascular event.” If this comes as news to you, you need to get out more.
Pathophysiology and Treatment of Type 2 Diabetes (pg. 1068): Here is a review with the title “Pathophysiology and treatment of type 2 diabetes: perspectives on the past, present, and future.” Do read it if you can get access to it, but only in order to remind yourself of how little things have changed since these words were written: “In general, the treatment of mature diabetics would seem to be an example of the large-scale use of ineffective and possibly dangerous therapies in a particularly inefficient way. The cause of the sad situation seems to be the assumption that if some biochemical parameter is abnormally distributed in a defined group of people, “normalizing” the distribution must do more good than harm. In mature diabetics it may well be that the wrong parameter is being altered.” A.L. Cochrane Effectiveness and Efficiency 1973.
The Many Faces of Diabetes (pg. 1084): The next review is called “The many faces of diabetes: a disease with increasing heterogeneity.” That would not be my choice of title. Why not call it “Diabetes: heterogeneous diseases with a single label”? After all, diabetes is scarcely more heterogeneous now than it has ever been; it’s just that diabetes specialists are beginning to wake up to the fact. Let’s hope they may finally be recovering from “diabetologist retinopathy”—a condition which frequently blinds people to what is staring them in the face.