January 17th, 2012
Selections from Richard Lehman’s Weekly Review: Week of January 16th
CardioExchange is pleased to reprint selections from Dr. Richard Lehman’s weekly journal review blog at BMJ.com. A British general practitioner, Dr. Lehman writes in an engaging, sometimes provoking, style that conveys his generalist point of view on what matters for patients. These chosen summaries are relevant to our audience, but we encourage members to engage with the entire blog.
Week of January 16th
(click here to read the full review at BMJ.com)
JAMA 11 Jan 2012 Vol 307
157 There’s a general feeling among cardiologists that low potassium is a bad thing, but this interesting observational study of 38,689 patients with acute myocardial infarction shows that high potassium can be even worse. On admission with AMI, potassium levels are normally distributed (figure 1): mortality in relation to potassium levels thereafter follows a classic U-shaped distribution, bottoming out under 10% between 3.5 and 4.5 mmol/L but hitting an alarming 60+% by the time you reach the pretty modest level of 5.5 mmol/L. The strength of the association on both sides of the curve really is quite dramatic, which presumably is why JAMA is releasing the full text of this paper free online. What it means for clinical practice is not for me to guess: go instead to the learned editorial.
NEJM 12 Jan 2012 Vol 366
130 The Greek word for fennel is marathon, and it was on a fennel-covered field that the Greeks repulsed the army of Persia — a most regrettable encounter which has retarded the progress of civilization to this day. To quote Wikipedia: “The traditional story relates that Pheidippides (530 BC–490 BC), an Athenian herald, was sent to Sparta to request help when the Persians landed at Marathon, Greece. He ran 240 km (150 mi) in two days. He then ran the 40 km (25 mi) from the battlefield near Marathon to Athens to announce the Greek victory over Persia in the Battle of Marathon (490 BC) with the word “Νενικήκαμεν” (Nenikékamen, “We have won”) and collapsed and died on the spot from exhaustion.” Serves him right: it was a very foolish thing for a forty-year-old man to do. Moreover, if he was so out of breath, he did not need to use the reduplicative perfect tense. Male marathon runners continue to drop dead at an increasing rate (2 per 100,000), and this study identifies the chief causes as atherosclerotic coronary disease in the older runners and hypertrophic cardiomyopathy in the younger. If only the Persians had won: we might have a world free of marathons, Olympic games and unhelpful Greek medical terms like hypertrophic cardiomyopathy (or such really exotic examples as paragonimiasis).
Lancet 14 Jan 2011 Vol 379
123 Idrabiotaparinux is a word which belongs to no known human language: it is made up of “idraparinux” (perhaps inspired by the characters in Astérix, as this is a French drug) and biotin, sometimes known as vitamin H (a Greek root sneaks back in here). You will, I am afraid, have to memorize this word, because idrabiotaparinux marks a breakthrough in anticoagulation. It is a safe, effective anticoagulant which inhibits factor Xa: it has a terminal half-life of 66 days and a simple antidote in the form of avidin (an egg-derived substance). In this study, it was given by weekly subcutaneous injection, but there seems no reason why that could not be monthly. Patients with acute symptomatic pulmonary embolism were started on enoxaparin and then allocated (with complex blinding) either to idrabiotaparinux or to INR-adjusted warfarin. As usual in The Lancet, the manufacturers are allowed to sneak statistically non-significant claims for their product into the abstract: but the fact remains that idrabiotaparinux is non-inferior to warfarin in preventing VTE following PE, and probably a lot more convenient for most patients.
BMJ 14 Jan 2012 Vol 344
The Hypertension in the Very Elderly Trial (HYVET) recruited 3,845 subjects over the age of 80 using a huge team of investigators from 11 countries, dominated by Bulgaria, Tunisia, and China, between 2000 and 2003. Indapamide was the main intervention used to get the systolic BP under 160mm Hg — a strange choice since there are so many other thiazide diuretics that cost practically nothing. The second-line drug was perindopril, also made by the co-sponsor of the trial, Servier. Oh well: there are no doubt plenty of people still taking these drugs in the centres chosen. And they continue to benefit, as the BMJ shows us in this paper about an open-label follow-up cohort; though I imagine the subject who was 105 at the start may no longer be among them.