This week’s Clinical Update is titled “codeine maintenance in opioid dependence”, but it’s actually a useful summary of all varieties of opioid maintenance, with codeine mentioned briefly on the basis of a single Scottish trial.
In the last couple of years, drug-eluting stents and COX-2 specific anti-inflammatory drugs have come in for a bit of a bashing. Combine the two and you have – perhaps the best possible outcome for percutaneous revascularisation. But it’s early days: this South Korean trial added celecoxib to aspirin and clopidogrel following the insertion of paclitaxel-eluting stents and measured the formation of neointima within stents. There was considerably less in the celecoxib group. I should explain that it is intimal regrowth, not atheroma, that leads to stent blockage (see editorial). But of course we don’t really know whether giving celecoxib to post-stent patients in the long term is a good idea.
Another dotty-sounding notion is that by squeezing the arm you can protect the heart. This trial randomised patients about to have coronary artery bypass surgery to have three 5-minute cycles of right upper limb ischaemia caused by inflating a cuff to 200mg mercury after induction of anaesthesia, or none. The outcome measure was troponin release after surgery. But why on earth? Well, it’s long been known that patients with a history of angina before myocardial infarction do better than those who get infarcts out of the blue. The mechanism has been dignified with the name of ischaemic preconditioning, whereby the myocardium gets used to coping with periods of ischaemic stress, mediated by various inflammatory chemicals. So, the argument goes, if you release the inflammatory markers from some other part of the circulatory system before subjecting the myocardium to the stress of bypass surgery, fewer myocytes will get damaged. Bizarrely enough, it seemed to work in this small study. As ever, bigger trials with harder endpoints are needed.
Ever since the H5N1 avian flu virus started killing chicken farmers in East Asia, we have been preparing for a possible pandemic, and rapid vaccine production is seen as key to containment. Egg-based vaccines are slow to produce, but this study shows that much smaller amounts will be immunogenic if you mix them with an adjuvant consisting of a few cheap chemicals. Moreover the vaccine produces the kind of cross-immunogenicity which we might need if these viruses ever become capable of human-human transmission and mutation.
The Lancet is determined to its bit for stroke prevention this week by bringing us up to date on the two principal risk factors, hypertension and atrial fibrillation. Three international experts put together a serviceable summary of where we are with measuring and treating blood pressure, while the cover of the journal declares that the “The time has come to abandon the hypertension/normotension dichotomy and to focus on global risk reduction.” No, Richard Horton, the time really came long ago. Far below the ivory tower, there are little places where global risk reduction has been going on for years. I work in one.
And so to the management of atrial fibrillation. Over the last decade, I’ve heralded many false dawns – direct thrombin inhibitors to replace bothersome warfarin, better antirrhythmics to replace horrible amiodarone, and pathway ablation to replace shockingly crude direct current cardioversion. But alas, we are still largely where we were. People still even use digoxin.