Statins in people with kidney disease
People who need maintenance haemodialysis are well known to be at high risk of premature cardiovascular disease but, as their LDL cholesterol levels are often low or normal, it’s not always clear whether they would benefit from lipid-lowering therapy. A large RCT in the NEJM shows that they probably wouldn’t. Nearly 3000 people on haemodialysis were randomized either to rosuvastatin or placebo. While LDL cholesterol fell in those receiving the statin, there was no benefit in terms of reduced rates of death from cardiovascular causes, myocardial infarction or stroke.
Optimal dose of aspirin in cardiovascular disease prevention
Considering that aspirin is the most widely used drug in the world for the prevention of thrombotic cardiovascular events, evidence about the most effective dose is surprisingly weak. As little as 30 mg/day will inhibit platelet thromboxane production completely, but doses 10 times higher than this are routinely used in practice. Annals of Internal Medicine contains a post hoc analysis of data from 15,000 patients (obtained during a trial of clopidogrel), which shows that daily doses of aspirin greater than 75 mg are of no benefit and probably associated with harm.
CABG or PCI in coronary disease?
As mentioned last month , a trial in the NEJM concluded that CABG and PCI were roughly equivalent, judged by outcomes of death and acute myocardial infarction. A collaborative analysis of 10 RCTs in the Lancet agrees, but only for non-diabetic patients; in diabetics, CABG yielded substantially lower mortality (Hazard Ratio 0.7). An accompanying Editorial thinks this is ‘intuitive’ because the diabetics had more serious disease, even though the extent of coronary artery disease had no effect on the relative effectiveness of PCI and CABG (this finding is apparently ‘counterintuitive’). More pragmatically, the author warns against over-generalising from trial data, and questions whether patients with less severe disease require intervention at all.
Clopidogrel and PPIs again
By coincidence,the same March column also featured a JAMA report on the interaction between clopidogrel and proton pump inhibitors. And this too finds support from a new paper, this time in the Canadian Medical Association Journal . Like its predecessor, it is observational and doesn’t definitively establish a causal connection. However, the absence of such an effect for pantoprazole, which does not inhibit cytochrome P450 and hence would not be expected to interact with clopidogrel, is particularly convincing. An accompanying Commentary acknowledges that it’s unrealistic to expect RCT evidence here and, as last month, recommends only prescribing clopidogrel with a PPI when there is a compelling reason to do so.
Housing the homeless
People who have been homeless for a long time are often alcoholic and many also have mental health problems. Conventional interventions often fail to help them, and they are ineligible for most housing programs, which typically insist on abstinence as a condition of entry. A paper in JAMA, however, shows that housing such individuals regardless of their drinking status not only helps them to stop drinking, but is financially worthwhile, because they make far less use of acute services in hospitals, alcohol centres, and jails. Benefits appeared to increase the longer the period of housing continued, suggesting that future policy should concentrate on providing permanent, rather than temporary, accommodation.
Cleaning up relations with industry
The stories of MPs’ abuse of their expenses, which have provoked so much anger and derision recently, might also act as a stimulus to doctors to make sure that their own house is in order. An uncompromising article in JAMA starts by acknowledging that financial links between the pharmaceutical industry and professional medical associations (specialist societies and similar organisations) inevitably create conflicts of interest. It reckons that few associations have adequate policies to manage these conflicts, which raises justifiable anxiety that industry can affect decisions that are ultimately important to patients: for example, in clinical guideline development. The article makes 10 clear recommendations; anyone involved with a medical society that has links to the pharmaceutical industry will find them well worth reading.
Neonatal breast enlargement
The NEJM has a photograph of an 8-day-old girl, born at term without complications, and entirely normal except that she has bilateral breast enlargement. This striking image can be seen by clicking here. Neonatal breast enlargement is a response to falling levels of maternal oestrogen at the end of pregnancy; these trigger the release of prolactin from the newborn's pituitary. Apparently it’s common, although presumably usually far less extensive than in the photograph, and it’s independent of the sex of the baby. It usually occurs in the first few days of life, and resolves without treatment within a few weeks.
Mapping the eye
If you’ve ever wanted to see the retina in more detail than an ophthalmoscope provides, Wired has just the gallery for you. A team of researchers at the University of Utah have developed a technique that combines antibody staining, electron microscopy and custom software to map sensory organs cell by cell. The antibodies tag particular targets such as glutamine with tiny silver particles, enabling the electron microscope to produce strangely beautiful colour images: a technique with the catchy title of computational molecular phenotyping. The team plans to make the data generated freely available on the web for all researchers to use.
