JAMA 10 Jan 2007

Clopidogrel is a mongrelly sort of name, with some speakers emphasising the dog and others the clopido. It is of course very widely used by cardiologists, especially to prevent occlusion after coronary stenting. Because it costs about £400 per patient-year, our local boys were asked to come up with guidelines to restrict its use, but no sooner had these been issued than new evidence arrived about late occlusion of drug-eluting stents, and the cardiologists began to recommend its use for at least a year. In fact nobody knows how long to use it in this situation, even after this observational study which seems to indicate a benefit. What we need is a randomised trial, and by the time that reports, clopidogrel will be off patent.

Suppose that you were unable to access any test for diabetes other than a random blood sugar. You would quickly find that most people have a glucose which stays below 8 mmol/L, and they stay well. On the other hand you would identify a group of people whose sugars stay over 10, and who get symptoms such as thirst and polyuria the higher it climbs. But if you tried to manage their treatment by using the random blood sugar, you would be all over the place. You would need to control your sampling conditions (e.g. by fasting) or better still, use a marker for long-term control, such as HbA1c. We are in exactly this position with B-type natriuretic peptide and cardiac impairment. The study here – like many others – found that a single measurement of (NT pro-) BNP in patients with stable coronary disease is the best predictor of mortality and cardiovascular events. But unfortunately BNP secretion is highly variable, and BNP has a half-life of 22 minutes, and NT-proBNP of 70 minutes. So the promise held out by the accompanying editorial, that we might be able to titrate treatment in people with unhealthy hearts to lower BNP, will be very hard to fulfil. Believe me, we’ve tried, though we haven’t published our MRC pilot study yet.

177 We know that as a general rule, people who take their drugs after myocardial infarction live longer, whether the drugs are active or placebo. This trial shows that active drugs differ according to class, statins being especially beneficial to those who take them.