Patients who have suffered one stroke can dramatically reduce their chances of having a second by taking a statin drug such as Pfizer’s Lipitor, according to the results of the large-scale SPARCL study.

The data, reported in the New England Journal of Medicine (August 10), show that treatment with a high (80mg) dose of Lipitor (atorvastatin) reduced the risk of another stroke by 16% and other major cardiovascular events such as heart attack by 35% compared to placebo. All patients also received standard treatment with aspirin and antihypertensive drugs.

Although other studies have shown that statin treatment can reduce the risk of a first stroke, this is the first to show a benefit of the strategy in secondary prevention, said Pfizer in a statement.

At present, despite current secondary prevention strategies up to 40% of people who have a stroke will have a second within five years.

The absolute reduction in nonfatal or fatal stroke in the study was 2.2% compared to placebo, while major cardiovascular events were cut by 3.5%, which although modest were significant because they came about on top of standard therapy. There was also a small increase in the incidence of haemorrhagic stroke with Lipitor, and the researchers said use of statins should be limited to ischaemic stroke patients as a result.

Analysts are divided as to whether the SPARCL data will be a major boost to Lipitor, which is seeing its sales momentum decelerate as rival drugs in the statin class such as Merck & Co’s Zocor (simvastatin) lose patent protection and generics flood the market. The rub will be whether doctors see the benefit as being particular to Lipitor, or a class effect that could be reproduced by using other, cheaper statins.

Lipitor has the benefit of being a particularly potent statin in terms of reducing cholesterol on a per mg basis, and as the dose used was at the maximum end of its range it may be hard to match this with other, less potent statins.