More intensive cholesterol treatment reduces heart risk further

More intensive treatment using statin drugs to lower levels of bad cholesterol leads to even greater reductions in the risk of a heart attack or stroke than with regular statin doses. That’s the conclusion of two Oxford University-led studies published in the medical journal The Lancet today.

The reduction in risk is proportional to the reduction achieved in bad cholesterol levels, even in patients with already low levels. This suggests that a wide range of people at risk of heart disease may benefit from using statins to reduce their bad cholesterol levels further, whatever their starting point.

The first study, jointly coordinated by the Clinical Trial Service Unit (CTSU) at the University of Oxford and the NHMRC Clinical Trials Centre at the University of Sydney, brought together data from some 170,000 people from 26 randomised trials in a new analysis.

The researchers found that using more intensive statin treatment produced a highly significant 15% further reduction in major vascular events over standard statin doses.

‘Using aggressive statin treatment to lower levels of bad cholesterol further than would be achieved using standard doses produces even greater reductions in the incidence of heart attacks or strokes,’ says Professor Colin Baigent of CTSU, who led this study. ‘This is particularly relevant to people who have had heart attack or stroke and are at risk of recurrent problems.’

The second study, a randomized trial in around 12,000 heart attack survivors, assessed intensive statin therapy using 80 mg simvastatin against a daily 20 mg dose of simvastatin. This large trial was led by Professor Jane Armitage, also of the CTSU at Oxford University.

People receiving 80 mg simvastatin showed a greater reduction in bad cholesterol levels over the 6–7 year course of the trial. This reduction produced a 6% further reduction in major vascular events. Although this result was not statistically significant on its own, it is entirely consistent with the benefit that, based on the results of the analysis in the first study, would be expected from a cholesterol reduction of this size.

Muscle weakness, or myopathy, is a rare side effect sometimes reported in people taking statins. There were two (0.03%) cases of muscle weakness in patients taking 20 mg simvastatin daily, but there were 53 (0.9%) cases among the 6000 patients in the 80 mg group, including 7 cases of more serious muscle damage.

Dr Louise Bowman, clinical coordinator of the trial at CTSU, explains: ‘Myopathy is a rare side-effect of statins. It occurs in only about 1 in 10,000 patients per year with standard daily doses of 20–40 mg simvastatin but in this trial we saw that myopathy is more common with 80mg simvastatin daily. So, it may be safer to lower cholesterol using low doses of more potent statins rather than by increasing the dose of simvastatin – the most commonly used statin.

‘In light of these new findings, the current NICE guidelines for statins may need to be re-examined,’ she adds.

‘Taken together, these two studies suggest that using statins more intensively to reduce levels of bad cholesterol is generally safe, effective and does lead to further benefits in reducing risk of heart disease,’ says Professor Armitage. ‘This is true even if people have low levels of bad cholesterol in their blood already.’