Half of patients prescribed statins in primary care fail to reach "healthy" cholesterol levels after two years of treatment with these drugs, research* published online in the journal Heart has found.
The findings back up those from previous studies and highlight the need for personalised medicine to tackle high cholesterol, the researchers say.
The researchers assessed how well patients respond to statins, based on the National Institute for Health and Care Excellence (NICE) target of a reduction of 40% or more in LDL cholesterol, and how this might affect future risk of cardiovascular disease.
They used diagnostic and prescribing data submitted anonymously by 681 GP practices to the UK Clinical Practice Research Datalink, and linked them to episodes of hospital treatment (HES data) and statistics on cause of death (ONS data). Complete information was available for 165,411 patients, who had not been treated for heart disease or stroke, and who had had their cholesterol measured at least once in the year before statin treatment and at least once within two years of starting it.
The average age at which patients started on statins was 62, nearly half (48.5%) of them were women, and all had started treatment between 1990 and 2016.
Any reduction in cholesterol below 40% after two years of statin treatment was deemed to be a "suboptimal" response, and this was the case for half (51%; 84,609) of patients.
During an average monitoring period of six years, new cases of cardiovascular disease were reported in 22,798 (just under 14%) patients. Of these 12,142 cases arose in patients who failed to reach a healthy cholesterol, and 10,656 arose in those whose cholesterol did drop by 40%.
After taking account of potentially influential factors, including age, cholesterol level, and any underlying conditions before treatment, patients who failed to reach a 40% reduction after two years were 22% more likely to develop cardiovascular disease than those who did respond well who had a 13% lower risk of cardiovascular disease. Every 1 mmol/l fall in low density cholesterol was associated with a 6% lower risk of stroke and mini stroke in those who failed to reach the 40% target.
Several factors may be behind the difference in response, but genetic make-up and an inability to stick to treatment may explain some of the observed variation, the researchers suggested.
“Currently, there is no management strategy in clinical practice which takes into account patient variations in [low density cholesterol] response, and no guidelines for predictive screening before commencement of statin therapy,” they said.
“These findings contribute to the debate on the effectiveness of statin therapy and highlight the need for personalised medicine in lipid management for patients.”
In a linked editorial**, Dr Márcio Bittencourt, of University Hospital Sao Paolo, Brazil, describes the high rate of poor responders as “clearly alarming”, and suggested the reasons may lie as much with doctors as with patients. Doctors might prescribe lower doses of less powerful drugs, because they aren’t aware of official guidance, or because they remain unconvinced that more powerful statins will be more effective or won’t produce unwanted side effects, he said.
*Akyea RK, Kai J, Qureshi N, et al. Sub-optimal cholesterol response to initiation of statins and future risk of cardiovascular disease. Heart Published Online First: 15 April 2019. doi: 10.1136/heartjnl-2018-314253
**Bittencourt MS, Cesena FHY. Statin dose in primary prevention: aim for the target! Heart Published Online First: 15 April 2019. doi: 10.1136/heartjnl-2019-314723