Patients who experienced side effects were 3 times more likely not to meet LDL cholesterol targets.
Results from a new study suggest that side effects experienced from statin therapy were the strongest predictor of a patient failing to meet optimal low-density lipoprotein (LDL) cholesterol levels. Nonadherence and weaker statins were also associated with not meeting LDL targets.
"The beneficial effect of reducing LDL cholesterol on slowing the progression of coronary heart disease is overwhelmingly documented today in epidemiologic and randomised [sic] controlled studies," said lead author John Munkhaugen, PhD. "European guidelines recommend a blood LDL cholesterol goal of less than 1.8 mmol/l but just one in five cardiac patients taking lipid-lowering drugs achieve this.”
In the Norwegian COR (NOR-COR) prevention project, researchers analyzed why patients fail to control cardiovascular risk factors, such as lipids and blood pressure, after experiencing a cardiovascular event. In the study, published by the European Journal of Preventive Cardiology, the researchers discovered why certain patients are unable to achieve optimal LDL cholesterol levels.
Included in the study were 1095 patients hospitalized with a coronary event or procedure, such as a heart attack, coronary artery bypass graft, or coronary stent.
The investigators collected sociodemographic, medical, and psychosocial information from medical records, a self-reporting questionnaire, clinical examinations, and blood samples during patient hospitalization and after a follow-up of 2 to 36 months.
The impact of barriers to achieving LDL targets was determined with LDL as a dichotomous (above or below 1.8 mmol/l) and continuous variable, according to the study.
Interestingly, 57% of patients did not meet the LDL target at follow-up. Side effects of statins, such as muscle problems, adherence, and moderate or low intensity statin, were discovered to be the driving factors for not meeting the target.
The investigators found that patients who experienced side effects were more than 3 times as likely to miss the target, compared with those who had not experienced side effects, according to the study. Patients who did not take the medication were 3 times more likely to miss the target, compared with those who adhered to treatment.
Notably, patients who were prescribed weaker statins were 62% more likely to miss the cholesterol target, compared with patients prescribed stronger drugs, according to the study.
"We found the same three reasons for not meeting the target when LDL was analysed [sic] as a dichotomous or continuous variable which confirms the strength of the associations. “Surprisingly, low socioeconomic status and psychosocial factors did not predict failure to control LDL cholesterol,” Dr Munkhaugen said. "The findings show that the focus for interventions to improve LDL cholesterol control are statin side effects, and adherence to and prescription of sufficiently potent statins.”
The authors said that additional research is needed to determine why side effects had such a significant impact on cholesterol goals.
"Patients who experience side effects are probably more likely to reduce or terminate statin use, or their doctor may prescribe a weaker drug or take them off statins altogether," Dr Munkhaugen said. "Individual variations in how the body reacts to and uses the drug may also play a role."
The investigators point to pharmacological effects of the drug when looking at the link between non-adherence and intensity of dose with LDL cholesterol, according to the study.
"Not taking the prescribed amount of statins or being prescribed a weaker statin means there is less drug in the body to act and lower LDL," Dr Munkhaugen said. "The reasons for statin non-adherence are a complex interaction between factors related to the patient and the healthcare system. Interventions aiming to improve statin adherence have been a priority in recent years, but the success has been modest and short-lived."
Overall, the investigators found that patients who met their cholesterol targets were taking high-intensity statins, which suggests that patients who may be at an extremely high risk of a first or recurrent cardiovascular event should be prescribed high-intensity statins.
“The relationship with adherence and side effects needs to be clarified before advice can be given about the potency of statins that should be prescribed,” Dr Munkhaugen concluded. “Our findings point to the need for more research on ways to ensure adherence and prescription of sufficiently potent statins, while at the same time addressing side effects."