Prescription of statins in primary prevention: major disparities depending on how risk is calculated

As with many treatments, the prescription of statins, the most important drugs for reducing cardiovascular risk (CVR), is based on recommendations. These are rightly based on the estimation of the level of cardiovascular risk (CVR). However, there are several ways of assessing this CVR, and the prescription of a treatment depends on a different threshold for each method of calculation.
A study has compared the 4 most commonly used methods in North America and Europe for identifying patients warranting statin therapy.

The methods chosen
All calculation methods take into account gender, age, total cholesterol, HDL cholesterol, smoking and systolic blood pressure. Only some consider ethnicity (e.g. Hispanic or black), treatment of hypertension, treatment of dyslipidemia or family history of premature cardiovascular disease. As most diabetic patients are thought to warrant statin treatment, this point was not studied in this analysis.
All of which makes it possible to classify subjects as low, intermediate or high risk.

Results
The concordance rates of risk estimation between the different methods show a very wide range between 19% and 85%!
Only SCORE 2, high-risk and very high-risk versions identified equal proportions of high-risk men and women.
Discussion
With several validated and widely used methods, there is marked variability in recommendations for the use of statins for high-risk patients in primary prevention. Although women should be at lower risk than men, the trends observed show a very marked disparity in treatment for women, even with the same risk factor profile. Only the SCORE 2 versions recommended for high- and very-high-risk regions identify almost equal numbers of men and women for statin treatment in primary prevention.
The large studies that have established the efficacy of statins in primary prevention have not used a risk calculation to identify eligible subjects, and it is well recognized that the benefits of statins extend even to low-risk patients, further calling into question the validity of a calculation to guide the prescription of treatment.However, it has been argued that the benefit of treating low-risk populations would lead to treating an excessive number of people and therefore less cost-effectiveness.
Admittedly, many physicians find the "algorithms" tedious and don't use them at all, contributing to international and even local discrepancies in recommendations for statins in primary prevention and potential "under-treatment".
In these circumstances, many recommendations propose the use of other factors and tests that are not quantified in the risk calculation. There is some degree of consensus regarding Lipoprotein aas a risk-aggravating factor, the options are otherwise very diverse, ranging from obtaining the calcium score (CAC): radiological slice in CT quantifying coronary artery calcifications, also the search for plaques on the carotid arteries, to the simple reassessment of family history. In addition, a patient-physician discussion of long-term treatment is warranted in patients with LDL cholesterol levels above 1.35 g/l and also in those with lower levels but with the additional risk factors of diabetes, hypertension, chronic kidney disease or various risk-aggravating factors including pre-diabetes, metabolic syndrome and family history of premature cardiovascular disease.
Other societies have indicated that anoptimal LDL cholesterol level for primary prevention should be around 1g/l.
If a given patient does not fit this profile, or if the patient-physician discussion suggests concerns about chronic statin therapy, then a second step based on risk assessment methods could be considered to further enrich the discussion.
This next step could include lifelong risk calculations, and incorporating elements impacting cardiovascular risk (e.g. socio-economic factors, ethnicity) and other risk modifiers. .

In conclusion
The process of estimating risk level as the first step in determining statin prescription in primary prevention leads to marked heterogeneity and differs considerably depending on the method used in risk estimation.
In this context, most methods systematically identify candidates for treatment who are predominantly male, of advanced age and hypertensive and/or smokers. A strong family history of premature cardiovascular disease and the inclusion of additional and/or novel risk factors (e.g. socio-economic status and biological risk factors such as those related to inflammation) could help to limit discordance.
In the end, the SCORE 2 model proved to be the most effective in predicting who will need and benefit most from treatment.
Good news, since this is the model recommended by the European Recommendations!
(It's true that it's their model...)

All in all, the treatment decision should not depend on a single parameter, but rather on a consideration of the situation as a whole, and on clinical common sense, enabling an "enlightened" discussion between doctor and patient.

Reference
Mancini G. B. J. et al. Recommendations for statin management in primary prevention: disparities among international risk scores. European Heart Journal, 28 August 2023.