Heart Disease Risk Assessment and Statin Guidelines
A recent development in cardiovascular health presents a pressing dilemma. In November 2023, a new model for estimating the risk of atherosclerotic cardiovascular disease was introduced, generating positive reactions for its use of a broader, more current, and diverse pool of American data compared to earlier versions. However, alongside this praise, forecasts suggested that about 40% of U.S. adults might not qualify for statins, the commonly prescribed medications aimed at combating cholesterol issues.
These projections recognized a looming challenge. While equations can identify those at risk, establishing treatment thresholds is vital before determining who might benefit from medication. New findings indicate that adjusting the threshold based on the enhanced risk calculator would likely maintain the same number of people eligible for statins as before.
This decision is particularly significant since cardiovascular diseases remain the leading cause of death, with atherosclerotic cardiovascular disease being the top contributor to preventable fatalities among both men and women in the U.S. Finding a balance in treatment recommendations is why medical organizations have yet to formulate updated guidelines based on these new calculations. Presently, many individuals who could benefit from statins are not on them, with numerous patients discontinuing the medication.
A recent research letter in JAMA Cardiology explored varying thresholds for treatment based on data from the PREVENT model, which assesses the risk of cardiovascular events while accounting for factors like chronic kidney disease, diabetes, and obesity. In contrast, the older Pooled Cohort Equations model from 2013 recommended statins for those with a 10-year cardiovascular event risk of 7.5%. When applying the PREVENT model using this threshold, significantly fewer adults were found eligible for statins.
The PREVENT analysis suggested lowering the risk threshold to 3%, 4%, or 5% over ten years. Choosing the 3% benchmark would keep the number eligible for statins similar to current standards, reflecting the robustness of the PREVENT data, according to co-author Sadiya Khan, a preventive cardiologist and epidemiologist at Northwestern University.
The previous model also suggested discussions between physicians and patients if their ten-year risk hit 5%, acknowledging that benefits from statins could apply even at a 3% risk.
While statins offer considerable benefits, they are not without risks. Some users experience muscle pain, while a notable concern is the increased chance of developing type 2 diabetes. Research shows that around 3% of people treated with statins over a decade may face this risk, particularly if they are near diabetes diagnostic criteria. However, those individuals with prediabetes also face heightened cardiovascular risks, raising the question of whether the advantages of statin treatment outweigh the diabetes risks.
Lowering the risk threshold aligns with trends aimed at identifying more patients who could benefit from preventive treatment. Last year, Khan and her colleagues noted in JAMA that evolving risk prediction tools are expanding the range of candidates for medication. Gregg Fonarow, a cardiologist and UCLA professor, added that the advantages of statins might justify treatment even at a 2.5% risk threshold, suggesting that reducing the threshold would help prevent more cardiovascular incidents.
This analysis highlights how many individuals in the U.S. would qualify for statin therapy under different thresholds, which Fonarow believes will be crucial for shaping future guidelines, anticipated to be released by the American Heart Association and the American College of Cardiology in the spring.
Khan clarified that maintaining the current number of eligible individuals was not the researchers’ goal. Instead, they aimed to illustrate how different risk scores correlate with the previous 7.5% standard, emphasizing a more accurate risk assessment for the U.S. population.
The older Pooled Cohort Equations have faced criticisms for potentially overestimating risk, even while being more advanced than solely relying on LDL cholesterol levels. Since the introduction of statins in the 1980s, studies have shown that combining statin use with lifestyle changes can reduce the risk of cardiovascular events significantly, often at a low annual cost.
Jeremy Sussman, a primary care physician at the VA Ann Arbor Healthcare System, expressed concerns that a low 3% threshold might lead to more diabetes cases than the heart attacks it prevents. He argued that the goal should be to find the balance where the benefits of statins truly outweigh the risks. This inherently complex question requires careful consideration of individual circumstances.
Khan emphasized the intent behind risk estimation: to ensure appropriate individuals receive statins, regardless of current prescription numbers. She noted, “It’s all about understanding the risk and identifying those who will truly benefit from the medication.”
Khan, Fonarow, and Sussman agree on the importance of integrating individual needs and values into discussions around treatment. As Sussman pointed out, some situations necessitate clear action, such as treating someone who has already experienced a heart attack. However, it becomes more challenging when weighing the benefits of treatment against the potential harms for lower-risk individuals, as this balance involves complex medical reasoning coupled with personal values.
