With the profusion of blood and radiologic tests that may or may not manage an asymptomatic patient’s risk for an acute coronary event, it is useful to revisit an underutilized, easy-to-calculate method to guide primary prevention of coronary artery disease: the Framingham Risk Calculator, which is recommended by the American College of Cardiology to be included in a patient’s preventive health assessment.
Use of the calculator could help guide decisions about statins for preventing hyperlipidemia. It’s my opinion that statins are probably over prescribed for primary prevention in patients with LDL cholesterol levels between 130 mg/dL and 160 mg/dL. Guidelines recommend starting statin therapy only if the Framingham Risk Index is over 10% for an acute event in 10 years to achieve a target LDL level under 130 mg/dL, for a 10-year risk between 10% and 20%, and 100% for a ten-year risk over 20%.
Most nonsmoking 30-somethings with LDLs of 135 mg/dL have risk scores well under 10%. And by using the calculator, it would appear that there are even many nonsmoking patients under age 45 with elevated LDLs (135-145 mg/dL) that are probably also receiving statins unnecessarily.
On the use of another preventive therapy, I recently came across a blanket recommendation to start aspirin prophylaxis for patients with Framingham Risk Scores over 6%, a fairly low threshold. Searching for the source of this recommendation, I found a complicated framework for this recommendation proposed by the U.S. Preventive Services Task Force. Essentially, aspirin prophylaxis is worthwhile if the benefits exceed the risk of GI bleeding. Interestingly, the threshold gets higher with age: Older patients have greater risks of bleeding and should have a higher threshold for primary preventive aspirin. The tripwire for patients under age 60 years is only 4%, rising to 9% for the next decade, and then 12% for patients over age 70 years.
The take home is that we really should keep using the Framingham Risk Score as a core framework for our prevention decision making. Use of it could help us avoid overprescribing statins and underprescribing aspirin. I will start my aspirin this week!