Life Saving Calculators
January 20, 2019
My patients often worry, “Am I going to have a heart attack?” or “Could I have a stroke?” The answers to these questions are very important because they guide how physicians treat patients. Medical science cannot definitively give us answers for any individual person, but we have data and tools that can give us a good idea of your risk level. Some of the most underused tools in medicine are calculators that can estimate your risk of a heart attack or stroke. These calculators are so important that the cholesterol management guidelines and blood pressure guidelines (two of the most important risk factors for heart disease) both use the data from these tools to guide therapy.
You can use these calculators yourself below. You will need to know your blood pressure and cholesterol numbers. Don’t know your cholesterol numbers? Read about cholesterol. Get your levels checked. Your life may depend on it. (But one of the calculators doesn’t require your cholesterol numbers.)
Why is your risk level important?
One of the fundamental principles of medicine is that a sick person is more likely to benefit from an intervention (test, medication, procedure, etc.) than a healthy person. Tests can have false positive results, medications can have side effects, and procedures/surgeries can have complications. A sicker person is more likely to achieve benefit from the intervention, and a healthier person has more to lose from a negative outcome. Physicians always assess the risk to benefit ratio of anything they do, and the decision requires understanding of how sick the patient is.
The same principle applies to prevention of disease. If someone is at high risk of developing a disease, they are more likely to benefit from a preventative medication than someone who is at low risk. Meanwhile, both people are at the same risk of having adverse effects from the medication.
For example if I see 100 patients who have a 20% risk of having a heart attack, and I prescribe them all a medication that cuts the risk of heart attack in half, I will have prevented 10 heart attacks. This means I need to treat 10 patients with that risk level to prevent one heart attack – that’s pretty good! But if I treat patients with a 2% risk, I would need to treat 100 patients to prevent one heart attack. That’s not as good.
Motivation is the other reason risk assessment is so important. If you knew you had a 1 in 5 chance of having a heart attack or stroke over the next 10 years, it would probably motivate you to eat better and exercise more, in addition to following your doctor’s recommendations. I don’t like to scare people if I don’t have to, but sometimes fear is the best motivator.
“Sometimes fear is the best motivator.”
– Doctor T
How do we assess risk?
We have established the importance of risk assessment. Now, how do we do it? We generally use data from large studies where people were followed over a long period of time. The current guidelines for cholesterol and blood pressure management call for use of the “pooled cohort” risk equations to help guide therapy. Other calculators use data from the Framingham study and the MESA study. You can use the links below to calculate your own risk:
Pooled cohorts equation:
This calculator is the one recommended for use in the cholesterol and blood pressure guidelines. If you are aged 20-39, it does not provide a 10-year risk estimate, but it does estimate a lifetime risk.
MESA study:
This calculator also allows you to input a coronary calcium score if you have had one done. Stay tuned to PagingDoctorT for an upcoming post on coronary calcium scoring!
Framingham Risk Score:
Click on the box that says “Using lipids” if you have your cholesterol numbers. If you don’t have your lipid results, you can use your BMI.
Reynolds risk score:
This calculator also uses a high-sensitivity CRP level, which is a marker of inflammation. Inflammation is known to be a contributor to vascular disease. If you have concerns about your risk levels, you can ask your doctor to check your CRP level, and use this calculator.
Summary
Risk assessment is a crucial part of prevention. If you are at high risk for cardiovascular events, you want to know about it! That way, you and your physician can take steps to decrease your risk. The above calculators can be used to quantify risk, since “gut feeling” or non-calculated risk assessments can often be inaccurate.