Heart failure risk calculator

What the score predicts

The profile gives the chance of developing heart failure over the next 4 years in people who are predisposed by coronary disease, high blood pressure or valve disease (Kannel 1999). The authors built it to help general practitioners and internists pick out people at high risk who may need further tests of how well the heart pumps and stronger prevention (Kannel 1999).

It is a different tool from the PREVENT heart risk calculator. PREVENT estimates the chance of a first heart attack, stroke or heart failure for adults 30 to 79 who do not have cardiovascular disease (Khan 2024). This profile is for people who already have one of the conditions that lead to heart failure.

What goes into it

The paper used routinely measured risk factors: age, left ventricular hypertrophy on the ECG, an enlarged heart on chest X-ray, heart rate, systolic blood pressure, vital capacity, diabetes, evidence of a heart attack, and valve disease or high blood pressure (Kannel 1999). Because vital capacity (a breathing test) and a chest X-ray may not be at hand, the authors also made a profile without them (Kannel 1999), and that is the one this calculator uses. In it, women's BMI also counts (Framingham Heart Study).

The model is a pooled logistic regression for each sex (Kannel 1999). The 4-year risk is 1 divided by (1 plus exp(minus x)), where x is the intercept plus each coefficient times your value (Framingham Heart Study). The coefficients for the model without vital capacity and chest X-ray are:

The Framingham page prints an odds ratio beside each coefficient, per 10 years of age, 10 beats a minute and 20 mm Hg (Framingham Heart Study). Our tests check every coefficient against its printed odds ratio. The page also prints simpler point sheets (Framingham Heart Study); this calculator uses the full equation instead. For women, diabetes and valve disease each raise risk a lot, but having both adds less than the two added up, which is what the negative combined term does.

Coronary heart disease weighed most for both sexes, with odds about 5 times higher (Framingham Heart Study).

How well it worked

In the study, 60% of heart failure cases in men and 73% in women happened in people in the top fifth of predicted risk (Kannel 1999). The authors say the profile can also flag people at high risk because of several borderline risk factors that might otherwise be overlooked (Kannel 1999).

Limits

• It is only for people aged 45 to 94 with coronary disease, high blood pressure or valve disease (Kannel 1999) (Framingham Heart Study). If you have none of these, use the PREVENT heart risk calculator.
• It was built in one community, Framingham, Massachusetts, from up to 38 years of follow-up, and published in 1999 (Kannel 1999). It may fit other groups, or people on today's treatments, less well.
• It uses single readings of blood pressure and heart rate. A different day can give a different result.
• It does not diagnose heart failure. Only your clinician, with tests such as a heart ultrasound, can tell you how well your heart pumps.

What to do with the number

Bring the result to your clinician, who knows your full history and may already have tests that answer the question more directly. Symptoms of heart failure can include shortness of breath after routine activities or when lying flat, tiredness, swelling in the ankles, feet, legs or belly, and weight gain (NHLBI). Tell your clinician if you notice them.

General safety advice (not part of the source recommendations): chest pain, fainting or sudden, severe trouble breathing needs urgent care. Call 911.

For your chance of a first heart attack, stroke or heart failure, see the PREVENT heart risk calculator and PREVENT vs ASCVD. Related Framingham tools: the hypertension risk calculator the atrial fibrillation risk calculator and the PAD risk calculator.