The calculator takes measurements of a person's cardiovascular health and analyzes them to predict the risk of developing atherosclerotic cardiovascular disease (ASCVD).
This information can be used for guidance on future potential problems and how to prevent them.
Different methods are available, but it is important to use a calculator that is recommended by a doctor and validated for scientific accuracy, as far as possible.
This article will examine what factors are used by cardiac risk calculators and why, and what lifestyle measures and medical assistance can do to affect them.
Here are some key points about cardiovascular risk calculation.
- Data from population studies have enabled scientists to work out the most important risk factors for cardiovascular disease.
- Individual heart attack risk can be calculated, based on factors that can lead to blocked arteries.
- This can lead to recommendations about lifestyle changes that help adjust blood pressure, weight, and cholesterol levels.
- If results suggest a high risk of heart problems, medical help — such as statins — may be recommended.
- The calculator can be used by anyone, regardless of their risk of heart disease.
What is a cardiac risk calculator?
Assessing cardiovascular risk involves taking a number of measurements and calculating a percentage chance of a problem occurring.
A cardiac risk calculator takes data for an individual's predictors of disease — such as blood pressure — and compares the results with population-level statistics to try and predict their chances of cardiovascular problems.
The person will find out their percentage risk of having cardiovascular problems.
This information can help the individual to take measures to prevent cardiovascular problems, if necessary.
If the risk is very low, no further screening may be needed. If the risk is high, a health professional will discuss lifestyle and other measures that may prevent an adverse event.
People who are undergoing treatment for a cardiovascular condition will probably not use a calculator, as their risks are already being managed through treatment.
What factors are used?
All cardiac risk calculators use biological factors that have been shown to affect the chances of developing problems in the arteries.
Three key factors cannot be adjusted when assessing for cardiac risk. These are age, ethnicity, and sex. Other factors are modifiable.
These modifiable risk factors can be treated. As a result, some of the causes of atherosclerosis and heart disease can be avoided or reduced.
Atherosclerosis refers to the narrowing of arteries due to the formation of plaque in the coronary arteries, the ones that supply the heart.
Preventing heart disease can also reduce the risk of other problems. For example, atherosclerosis can cause the blood supply to the brain to be cut off, leading to a stroke.
One example of a calculator is the one produced by the American College of Cardiology (ACC) and the American Heart Association (AHA). You can access it here.
For the final result, the following data must be entered:
- patient characteristics, such as smoking habits, ethnicity, and biological sex
- doctor's office measurements, including body mass index and blood pressure
- laboratory test results, for example, cholesterol levels
How often the assessment is recommended depends on the age of the patient. Older groups may be assessed as often as every 4 years.
The risk assessment guidelines are suitable for people between the ages of 20 and 79 years who do not yet have any outward signs of cardiovascular disease
All cardiac risk calculators do a similar job, but there are various options available. A calculator should be selected for its relevance to the patient population overall and for the individual's state of health.
In the United States, for example, doctors might base heart prediction scores and prevention recommendations on guidance from experts across the ACC, AHA, and the American Stroke Association (ASA).
Another calculator is provided by the U.S. National Heart, Lung, and Blood Institute (NHLBI). It requires the same input, but ethnicity and genetic status do not feature as prominently, so it may not be sensitive to people from all ethnic backgrounds.
The JBS3 calculator, commonly used in the United Kingdom, also factors in a person's socioeconomic status, based on their residential location. Research shows that this, too, can impact cardiovascular risk.
What can I do about my result?
The resulting score will suggest the percentage chance of experiencing a heart attack or stroke within an individual's lifetime and within the next 10 years.
The results also indicate whether lifestyle adjustments or other preventive steps are needed to reduce cardiovascular risk.
Clogged arteries can result from poor dietary choices, smoking, and a lack of exercise.
The health professional will explain the results to the patient and make recommendations.
Patients with a low risk of cardiovascular disease may be advised to continue with their current behavior or to increase exercise levels slightly.
If there is some risk, the health worker may:
- discuss treatment measures patients can take themselves, such as tackling cholesterol levels through diet, making an exercise plan, and quitting smoking
- recommend following up with tests, specialist advice, and appropriate medical interventions
Avoiding or quitting smoking is a key lifestyle measure that can reduce cardiac risk.
Researchers who published results of a meta-analysis covering 141 cohort studies in The BMJ in January 2018 concluded:
Smoking only about one cigarette per day carries a risk of developing coronary heart disease and stroke much greater than expected: around half that for people who smoke 20 per day. No safe level of smoking exists for cardiovascular disease. Smokers should aim to quit instead of cutting down to significantly reduce their risk of these two common major disorders.
In other words, when it comes to smoking and heart health, even one cigarette a day is too much.
A major factor that can increase the cardiac risk is cholesterol levels in the blood.
A blood test can measure low-density lipoprotein (LDL), or "bad" cholesterol, high-density lipoprotein (HDL) or "good" cholesterol, and total cholesterol.
It is better to have more good cholesterol than bad, and not too much cholesterol overall.
Diet and exercise can help treat or prevent high cholesterol.
Limiting the consumption of fats, and especially saturated fats in the diet can help manage cholesterol levels.
Intake of the following should be kept to a minimum:
- saturated fats from some meats, dairy products, chocolate, baked goods, and deep-fried and processed foods
- trans fats found in some fried and processed foods
People who already have cardiovascular disease, or who have a higher risk due to other conditions, such as diabetes, might be offered cholesterol-lowering drug therapy such as statins.
Statins may also be used by people who have not been able to reduce their cholesterol levels through lifestyle measures alone.
Managing blood pressure
Blood pressure is considered high if it is 130/80 mm Hg or above, according to guidelines published by the AHA in 2017.
Tips for controlling high blood pressure include:
- controlling body weight
- managing stress
- dietary measures, such as reducing sodium intake
- limiting alcohol
Medications may be necessary to help some people control high blood pressure.
Controlling body weight
There are different ways of assessing a healthy weight.
Body mass index (BMI) offers a useful guideline, but the distribution of fat may be a better indication of cardiovascular risk.
Studies show that people who carry excess weight around their abdomen may be at higher risk of heart disease than those whose weight is around their hips.
Use this calculator, provided by the Centers for Disease Control and Prevention (CDC), to work out your BMI.
Some recommendations from the AHA for losing weight include:
- getting at least 2 hours and 30 minutes moderate exercise a week
- learning how to eat healthfully when dining out
- becoming familiar with nutrition labels and what they mean
The DASH diet, which involves plenty of fresh fruit and vegetables, can help you control your blood pressure, cholesterol levels, and, with adjusted calorie targets, your weight too.