Testing for Cardiovascular Disease: What You Need to Know
Before heart month closes out, we share the more advanced tests to assess your heart health.
Knowing the health of your heart is important because cardiovascular disease (CVD) is the leading cause of death and disability for both men and women worldwide. CVD has impacted me and I am sure so many of you. I have witnessed my father, mother, grandmother and step-mother all experience heart-health related events from heart attacks to sudden cardiac death. This is truly a devastating and silent killer. You can have blocked arteries and have no symptoms at all until the system fails.
- Prevalence: CVD is the leading cause of death in men and women worldwide and is the same in the US alone. But how it shows up is different.
- Age of onset: Women tend to develop CVD later in life than men. The average age of onset for women is 72 years, compared to 65 years for men.
- Risk factors: Some risk factors for CVD are more common in women than in men. For example, women who have had gestational diabetes, preeclampsia, or high blood pressure during pregnancy have a higher risk of developing CVD. This is an observed correlation many do not know.
- Symptoms: Women may experience different symptoms of a heart attack than men. For example, women may have more subtle symptoms such as fatigue, nausea, or back pain, which can be easily overlooked or attributed to other causes.
- Treatment: Women tend to receive different treatment for CVD than men. For example, women are less likely to undergo certain procedures such as angiography or revascularization (here’s another study), even when they have similar symptoms and disease severity as men. This is likely due, in large part, to the difference in symptoms described above. Nonetheless this is frustrating as we know that 64% of women who die suddenly of coronary heart disease had no previous symptoms.
Overall, it is important to recognize that CVD is a significant health issue for women as well as men, and to ensure that women receive appropriate screening, diagnosis, and treatment for this condition.
But, we can all do something to prevent CVD. And it can start with testing to learn where we stand.
Knowing your own factors that can increase your risk is helpful. In our 20 years of clinical experience the factors we see as most important are:
- chronic inflammation levels,
- high very low density lipoproteins (VLDL) and
- damage to the vessel walls due to factors such as high oxidative stress or high blood pressure.
This is the trifecta that leads to plaque buildup in the arteries, indicative of CVD.
Tests to consider
A simple blood test can easily test inflammatory markers such as hs-CRP, LpPLA2, high ferritin levels over 150 and are best looked at together to predict risk of CVD.
hs-CRP, or High sensitivity C-reactive Protein, is a marker of heart-specific inflammation and can be done in your next routine blood work. A regular CRP test can check for inflammation but hs-CRP can find smaller increases in CRP and is preferred if checking for risk of coronary artery disease (which falls under CVD).
Lp-PLA2, or lipoprotein-associated phospholipase A2, is an enzyme that is primarily produced by inflammatory cells such as macrophages and T-lymphocytes. It is also found in low levels in circulating blood and is bound to LDL cholesterol particles. Lp-PLA2 is also involved in the metabolism of lipoproteins and the breakdown of phospholipids in cell membranes. Elevated levels of Lp-PLA2 have been associated with increased risk of CVD, including heart attack and stroke, as well as other inflammatory conditions such as rheumatoid arthritis and certain cancers. Lp-PLA2 is often measured through a blood test, and high levels of Lp-PLA2 are considered a marker of increased cardiovascular risk. While Lp-PLA2 is not widely used in routine clinical practice, it may be useful in certain cases, such as when traditional risk factors are inconclusive or when determining optimal treatment strategies for patients at high risk for CVD. Specialty labs run this test.
Ferritin is a protein that stores iron in blood cells and iron is necessary not only for healthy red blood cells, which carry oxygen from the lungs to the rest of the body but healthy muscles and organ function. When the body uses iron, cells release a small amount of ferritin into the bloodstream. High ferritin levels can suggest inflammatory diseases such as rheumatoid arthritis and Still’s disease, both of which can lead to inflammation of the sac-like covering of the heart. Rheumatoid arthritis can also increase the risk of hardened and blocked arteries.
When it comes to cholesterol, it is important to remember that cholesterol is essential for many functions. Our liver makes, on average, 70% of our cholesterol simply because our body uses cholesterol in a multitude of pathways, such as:
- Cell membrane structure: Cholesterol is a key component of cell membranes, which are the outer layer of cells that separate the cell from its environment. Cholesterol helps maintain the integrity and stability of the cell membrane.
- Hormone production: Cholesterol is a precursor to several important hormones, including estrogen, testosterone, and cortisol. These hormones play critical roles in regulating various bodily processes, such as growth and development, metabolism, and stress response.
- Vitamin D synthesis: Cholesterol is necessary for the synthesis of vitamin D, which is essential for bone health and other bodily functions.
- Bile acid production: Cholesterol is a precursor to bile acids, which are produced in the liver and stored in the gallbladder. Bile acids help digest and absorb dietary fats in the small intestine.
As for cholesterol testing, a traditional lipid blood test is not enough for cholesterol and CVD risk assessment. LDL, or low-density lipoprotein, is a type of cholesterol that can accumulate in the walls of arteries and contribute to the development of atherosclerosis, a condition characterized by the buildup of plaque in the arteries. However, when LDL cholesterol is exposed to oxidative stress, it can become modified and transformed into oxidized LDL, which is considered to be a more dangerous form of LDL and simply put, means rusting from the inside out.
Oxidized LDL is a pro-inflammatory and pro-atherogenic particle, meaning that it can promote inflammation and damage to the lining of blood vessels, leading to the formation of plaque and increasing the risk of heart disease. Oxidized LDL can also stimulate the production of cytokines, which are inflammatory molecules that contribute to the development of chronic diseases.
Oxidized LDL can be measured through a blood test that detects antibodies against oxidized LDL, or by directly measuring the amount of oxidized LDL in the blood. Oxidized LDL can be more indicative of CVD than LDL levels alone. Elevated levels of oxidized LDL are considered a marker of increased cardiovascular risk, and may be useful in assessing a person’s risk of heart disease, particularly in people with known risk factors such as high cholesterol, hypertension, or diabetes. Preventing the oxidation of LDL is an important part of reducing the risk of heart disease. This can be achieved through lifestyle changes such as
- eating a healthy diet,
- exercising regularly,
- quitting smoking, and
- managing stress.
Additionally, certain medications such as statins may also help reduce the oxidation of LDL and lower the risk of heart disease.
Homocysteine is another marker, found in blood, that can impact risk for CVD. This marker is associated with increased oxidative stress. Elevated levels of homocysteine, known as hyperhomocysteinemia, have been associated with an increased risk of CVD.
One proposed mechanism for this association is that high levels of homocysteine can damage the inner lining of blood vessels, or endothelium, leading to inflammation and the formation of plaques that can narrow and stiffen arteries. This process, known as atherosclerosis, can eventually lead to heart disease, stroke, and other cardiovascular complications.
In addition to damaging blood vessels directly, high levels of homocysteine have also been linked to an increased risk of blood clots, which can lead to heart attacks and strokes.
There are many factors that can contribute to high levels of homocysteine in the blood, including genetic factors, poor nutrition, and certain medical conditions, like vitamin B deficiency, kidney disease, underactive thyroid and psoriasis and therefore cannot be looked at in isolation when in regards to CVD risk assessment. Treatment typically involves addressing any underlying causes of hyperhomocysteinemia and supplementing with folate, vitamin B6, and vitamin B12, which have been shown to lower homocysteine levels in some cases. Having said that, despite evidence that shows lowering homocysteine levels decreases cardiovascular risks in patients with homocystinuria (a rare genetic disorder, which can lead to atherosclerosis at a young age), a meta-analysis by the American Heart Association showed that homocysteine-lowering therapies did not significantly affect reducing the chances of stroke nor have a significant impact on coronary heart disease. Bottom line is – having high levels of homocysteine can point to many diseases and simply lowering it does not guarantee a reduced risk of CVD.
The last test is a direct look into your vessel walls and the level of calcium/mineral building up on your vessel walls.
A CT (computed tomography) Heart Calcium score test, also known as a coronary calcium scan or even heart scan, is a non-invasive diagnostic imaging test that uses computed tomography to detect the buildup of calcium in the walls of the coronary arteries. The test can help assess a person’s risk for heart disease by evaluating the degree of atherosclerosis, or plaque buildup, in the arteries that supply blood to the heart. This is a newer test in Cardiology and not usually covered by insurance.
During the test, the patient lies on a table and a CT scanner takes multiple X-ray images of the heart from different angles. These images are then combined by a computer to create a detailed picture of the heart and the coronary arteries. The scan takes only a few minutes and is painless, although some people may feel uncomfortable from lying still for that amount of time.
The CT Heart Calcium test produces a score that reflects the amount of calcium detected in the coronary arteries. The score ranges from 0 (no detectable calcium) to more than 400 (severe calcium buildup), with higher scores indicating a higher risk of heart disease.
The CT Heart Calcium test is generally recommended for people who are at intermediate risk for heart disease but do not have any symptoms. The test is not recommended for people who already have a known heart condition or have already been diagnosed with heart disease, as it is not useful in assessing the severity of existing plaque buildup.
The test can help doctors identify people who may benefit from lifestyle changes or medical interventions to reduce their risk of heart disease – all the same as listed above for reducing oxidative stress and taking medication to lower cholesterol or blood pressure.
Research has shown that a CT Heart Calcium test is an effective tool for predicting the risk of heart disease. The following are some key findings from various studies:
- A study published in the New England Journal of Medicine in 2008 found that the CT Heart Calcium test was a better predictor of coronary heart disease risk than traditional risk factors such as age, gender, blood pressure, and cholesterol levels.
- A 2010 study published in The Journal of the American Medical Association found that adding the CT Heart Calcium test to traditional risk assessment tools improved the accuracy of risk prediction and could help prevent unnecessary treatments.
- A 2018 study published in the Journal of the American College of Cardiology found that the CT Heart Calcium test was a strong predictor of cardiovascular events and that a calcium score could be useful in making decisions about statin and/or aspirin use.
Overall, the research suggests that the calcium score CT is a valuable tool for assessing a person’s risk of heart disease and can help guide prevention and treatment strategies. However, like any diagnostic test, it has limitations and should be used in combination with other clinical information to make informed decisions about patient care.
As always, speak to your doctor if you and/or your family has a history of heart disease. List your symptoms in detail, get regular blood work done, ask if these tests are appropriate for you and what you can do specifically to reduce your risk of CVD.
