A computed tomography (CT) coronary angiogram is a non-invasive imaging procedure that uses X-ray technology and an injected contrast dye to produce detailed pictures of the arteries supplying blood to the heart. This test allows medical professionals to visualize the coronary arteries and detect various heart conditions. An abnormal result from this scan is not a final diagnosis, but a starting point for further medical discussion and potential investigation.
What an Abnormal Result Indicates
An abnormal CT coronary angiogram most frequently indicates coronary artery disease (CAD), a condition characterized by the buildup of fatty deposits, known as plaque, within the heart’s arteries. Plaque can be calcified (“hard”) or non-calcified (“soft”). While calcified plaque is visible and signals atherosclerosis, non-calcified plaque can be more concerning as it may be less stable.
The presence of plaque often leads to stenosis, which is the narrowing of an artery. The degree of narrowing is commonly reported as a percentage, classifying severity from minimal (1-24% narrowing) to mild (25-49%), moderate (50-69%), or severe (70-99%). A complete obstruction of blood flow is a total occlusion, signifying a 100% blockage.
To standardize interpretation, medical professionals use the Coronary Artery Disease Reporting and Data System (CAD-RADS). This system assigns a score from 0 to 5 based on the highest grade of stenosis. CAD-RADS 0 indicates no plaque or stenosis, while CAD-RADS 1 signifies minimal non-obstructive disease (1-24% narrowing).
CAD-RADS 2 corresponds to mild non-obstructive disease (25-49% stenosis), and CAD-RADS 3 denotes moderate stenosis (50-69%). CAD-RADS 4 indicates severe stenosis (70-99%), which may involve single or multiple vessels or high-risk anatomy like left main artery stenosis. A CAD-RADS 5 is assigned for a total occlusion of at least one coronary vessel. Less common abnormal findings, such as coronary artery aneurysms or congenital anomalies, can also be detected.
Common Causes of Abnormal Findings
The underlying process behind most abnormal CT coronary angiogram findings, particularly plaque, is atherosclerosis. This condition develops over time due to various risk factors that contribute to fatty deposits within arterial walls. Understanding these factors can help individuals take proactive steps to support their heart health.
Lifestyle choices significantly influence atherosclerosis. Smoking, for instance, damages the lining of coronary arteries, increasing strain on the heart. Diets high in saturated fats, trans fats, cholesterol, sodium, and sugar also promote plaque buildup.
A sedentary lifestyle can lead to increased fatty deposits. Being overweight or obese places additional stress on blood vessels and is associated with higher levels of cholesterol, blood pressure, and a greater risk of diabetes.
Several medical conditions are linked to atherosclerosis. High blood pressure (hypertension) weakens artery walls, reducing blood flow. Elevated cholesterol (hyperlipidemia) leads to excess plaque deposition. Diabetes, with high blood sugar, also damages coronary arteries, accelerating atherosclerosis.
Non-modifiable factors also play a role. Age is significant, with risk generally increasing after age 45 for men and after 55 for women. Biological sex plays a role, with men typically experiencing a higher risk earlier. A family history of heart disease, especially if it occurred at an early age, increases susceptibility.
Immediate Next Steps After an Abnormal Result
Receiving an abnormal CT coronary angiogram result is the first step in a diagnostic journey. The immediate follow-up focuses on a thorough evaluation of the findings. The most important action is a comprehensive discussion with a cardiologist, who will interpret the scan results within the broader context of a patient’s medical history, symptoms, and overall health.
A key concept is assessing the “functional significance” of any detected blockages. The CT angiogram provides anatomical information, showing plaque or narrowing. However, it does not always indicate whether these findings restrict blood flow to the heart muscle or cause symptoms.
To evaluate functional significance, a cardiologist may recommend further diagnostic tests. A stress test helps assess how the heart performs under increased demand and whether blood flow is limited. An echocardiogram might be performed to visualize the heart’s structure and how well it pumps blood. In some cases, a conventional cardiac catheterization, also known as an invasive angiogram, may be suggested. This procedure is often used to confirm the severity of blockages and provide additional detail, especially if surgical intervention is being considered.
Long-Term Management and Treatment Options
Following a comprehensive diagnostic workup, a long-term management and treatment plan is developed. This plan is multi-faceted, starting with fundamental lifestyle changes. Embracing a heart-healthy diet, such as the Mediterranean diet, which emphasizes fruits, vegetables, whole grains, and lean proteins while limiting unhealthy fats, sodium, and added sugars, is highly recommended. Engaging in regular physical activity, smoking cessation, and maintaining a healthy weight are also integral components.
Medications often play a role in managing coronary artery disease. Statins are commonly prescribed to lower LDL cholesterol, which can reduce plaque buildup and help stabilize existing plaques. Blood pressure medications may be used to reduce the heart’s workload and prevent disease worsening. Antiplatelet drugs, such as aspirin or clopidogrel, are frequently prescribed to help prevent blood clots. For individuals experiencing chest pain, nitrates can be used to widen blood vessels and improve blood flow to the heart.
For significant blockages that cause symptoms or pose a high risk, procedures or surgery may be recommended. Percutaneous Coronary Intervention (PCI), also known as angioplasty with stenting, is a less invasive procedure. A tiny balloon widens a clogged artery, and a small mesh tube (stent) is typically placed to keep it open. Many stents are coated with medication to help prevent re-narrowing. This approach is often suitable for less severe or localized disease.
For more extensive or complex coronary artery disease, such as blockages in multiple vessels or the main left coronary artery, coronary artery bypass grafting (CABG) surgery may be considered. During CABG, a healthy blood vessel is used to create a new path for blood to flow around a blocked section. This open-heart surgery is often recommended for severe multi-vessel disease. The decision between PCI and CABG is made by a cardiologist based on the specifics of the blockages and the patient’s overall health.