Are you aware of the advantages of cardiac catheterization for people with coronary heart disease? Then this article is for you! For more information, connect with our Arizona heart specialists from Advanced Cardiovascular Center.
One of the primary causes of chest pain is the obstruction of blood flow in the coronary arteries. These arteries are responsible for delivering oxygenated blood to the heart muscle, allowing it to function properly. Depending on how quickly the blockage forms, it can be categorized as either stable or unstable.
Unstable blockages occur when a plaque in the coronary artery ruptures and a clot forms on top of it. This clot, along with the plaque, can obstruct blood flow and deprive the heart muscle of oxygen, leading to a heart attack. This condition is known as acute coronary syndrome and is often diagnosed and treated through a minimally invasive procedure called cardiac catheterization.
On the other hand, when plaque gradually builds up in the coronary arteries, patients may experience little to no symptoms. As the blockage progresses over time, they may start to experience chest pain during physical activity, which subsides with rest. This type of chest pain is referred to as stable coronary artery disease (CAD). Managing stable CAD may or may not require cardiac catheterization.
To determine the likelihood of having a coronary artery blockage, a stress test can be conducted by our Arizona heart specialists. The primary objective of this test is to evaluate how the heart functions during physical activity. By observing the heart’s response to exercise, a stress test can identify any issues with blood flow in the coronary arteries. In some cases, stress tests can also determine the extent of ischemia, which refers to inadequate blood supply to the heart.
During a stress test, patients typically walk on a treadmill or use a stationary bike while their blood pressure, heart rate rhythm, and symptoms are closely monitored. In cases where patients are unable to exercise, medications may be administered to simulate the effects of physical activity.
Depending on the specific type of stress test, a radioactive tracer may be used to create an image of how well blood reaches different areas of the heart muscle, both during exercise and at rest, in order to detect ischemia. If the stress test results are abnormal, patients may require cardiac catheterization to confirm the presence of any potential blockages and, if necessary, undergo invasive treatment by our interventional cardiologist.
What is cardiac catheterization?
Cardiac catheterization is a test used to determine heart ailments. It involves inserting a thin tube called a catheter into an artery in the arm or leg, which is then guided to the coronary arteries. Contrast dye is injected into the coronary arteries to identify any blockages.
Depending on the location and severity of the blockages, they can be treated with medication alone, angioplasty with stent placement (using a balloon attached to the catheter to open the blockage and placing a stent), or coronary artery bypass surgery (rerouting blood around the blockage).
Research has indicated that cardiac catheterization, followed by angioplasty with stenting or bypass surgery, can improve survival rates and reduce the occurrence of heart attacks in patients with acute coronary syndromes. However, the advantages of cardiac catheterization among people with stable coronary artery disease (CAD) are still being studied by every interventional cardiologist.
How should you treat stable CAD – Cardiac catheterization or medications only?
One study called the COURAGE trial, found that in patients with stable CAD, stenting combined with medication therapy did not reduce the risk of death or major cardiovascular events compared to medication therapy alone. However, stenting did provide faster relief from symptoms.
A more recent study, the ISCHEMIA trial, focused on stable CAD patients with moderate to severe ischemia (a lack of blood flow) detected during stress testing. The study compared outcomes in patients who underwent cardiac catheterization, angioplasty with stenting, or bypass surgery when feasible, along with medication therapy, to those who received medication therapy alone.
The study found no significant difference in the primary endpoint (a combination of cardiovascular death, heart attack, cardiac resuscitation, or hospitalizations for unstable chest pain or heart failure) between the two groups.
The ISCHEMIA trial did observe a slight increase in procedural heart attacks in patients who underwent cardiac catheterization. However, there was an even greater increase in spontaneous heart attacks in patients who did not undergo the procedure.
The study also noted that patients who underwent cardiac catheterization experienced more relief from symptoms compared to those on medication therapy alone.
The ISCHEMIA trial did not demonstrate a clear advantage of cardiac catheterization (including angioplasty with stenting or CABG when feasible, in addition to medications) over medications alone. Consequently, current treatment guidelines advise that patients with stable CAD should initially have their medication doses maximized to the highest level tolerated. Nonetheless, cardiac catheterization would be a suitable option for these patients if they persistently experience intolerable symptoms or have difficulty tolerating their medication therapy.