How do we treat blockages in the coronary arteries once they are found?
Blockages in the blood vessels of the heart are treated in 3 different ways.
1. Your doctor might decide that your coronary blockages are only borderline in nature or insignificant, and preventative therapy and medical therapy might be advised.
2. If your blockages, however, are severe, the treatment can be done by either an angioplasty or a bypass surgery. During an angioplasty, your cardiologist passes a balloon into the blocked arteries. Once the balloon is inflated at the area of the blockage (see Figure 3), the blockage will be compressed and the artery is stretched. A stent, or a stainless steel mesh, is most frequently deployed in the area of treatment to keep the artery widely open and prevent it from collapse. The choice of the stent depends on the type of blockages, their location, and the ability to deliver the stent to that part of your coronary arteries.
Although the current standard of treating blockages is withthe use of a stent, some blockages are not amenable to stenting because of their size or the difficulty of delivering the stents to a particular blockage because of blood vessel tortuosity and calcification. Current stents also have medications in them. These medications prevent the recurrence of blockages within the area of the treatment. The choice of the stents is also guided by certain rules that your doctor might follow. Currently, the majority of the blockages are managed through the angioplasty process.
3. However, some blockages might be in locations too dangerous to treat with angioplasty or might be extensive for an angioplasty procedure. They might be complex in nature, particularly if they occur in a person with diabetes. Currently, the trend is to treat those blockages with a bypass operation. During the bypass operation, a blood vessel under the collarbone or a vein derived from under the skin of the legs is utilized to bypass the area of the blockage (see Figure 4).
How long does it take to recover from the treatment of a blockage in the heart?
If an angioplasty is utilized as the primary method of treating a blockage, generally you stay in the hospital for 23 hours. Within 72 hours, you should be able to drive and resume your normal activities.
The exception to this is if you have had a heart attack. After a heart attack, typically a patient cannot drive for 2 weeks and should be undergoing cardiac rehabilitation for a minimum of 4 weeks prior to release back to work. Your doctor will decide on the size of heart attack that you had, the extent of cardiac rehabilitation required, and the optimal time for you to return to work.
On the other hand, bypass surgery would require that you stay in the hospital for an average of 5 to 6 days. This can be significantly more prolonged if complications occur. The recovery phase is in the range of about 6 weeks. For about 3 months, you should avoid carrying any weight that exceeds 10 pounds and avoid any form of exertion that requires pulling and pushing. It is also important to minimize any trauma to the area of the wound in the middle of the chest. Driving typically is not permitted during the first month after bypass surgery.
There are many exceptions to the above rules based on your condition, complications occurring during surgery, and your recovery.
What is the long-term outcome following treatment of blockages in the heart?
Following the treatment of a blockage with an angioplasty, there is an immediate inflammation that occurs at the site of the treatment. This response of the blood vessel to the injury that the balloon has caused triggers the formation of scar tissue at the site of the treatment. Patients develop scar tissue to a different extent for unclear reasons. The scar tissue that develops within the stent can potentially cause a recurrence of a blockage in the area of the treatment.
When balloon angioplasty alone is utilized without stenting, the recurrence of the blockage is in the range of about 40%. When a stent is used, the recurrence of a blockage is in the range of 15 to 20%.
Higher rate of recurrence occurs in people with diabetes, patients with small blood vessels, and those with long areas of blockages.
With the advent of stents loaded with drugs that suppress these blockages (drug-eluting stents), the rate of recurrence of scar tissue is currently about 5 to 9%.
It is typical for scar tissue to form within the first 6 months following an angioplasty. If this does not occur within the first 6 months, it is extremely less likely that it will occur afterward.
Your doctor might elect to proceed with a stress test at about 4 to 6 months following an angioplasty to determine whether enough scar tissue has occurred to block the artery again. The decision to do this stress test is generally a clinical one and physician-dependent.
The overall outcome of the patient, however, from the standpoint of preventing a heart attack is mostly dependent on preventative measures rather than the angioplasty process itself. In other words, angioplasty for blockages that have caused no symptoms or only stable symptoms generally does not affect a person's survival. The major impact of angioplasty is on improving the quality of life and lessening the need for medications.
In order to prevent death or a heart attack long-term, strict control of cardiac risk factors becomes important. This includes controlling blood pressure, cholesterol, blood sugar, and weight and avoiding smoking. Dietary modification, exercise, and stress reduction also become very important. These will be covered in detail in the preventative chapter of this book.
Following a bypass surgery, the procedure's long-term success depends on the continued normal functioning of the bypass grafts. It is known that 10 to 15% of bypass grafts can deteriorate within the first year of surgery. Also, at about 10 years from a bypass, two-thirds of all bypasses are expected to have significant buildup of plaques and blockages. There has been a lot of progress made recently in the treatment of those bypass grafts.
However, again, the overall long-term survival and benefit is highly dependent on preventative measures. Several studies have indicated that the viability of bypass grafts and their overall health is related to taking blood thinners, such as aspirin or clopidogrel, and the use of some cholesterol-lowering medications, such as statins. Research is continually ongoing to find ways to preserve those bypasses and prevent them from deteriorating or blocking shortly after the surgery.
What is a heart attack and how does it happen?
Heart attack happens when there is a sudden interruption of the blood supply to a part of the heart muscle. This leads to death ofthe muscle tissue.A heart attack leads to symptoms similar to angina. However, these symptoms tend to be more prolonged and generally are more than a half hour in duration. The interruption of the blood supply to the heart occurs because of a plaque rupture. A plaque, irrespective of severity, can break, exposing the inside of the plaque to the blood elements. The blood forms a clot on the top of the ruptured plaque. If the clot does not block the artery entirely, unstable angina certainly will occur, as described previously. However, if the interruption in the blood supply is complete because of a full clot, the muscle of the heart supplied by this particular blood vessel will be deprived of nutrients and oxygen and will die.
The most important step in the management of a heart attack is to restore the blood supply to the heart muscle as quickly as possible. The current guidelines strongly suggest that the artery should be opened with the angioplasty procedure within 90 minutes of a patient's arrival to the emergency room. If the angioplasty procedure is not available to this particular emergency room and hospital, a clot-dissolving (or thrombolytic) medicine needs to be used immediately,within 30 minutes of arrival to the emergency room. Most hospitals are able to initiate the use of these thrombolytic drugs within about 20 minutes of a patient arriving to the emergency room.
Current data strongly suggest, however, that angioplasty is a more effective way of opening up an artery in a heart attack situation and probably leads to better short- and long-term outcomes.
Therefore, it is imperative that when the pain starts or when symptoms of a heart attack start, the patient needs to be transported to an emergency room as soon as possible. Time is extremely precious, and the longer the delay in opening a closed artery, the more damage will happen to the heart muscle. In fact, in 4 to 6 hours after the artery is closed, the damage is essentially complete. There is strong data to suggest that the earlier the artery is opened, the higher the likelihood of survival from a heart attack.
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