Important Information About the Risk Calculation
- The risk results shown in this program are estimates.
- The results show your current potential risks & benefits of this treatment option. However, this result is not an actual prediction. It will only give you a general idea of your future risk with this option.
- Your actual risks may or may not be the same as the estimates shown. This program shows the estimated health risks of people with your same age, gender, and risk factor levels. Every person is different. Your current health status, your medical history and the traits you inherited from your family make you unique. This program is not meant to provide medical or other professional advice. Talk with your doctor or other healthcare professionals for information specific to you and for advice in making final decisions on managing your care and improving your health.
If successful, both interventions will improve or restore the bloodflow to your heart. A PCI or stent can be performed in a relatively short timespan and taxes your body to a much lesser degree than a CABG. However, after a stent procedure, intense medical therapy is required to prevent it from closing off within the next year or so, and it is not uncommon that multiple stents are placed, ultimately still followed by a CABG.
In contrast with a stent, a CABG usually restores the blood flow to your heart back to normal, the price being a bigger procedure with a longer recovery. Remember that the disease process, atherosclerosis, which causes blockages in your coronary arteries will not change with this procedure and will also require continual medical treatment.
Your specific situation may well require a different recommendation that will depend on factors that cannot be evaluated here. Any procedure has distinct consequences that you should consider before agreeing to undergo an intervention. Irrespective of the choice you make, you will need intense medical therapy as well as lifestyle changes to fight the disease that causes blockages to your arteries.
To help you with the decisions youi have to make, we will review here all three options of treatment, medical therapy, PCI or CABG. Medical therapy and lifestyle modifications for the treatment of the disease of atherosclerosis will always have to be part of whatever intervention you undergo:
MEDICAL TREATMENT of ANGINA
Medical treatment for coronary heart disease includes drugs that
- treat symptoms by slowing the heart down, so that a limited blood supply matches less demand, or
- relax (dilate) arteries so that more blood can pass through,
- lower blood pressure so that the heart has to work less,
- lower cholesterol to slow down or even stop the process of atherosclerosis (hardening of the arteries).
None of these are very effective unless combined with lifestyle modifications (smoke cessation, diet, exercise and weight loss).
No present treatment can cure CAD! The diseases that cause CAD are determined by things such as your genes, diet, smoking and your environment. Treatments all have the same goals: to improve quality of life and to alleviate symptoms by balancing the supply and demand of blood to the heart. Medical treatments, diet and exercise may also delay or stop the progression of the disease and thereby prolong life. However, there are some important differences between medications and life style modification on the one hand and procedures on the other.
Procedures are usually more beneficial than medical treatment when there are severe blockages (stenoses) and/or when many coronary arteries are involved, or when the left main coronary artery (the artery that supplies blood to the left side of the heart) is narrowed.
Heart failure is caused by poor function of the heart (which is to pumps blood to the body). If this is due to extensive damage from a previous heart attack, improving the blood supply may not help the heart function. However, if heart failure is caused by severely impaired blood supply to an otherwise viable heart muscle, restoring the blood flow back to normal may have dramatic improvement as a result. Patients with these types of heart disease benefit more from bypass surgery, than from medical treatment.
- Angioplasty, with or without stent placement, also called PTCA or PCI (Percutaneous Coronary Intervention),
- Coronary artery bypass graft surgery (CABG).
Procedures such as PCI and CABG improve the blood supply to the heart. They do not influence the disease process that causes CAD. If successful, they effectively relieve symptoms of coronary heart disease, such as angina.
PCI uses a balloon to dilate (stretch) narrowed arteries in the heart and may include placement of a stent to hold the artery open.
CABG involves sewing one end of an artery or vein upstream to a blocked coronary artery and the other end below the blockage (stenosis), thereby allowing the blood stream to bypass the obstruction. The arteries or veins used for the bypass are like spare parts your body has for just these types of procedures. The veins are usually found in the leg and the arteries behind and parallel to your breast bone (the sternum).
- Persistent and intolerable symptoms despite adequate medical treatment
- Specific patterns of blockage and a high risk of either a heart attack or death
Limitations of PCI
PCI has not been shown to prolong life compared with medical therapy. PCI is used principally to improve angina symptoms when medications have failed. Although PCI restores blood flow and relieves symptoms in over 90 percent of patients, there is a 10-15% risk of recurrent symptoms within six months, often due to recurrent narrowing (restenosis) of the artery. Restenosis that is severe enough to cause bothersome or life-threatening symptoms occurs in:
- About 30 % in patients with angioplasty alone.
- About 15% in patients with a bare metal stent.
- 10-15% in patients with a drug coated stent.
Some coronary artery sites are more prone to re-narrowing than others. In addition, some conditions increase the risk of re-stenosis:
- Obesity and overweight
- Continued smoking
- High blood pressure
- Small and narrow arteries
- High cholesterol
- Stenosis in a major blood vessel at or near the beginning of a side branch
Indications for CABG
Patients who have extensive coronary heart disease, including a large number of narrowed coronary arteries or narrowing of the left main coronary artery and poor pumping function of the heart tend to live longer when they have coronary artery bypass surgery rather than medical treatment.
- Patients who have three narrowed coronary arteries are usually advised to undergo bypass surgery.
- When the left main coronary artery (the artery that supplies blood to the left side of the heart) is narrowed.
- Patients with poor heart function
- Patients with Diabetes and extensive CAD
Limitations of CABG
CABG restores blood flow and relieves symptoms in 95 percent of people immediately after surgery.
Patients with symptomatic angina who undergo CABG can have greatly improved outcomes. As an example, in the Coronary Artery Surgery Study (CASS) of 8221 patients undergoing CABG, 56 percent were alive at 15 years. Among those 65 and 75 years of age at the time of surgery, 15 year survival was 54 and 33 percent, which was higher than a similar age group in the United States who did not have CABG.
Reasons for recurrence of angina include graft failure and/or progression of disease in the bypassed or non-bypassed vessels.
The recurrence of angina is less frequently seen when the graft used for the bypass is an artery as compared to a vein. By 10 years, 90 percent of arterial grafts are still open; in contrast, about one-half of all vein grafts become narrowed or occluded at 10 years after bypass surgery.
However CABG is a difficult procedure and complications may occur that will affect long term outcomes.
- 2- 4 percent of patients experience a heart attack after surgery. This occurs less frequently in patients who are low risk as compared to patients who are high risk, undergoing repeat CABG, or CABG combined with other cardiac surgery. Generally post-operative heart attacks are small to moderate in size.
- Low cardiac output (when a reduced volume of blood is pumped out of the heart to the body) can occur during or after surgery. This is often temporary and responds to intravenous fluids and/or a brief period of therapy to improve heart function.
- Sternal wound infection of the chest incision (called the sternal wound) occurs in approximately 1 percent of patients. Diabetes mellitus, obesity, and the use of both left and right internal mammary arteries increase the risk of sternal wound infection. Women with a history of breast cancer are at especially high risk, possibly related to therapies used during breast cancer treatment.
- Renal failure: a temporary decrease in kidney function occurs in approximately 5 to 10 percent of patients undergoing CABG.
Most PCI procedures entail the implantation of a coronary stent. Most stent studies are funded by equipment manufacturers and are designed and conducted by researchers who believe in coronary intervention despite the lack of hard evidence of cost effectiveness or clinical superiority over optimal medical therapy.
A recent (2007) study, published in the New England Journal of Medicine concluded that patients with stable coronary artery disease do just as well with medical therapy as they do with percutaneous revascularization procedures. The risk of death, myocardial infarction, or other major cardiovascular events in patients with stable coronary artery disease is no lower with percutaneous coronary intervention (PCI) than with the optimal therapy of drug treatment with lifestyle intervention, says a major prospective study that is predicted to change practice.
The trial randomized more than 2000 patients with objective evidence of myocardial ischemia and significant coronary artery disease to PCI or optimal medical treatment. The results showed no difference in mortality from any cause or in the risk of non-fatal myocardial infarction at a median follow up of 4.6 years.
Currently available data emphasize the fact that CABG remains an excellent and often superior long-term form of revascularization in some selected groups of patients with two-vessel diseases and most groups of patients with three-vessels CAD.
In patients with severe coronary artery disease, including those with left main coronary artery (Lmain) disease and those with three-vessel disease, the usual practice of revascularization with PCI does not reduce the risk of myocardial infarction or improve survival and CABG remains the gold standard for optimal treatment.
In a 2009 large international study (SYNTAX), patients with three vessel coronary artery disease (including a Lmain stenosis) were compared now up to four years after treatment. While survival was similar, PCI patients were re-operated at more than twice the rate of CABG patients, even though almost 15% underwent a staged procedure to begin with and CABG patients had significantly worse disease.
Although not mentioned in this study, consideration of costs should play a role. More than four stents on average were implanted per patient, and a third of patients had placement of stents with a total length of more than 100 mm (3.9 inches). Given the fact that an artery is effectively destroyed locally when a stent is placed, there is a risk of building “a bridge to nowhere”.
In 2003, a cost-effectiveness analysis of medical therapy vs. PCI and CABG concluded that while medical therapy and CABG were cost-effective, PCI was not. The additional benefit of stenting over best medical therapy was ‘too small to justify the additional cost’.
Everything mentioned here is ultimately dependent on the skills of the people involved, not only of the cardiologists and cardiac surgeons involved with the procedure, but also their respective teams and the hospital. It is therefore vital that you know the answer to questions such as:
- What kind of results does your doctor have with the procedure he recommends?
- How often does a complication occur?
- How experienced is the team?
- What is the reputation of the hospital, doctors etc.
- In stable patients, optimal medical therapy should be the initial treatment of choice;
- If you have only one or two blockages (unless it includes a “Left Main Lesion”) and a good heart function , a Stent is usually the best option;
- If you have three or more blockages, a “Left Main”, damage to your heart, or are a Diabetic, you are usually better off with a CABG;
- There are important exceptions to these recommendations, but they should be dictated by your condition.