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.
The results of this questionnaire indicate that patients like you may benefit from a Coronary Artery Bypass Graft procedure (CABG). If successful, a CABG will improve or restore the bloodflow to your heart. 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 require continued treatment. Your specific situation may well require a different recommendation that will depend on factors that cannot be evaluated here. Any procedure has distinct consquences that you should consider before agreeing to undergo an intervention.
There are some other factors that you need to know about, which may help you make the best decision in your own care:
What are the risks and benefits of a CABG procedure?
Let’s start with the benefits:
CABG is a remarkably safe and effective procedure, and has a good, long range prognosis. Often a patient will be discharged earlier after CABG than someone who underwent a Percutaneous Coronary Intervention (PCI) and who needs to stay on IV medications in a Special Care Unit for a week or longer. If you are relatively young and in good shape, you can expect to be discharged within 5-7 days after your operation, the blood flow to your heart restored back to normal and with post-operative pain controlled with routine medications. You can expect to be able to go back to a normal life in about two months. While your recovery is different with PCI, most often this is the only time patients will need a procedure and if you take care of yourself, your life expectancy will be the same as those without coronary artery disease.
A CABG procedure looks like this (from:: http://www.heartpoint.com/bypass.html):
For those who have multi-vessel or Left main coronary artery disease, CABG surgery offers the best long-range outcome, not Percutaneous Coronary Intervention (PCI). This specifically includes patients with impaired heart function (“damage”) and patients with Diabetes.
Stenting carries a higher risk of death long term than does open heart bypass surgery as a treatment for blocked arteries. Recent studies also reported that more than a third of patients who received stents needed either surgery or additional angioplasties with stents within three years. Despite many new studies, this conclusion has not changed.
CABG bypasses the current blockage and two-thirds of the upstream portion of a coronary artery where most future blockages occur, in contrast to PCI where stenting treats isolated blockages, and progression of disease elsewhere, even in the same artery, will require another procedure.
Patients often want less invasive treatment, assuming the results are the same. But that is frequently not the case. Part of the problem involves who recommends what procedure is best. When patients are informed of possible heart problems, often CABG is not discussed as a real option, thus denying the patient an optimal choice. Consent for PCI is often obtained when discussing the need for cardiac catherization (“as long as we are there anyway”). Doctors are obligated to explain alternate options if they are more effective. Usually, the cardiologist is the gatekeeper, and there is a conflict of self-interest when it becomes a referral to a partner in his practice. All patients with multi vessel disease should be treated by a multidisciplinary team, including a surgeon.
Now the Risks:
A routine (non-emergency) CABG can be performed at very little risk to a patient who is in otherwise good health. The questions you just answered in this questionnaire determine not only what the optimal treatment is for patients like you, but also what the associated risks of that treatment are. Factors that determine your risks involve your age, gender, general health and specifically your heart, lung and kidney functions. Too a much lesser extent than in PCI, the condition of your coronary arteries, or how many blockages there are also influence success. Most patients who undergo CABG need three or more bypasses, and again unlike PCI will have the blood supply to their heart restored towards normal at the end of the operation.
CABG is a major operation that requires anesthesia, and involves making an incision that often includes a “median sternotomy”, which is dividing your breast bone to get to your heart. Although put together in the end, this means that you may end up with breast bone that needs to heal like a broken bone (about six weeks). This is a major difference with PCI, which is performed under local anesthesia and only requires a local puncture into an artery.
Successful CABG depends on a number of factors that include not only your general condition, but specifically how good the parts needed for the bypass are. The Left Internal Mammary Artery (LIMA) is traditionally used to bypass an artery in the front of your heart, the Left Anterior Descending (LAD) coronary artery and it is almost invariably an excellent graft (conduit) that will function for 15 years or more. However, most of the time it is best used to bypass the LAD only, and other grafts are needed to bypass other blocked arteries. The most common conduit for these is the saphenous vein that needs to be removed from your leg. If you have varicose veins or other problems, they may not be suitable as conduits and other possibilities need to be considered. Luckily you have other spare parts in your body that can be used for bypass, but most of the information about results of bypass surgery uses these two conduits.
Here is a list of potential complications of CABG:
The risk of dying after CABG averaged about 1 % for the lowest risk elective patients, and 2 to 5% for all patients, and is closely related to the risk factors mentioned before. Early postoperative complications may result from preexisting co-morbidities or as consequences of cardiac surgery. In addition to mechanical injuries due to surgery, postoperative organ dysfunction may occur secondary to other processes such as:
- Transient heart dysfunction
- Postoperative bleeding and infection
- Heart dysfunction
Peri-operative Heart damage ((Myocardial Infarction). The incidence of MI is less in low-risk patients and higher in those with one or more of the following risk factors:
- A big heart]
- A prolonged operation
- Repeat CABG
- CABG combined with other cardiac surgery
Early graft failure — within the first 30 days after surgery, occlusion may occur in approximately 5 to 10 percent of patients, and is usually related to the size of the artery that was bypass, a problem with the graft, or a technical problem .
Impaired heart function is often transient and responds t is often transient and responds to medical treatment. However, shock after CABG is a serious problem and may need specialized support, including a return to the operating room for bleeding or other causes.
Atrial fibrillation occurs in 10-15% of patients and is usually not a major problem. Other more serious rhythm problems may occur, including the most dangerous one of all, ventricular fibrillation, with a risk of dying of about 25%.
Impaired Lung function
This is usually temporary, unless you have a serious pre-existing condition such as Emphysema. The operation causes pain that impair the ability to cough and breathe deeply, especially if there is a collection of fluid (usually from post operative bleeding pressing on the lungs. Most of these can be managed with intense treatment of your lung condition.
Postoperative neurologic complications
The incidence stroke after CABG is approximately 2 to 4 percent, with the frequency increasing in older patients. Patients with cerebral complications had higher in-hospital mortality and longer hospitalizations.
Acute renal failure, if severe (requiring dialysis) occurs in 1 to 5 percent of patients and is associated with a very high mortality risk of up to 64 percent! Risk factors for acute renal failure include poor cardiac performance, advanced atherosclerotic vascular disease, and pre-operative kidney dysfunction. A long operation and the presence of post-operative shock also influence the degree of postoperative renal dysfunction.
Postoperative severe bleeding may occur in 3 to 5 percent of patients. This is usually due to one or more of the following factors:
- Continued postoperative bleeding
- Residual effect of the use of the heart lung machine (if used)
- A long operation
Clotting factor depletion after a long operation or in patients who were treated with blood thinners before surgery (as often occurs in the coronary care unit)
Approximately 30 percent of patients require a blood transfusion after CABG, which also means that most don’t need any blood after their operation.
The incidence of postoperative infection of the median sternotomy (the traditional way of getting to your heart via division of the sternum) ranges from 0.4 to 5 percent, with the incidence in most centers being between 1 and 2 percent.
The following risk factors for postoperative infections have been described:
- Vascular disease
- Tobacco use
- Previous cardiac surgery
- Prolonged surgical procedure (greater than five hours)
- Repeat surgical intervention within 4 days postoperatively
- Prolonged postoperative intensive care
The majority of patients show evidence of infection within 14 days of surgery. The mortality rate of this severe (if rare) complication is between 12 – 47%. In addition, the interval mortality between one and two years after surgery is much higher in these patients (8 versus 2 percent).
If a CABG procedure is offered, will it be in the best hospital with my surgeon well qualified?
Look for a hospital with a long history of performing heart surgery and Board Certified Cardiac Surgeons. Outcomes are closely related to experience. It is possible to obtain outcome information on both hospitals and individual surgeons, but make sure you also inquire about things as length-of-stay and infection rates and not least, the team of nurses PAs etc. that will take care of you! Here is a website that lists the highest ranked hospitals in the US:
What are my chances that a repeat procedure is needed within the next year or so?
Graft failure occurs as well as progression of disease beyond portions of the coronary arteries that were bypassed. Early failure is usually due to technical problems with the operation, but late graft failure occurs mainly due to progression of disease. Remember, neither CABG nor PCI treat atherosclerosis which causes blockages to happen. Therefore irrespective of the type of procedure you will need continued treatment with diet, exercise, cessation of smoking and medications. That said, less than 5% of patients will need a repeat procedure within three years vs. 30% of patient after PCI.
What are the costs involved, not only now, but over the next few years (including the costs of medications)?
The cost of a CABG in the US is about $60,000, including professional fees. Medications include only initial pain therapy and those needed for control of atherosclerosis and diseases like Diabetes and hypertension. It is for these reasons that after one year the cost of a PCI equals that of surgery and exceeds it from there. Don’t forget to include the costs of loss of work that are associated with recurrence of disease and repeat procedures.