- Initial medical management
- Opening up of the artery (revascularization)
- Coronary angiography, angioplasty and stents
- Coronary bypass surgery
In order to resupply the heart muscle with oxygen, several treatments are started as soon as the emergency staff arrives:
- If necessary, supplemental oxygen is provided with an oxygen mask or other device;
- Administration of certain medication, mostly intra-venously, aimed either at rendering the blood more fluid (aspirin, anti-coagulants), at putting the heart at rest (beta-blockers) or at decreasing your pain and your blood pressure (nitroglycerine, morphine).
During this period, you will be constantly monitored by medical staff using technological tools to track your electrocardiogram, your blood pressure and your oxygen levels.
Based on your electrocardiogram results and dosages of substances in your blood called cardiac enzymes (troponin and CK), will give rise to 2 likely situations:
Heart attack (myocardial infarction)
- A coronary artery is blocked: it has to be reopened as quickly as possible with an intervention called revascularization as as an emergency;
- A coronary artery is only partially blocked: we have more time to take action. In this situation, coronary angiography will be performed within 24 or 48 hours after your admission to the hospital. Until this coronary angiography is performed, proper monitoring continues in the intensive care unit. Coronary angioplasty, coronary artery bypass surgery or medical treatment without further intervention can be considered.
A coronary artery is constricted without any harm to your heart. In this case coronary angiography or another “non-invasive” exam such as a stress test or other cardiac imaging can be performed (stress echocardiography, myocardial perfusion scintigraphy, CT or MRI).
A coronary angiogram is an exam that enables coronary arteries to be visualized. Under local anesthetic, a plastic catheter is inserted into an artery located in the groin or at the wrist and pushed up into the coronary arteries. The local anesthetic can create a burning sensation. An iodine based contrast product is then injected into the left and right coronary arteries to make the arteries visible using X-rays. It is therefore possible to highlight potential constrictions or complete obstructions that cause heart attacks or unstable angina.
This intervention can also be used to treat constricted arteries, or unblock the blocked arteries. This procedure is called coronary angioplasty. A balloon is placed inside the constricted area and then inflated to unblock the artery and re-establish blood flow. In general, to improve the outcome of the procedure, and prevent a recurrence of constriction, by implanting cylindrical metallic lattices, called stents, inside diseased arteries.
The main discomfort with the procedure is that the patient must remain still and calm on an examination bed for the entire procedure, which lasts between 1 to 2 hours, as well as remain in bed for a few hours after the procedure. This is to help with healing and to prevent bleeding from the puncture site in the groin or on the wrist.
There are 2 types of stents: bare metal stents and stents encoated with medication known as drug eluting stents. These medications are aimed at preventing re-constriction of the arteries. The use of drug eluting stents requires, in addition to aspirin, another type of blood thinner to be taken for at least 12 months (as opposed to only 1 month for bare metal stents). This is because drug eluting stents slightly increase the risk of blood clots (thrombosis); the metal lattice takes longer to be covered with body tissue. Choosing the most suitable stent will depend on factors such as whether surgery is planned for the immediate future. In this case, a bare metal stent will no longer be suitable as risk of bleeding is increased when 2 blood thinners (platelet aggregation inhibitors) are used simultaneously.
Therefore, you must never stop taking platelet aggregation inhibitors without speaking to your physician or cardiologist first.
As with any procedure, coronary angiography and angioplasty carry some risk:
- The most common complication is bleeding at the puncture site, which is the place where the needle was inserted. Your cooperation is essential in order to minimize this occurrence. At the end of the procedure the arterial puncture site is sealed with either a stitch, a plug or compressed for a prolonged time period. Once the artery is no longer bleeding, it is important to keep the affected leg outstretched until a nurse or the physician instructs you to move it. One must avoid carrying weights greater than 5 kg or exerting yourself with physical exercise for 2 days after the procedure.
Other rare complications that may occur are:
- Cardiac arrhythmias (acceleration or slowing of the heart, or even cardiac arrest).
- A heart attack provoked by the procedure itself.
- Decreased kidney function resulting from the contrast product.
- A very complex situation may be impossible to treat with angioplasty and may require coronary artery bypass surgery.
- Transitory or permanent neurological deficits are very rare but can result from a blood clot migrating to the brain.
This is surgery that usually requires opening the chest (thoracotomy) and temporarily arresting the heart. The aim is to use segments of your own veins or arteries and to graft them to your coronary arteries so as to by-pass the areas that are narrow or blocked by atherosclerosis.
These days, cardiac revascularization surgery is proposed less frequently because coronary angioplasty has become effective and safe. However, there are situations when coronary artery bypass surgery is more suitable:
- Atherosclerosis lesions that are too complex or difficult to treat with angioplasty.
- Complications during the angioplasty procedure.