Coronary Artery Diseases
Coronary artery disease (CAD) is the most common form of acquired heart disease and is one of the leading causes of death the world over.
The heart is supplied by vessels called the coronary arteries which carry oxygen and nutrients to the heart muscles enabling it to carry out its function of pumping blood to the various organs of the body.
When these vessels are blocked a person is diagnosed to have coronary artery disease.
When a person is diagnosed to have Coronary artery disease it signifies that one has developed significant blockage of the one or more of the vessels supplying the heart.
The same occurs due to the deposition of cholesterol in the form of fatty deposits over the course of many years. These deposits called plaques cause significant resistance to total obstruction to the flow of blood to areas of the heart supplied by them.
This can have two effects – critical reduction of blood flow causes the heart muscle to not receive adequate amounts of oxygen and nutrients carried by blood especially at times of increased need like brisk walking, running or other forms of physical exertion. This in turn causes one to experience chest pain or angina.
When the good supply is abruptly cut off – the heart has no time to compensate and that part of the heart muscle can die – myocardial infarction or in common parlance a heart attack.
There are two major coronary arteries that arise from the aorta to supply blood to the heart. They are called the right coronary artery and the left main coronary artery. The left main coronary artery further divides into two – the left anterior descending and the circumflex coronary artery.
The following patient population is more prone to develop CAD. Those with:
- Long standing Diabetes Mellitus – the more poorly controlled the higher the risk
- High blood pressure
- Cholesterol – high levels of HDL and low levels of LDL
- Obese people
Besides these studies have revealed a higher incidence of CAD in those with other family members having early CAD, those with high stress levels, older age and those with a sedentary lifestyle and people with a diet having a high proportion of trans fats.
Among these risk factors there exist modifiable and non-modifiable risk factors -age, genetics, gender are non modifiable.
Primary prevention is directed towards the modifiable risk factors –
Smoking cessation, good control of blood pressure, tight glycemic control in diabetics, a healthy lifestyle – exercise, a healthy diet, control of cholesterol among others.
Acritical reduction of blood flow due to narrowing of the coronary arteries causes the heart muscle to not receive adequate amounts of oxygen and nutrients carried by blood especially at times of increased need like brisk walking, running or other forms of physical exertion. This in turn causes one to experience chest pain or angina.
Chest pain varies in its intensity and nature ranging from tightness, burning, pressure, fullness or number among a myriad other descriptions.
Some patients experience nausea, vomiting, pain in the left arm, neck and jaw or the upper abdomen.
Shortness of breath/ easy fatiguability
In some patients who may have ignored symptoms for a period of time or in diabetics in whom symptoms may be masked – presentation may be with breathlessness/ decreased exercise tolerance or easy fatiguability.
These are because of chronic impairment of blood supply to the heart resulting in a decrease in its overall function.
A diagnosis is arrived based on a combination of the history, physical exam and confirmed by a combination of blood tests, an ECG, echo, stress test and a cardiac catheterization (coronary angiogram).
A majority of the patients with coronary artery disease are treated with medications and advise on lifestyle modification.
Patients considered for intervention would be those with critical blocks with recurrent chest pain (angina) or those with a large territory of heart muscle that would be jeopardised if the vessel would to suddenly close.
The commonly employed procedures are a Coronary Artery Bypass Surgery (CABG) and a Percutaneous Coronary Intervention (PCI).
The decision what treatment the patient will be best served by is arrived at based on the number of vessels blocked, suitability for PCI, age of the patient, factors like left heart function, diabetes mellitus and the potential risks/ benefits of the procedure.
Patients with mild coronary artery disease are to be on regular follow up with their physician with appropriate control of blood pressure, diabetes mellitus and lifestyle modifications like smoking cessation, a healthy diet, exercise and weight loss.
This is best decided in centers with deal with a high volume of coronary artery disease. The optimum intervention is decided by the heart team wherein the cardiac surgeon and cardiologist in conjunction with the patient would decide on the best procedure.
PCI or angioplasty, is procedure wherein a wire is threaded into the affected coronary artery and the blockage is opened up with a balloon – in most circumstances a wire mesh called a stent is then inserted to keep the vessel open and prevent further blocklage. This is suitable for patients with fewer blockages and discrete blockages.
Coronary Artery Bypass Grafting (CABG) Surgery
CABG is performed to provide an alternative source of blood by bypassing the blocked vessels supplying the heart.
This is done by using arteries and veins from the patient’s own body undergoing surgery. The vessels are then stitched onto the blood vessels of the heart to provide an unobstructed source of blood supply.
Conventionally the procedure is performed by splitting the breast bone (sternum) and accessing the heart – veins are harvested from the leg and arteries form the chest wall or the arm for bypass. To minimize the chance of wound infection the vein harvest from the legs is performed by using endoscopic techniques in advanced centres.
Most of the procedures in Indiaare performed with the heart beating (off pump)
To know more about CABG (click here)
CABG is the preferred option in and has been proven to be superior in:
- Left main disease
- Triple vessel coronary artery disease
- CAD with depressed ventricular function
- Diabetes with extensive CAD
As part of recovery and to reduce the risk of developing further blockages – follow up includes maintaining a healthy lifestyle with regular exercise, following a healthy diet, weight loss, reducing stress, and quitting smoking.
CABG surgery is a major operation; one should expect to be in the hospital for about a 5-7 days after surgery.
It is better to discuss with the treating cardiac surgeon in detail regarding the procedure, likely complications, post-operative course, recovery and restrictions in detail prior to undergoing surgery.