Coronary Heart Disease : Medical Treatment

Medical Treatment

Coronary artery disease decreases blood supply to the heart from the blocked coronary artery. The lower blood flow may fail to meet the heart's demand for oxygen. Treatment aims to balance blood supply to the heart with heart oxygen demand, and prevent worsening of coronary heart disease.
Aspirin: When taken daily or every other day, aspirin reduces the risk of developing angina or heart attack by reducing the tendency of your blood to clot.

• It reduces the chance that a clot will form over a rupturing plaque in the coronary artery, a common underlying phenomenon in heart attack (myocardial infarction).
  
  
• Side effects of aspirin include ulcers or bleeding problems.
  
  
• Talk to your health care provider before starting aspirin.

Beta-blockers: Beta-blockers decrease your heart rate and blood pressure, thus reducing your heart's demand for oxygen. Clinical trials have shown prevention of future heart attacks and sudden death. Nitroglycerin: This medication reduces chest pain both by decreasing your heart's oxygen demand and by dilating the coronary arteries, increasing the oxygen supply.

• Sprays or tablets placed under your tongue are designed to be taken when you need instant relief from angina.
  
  
• Long-acting nitroglycerin tablets or skin patches work slowly over many hours.
  
  

Calcium channel blockers: Calcium channel blockers dilate the coronary arteries to improve blood flow. They also reduce blood pressure, and slow heart rate. ACE inhibitors: Angiotensin-converting enzyme (ACE) inhibitors work by dilating blood vessels, increasing blood flow.

• They recently have been shown to reduce the numbers of cardiac events, heart attacks, and deaths in people with coronary heart disease, unrelated to their blood pressure lowering effect. Therefore, additional beneficial tissue effects on blood vessels and heart muscle is thought to occur.

• They are immensely useful in people with diabetes and those with weakened heart muscles.
  
  

Statins: Statin drugs work by reducing the amounts of lipids (cholesterol and other fats) in your blood.

• This changes the inner lining of the blood vessels so plaques are less likely to form or get large.
  
  
• They slow or stop the progression of coronary heart disease and also deter repeat heart attacks.
  
  
• Recently, clinical trials have shown beneficial effects immediately after a heart attack or threatened heart attack, even before the fat lowering effect is maximal, meaning they stabilize the plaque.
  
  
• Examples include atorvastatin (Lipitor), pravastatin (Pravachol), simvastatin (Zocor), lovastatin (Mevacor), and rosuvastatin (Crestor).
  
  

Invasive procedures: When angina symptoms worsen despite medications, you may need an invasive procedure in the cardiac catheterization lab to clear the blocked artery. These procedures are performed by a cardiologist, not a cardiac surgeon, and have fewer complications.
Coronary angioplasty (PTCA): This procedure is similar to coronary angiography (cardiac catheterization or a dye study to visualize the inside of coronary arteries) but is therapeutic as well as diagnostic.

• A similar but sturdier tube (guide catheter) is inserted into an artery in your groin or arm, and a hair-thin guide wire is threaded through it into your coronary artery.
  
  
• A much thinner catheter is threaded over the guide wire into the blocked artery.
  
  
• This thinner catheter has a tiny balloon at the end.
  
  
• Once the balloon is positioned at the blockage, the balloon is inflated to widen your artery and improve blood flow. The plaque is still there, just flattened against the wall of the artery.
  
  
• The balloon catheter is then withdrawn.
  
  
• This procedure is sometimes referred to as PTCA, which stands for its full formal name: percutaneous (through the skin) transluminal (through the hollow center of the blood vessel) coronary angioplasty.
  
  

Stent: A stent is a small, sieved, coil-like metallic tube or scaffold mounted over a balloon.

• The balloon is inflated at the blockage, which expands the stent.
  
  
• The balloon is then withdrawn, but the stent stays in place, keeping the artery from narrowing again.
  
  
• Like arteries treated with angioplasty alone, arteries treated with a stent can eventually close up again.
  
  
• The stent is a longer lasting solution for many people.
  
  

Atherectomy: Sometimes the plaques become too rigid, bulky, or calcified to be treated with angioplasty or a stent.

• In such cases, the plaques must be removed by cutting with a drill-like device.
  
  
• This works only if the narrowing or blockage is limited to a relatively small and self-contained portion of an artery.
  
  
• Devices commonly used for atherectomy include directional atherectomy (DCA) catheter, rotational atherectomy or rotablator (PTRA), transluminal extraction catheter (TEC), or AngioJet.
  
  
• Plaques also may be burned away with an excimer laser atherectomy (ELCA).
  
  

Brachytherapy: Radiation is applied to the blockage to clear it.

• The radiation comes from a very tiny source placed inside or near the artery.
  
  
• This procedure is used to treat arteries that have undergone angioplasty or stenting but have blockage that keeps coming back (restenosis).

Surgery

Surgery in coronary heart disease is reserved for people whose disease is either severe or is not improved or stabilized by medication and other less invasive therapies.


Coronary artery bypass grafting (CABG): This is the standard operation for blockages of coronary arteries.

• If multiple coronary arteries are blocked, or if the left main artery shows significant blockage, bypass surgeryis usually the best treatment choice.
  
  
• The blocked parts of the arteries are detoured or bypassedwith blood vessels "harvested" from your chest (internal mammary), arm (radial artery),or a leg (saphenous vein).
  
  
• During the surgery, the heart is stopped temporarily and you are connected to a machine called a bypass pump that takes over the functions of the heart.
  
  
• These operations are very successful and have a low rate of complications.

Off-pump bypass surgery: Sometimes surgeons can perform open heart surgery without using a bypass pump and while the heart is beating. The procedure causes fewer side effects than the standard procedure, but it is not feasible in all situations.

Minimally invasive coronary bypass (MINI-CABS): If just your front or right coronary arteries need bypass, a surgeon may replace the blocked artery with an artery from the chest via a small keyhole incision, without opening your chest, to detour the blockage

Transmyocardial laser revascularization (TMR): TMR offers an alternative for people who are not good candidates for either angioplasty or bypass surgery.

• A surgeon uses a laser catheter to create multiple pinholes in your heart muscle.
  
  
• The holes encourage growth of new vessels into the diseased heart muscle.
  
  
• This procedure can be done by itself or in conjunction with coronary bypass surgery.