Refers to a "mechanical" restoration of bloodflow to myocardium.
This is always used in conjunction with medical therapy.
When to Consider Revascularization
1. When there is a known mortality benefit - the patient will live longer
2. To control symptoms that have failed medical therapy
Degree of Blockage in Athelosclerosis Before Symptoms
Typically above 70% blockage the patient will start to display symptoms.
Cardiac Dye Catheter
The catheter is inserted into the coronary arteries of the heart via the radial artery or the femoral artery. Theoretically you can use anything, but these are the most commonly used.
Once you reach the coronary arteries, you can inject dye and image the patient to look for blockages in the arteries. This is important so you know where to place stents or for the degree of blockage and the location for doing a bypass.
Percutaneous Coronary Intervention
Stents are placed in a blocked artery and then expanded to restore bloodflow.
Stents usually come in two main categores; a bare metal stent, or a drug-eluting stent.
It is complicated, but drug-eluting stents may be used in people who are particularly prone to getting a thrombus.
Complications of PCI
The most common complication is restenosis. This has a 10% chance of occuring in the following 6 months after the operation.
Other rare complications range from subacute thrombosis, to strokes, to having to perform an emergency CABG.
Overall, this is a very effective treatment.
Prevention of Stent Thrombosis
Bare metal stent - dual anti-platelet agents for at least 1 month and then followed by ASA indefinitely
Drug-eluting stent - dual anti-platelet agents for at least 12 months and then followed by ASA indefinitely
Coronary Artery Bypass Grafting (CABG)
Uses another vessel (conduit) to create a detour around the blockage and restore blood flow to the distal myocardium.
Usually done with open-heart procedure, circulatory arrest, and heart-lung machine for perfusion. Can also be done off-pump in some cases.
Conduits are usually the right or left intrathorasic artery (durable and best-suited) or saphenous vein grafts.
Complications of CABG
Atrial fibrillation (25%)
Late graft failure
When to Use PCI
Angina that is refractory to medical therapy
When to Use CABG
Advanced 3 vessel disease
LV systolic impairment
Left main disease
PCI is not feasible
Combination procedure (valve replacement)
Why Not PCI Left Main Stenosis
Don't use PCI because of the higher risk of restenosis. If this happens in this crucial area, it can kill the patient.