Interventional cardiac catheterization employs the use of specially designed catheters and devices such as balloons and stents to actually treat an intracardiac or vascular problem as opposed to just diagnosing it.

Once the catheter is inserted in place, it can be used to perform a number of procedures including percutaneous coronary intervention or coronary angioplasty, valvuloplasty, or balloon reconstruction of deformed cardiac valves, pericardiocentesis, or drainage of the pericardium, and corrective procedures specific to congenital heart disease such as septal defects.

The most common indication of interventional cardiac catheterization is for the treatment of coronary artery disease using percutaneous coronary intervention, also known as coronary angioplasty, or percutaneous transluminal coronary angioplasty (PTCA). In coronary angioplasty, a balloon is inserted through the catheter and into the narrowed coronary artery. The balloon is then inflated causing the compression of the plaque and therefore unblocking the artery. This improves the flow of blood to cardiac muscle. Balloon angioplasty is usually followed by the placement of a small metal mesh tube, called a stent, in the newly widened part of the coronary artery. A stent provides support to the walls of the widened artery and therefore lowers the risk of re-narrowing of the artery.

The placement of a stent can also damage arterial walls causing fibrous scar tissue to grow and promoting the formation of blood clots. Although, antiplatelet therapy is given to prevent clotting, re-narrowing or blockage of the stented artery can still occur in certain patients. Drug-eluting stents (DES), which release anti-inflammatory or anti-proliferative agents, are used as an alternative to metal stents. Compared with metal stents, DES are considerably more expensive. Studies have shown that DES reduce the need for repeat revascularization procedures but do not appear to reduce the risk of death or myocardial infarct.