Coronary Angioplasty and Drug-Eluting Stents - Applications of Biotechnology in Cardiovascular Therapeutics - page 260

PTCA or
Stenting

Rupture of
plaque

Plaque
debris

Occlusion of
coronary
side branch

Thrombosis

Microvascular
dysfunction

Release of
vasoactive
peptides

Reduction of
blood flow

Vasoconstriction

Release of
biomarkers

Myocardial
infarction

© Jain PharmaBiotech

Fig. 9.1 Myocardial infarction following procedures on coronary arteries

Release of biomarkers of myocardial injury following periprocedural MI is
schematically depicted in Fig. 9.1 .

Stents

A coronary stent is a tiny expandable mesh tube made of medical grade stainless
steel. A stent is delivered on a balloon catheter and implanted in the coronary artery
after balloon angioplasty to help keep the artery open. After the plaque is com-
pressed against the arterial wall, the stent is fully expanded into position, thereby
acting as miniature “scaffolding” for the artery. The balloon is then deflated and
removed and the coronary stent is left behind in the patient's blood vessel. It may
be necessary to place more than one stent, depending on the length of the blockage.
The inside lining of the artery eventually heals around the stent. Restenosis after
stenting and its treatment is described later in this chapter.

Restenosis

Restenosis - the reclosure or narrowing of an artery - can be a concern with coro-
nary stents and with balloon angioplasty procedures. Restenosis occurs when
blockages return a few weeks or months after the coronary stent procedure.