PCI in the patient with in stent restenosis


 * Associate Editors-In-Chief: Laura Nasrallah, M.D.;

Synonyms and Keywords: ISR

Overview
In-stent restenosis (ISR) is the most frequent late complication of stent implantation and occurs when there is a reoccurrence of stenosis in a lesion that was previously treated with a stent. In stent restenosis results from exaggerated neointimal formation. The lesion is primarily composed of smooth muscle cells and extracellular matrix. Intravascular ultrasound studies demonstrate that in stent restenosis is not due to extrinsic compression of the stent by scar tissue (i.e. there is not compression of the stent).

Epidemiology and Demographics
Although ISR has traditionally occurred in 30-40% of treated lesions, its incidence has been dramatically reduced by the development of drug-eluting stents.

Patient-based Risk Factors

 * Diabetes
 * Chronic kidney disease

Lesion-based Risk Factors

 * Longer lesion length
 * Smaller caliber vessel
 * Greater plaque burden
 * Ostial lesion location
 * The presence of a chronic total occlusion
 * Left anterior descending coronary artery location
 * Saphenous vein graft lesion

Procedure Based Risk Factors

 * A residual stenosis >30%
 * A residual pressure gradient > 20 mmHg
 * An increased number, overlap, and length of stents

Treatment
The major goal of treating in-stent restenosis is to minimize the chance of recurrent restenosis. If a bare metal stent develops ISR, then a drug eluting stent should be placed. If ISR develops in a drug eluting stent, there is no data to suggest that a different type of drug eluting stent will prevent a recurrence (e.g. switching from sirolimus to paclitaxel). While use of a cutting balloon may improve acute angiographic results, there is no data to suggests that the use of a cutting balloon reduces the risk of a recurrence. Radiation treatment or brachytherapy was used in the past to treat ISR, but this procedure was associated with a higher rate of late stent thrombosis, and had fallen out of favor.