test 9 angioplast therapy

Question 1

Percutaneous Transluminal Coronary Angioplasty (PTCA)

Answer 1

 balloon advanced to level of blockage – balloon inflated – plaque pushed back against vessel wall / small cracks created with the plaque (plaque fissures)/artery stretched

Question 2

Stenting

Answer 2

 balloon advanced to level of blockage – balloon inflated to deploy the stent
 bare-metal versus drug-eluting stents

Question 3

Criteria for Angioplasty

Answer 3

 Balloon can be passed through the blockage
 Blockage can be reached by the catheter
 Blocked vessel is not the left main
 original use for one or two vessel disease – now being applied to multi-vessel cases
 Patient is not in heart failure
 Patient is having a heart attack (if treatment can begin within two to six hours of onset)

Question 4

Advantages of Angioplasty

Answer 4

 Less invasive than bypass surgery
 Relatively low risk
 Relatively low cost
 Local anesthesia versus general
 Percutaneous incision
 Patient able to return to normal activity shortly after procedure (most go home after 24 hours – return to normal activity within one week)

Question 5

Risks/Complications of Angioplasty

Answer 5

 Bleeding from the insertion artery
 Damage to the insertion artery by the catheter
 Damage to the coronary artery by the catheter
 Re-stenosis (long term)
 Sudden vessel closure
 5% of patients with PTCA only
 Stents may cause clot formation
 most patients placed on
antiplatelet therapy including aspirin and clopidogrel ticlopidine (Plavix & Ticlid)
 must continue therapy for at least one year – additional benefit has been shown if therapy started one to three days before procedure
 Infection
 Allergic reaction to dye
 Myocardial infarction
 Need for emergency bypass
surgery
 2 to 5 percent for PTCA / 0.5 percent with stenting
 Stroke
 Death

Question 6

Restenosis Rates

Answer 6

 PTCA – 10% to 40% during the first six months
 Bare-metal stent – 30% to 50% during first six months
 Drug eluting stent – 7% to 15% during first six months

Question 7

Patient Restrictions Following Angioplasty

Answer 7

 Refrain from lifting heavy objects, engaging in strenuous exercise for at least 24 hours
 Increased fluid intake first 24 hours – help remove dye
 Most patients will receive some sort of anti-platelet therapy

Question 8

Stents

Answer 8

 75% of the stent insertions follow plaque treatment with PTCA or atherectomy
 One size does not fit all
 stent must cover the complete length of the blockage
 stent must be fully expanded so there are no gaps between the surface of the plaque and the stent
 Difficult to stent plaque occurring at the bifurcation of two vessels
 Within four to six weeks the stent is covered with a thin layer of endothelial cells

Question 9

Drug-Eluting Stents

Answer 9

 Bare-metal stent coated with slow-to-moderate-release drug formulation that is embedded in a polymer
 restenosis not a recurrence of CAD – actually bodies response to the “controlled injury” of angioplasty
 restenosis characterized by growth of smooth muscle cells (i.e. scar formation)
 why not use drugs that are known to interrupt the process
 Boston Scientific – Taxus paclitaxel-eluting stent
 chemotherapeutic drug
 Johnson & Johnson / Cordis = Cypher sirolimus-eluting stent
 immunosuppressive agent
 Medtronic – Endeavor Zotarolimus-eluting stent
 Immunosuppressive
 Biggest impact may be on patients with diabetes
 Potential market - - - $5 billion annually

Question 10

Atherectomy

Answer 10

 Currently used as adjunct to PTCA and stent placement
 May work best on complex lesions
 heavily calcified / fibrotic / undilatable lesions
 ostial & branch-ostial lesions
 chronic total occlusions
 in-stent restenosis
 Actually removes plaque material