The treatment of coronary artery disease aims to improve angina symptoms and reduce mortality or nonfatal myocardial infarction. Coronary angioplasty quickly relieves angina but carries risks of death or myocardial infarction (~5%) and restenosis (~30%) requiring repeat procedures. Newer treatments like coronary stents and platelet glycoprotein IIb/IIIa inhibitors have reduced complications and restenosis.
Advances in Coronary Angioplasty Technology
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Balloon catheters have improved since 1994, with smaller profiles (from 0.94 mm to 0.76 mm) allowing increased success rates.
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Patients now often have more unstable angina and multivessel disease when receiving percutaneous transluminal coronary angioplasty (PTCA).
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PTCA does not always achieve large enough lumen size, which is important because larger lumens reduce restenosis risk.
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Overexpanding balloons increase risk of vessel dissection and ischemic complications.
Alternative Techniques to PTCA
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Directional Coronary Atherectomy: Removes plaque using a high-speed cutting blade. It creates larger lumens than PTCA but has higher complication rates, including higher enzyme release and mortality, likely from embolization.
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Excimer-Laser Angioplasty: Uses 308 nm light to vaporize plaque, sometimes creating bigger lumens but with risks like vessel dissection and perforation due to vapor bubbles.
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Rotational Atherectomy: Uses a diamond-coated burr spinning at ~180,000 rpm to remove calcified plaque. It shows higher short-term success than PTCA but has no multicenter data proving superiority.
Clinical Data from Angioplasty Studies
| Variable | NHLBI Angioplasty Study I (1977-1981) | NHLBI Angioplasty Study II (1985-1986) | MAPS (1991) | Multicenter Database (1990-1994) |
|---|---|---|---|---|
| Number of patients | 1155 | 1802 | 200 | 3787 |
| Median age (years) | 54 | 58 | 62 | 61 |
| Unstable angina (%) | 37 | 49 | 52 | 63 |
| Multivessel CAD (%) | 25 | 53 | 100 | 51 |
| Success rate (%) | 61 | 78 | 90 | 87 |
| Death rate (%) | 1.2 | 1.0 | 1.0 | 0.9 |
| Myocardial infarction (MI) (%) | 4.9 | 4.3 | 1.5 | 5.2 |
| Emergency CABG (%) | 5.8 | 3.4 | 1.0 | 2.7 |
Coronary Stent Developments
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Stents, such as those tested in the Belgium–Netherlands Stent II study, reduce acute complications and restenosis.
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New stent designs include heparin-coated, welded tubular, flexible-coil, self-expanding, interlocking coil–strut, and radiation-emitting stents.
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Use of different stent structures/materials affects thrombosis risk and restenosis.
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A stainless-steel corrugated-ring stent showed reduced thrombosis and lumen contraction compared to a slotted-tube stent.
Summary
Modern coronary artery disease treatment combines improved angioplasty tools, stent technologies, and medical/surgical options to optimize outcomes. Balloon angioplasty has evolved technologically, but adjunctive devices and new therapies are key for better long-term results. Selection of treatment depends on patient characteristics to maximize benefits.
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