Drug-coated stents
		Cardiac function modulators
		Therapeutic angiogenesis
		Human Genome project

If you've had surgery and tried various drugs to control your angina and still don't enjoy full relief from pain or discomfort, these potential new treatments may offer hope in the future if they are shown to be safe and effective for chronic angina.

• Drug-coated stents. A stent is a hollow wire mesh placed in a coronary artery after it has been opened by a balloon angioplasty. Stents act as a scaffold for the artery, propping it up and open for improved blood flow. They help prevent the artery from narrowing again, a condition called restenosis. Unfortunately, stents aren't foolproof—restenosis may still occur after the procedure, sometimes within months.

  Researchers are testing drug-coated stents to see if they can potentially prevent restenosis. These stents are coated with a small amount of a drug that only works in the specific area of the coronary artery where the stent is placed. A variety of drugs are being tested. They range from drugs that help prevent rejection of transplanted organs and anti-cancer drugs to medications that help break down or prevent blood clots from forming. In addition, some non-drug-coated stents inserted with a small dose of radiation may be used to help prevent restenosis. Ultrasound is also being tested.² The FDA has not approved any of these therapies yet and research is continuing.

  Early results on some drug-coated stents have been extremely encouraging, according to research presented at the 2002 annual meeting of the American College of Cardiology. Some of the devices appear to work well in keeping arteries from narrowing again. For example, in one study from the Netherlands, 238 patients received stents coated with sirolimus, a drug used to help prevent the rejection of transplanted organs. Seven months later, none of the patients were reported to have restenosis.³ Other, smaller studies have shown that patients with drug-coated stents stayed free of restenosis even longer. If scientists can confirm such findings in further testing, drug-coated stents may be very helpful for helping improve angioplasty results.





• Cardiac function modulators. Partial blockages caused by plaque in the coronary arteries may keep your heart from getting all the oxygen-rich blood it needs to work efficiently. As a result, when the heart needs to work harder, such as during exercise or stress, chronic angina pain or discomfort may occur.

  For the past 25 years, the drugs available in the United States for chronic angina have included beta-blockers, calcium channel blockers, and nitrates. These medications all depend on changes in heart rate or blood pressure to help prevent, or reduce, the number of angina attacks. Read more in Angina Medications.

  One potential new way to help make the heart more efficient during times of increased stress and demand is to help the heart improve the way it makes and uses energy (called cardiac function modulation). This is especially important when the blood is oxygen-poor. Clinical trials are being conducted to see whether this type of therapy is safe and effective for the treatment of chronic angina.





• Therapeutic angiogenesis. Angiogenesis is the growth of new blood vessels. The body already does this naturally when it heals wounds and restores blood flow to an injured area. Special substances in the body called growth factors signal the beginning of angiogenesis.

  Some growth factors are being studied for the treatment of coronary artery disease. The goal is to stimulate the growth of more blood vessels in the heart, providing more of the oxygen-rich blood it needs to keep functioning. The result could be less angina pain.

  Growth factors might also be helpful for preventing closure of new detour vessels (the vessels taken from a leg or the breast area to be connected to the heart) after open heart surgery.⁴

  However, the body's response to growth factors is very complex. Some growth factors may not work if not used in exactly the same way as they work in the body naturally. Growth of new blood vessels may also occur in unwanted areas.⁵ Therapeutic angiogenesis, while intriguing, requires more research to evaluate safety and effectiveness.

  In one promising new approach, scientists injected a growth factor gene into the hearts of 79 men and women with angina.⁶ In the study, which was recently published in the journal Circulation, the group who received the growth factor gene showed greater improvement at enduring an exercise tolerance test than a control group given a placebo. This study evaluated only a small number of subjects, but a much larger trial, called AGENT 3, is currently ongoing in the United States. Its results may help shed more light on whether this type of gene therapy can benefit heart patients.

  To date, proteins have been unsuccessful in the long run at stimulating new vessels, perhaps because the proteins are quickly used up. But the growth factor gene seems to bind to heart cells, which allows it to work much longer to promote new vessel growth.





• Human Genome Project. Cardiologists and other physicians may one day be able to prevent heart disease by examining some of your genes⁷.

  How exactly do genes come into play? Each organ in your body has specific directions about how it is made and what work it is expected to do. In fact, every cell in the body has an internal blueprint for making carbon copies of cells in the body. Once created, each copy has the same structure and does the same work as the cell from which it was copied. This internal blueprint is called the genome.

  The United States National Institutes of Health and the Department of Energy are funding the Human Genome Project. The goal is to identify and "map" all the genes in the human body and to determine their structure. This information can give scientists some clues to help them understand how the human body works and, ultimately, how some genes may be related to illness.

  How can this help heart disease patients? Just by taking a blood sample, your doctor may one day be able to choose exactly the right therapies to relieve your angina pain or discomfort, including the right drug with the fewest side effects. For those who have not developed heart disease, the same blood sample may point to risk factors that could be avoided or minimized ahead of time. All this information—and more—may be available in your genes, and is expected to be accessible to doctors and researchers sometime in the future.

	Emotional stress may cause which of these physical symptoms? Click here.

Sources

1. Schofield, R.S. and J.A. Hill. "Role of Metabolically Active Drugs in the Management of Ischemic Heart Disease." American Journal of Cardiovascular Drugs, 2001, Vol. 1, Number 1. 23-35.

2. Kuntz, R.E., J.W. Moses, et al. "Intravascular Sonotherapy in Human Coronary Arteries: First Results of a Feasibility Trial." American College of Cardiology Annual Meeting, 2001. Abstract #1158-35.

3. Fajadet, J., Perin M., et al. "210-Day Follow-up of the RAVEL Study: A Randomized Study with the Sirolimus-Eluting Bx VELOCITY^TMBalloon-Expandable Stent In the Treatment of Patients With De Novo Native Coronary Artery Lesions." American College of Cardiology Annual Meeting, 2001. Abstract: 0032-1.

4. Mangi, A.A. and V. J. Dzau. "Gene Therapy for Human Bypass Grafts." Annals of Medicine, 2001, Vol. 33, Number 3. 153-155. PubMed

5. Esptein, S.E., S. Fuch, et al. "Therapeutic Interventions for Enhancing Collateral Development by Administration of Growth Factors: Basic Principles, Early Results, and Potential Hazards." Cardiovascular Research, 2001, Vol. 16, Number 3. 532-542. PubMed

6. Grines, C.L., Watkins M.W., et al. "Angiogenic Gene Therapy (AGENT) trial in patients with stable angina pectoris." Circulation, 2002 Mar 19:105(11):1291-1297. PubMed

7. Roberts, R. and R. Lifton. "Unraveling the Genome and Its Future Implications for Cardiology." Hurst's The Heart 10th ed. Ed. V. Fuster, et al. New York: McGraw-Hill, 2001. 154.