What is balloon angioplasty and stent placement?

During balloon angioplasty a long, thin tube called a catheter is inserted through an artery in your groin or forearm, and a thin wire known as a guidewire is used to guide the catheter into the various arteries of the heart.  The catheter has a small balloon at its tip that is inflated to push the fatty plaque blocking the artery back against the artery wall. Balloon angioplasty is nearly always combined with stent placement, when a tiny wire-mesh tube is inserted into the artery to prop it open.
Balloon angioplasty is also known as percutaneous transluminal coronary angioplasty or PTCA.  These days, the term most doctors use is percutaneous coronary intervention or PCI.  This refers to a variety of devices used to treat clogged arteries, including balloon angioplasty, stents, and atherectomy devices that cut away at hardened plaque.  In 2004, almost 1.3 million PCI procedures were performed in the US, 34% of which were in women.

Are women undertreated?

Before doctors decide whether you need to undergo treatment such as balloon angioplasty or bypass surgery, they take an X-ray of the arteries of the heart to see whether there is a blockage present.  This X-ray is called a coronary angiogram or, more generally, cardiac catheterization.  As in angioplasty, a catheter is guided into the arteries of the heart, then a special dye, known as a contrast medium, is injected into the arteries that supply blood to the heart so that the X-rays can be taken.  The angiogram can pinpoint the location and extent of any blockages.
A 1987 study of more than 80,000 heart disease patients showed that women were less likely to undergo cardiac catheterization than men.  More recent research finds that women are as likely to receive this test if their age and risk factors are taken into account.  Even so, a study using videotapes of actors describing identical chest pain symptoms found that the race and sex of the actor influenced the doctor's decision to refer them for cardiac catheterization.  Black women were less likely than white men to be referred for cardiac catheterization.
Once women undergo cardiac catheterization, they are just as likely as men to be treated with angioplasty or stents.

What is Bypass Surgery?

Coronary artery bypass graft surgery (CABG, pronounced "cabbage") is the most commonly performed type of heart surgery.  In the year 2003 there were 467,000 bypass surgeries performed in the United States, and 26% of these were performed on women.
During bypass surgery, a healthy artery or vein is removed from another part of your body and used to re-route blood flow around a blocked or narrowed coronary artery. The healthy vein or artery is called a bypass graft.  One end is sewn to the aorta (the largest artery that comes out of your heart) and the other end is attached to the coronary artery just below the blockage. A vein in the leg (the saphenous vein) or an artery in the chest (the internal mammary artery) is usually used to create the bypass graft. More rarely, an artery from the arm or the stomach may be used. Removing these healthy vessels is harmless since there are many other arteries and veins that can take over for them. 

What Are Clot Busters?

Clot busting medications break up blood clots.  During a heart attack, clot busters-also called thrombolytics-dissolve the blood clot that is blocking the artery and help restore blood flow to the heart.  These medications are injected into the arm through an intravenous (IV) line.  They are usually given to heart attack patients in the emergency department; however, they may sometimes be given in the ambulance en route to the hospital. 

Benefits of Clot Busters

Women treated with clot busting drugs during a heart attack fare better than women who do not receive these medications.  In an overview of nine research studies, clot busting medications reduced the risk of a woman dying within 35 days after a heart attack by 12%.  The benefits are even greater if nonfatal complications are counted.  An analysis of the national registry of heart attack patients (called the National Registry of Myocardial Infarction, or NRMI for short) found that 13% of women treated with the clot buster tissue plasminogen activator (tPA or Activase), died or had a stroke while in-hospital compared with nearly 21% of women who did not receive clot busting drugs.  Even so, women did not benefit from clot busting drugs as much as men.  Significantly more women treated with clot busters died or had a stroke compared with men treated with clot busters.  This is partly because clot busters may be more
likely to trigger a stroke in women than in men. 
In terms of restoring blood flow to blocked arteries, clot busters work equally well in men and women. Why this does not translate into a similar reduction in death rates is unclear.  Some researchers suggest that factors other than clogged arteries may play more of a role in women and elderly patients.

What is TMR?

Transmyocardial revascularization (TMR) is a surgical procedure that may be performed in people with stable angina (chest pain that occurs in a predictable manner, often triggered by exercise or stress) who do not find relief with medication.  TMR is a "last resort" for relief of stable angina. It is used only when more conventional treatments, such as angioplasty or bypass surgery, are not possible. This can be the case for people whose heart disease has progressed to such a point that these treatments would not work (too many blockages in the arteries) or those who are too sick to undergo surgery.
During the procedure, a laser is used to create small holes ("channels") in the heart muscle of the left ventricle, the chamber of the heart responsible for pumping blood throughout the body.
There is no gender-specific information available on TMR.  About 8,000 people underwent TMR from 1995 through 2003.

What is PMR?

PMR is very similar to TMR, except that it is a not a surgical procedure.  A catheter is threaded into your heart through your groin, eliminating the need for your chest to be cut open. 

How well do TMR and PMR work?

There are few studies on TMR and even fewer on PMR.  Early studies of TMR and PMR suggested that these procedures did relieve chest pain, but it was not clear why or how.  One theory to explain their benefit was that they might cause angiogenesis, the growth of small new blood vessels in the heart. Another was sympathetic denervation, destruction of nerves in the heart so that the patient couldn't feel chest pain.  Recent studies indicate that, especially for PMR, the benefits may be due to a placebo effect - people feel better just because they have received treatment. 
Most studies find that TMR is effective at relieving chest pain compared with medication alone.  Angina is measured by class with Roman numerals from I to IV with IV being the worst.  In most small studies, TMR improved angina by 2 classes, and some people were also able to exercise more.  There have been no large randomized, placebo-controlled studies on TMR - the standard for determining the effectiveness of a treatment - because it would be unethical to subject people to a serious surgical procedure without giving any treatment.
Early small PMR studies that were not placebo-controlled found that it was also effective at reducing chest pain.  However, in the year 2000, the results of the largest randomized, placebo-controlled trial of PMR strongly suggested that it was no better than a mock procedure.  In the study, people were assigned to a high dose PMR group (where 20 to 25 channels were made), a low dose PMR group (where 10 to 15 channels were made), or a placebo group that underwent a mock procedure where no laser pulses were actually delivered.  All of the people were blindfolded, wore headphones, and were heavily sedated so that they would not know whether or not they had actually received PMR.  The PMR group had decreased chest pain, but so did the patients in the mock procedure group.  Both groups had the same amount of pain relief, were better able to exercise, and reported a higher quality of life-despite the fact that the people in the placebo group received no actual therapy. This indicates that the reduction in chest pain that people experienced was really due to a placebo effect, meaning that they felt better only because they believed they had received a helpful treatment. 

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