Hope for the Heart: Advances in Treatment
Today two-thirds of people survive their heart attacks, thanks to medical advances. Learn how some of these medical marvels evolved.
Clot Busters to Prevent Heart Attacks
The full significance of what Forssmann did in 1929 was not realized until the mid-1970s, when Marcus DeWood, MD, of Spokane, Wash., began to use angiography, a procedure based on Forssmann's techniques, to look at blockages in the arteries of heart attack victims. At the time, conventional wisdom held that heart attacks were merely the last gasp of a dying heart, and that they couldn't be reversed once in progress. DeWood's research on coronary blockages was widely derided.
But challenging entrenched ideas by constant scientific inquiry is an essential driving force behind every medical marvel. "Once you actually start looking at stuff, it changes your understanding; your insights change, and what you can do changes," James says.
In 1980, DeWood published data showing that in virtually every heart attack observed by angiography, there was a clot blocking an artery.
"This was a revolutionary change in cardiology," says Jon Resar, MD, director of the Adult Cardiac Catheterization Laboratory at Johns Hopkins University School of Medicine in Baltimore, Md.
At that point, doctors realized that clot-busting medicines, which had been around in various forms since the 1930s, might save lives when given immediately after a heart attack. Now it was known that during a heart attack, a clot starves part of the heart of oxygenated blood, causing the muscle to die. The longer it lasts, the more damage is done. If the clot can be broken up quickly, less heart tissue dies, and you have better odds of survival.
Clinical trials on clot-busting drugs followed, which sought to find out if survival improved when they were used in treating heart attacks. "The improvement was quite pronounced," Resar says.
The best clot buster available in the early 1980s was streptokinase, a drug made from a bacterial culture. But drug companies soon got to work on making "designer" clot busters. In 1987, the FDA approved the first of the next-generation drugs, called tissue plasminogen activator (tPA), for dissolving coronary clots after heart attacks. In 1996, the FDA approved tPA for treating stroke.
Although tPA is no doubt a lifesaver, current medical opinion holds that the best treatment for a heart attack is angioplasty, a procedure in which a catheter with an inflatable segment is pushed through to the blocked artery, and inflated to break up the clot.