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More and more Americans are living with chronic ailments like coronary artery disease, hypertension and diabetes, with many surviving multiple heart attacks. But as the population ages, the number of men and women with heart failure, a weakening of the heart’s ability to pump blood and oxygen, is expected to increase exponentially.

Paradoxically, many specialists link the significant increase in the number of cases of heart failure, and the fatigue, shortness of breath and fluid retention that come with it, to advances in heart attack treatment.

“While we have done a great job in improving survival of patients suffering a heart attack earlier in life, we haven’t been able to save that much heart muscle,” said Dr. Stuart D. Russell, chief of heart failure and transplantation at Johns Hopkins Hospital in Baltimore. “Over time, those patients will develop heart failure because injured heart muscle tissue damaged by the heart attack will eventually be replaced by stiff scar tissue.”

This process, called fibrosis, causes the heart to become inflexible, unable to contract and pump blood efficiently.

“Thirty years ago, patients would have died from their heart attacks,” said Dr. Christopher M. O’Connor, director of the Duke Heart Center in Durham, N.C. “Thanks to thrombolytic therapy and angioplasty, these patients are surviving their heart attacks, only to go on and develop fibrosis and heart failure. We have converted an entire new population of patients to heart failure.”

About 22 percent of men and 46 percent of women will develop heart failure within six years of having a heart attack.

Dr. Kenneth L. Baughman, section leader in the division of cardiovascular medicine at the Brigham and Women’s Hospital in Boston, stresses the importance of quick treatment in the case of a heart attack, which leaves the heart muscle starved for oxygen. “Time is muscle,” he said.

“Heart failure is still a diagnosis that carries a relatively poor prognosis,” he added. Fewer than half of patients survive 5 years after the original diagnosis, and only 25 percent are alive at 10 years.

Despite the grim statistics, a growing array of heart devices and innovative machines has slowed the natural course of heart failure over the past 20 years.

“I feel a lot better knowing I have more firepower than ever before in the armamentarium to offer patients,” Dr. Baughman said. “We are not only allowing patients to live longer, but their ability to enjoy life and have fewer restrictions has been increased.”

Since the 1990s, ventricular assist devices, or VADs — machines that take over or assist the pumping action of the left ventricle, the heart’s main pump — have played a major role in extending survival for those with advanced disease who can no longer benefit from beta blockers and other medications. These miniature devices, partially implanted in the heart, with a fist-size battery pack left outside the body, may even allow some of the damaged heart muscle to heal, helping some patients with advanced disease to avoid a heart transplant. For others, VADs can be effective bridge-to-transplant devices.

“I have seen totally bedbound, incapacitated patients become dramatically better patients,” Dr. Baughman said. “They are able to get about, enhance their physical strength and become dramatically better patients while they await a heart transplant.”

A 2008 study in The Journal of the American Medical Association reported high death rates, repeat hospital stays and soaring medical bills among Medicare patients who had VADs implanted to help their failing hearts. To get the best outcome, Dr. Russell urges patients to seek an experienced surgeon who uses the most up-to-date pumps.

“The take-home message is that the prospective surgeon should not only be qualified but also work at a high-volume heart center where many VAD implantation procedures are routinely performed,” he said.

It also pays to be an informed consumer. “The next-generation VAD will be totally implantable,” said Dr. Russell, who also consults for Thoratec, a leading manufacturer of the devices. “Some of these units are available in Europe, and we expect to have clinical trials with similar devices here within two years.”

As researchers begin to unravel the complex genetic underpinnings of heart failure, new drugs and biological approaches to managing heart failure are being investigated as well.

Researchers led by Dr. Amit N. Patel, a cardiac surgeon formerly at the University of Pittsburgh School of Medicine and now at the University of Utah, have reported some success using adult stem cells taken from the patient’s own bone marrow and injected into damaged heart tissue. Much work remains to be done in finding which stem cells, the master cells of the body and one-thousandth the size of a grain of sand, help regenerate new cardiac muscle and enhance the ailing heart’s ability to pump blood.

Taking a different approach, researchers at Weill Cornell Medical College in New York are investigating ways to prevent heart muscle from stiffening after a heart attack. In animal studies, they have reported that by limiting the function of a class of molecules known as secreted frizzled-related proteins that trigger muscle scarring, they can preserve muscle tissue after a heart attack.

In other research, scientists at the Emory University School of Medicine in Atlanta reported that blood levels of resistin, a hormone produced by fat cells, are an effective biomarker that can predict a person’s risk for heart failure. The hope is that by identifying who is at greatest risk as early as possible, patients can benefit from aggressive risk reduction and lifelong surveillance to reduce the rate of progression to symptomatic heart failure.

“By taking a more biological approach to heart failure with stem cells and maybe even with gene therapy,” Dr. O’Connor said, “we will have more to offer our patients.”



Publish date: 1/29/2009